Test instrument catalog metadata

Sources/MusicAssistantApp/Presentation/ArabicLyricsReviewView.swift

@@ -0,0 +1,108 @@
+import MusicAssistantCore
+import SwiftUI
+
+struct ArabicLyricsReviewView: View {
+    @Binding var project: SongProject
+
+    private let processor = ArabicPronunciationProcessor()
+
+    @State private var processedLyrics = ""
+    @State private var processingNotes: [ArabicPronunciationProcessingNote] = []
+
+    var body: some View {
+        VStack(alignment: .leading, spacing: 10) {
+            HStack {
+                Text("Arabic lyrics review")
+                    .font(.headline)
+
+                Spacer()
+
+                Button(action: refreshProcessedLyrics) {
+                    Label("Refresh processed lyrics", systemImage: "arrow.clockwise")
+                        .labelStyle(.iconOnly)
+                }
+                .buttonStyle(.borderless)
+                .help("Refresh processed lyrics")
+            }
+
+            Text("Original lyrics")
+                .font(.subheadline)
+                .foregroundStyle(.secondary)
+
+            TextEditor(text: .constant(project.lyrics.text))
+                .font(.body)
+                .frame(minHeight: 96)
+                .disabled(true)
+
+            Text("Processed lyrics")
+                .font(.subheadline)
+                .foregroundStyle(.secondary)
+
+            TextEditor(text: $processedLyrics)
+                .font(.body)
+                .frame(minHeight: 96)
+
+            ForEach(Array(processingNotes.enumerated()), id: \.offset) { entry in
+                Label(entry.element.title, systemImage: entry.element.systemImage)
+                    .font(.caption)
+                    .foregroundStyle(.secondary)
+            }
+
+            Button(action: applyProcessedLyrics) {
+                Label("Use processed lyrics", systemImage: "checkmark.circle")
+            }
+            .disabled(!canApplyProcessedLyrics)
+        }
+        .onAppear(perform: refreshProcessedLyrics)
+    }
+
+    private var canApplyProcessedLyrics: Bool {
+        let trimmedLyrics = processedLyrics.trimmingCharacters(in: .whitespacesAndNewlines)
+        return !trimmedLyrics.isEmpty && processedLyrics != project.lyrics.text
+    }
+
+    private func refreshProcessedLyrics() {
+        let result = processor.process(
+            lyrics: project.lyrics.text,
+            settings: project.arabicPronunciationSettings
+        )
+        processedLyrics = result.text
+        processingNotes = result.notes
+    }
+
+    private func applyProcessedLyrics() {
+        project.applyReviewedArabicLyrics(processedLyrics)
+    }
+}
+
+private extension ArabicPronunciationProcessingNote {
+    var title: String {
+        switch self {
+        case .processingDisabled:
+            return "Arabic processing is disabled"
+        case .diacritizationPolicyUnspecified:
+            return "Select a diacritics policy to continue"
+        case .pronunciationTargetedDiacriticsNeedReview:
+            return "Targeted diacritics need review"
+        case .fullTashkeelNeedsReview:
+            return "Full tashkeel needs review"
+        case .tanweenAdditionNeedsReview:
+            return "Tanween addition needs review"
+        case let .preservedSpellingsProtected(count):
+            return "Protected \(count) preserved spelling\(count == 1 ? "" : "s")"
+        }
+    }
+
+    var systemImage: String {
+        switch self {
+        case .processingDisabled, .diacritizationPolicyUnspecified:
+            return "info.circle"
+        case .pronunciationTargetedDiacriticsNeedReview,
+             .fullTashkeelNeedsReview,
+             .tanweenAdditionNeedsReview:
+            return "exclamationmark.triangle"
+        case .preservedSpellingsProtected:
+            return "checkmark.shield"
+        }
+    }
+}

Sources/MusicAssistantApp/Presentation/ArabicPronunciationSettingsView.swift

@@ -0,0 +1,91 @@
+import MusicAssistantCore
+import SwiftUI
+
+struct ArabicPronunciationSettingsView: View {
+    @Binding var settings: ArabicPronunciationSettings
+
+    @State private var newPreservedSpelling = ""
+
+    var body: some View {
+        Toggle("Enable Arabic pronunciation processing", isOn: $settings.isEnabled)
+
+        Picker("Diacritics", selection: $settings.diacritizationPolicy) {
+            Text("Unspecified").tag(ArabicDiacritizationPolicy.unspecified)
+            Text("Pronunciation targeted").tag(ArabicDiacritizationPolicy.pronunciationTargeted)
+            Text("Full tashkeel").tag(ArabicDiacritizationPolicy.fullTashkeel)
+        }
+        .disabled(!settings.isEnabled)
+
+        Picker("Tanween", selection: $settings.tanweenPolicy) {
+            Text("Unspecified").tag(ArabicTanweenPolicy.unspecified)
+            Text("Preserve user input").tag(ArabicTanweenPolicy.preserveUserInput)
+            Text("Add when pronunciation needs it").tag(ArabicTanweenPolicy.addWhenPronunciationRequires)
+            Text("Remove when unwanted").tag(ArabicTanweenPolicy.removeWhenUnwanted)
+        }
+        .disabled(!settings.isEnabled)
+
+        TextField("Pronunciation notes", text: userNotesBinding, axis: .vertical)
+            .lineLimit(2...4)
+            .disabled(!settings.isEnabled)
+
+        if settings.preservedSpellings.isEmpty {
+            Text("No preserved spellings")
+                .foregroundStyle(.secondary)
+        } else {
+            ForEach(settings.preservedSpellings.indices, id: \.self) { index in
+                HStack {
+                    Text(settings.preservedSpellings[index])
+                        .lineLimit(1)
+
+                    Spacer()
+
+                    Button {
+                        settings.preservedSpellings.remove(at: index)
+                    } label: {
+                        Label("Remove preserved spelling", systemImage: "minus.circle")
+                            .labelStyle(.iconOnly)
+                    }
+                    .buttonStyle(.borderless)
+                    .help("Remove preserved spelling")
+                }
+            }
+        }
+
+        HStack {
+            TextField("Preserve spelling", text: $newPreservedSpelling)
+                .onSubmit(addPreservedSpelling)
+
+            Button(action: addPreservedSpelling) {
+                Label("Add preserved spelling", systemImage: "plus.circle.fill")
+                    .labelStyle(.iconOnly)
+            }
+            .buttonStyle(.borderless)
+            .disabled(trimmedNewPreservedSpelling.isEmpty)
+            .help("Add preserved spelling")
+        }
+        .disabled(!settings.isEnabled)
+    }
+
+    private var userNotesBinding: Binding<String> {
+        Binding {
+            settings.userNotes ?? ""
+        } set: { newValue in
+            let trimmedValue = newValue.trimmingCharacters(in: .whitespacesAndNewlines)
+            settings.userNotes = trimmedValue.isEmpty ? nil : trimmedValue
+        }
+    }
+
+    private var trimmedNewPreservedSpelling: String {
+        newPreservedSpelling.trimmingCharacters(in: .whitespacesAndNewlines)
+    }
+
+    private func addPreservedSpelling() {
+        let spelling = trimmedNewPreservedSpelling
+        guard !spelling.isEmpty, !settings.preservedSpellings.contains(spelling) else {
+            return
+        }
+
+        settings.preservedSpellings.append(spelling)
+        newPreservedSpelling = ""
+    }
+}

Sources/MusicAssistantApp/Presentation/FinalReviewView.swift

@@ -9,6 +9,10 @@ struct FinalReviewView: View {
 
     var body: some View {
         VStack(alignment: .leading, spacing: 12) {
+            ArabicLyricsReviewView(project: $project)
+
+            Divider()
+
             TextField("Approved lyrics", text: $project.lyrics.text, axis: .vertical)
                 .lineLimit(4...10)
 

Sources/MusicAssistantApp/Presentation/ProjectInspectorView.swift

@@ -38,6 +38,11 @@ struct ProjectInspectorView: View {
                     TextField("Title", text: $project.title)
                     TextField("Idea", text: $project.idea, axis: .vertical)
                         .lineLimit(2...4)
+                    Picker("AI mode", selection: $project.conversationMode) {
+                        Text("Auto").tag(ConversationMode.auto)
+                        Text("Discuss").tag(ConversationMode.discuss)
+                    }
+                    .pickerStyle(.segmented)
                     TextField("Duration seconds", text: durationSecondsBinding)
                     TextField("Duration note", text: durationDescriptionBinding)
                 }
@@ -98,6 +103,12 @@ struct ProjectInspectorView: View {
                     )
                 }
 
+                Section("Arabic Pronunciation") {
+                    ArabicPronunciationSettingsView(
+                        settings: $project.arabicPronunciationSettings
+                    )
+                }
+
                 Section("Song Structure") {
                     SongStructureEditorView(project: $project)
                 }

Sources/MusicAssistantCore/Domain/SongProject.swift

@@ -16,11 +16,14 @@ public struct SongProject: Codable, Equatable, Identifiable, Sendable {
     public var key: ManualAutoValue<String>?
     public var scale: ManualAutoValue<String>?
     public var maqam: ManualAutoValue<String>?
+    public var structureMode: ControlMode?
     public var sections: [SongSection]
     public var instruments: [InstrumentTrack]
     public var vocalists: [Vocalist]
     public var lyrics: Lyrics
     public var productionDirections: [ProductionDirection]
+    public var productionMode: ControlMode?
+    public var userLocks: SongProjectUserLocks?
     public var sunoOutput: SunoOutput?
     public var versions: [SongVersion]
     public let createdAt: Date
@@ -42,11 +45,14 @@ public struct SongProject: Codable, Equatable, Identifiable, Sendable {
         key: ManualAutoValue<String>? = nil,
         scale: ManualAutoValue<String>? = nil,
         maqam: ManualAutoValue<String>? = nil,
+        structureMode: ControlMode? = .auto,
         sections: [SongSection] = [],
         instruments: [InstrumentTrack] = [],
         vocalists: [Vocalist] = [],
         lyrics: Lyrics = Lyrics(),
         productionDirections: [ProductionDirection] = [],
+        productionMode: ControlMode? = .auto,
+        userLocks: SongProjectUserLocks? = SongProjectUserLocks(),
         sunoOutput: SunoOutput? = nil,
         versions: [SongVersion] = [],
         createdAt: Date = Date(),
@@ -67,11 +73,14 @@ public struct SongProject: Codable, Equatable, Identifiable, Sendable {
         self.key = key
         self.scale = scale
         self.maqam = maqam
+        self.structureMode = structureMode
         self.sections = sections
         self.instruments = instruments
         self.vocalists = vocalists
         self.lyrics = lyrics
         self.productionDirections = productionDirections
+        self.productionMode = productionMode
+        self.userLocks = userLocks
         self.sunoOutput = sunoOutput
         self.versions = versions
         self.createdAt = createdAt
@@ -80,6 +89,42 @@ public struct SongProject: Codable, Equatable, Identifiable, Sendable {
 }
 
 public extension SongProject {
+    var isStructureAutomatic: Bool {
+        structureMode != .manual
+    }
+
+    var isProductionAutomatic: Bool {
+        productionMode != .manual
+    }
+
+    mutating func setStructureMode(_ mode: ControlMode) {
+        structureMode = mode
+    }
+
+    mutating func setProductionMode(_ mode: ControlMode) {
+        productionMode = mode
+    }
+
+    var lockedUpdateScopes: [SongProjectUpdateScope] {
+        userLocks?.scopes ?? []
+    }
+
+    func isUpdateScopeLocked(_ scope: SongProjectUpdateScope) -> Bool {
+        userLocks?.contains(scope) ?? false
+    }
+
+    mutating func lockUpdateScope(_ scope: SongProjectUpdateScope) {
+        var userLocks = userLocks ?? SongProjectUserLocks()
+        userLocks.insert(scope)
+        self.userLocks = userLocks
+    }
+
+    mutating func unlockUpdateScope(_ scope: SongProjectUpdateScope) {
+        guard var userLocks else { return }
+        userLocks.remove(scope)
+        self.userLocks = userLocks
+    }
+
     var orderedSections: [SongSection] {
         sections
             .enumerated()
@@ -154,6 +199,15 @@ public extension SongProject {
         dialects.removeAll { $0.id == dialectID }
     }
 
+    mutating func applyReviewedArabicLyrics(_ reviewedLyrics: String) {
+        let originalLyrics = lyrics.text
+        lyrics.text = reviewedLyrics
+
+        if sunoOutput?.lyricsText == originalLyrics {
+            sunoOutput?.lyricsText = reviewedLyrics
+        }
+    }
+
     mutating func setBPMManually(_ value: Int) {
         bpm = ManualAutoValue(mode: .manual, value: value)
     }
@@ -364,11 +418,14 @@ public extension SongProject {
         key = snapshot.key
         scale = snapshot.scale
         maqam = snapshot.maqam
+        structureMode = snapshot.structureMode
         sections = snapshot.sections
         instruments = snapshot.instruments
         vocalists = snapshot.vocalists
         lyrics = snapshot.lyrics
         productionDirections = snapshot.productionDirections
+        productionMode = snapshot.productionMode
+        userLocks = snapshot.userLocks
         sunoOutput = snapshot.sunoOutput
         self.updatedAt = updatedAt
     }
@@ -764,11 +821,14 @@ public struct SongProjectSnapshot: Codable, Equatable, Sendable {
     public var key: ManualAutoValue<String>?
     public var scale: ManualAutoValue<String>?
     public var maqam: ManualAutoValue<String>?
+    public var structureMode: ControlMode?
     public var sections: [SongSection]
     public var instruments: [InstrumentTrack]
     public var vocalists: [Vocalist]
     public var lyrics: Lyrics
     public var productionDirections: [ProductionDirection]
+    public var productionMode: ControlMode?
+    public var userLocks: SongProjectUserLocks?
     public var sunoOutput: SunoOutput?
 
     public init(
@@ -786,11 +846,14 @@ public struct SongProjectSnapshot: Codable, Equatable, Sendable {
         key: ManualAutoValue<String>? = nil,
         scale: ManualAutoValue<String>? = nil,
         maqam: ManualAutoValue<String>? = nil,
+        structureMode: ControlMode? = .auto,
         sections: [SongSection] = [],
         instruments: [InstrumentTrack] = [],
         vocalists: [Vocalist] = [],
         lyrics: Lyrics = Lyrics(),
         productionDirections: [ProductionDirection] = [],
+        productionMode: ControlMode? = .auto,
+        userLocks: SongProjectUserLocks? = SongProjectUserLocks(),
         sunoOutput: SunoOutput? = nil
     ) {
         self.title = title
@@ -807,11 +870,14 @@ public struct SongProjectSnapshot: Codable, Equatable, Sendable {
         self.key = key
         self.scale = scale
         self.maqam = maqam
+        self.structureMode = structureMode
         self.sections = sections
         self.instruments = instruments
         self.vocalists = vocalists
         self.lyrics = lyrics
         self.productionDirections = productionDirections
+        self.productionMode = productionMode
+        self.userLocks = userLocks
         self.sunoOutput = sunoOutput
     }
 
@@ -831,11 +897,14 @@ public struct SongProjectSnapshot: Codable, Equatable, Sendable {
             key: project.key,
             scale: project.scale,
             maqam: project.maqam,
+            structureMode: project.structureMode,
             sections: project.sections,
             instruments: project.instruments,
             vocalists: project.vocalists,
             lyrics: project.lyrics,
             productionDirections: project.productionDirections,
+            productionMode: project.productionMode,
+            userLocks: project.userLocks,
             sunoOutput: project.sunoOutput
         )
     }

Sources/MusicAssistantCore/Domain/SongProjectUpdateScope.swift

@@ -0,0 +1,42 @@
+import Foundation
+
+public enum SongProjectUpdateScope: String, CaseIterable, Codable, Equatable, Hashable, Sendable {
+    case duration
+    case genres
+    case instruments
+    case vocals
+    case languages
+    case lyrics
+    case structure
+    case arrangement
+    case musicalParameters
+    case emotionalArc
+    case productionDirections
+    case sunoOutput
+}
+
+public struct SongProjectUserLocks: Codable, Equatable, Sendable {
+    public var scopes: [SongProjectUpdateScope]
+
+    public init(scopes: [SongProjectUpdateScope] = []) {
+        self.scopes = Self.uniqueScopes(scopes)
+    }
+
+    public func contains(_ scope: SongProjectUpdateScope) -> Bool {
+        scopes.contains(scope)
+    }
+
+    public mutating func insert(_ scope: SongProjectUpdateScope) {
+        guard !contains(scope) else { return }
+        scopes.append(scope)
+    }
+
+    public mutating func remove(_ scope: SongProjectUpdateScope) {
+        scopes.removeAll { $0 == scope }
+    }
+
+    private static func uniqueScopes(_ scopes: [SongProjectUpdateScope]) -> [SongProjectUpdateScope] {
+        var seen = Set<SongProjectUpdateScope>()
+        return scopes.filter { seen.insert($0).inserted }
+    }
+}

Sources/MusicAssistantCore/Integrations/OpenAI/OpenAIClient.swift

@@ -49,6 +49,13 @@ public protocol OpenAIClientAdapter: Sendable {
 
     func decodeProjectGenerationResult(from data: Data) throws -> SongProjectGenerationResult
 
+    func makeSongProjectDiscussionRequest(
+        _ request: SongProjectDiscussionRequest,
+        configuration: OpenAIClientConfiguration
+    ) throws -> OpenAIClientRequest
+
+    func decodeSongProjectDiscussionResult(from data: Data) throws -> SongProjectDiscussionResult
+
     func makeLyricsRevisionRequest(
         _ request: LyricsRevisionRequest,
         configuration: OpenAIClientConfiguration
@@ -99,6 +106,12 @@ public final class OpenAIClient: AIService, Sendable {
         return try adapter.decodeProjectGenerationResult(from: data)
     }
 
+    public func discussSongProject(from request: SongProjectDiscussionRequest) async throws -> SongProjectDiscussionResult {
+        let clientRequest = try adapter.makeSongProjectDiscussionRequest(request, configuration: configuration)
+        let data = try await perform(clientRequest)
+        return try adapter.decodeSongProjectDiscussionResult(from: data)
+    }
+
     public func reviseLyrics(from request: LyricsRevisionRequest) async throws -> LyricsRevisionResult {
         let clientRequest = try adapter.makeLyricsRevisionRequest(request, configuration: configuration)
         let data = try await perform(clientRequest)
@@ -112,6 +125,8 @@ public final class OpenAIClient: AIService, Sendable {
     }
 
     private func perform(_ clientRequest: OpenAIClientRequest) async throws -> Data {
+        try Task.checkCancellation()
+
         guard !configuration.apiKey.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty else {
             throw OpenAIClientError.missingAPIKey
         }
@@ -136,15 +151,30 @@ public final class OpenAIClient: AIService, Sendable {
 
         let (data, response) = try await transport.data(for: request)
         guard (200..<300).contains(response.statusCode) else {
+            if response.statusCode == 429 {
+                throw OpenAIClientError.rateLimited(
+                    retryAfter: Self.retryAfterInterval(from: response)
+                )
+            }
+            if (500..<600).contains(response.statusCode) {
+                throw OpenAIClientError.serverError(response.statusCode)
+            }
             throw OpenAIClientError.unacceptableStatusCode(response.statusCode)
         }
 
         return data
     }
+
+    private static func retryAfterInterval(from response: HTTPURLResponse) -> TimeInterval? {
+        guard let value = response.value(forHTTPHeaderField: "Retry-After") else { return nil }
+        return TimeInterval(value.trimmingCharacters(in: .whitespacesAndNewlines))
+    }
 }
 
 public enum OpenAIClientError: Error, Equatable, Sendable {
     case missingAPIKey
     case invalidResponse
+    case rateLimited(retryAfter: TimeInterval?)
+    case serverError(Int)
     case unacceptableStatusCode(Int)
 }

Sources/MusicAssistantCore/Services/AI/AIService.swift

@@ -2,10 +2,21 @@ import Foundation
 
 public protocol AIService: Sendable {
     func generateSongProject(from request: SongProjectGenerationRequest) async throws -> SongProjectGenerationResult
+    func discussSongProject(from request: SongProjectDiscussionRequest) async throws -> SongProjectDiscussionResult
     func reviseLyrics(from request: LyricsRevisionRequest) async throws -> LyricsRevisionResult
     func proposeProjectUpdate(from request: SongProjectUpdateRequest) async throws -> SongProjectUpdateResult
 }
 
+public extension AIService {
+    func discussSongProject(from request: SongProjectDiscussionRequest) async throws -> SongProjectDiscussionResult {
+        throw AIServiceCapabilityError.discussionNotSupported
+    }
+}
+
+public enum AIServiceCapabilityError: Error, Equatable, Sendable {
+    case discussionNotSupported
+}
+
 public struct AIConversationMessage: Equatable, Identifiable, Sendable {
     public let id: String
     public var role: AIConversationRole
@@ -82,6 +93,26 @@ public struct SongProjectGenerationResult: Equatable, Sendable {
     }
 }
 
+public struct SongProjectDiscussionRequest: Equatable, Sendable {
+    public var context: AIRequestContext
+    public var project: SongProject
+
+    public init(context: AIRequestContext, project: SongProject) {
+        self.context = context
+        self.project = project
+    }
+}
+
+public struct SongProjectDiscussionResult: Equatable, Sendable {
+    public var questions: [String]
+    public var notes: [String]
+
+    public init(questions: [String], notes: [String] = []) {
+        self.questions = questions
+        self.notes = notes
+    }
+}
+
 public struct LyricsRevisionRequest: Equatable, Sendable {
     public var context: AIRequestContext
     public var project: SongProject
@@ -135,21 +166,6 @@ public struct SongProjectUpdateRequest: Equatable, Sendable {
     }
 }
 
-public enum SongProjectUpdateScope: String, Codable, Equatable, Sendable {
-    case duration
-    case genres
-    case instruments
-    case vocals
-    case languages
-    case lyrics
-    case structure
-    case arrangement
-    case musicalParameters
-    case emotionalArc
-    case productionDirections
-    case sunoOutput
-}
-
 public struct SongProjectUpdateResult: Equatable, Sendable {
     public var project: SongProject
     public var changedScopes: [SongProjectUpdateScope]

Sources/MusicAssistantCore/Services/AI/AIServiceRetrying.swift

@@ -0,0 +1,124 @@
+import Foundation
+
+public struct AIServiceRetryPolicy: Equatable, Sendable {
+    public static let `default` = AIServiceRetryPolicy()
+
+    public var maxAttempts: Int
+    public var baseDelay: TimeInterval
+    public var maximumDelay: TimeInterval
+
+    public init(
+        maxAttempts: Int = 3,
+        baseDelay: TimeInterval = 0.5,
+        maximumDelay: TimeInterval = 8
+    ) {
+        self.maxAttempts = max(1, maxAttempts)
+        self.baseDelay = max(0, baseDelay)
+        self.maximumDelay = max(0, maximumDelay)
+    }
+
+    func delay(forFailedAttempt attempt: Int, retryAfter: TimeInterval? = nil) -> TimeInterval {
+        if let retryAfter {
+            return max(0, retryAfter)
+        }
+
+        let multiplier = pow(2, Double(max(0, attempt - 1)))
+        return min(maximumDelay, baseDelay * multiplier)
+    }
+}
+
+public protocol AIServiceRetryScheduler: Sendable {
+    func sleep(for interval: TimeInterval) async throws
+}
+
+public struct TaskAIServiceRetryScheduler: AIServiceRetryScheduler {
+    public init() {}
+
+    public func sleep(for interval: TimeInterval) async throws {
+        guard interval > 0 else { return }
+        let maximumInterval = TimeInterval(UInt64.max / 1_000_000_000)
+        let clampedInterval = min(interval, maximumInterval)
+        let nanoseconds = UInt64((clampedInterval * 1_000_000_000).rounded())
+        try await Task.sleep(nanoseconds: nanoseconds)
+    }
+}
+
+public final class RetryingAIService: AIService, Sendable {
+    private let baseService: any AIService
+    private let policy: AIServiceRetryPolicy
+    private let scheduler: any AIServiceRetryScheduler
+
+    public init(
+        baseService: any AIService,
+        policy: AIServiceRetryPolicy = .default,
+        scheduler: any AIServiceRetryScheduler = TaskAIServiceRetryScheduler()
+    ) {
+        self.baseService = baseService
+        self.policy = policy
+        self.scheduler = scheduler
+    }
+
+    public func generateSongProject(from request: SongProjectGenerationRequest) async throws -> SongProjectGenerationResult {
+        try await perform { try await self.baseService.generateSongProject(from: request) }
+    }
+
+    public func discussSongProject(from request: SongProjectDiscussionRequest) async throws -> SongProjectDiscussionResult {
+        try await perform { try await self.baseService.discussSongProject(from: request) }
+    }
+
+    public func reviseLyrics(from request: LyricsRevisionRequest) async throws -> LyricsRevisionResult {
+        try await perform { try await self.baseService.reviseLyrics(from: request) }
+    }
+
+    public func proposeProjectUpdate(from request: SongProjectUpdateRequest) async throws -> SongProjectUpdateResult {
+        try await perform { try await self.baseService.proposeProjectUpdate(from: request) }
+    }
+
+    private func perform<Value: Sendable>(
+        _ operation: @escaping @Sendable () async throws -> Value
+    ) async throws -> Value {
+        var attempt = 0
+
+        while true {
+            try Task.checkCancellation()
+            attempt += 1
+
+            do {
+                return try await operation()
+            } catch is CancellationError {
+                throw CancellationError()
+            } catch {
+                guard attempt < policy.maxAttempts,
+                      let delay = retryDelay(for: error, failedAttempt: attempt) else {
+                    throw error
+                }
+
+                try await scheduler.sleep(for: delay)
+            }
+        }
+    }
+
+    private func retryDelay(for error: Error, failedAttempt attempt: Int) -> TimeInterval? {
+        if let error = error as? OpenAIClientError {
+            switch error {
+            case let .rateLimited(retryAfter):
+                return policy.delay(forFailedAttempt: attempt, retryAfter: retryAfter)
+            case .serverError:
+                return policy.delay(forFailedAttempt: attempt)
+            case .missingAPIKey, .invalidResponse, .unacceptableStatusCode:
+                return nil
+            }
+        }
+
+        if let error = error as? URLError {
+            switch error.code {
+            case .timedOut, .networkConnectionLost, .notConnectedToInternet, .cannotConnectToHost, .cannotFindHost, .dnsLookupFailed:
+                return policy.delay(forFailedAttempt: attempt)
+            default:
+                return nil
+            }
+        }
+
+        return nil
+    }
+}

Sources/MusicAssistantCore/Services/AI/ApplicationRules.swift

@@ -45,6 +45,10 @@ public final class ApplicationRuleInjectingAIService: AIService, Sendable {
         try await baseService.generateSongProject(from: requestWithInjectedRules(request))
     }
 
+    public func discussSongProject(from request: SongProjectDiscussionRequest) async throws -> SongProjectDiscussionResult {
+        try await baseService.discussSongProject(from: requestWithInjectedRules(request))
+    }
+
     public func reviseLyrics(from request: LyricsRevisionRequest) async throws -> LyricsRevisionResult {
         try await baseService.reviseLyrics(from: requestWithInjectedRules(request))
     }
@@ -59,6 +63,12 @@ public final class ApplicationRuleInjectingAIService: AIService, Sendable {
         return request
     }
 
+    private func requestWithInjectedRules(_ request: SongProjectDiscussionRequest) throws -> SongProjectDiscussionRequest {
+        var request = request
+        request.context.injectPrivateApplicationRules(try ruleProvider.privateApplicationRules())
+        return request
+    }
+
     private func requestWithInjectedRules(_ request: LyricsRevisionRequest) throws -> LyricsRevisionRequest {
         var request = request
         request.context.injectPrivateApplicationRules(try ruleProvider.privateApplicationRules())

Sources/MusicAssistantCore/Services/AI/AutoSongProjectDecisionsDirector.swift

@@ -0,0 +1,236 @@
+import Foundation
+
+public final class AutoSongProjectDecisionsDirector: Sendable {
+    private let aiService: any AIService
+
+    public init(aiService: any AIService) {
+        self.aiService = aiService
+    }
+
+    public func applyAutomaticDecisions(
+        to project: SongProject,
+        instruction: String? = nil,
+        conversation: [AIConversationMessage] = [],
+        localeIdentifier: String? = nil,
+        updatedAt: Date = Date()
+    ) async throws -> SongProjectUpdateResult {
+        let allowedScopes = automaticScopes(for: project)
+        guard !allowedScopes.isEmpty else {
+            return SongProjectUpdateResult(
+                project: project,
+                notes: ["No automatic decisions are enabled."]
+            )
+        }
+
+        let trimmedInstruction = instruction?.trimmingCharacters(in: .whitespacesAndNewlines)
+        let request = SongProjectUpdateRequest(
+            context: AIRequestContext(
+                userInstruction: trimmedInstruction?.isEmpty == false
+                    ? trimmedInstruction!
+                    : "Complete the enabled automatic song-project decisions.",
+                conversation: conversation,
+                localeIdentifier: localeIdentifier
+            ),
+            project: project,
+            allowedScopes: allowedScopes
+        )
+        let result = try await aiService.proposeProjectUpdate(from: request)
+        var updatedProject = mergeAutomaticDecisions(
+            from: result.project,
+            into: project
+        )
+        updatedProject.updatedAt = updatedAt
+
+        return SongProjectUpdateResult(
+            project: updatedProject,
+            changedScopes: changedScopes(from: project, to: updatedProject),
+            notes: result.notes,
+            followUpQuestions: result.followUpQuestions
+        )
+    }
+
+    private func automaticScopes(for project: SongProject) -> [SongProjectUpdateScope] {
+        var scopes: [SongProjectUpdateScope] = []
+
+        if project.isStructureAutomatic && !project.isUpdateScopeLocked(.structure) {
+            scopes.append(.structure)
+        }
+
+        if !project.isUpdateScopeLocked(.arrangement) &&
+            project.instruments.contains(where: { $0.selected && $0.autoArrangementEnabled }) {
+            scopes.append(.arrangement)
+        }
+
+        if !project.isUpdateScopeLocked(.musicalParameters) &&
+            (project.bpm?.mode != .manual ||
+            project.key?.mode != .manual ||
+            project.scale?.mode != .manual ||
+            project.maqam?.mode != .manual) {
+            scopes.append(.musicalParameters)
+        }
+
+        if project.isProductionAutomatic && !project.isUpdateScopeLocked(.productionDirections) {
+            scopes.append(.productionDirections)
+        }
+
+        return scopes
+    }
+
+    private func mergeAutomaticDecisions(
+        from proposedProject: SongProject,
+        into project: SongProject
+    ) -> SongProject {
+        var updatedProject = project
+
+        if project.isStructureAutomatic {
+            updatedProject.sections = proposedProject.sections
+        }
+
+        updatedProject.instruments = mergedInstruments(
+            current: project.instruments,
+            proposed: proposedProject.instruments
+        )
+        updatedProject.bpm = automaticValue(current: project.bpm, proposed: proposedProject.bpm)
+        updatedProject.key = automaticValue(current: project.key, proposed: proposedProject.key)
+        updatedProject.scale = automaticValue(current: project.scale, proposed: proposedProject.scale)
+        updatedProject.maqam = automaticValue(current: project.maqam, proposed: proposedProject.maqam)
+
+        if project.isProductionAutomatic {
+            updatedProject.productionDirections = proposedProject.productionDirections
+            updatedProject.sections = sections(
+                updatedProject.sections,
+                applyingProductionDirectionsFrom: proposedProject.sections
+            )
+        } else {
+            updatedProject.sections = sections(
+                updatedProject.sections,
+                preservingProductionDirectionsFrom: project.sections
+            )
+        }
+
+        return updatedProject
+    }
+
+    private func mergedInstruments(
+        current: [InstrumentTrack],
+        proposed: [InstrumentTrack]
+    ) -> [InstrumentTrack] {
+        var proposedByID: [String: InstrumentTrack] = [:]
+        for proposedTrack in proposed {
+            proposedByID[proposedTrack.instrumentId] = proposedTrack
+        }
+
+        return current.map { currentTrack in
+            guard currentTrack.selected,
+                  currentTrack.autoArrangementEnabled,
+                  let proposedTrack = proposedByID[currentTrack.instrumentId]
+            else {
+                return currentTrack
+            }
+
+            var mergedTrack = currentTrack
+            mergedTrack.playingStyle = proposedTrack.playingStyle
+            mergedTrack.role = proposedTrack.role
+            mergedTrack.placements = proposedTrack.placements
+            return mergedTrack
+        }
+    }
+
+    private func automaticValue<Value>(
+        current: ManualAutoValue<Value>?,
+        proposed: ManualAutoValue<Value>?
+    ) -> ManualAutoValue<Value>? where Value: Codable & Equatable & Sendable {
+        guard current?.mode != .manual, let proposed else {
+            return current
+        }
+
+        return ManualAutoValue(mode: .auto, value: proposed.value)
+    }
+
+    private func sections(
+        _ current: [SongSection],
+        applyingProductionDirectionsFrom proposed: [SongSection]
+    ) -> [SongSection] {
+        var proposedByID: [String: SongSection] = [:]
+        for proposedSection in proposed {
+            proposedByID[proposedSection.id] = proposedSection
+        }
+
+        return current.map { section in
+            guard let proposedSection = proposedByID[section.id] else { return section }
+            var updatedSection = section
+            updatedSection.productionDirection = proposedSection.productionDirection
+            return updatedSection
+        }
+    }
+
+    private func sections(
+        _ current: [SongSection],
+        preservingProductionDirectionsFrom existing: [SongSection]
+    ) -> [SongSection] {
+        var existingByID: [String: SongSection] = [:]
+        for existingSection in existing {
+            existingByID[existingSection.id] = existingSection
+        }
+
+        return current.map { section in
+            var updatedSection = section
+            updatedSection.productionDirection = existingByID[section.id]?.productionDirection
+            return updatedSection
+        }
+    }
+
+    private func changedScopes(
+        from project: SongProject,
+        to updatedProject: SongProject
+    ) -> [SongProjectUpdateScope] {
+        var scopes: [SongProjectUpdateScope] = []
+
+        if project.isStructureAutomatic &&
+            sectionsDifferIgnoringProductionDirections(project.sections, updatedProject.sections) {
+            scopes.append(.structure)
+        }
+        if project.instruments != updatedProject.instruments {
+            scopes.append(.arrangement)
+        }
+        if project.bpm != updatedProject.bpm ||
+            project.key != updatedProject.key ||
+            project.scale != updatedProject.scale ||
+            project.maqam != updatedProject.maqam {
+            scopes.append(.musicalParameters)
+        }
+        if project.isProductionAutomatic &&
+            (project.productionDirections != updatedProject.productionDirections ||
+                productionDirectionsDiffer(in: project.sections, and: updatedProject.sections)) {
+            scopes.append(.productionDirections)
+        }
+
+        return scopes
+    }
+
+    private func sectionsDifferIgnoringProductionDirections(
+        _ current: [SongSection],
+        _ updated: [SongSection]
+    ) -> Bool {
+        guard current.count == updated.count else { return true }
+
+        return zip(current, updated).contains { currentSection, updatedSection in
+            var currentWithoutProduction = currentSection
+            var updatedWithoutProduction = updatedSection
+            currentWithoutProduction.productionDirection = nil
+            updatedWithoutProduction.productionDirection = nil
+            return currentWithoutProduction != updatedWithoutProduction
+        }
+    }
+
+    private func productionDirectionsDiffer(
+        in current: [SongSection],
+        and updated: [SongSection]
+    ) -> Bool {
+        guard current.count == updated.count else { return true }
+
+        return zip(current, updated).contains { currentSection, updatedSection in
+            currentSection.productionDirection != updatedSection.productionDirection
+        }
+    }
+}

Sources/MusicAssistantCore/Services/AI/ExistingLyricsRevisionDirector.swift

@@ -30,6 +30,10 @@ public final class ExistingLyricsRevisionDirector: Sendable {
             throw ExistingLyricsRevisionDirectorError.emptySourceLyrics
         }
 
+        guard !project.isUpdateScopeLocked(.lyrics) else {
+            return SongProjectUpdateResult(project: project)
+        }
+
         let request = LyricsRevisionRequest(
             context: AIRequestContext(
                 userInstruction: trimmedInstruction,
@@ -42,14 +46,14 @@ public final class ExistingLyricsRevisionDirector: Sendable {
         )
         let result = try await aiService.reviseLyrics(from: request)
 
-        var updatedProject = project
-        updatedProject.lyrics = result.lyrics
-        updatedProject.updatedAt = revisedAt
-
-        return SongProjectUpdateResult(
-            project: updatedProject,
+        var proposedProject = project
+        proposedProject.lyrics = result.lyrics
+        return SongProjectAIUpdateMerger().apply(
+            snapshot: SongProjectSnapshot(project: proposedProject),
             changedScopes: [.lyrics],
-            notes: result.notes
+            notes: result.notes,
+            to: project,
+            updatedAt: revisedAt
         )
     }
 }

Sources/MusicAssistantCore/Services/AI/SongProjectAIUpdateMerger.swift

@@ -0,0 +1,251 @@
+import Foundation
+
+public struct SongProjectAIUpdateMerger: Sendable {
+    public init() {}
+
+    public func apply(
+        snapshot: SongProjectSnapshot,
+        changedScopes: [SongProjectUpdateScope],
+        notes: [String] = [],
+        followUpQuestions: [String] = [],
+        to existingProject: SongProject,
+        updatedAt: Date = Date()
+    ) -> SongProjectUpdateResult {
+        var updatedProject = existingProject
+        var appliedScopes: [SongProjectUpdateScope] = []
+
+        for scope in uniqueScopes(changedScopes) where !existingProject.isUpdateScopeLocked(scope) {
+            let projectBeforeScope = updatedProject
+            apply(scope, snapshot: snapshot, to: &updatedProject)
+
+            if didChange(scope, from: projectBeforeScope, to: updatedProject) {
+                appliedScopes.append(scope)
+            }
+        }
+
+        updatedProject.updatedAt = updatedAt
+        return SongProjectUpdateResult(
+            project: updatedProject,
+            changedScopes: appliedScopes,
+            notes: notes,
+            followUpQuestions: followUpQuestions
+        )
+    }
+
+    private func apply(
+        _ scope: SongProjectUpdateScope,
+        snapshot: SongProjectSnapshot,
+        to project: inout SongProject
+    ) {
+        switch scope {
+        case .duration:
+            project.duration = snapshot.duration
+        case .genres:
+            project.genres = snapshot.genres
+        case .instruments:
+            project.instruments = mergedInstrumentSelections(
+                current: project.instruments,
+                proposed: snapshot.instruments
+            )
+        case .vocals:
+            project.vocalists = snapshot.vocalists
+        case .languages:
+            project.languages = snapshot.languages
+            project.dialects = snapshot.dialects
+            project.arabicPronunciationSettings = snapshot.arabicPronunciationSettings
+        case .lyrics:
+            project.lyrics = snapshot.lyrics
+        case .structure:
+            guard project.isStructureAutomatic else { return }
+            project.sections = sections(
+                snapshot.sections,
+                preservingProductionDirectionsFrom: project.sections
+            )
+        case .arrangement:
+            project.instruments = mergedArrangement(
+                current: project.instruments,
+                proposed: snapshot.instruments
+            )
+        case .musicalParameters:
+            project.bpm = automaticValue(current: project.bpm, proposed: snapshot.bpm)
+            project.key = automaticValue(current: project.key, proposed: snapshot.key)
+            project.scale = automaticValue(current: project.scale, proposed: snapshot.scale)
+            project.maqam = automaticValue(current: project.maqam, proposed: snapshot.maqam)
+        case .emotionalArc:
+            project.emotionalArc = snapshot.emotionalArc
+        case .productionDirections:
+            guard project.isProductionAutomatic else { return }
+            project.productionDirections = snapshot.productionDirections
+            project.sections = sections(
+                project.sections,
+                applyingProductionDirectionsFrom: snapshot.sections
+            )
+        case .sunoOutput:
+            project.sunoOutput = snapshot.sunoOutput
+        }
+    }
+
+    private func mergedInstrumentSelections(
+        current: [InstrumentTrack],
+        proposed: [InstrumentTrack]
+    ) -> [InstrumentTrack] {
+        var proposedByID: [String: InstrumentTrack] = [:]
+        for proposedTrack in proposed {
+            proposedByID[proposedTrack.instrumentId] = proposedTrack
+        }
+
+        let mergedTracks = current.map { currentTrack in
+            guard currentTrack.autoArrangementEnabled,
+                  let proposedTrack = proposedByID[currentTrack.instrumentId]
+            else {
+                return currentTrack
+            }
+
+            var mergedTrack = currentTrack
+            mergedTrack.selected = proposedTrack.selected
+            mergedTrack.variant = proposedTrack.variant
+            return mergedTrack
+        }
+
+        var knownInstrumentIDs = Set(current.map(\.instrumentId))
+        let newTracks = proposed.filter { knownInstrumentIDs.insert($0.instrumentId).inserted }
+        return mergedTracks + newTracks
+    }
+
+    private func mergedArrangement(
+        current: [InstrumentTrack],
+        proposed: [InstrumentTrack]
+    ) -> [InstrumentTrack] {
+        var proposedByID: [String: InstrumentTrack] = [:]
+        for proposedTrack in proposed {
+            proposedByID[proposedTrack.instrumentId] = proposedTrack
+        }
+
+        return current.map { currentTrack in
+            guard currentTrack.selected,
+                  currentTrack.autoArrangementEnabled,
+                  let proposedTrack = proposedByID[currentTrack.instrumentId]
+            else {
+                return currentTrack
+            }
+
+            var mergedTrack = currentTrack
+            mergedTrack.playingStyle = proposedTrack.playingStyle
+            mergedTrack.role = proposedTrack.role
+            mergedTrack.placements = proposedTrack.placements
+            return mergedTrack
+        }
+    }
+
+    private func automaticValue<Value>(
+        current: ManualAutoValue<Value>?,
+        proposed: ManualAutoValue<Value>?
+    ) -> ManualAutoValue<Value>? where Value: Codable & Equatable & Sendable {
+        guard current?.mode != .manual, let proposed else {
+            return current
+        }
+
+        return ManualAutoValue(mode: .auto, value: proposed.value)
+    }
+
+    private func sections(
+        _ current: [SongSection],
+        applyingProductionDirectionsFrom proposed: [SongSection]
+    ) -> [SongSection] {
+        var proposedByID: [String: SongSection] = [:]
+        for proposedSection in proposed {
+            proposedByID[proposedSection.id] = proposedSection
+        }
+
+        return current.map { section in
+            guard let proposedSection = proposedByID[section.id] else { return section }
+            var updatedSection = section
+            updatedSection.productionDirection = proposedSection.productionDirection
+            return updatedSection
+        }
+    }
+
+    private func sections(
+        _ proposed: [SongSection],
+        preservingProductionDirectionsFrom current: [SongSection]
+    ) -> [SongSection] {
+        var currentByID: [String: SongSection] = [:]
+        for currentSection in current {
+            currentByID[currentSection.id] = currentSection
+        }
+
+        return proposed.map { section in
+            var updatedSection = section
+            updatedSection.productionDirection = currentByID[section.id]?.productionDirection
+            return updatedSection
+        }
+    }
+
+    private func didChange(
+        _ scope: SongProjectUpdateScope,
+        from current: SongProject,
+        to updated: SongProject
+    ) -> Bool {
+        switch scope {
+        case .duration:
+            return current.duration != updated.duration
+        case .genres:
+            return current.genres != updated.genres
+        case .instruments, .arrangement:
+            return current.instruments != updated.instruments
+        case .vocals:
+            return current.vocalists != updated.vocalists
+        case .languages:
+            return current.languages != updated.languages ||
+                current.dialects != updated.dialects ||
+                current.arabicPronunciationSettings != updated.arabicPronunciationSettings
+        case .lyrics:
+            return current.lyrics != updated.lyrics
+        case .structure:
+            return sectionsDifferIgnoringProductionDirections(current.sections, updated.sections)
+        case .musicalParameters:
+            return current.bpm != updated.bpm ||
+                current.key != updated.key ||
+                current.scale != updated.scale ||
+                current.maqam != updated.maqam
+        case .emotionalArc:
+            return current.emotionalArc != updated.emotionalArc
+        case .productionDirections:
+            return current.productionDirections != updated.productionDirections ||
+                productionDirectionsDiffer(in: current.sections, and: updated.sections)
+        case .sunoOutput:
+            return current.sunoOutput != updated.sunoOutput
+        }
+    }
+
+    private func uniqueScopes(_ scopes: [SongProjectUpdateScope]) -> [SongProjectUpdateScope] {
+        var seen = Set<SongProjectUpdateScope>()
+        return scopes.filter { seen.insert($0).inserted }
+    }
+
+    private func sectionsDifferIgnoringProductionDirections(
+        _ current: [SongSection],
+        _ updated: [SongSection]
+    ) -> Bool {
+        guard current.count == updated.count else { return true }
+
+        return zip(current, updated).contains { currentSection, updatedSection in
+            var currentWithoutProduction = currentSection
+            var updatedWithoutProduction = updatedSection
+            currentWithoutProduction.productionDirection = nil
+            updatedWithoutProduction.productionDirection = nil
+            return currentWithoutProduction != updatedWithoutProduction
+        }
+    }
+
+    private func productionDirectionsDiffer(
+        in current: [SongSection],
+        and updated: [SongSection]
+    ) -> Bool {
+        guard current.count == updated.count else { return true }
+
+        return zip(current, updated).contains { currentSection, updatedSection in
+            currentSection.productionDirection != updatedSection.productionDirection
+        }
+    }
+}

Sources/MusicAssistantCore/Services/AI/SongProjectDiscussionDirector.swift

@@ -0,0 +1,48 @@
+import Foundation
+
+public final class SongProjectDiscussionDirector: Sendable {
+    private let aiService: any AIService
+
+    public init(aiService: any AIService) {
+        self.aiService = aiService
+    }
+
+    public func discuss(
+        project: SongProject,
+        userMessage: String,
+        conversation: [AIConversationMessage] = [],
+        localeIdentifier: String? = nil
+    ) async throws -> SongProjectDiscussionResult {
+        guard project.conversationMode == .discuss else {
+            throw SongProjectDiscussionDirectorError.discussionModeNotEnabled
+        }
+
+        let trimmedMessage = userMessage.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !trimmedMessage.isEmpty else {
+            throw SongProjectDiscussionDirectorError.emptyUserMessage
+        }
+
+        let result = try await aiService.discussSongProject(
+            from: SongProjectDiscussionRequest(
+                context: AIRequestContext(
+                    userInstruction: trimmedMessage,
+                    conversation: conversation,
+                    localeIdentifier: localeIdentifier
+                ),
+                project: project
+            )
+        )
+
+        return SongProjectDiscussionResult(
+            questions: result.questions
+                .map { $0.trimmingCharacters(in: .whitespacesAndNewlines) }
+                .filter { !$0.isEmpty },
+            notes: result.notes
+        )
+    }
+}
+
+public enum SongProjectDiscussionDirectorError: Error, Equatable, Sendable {
+    case discussionModeNotEnabled
+    case emptyUserMessage
+}

Sources/MusicAssistantCore/Services/AI/SongProjectGenerationDirector.swift

@@ -64,32 +64,18 @@ public final class SongProjectGenerationDirector: Sendable {
             return project
         }
 
-        return SongProject(
-            id: seedProject.id,
-            title: generatedProject.title,
-            idea: normalizedIdea,
-            duration: generatedProject.duration,
-            conversationMode: discussionMode,
-            languages: generatedProject.languages,
-            dialects: generatedProject.dialects,
-            arabicPronunciationSettings: generatedProject.arabicPronunciationSettings,
-            genres: generatedProject.genres,
-            moods: generatedProject.moods,
-            emotionalArc: generatedProject.emotionalArc,
-            bpm: generatedProject.bpm,
-            key: generatedProject.key,
-            scale: generatedProject.scale,
-            maqam: generatedProject.maqam,
-            sections: generatedProject.sections,
-            instruments: generatedProject.instruments,
-            vocalists: generatedProject.vocalists,
-            lyrics: generatedProject.lyrics,
-            productionDirections: generatedProject.productionDirections,
-            sunoOutput: generatedProject.sunoOutput,
-            versions: seedProject.versions,
-            createdAt: seedProject.createdAt,
+        let update = SongProjectAIUpdateMerger().apply(
+            snapshot: SongProjectSnapshot(project: generatedProject),
+            changedScopes: SongProjectUpdateScope.allCases,
+            to: seedProject,
             updatedAt: generatedAt
         )
+        var project = update.project
+        project.title = generatedProject.title
+        project.idea = normalizedIdea
+        project.conversationMode = discussionMode
+        project.moods = generatedProject.moods
+        return project
     }
 }
 

Sources/MusicAssistantCore/Services/AI/StructuredAIResponseSchema.swift

@@ -24,14 +24,13 @@ public struct StructuredSongProjectUpdateResponse: Codable, Equatable, Sendable
         updating existingProject: SongProject,
         updatedAt: Date = Date()
     ) -> SongProjectUpdateResult {
-        var updatedProject = existingProject
-        updatedProject.restoreSnapshot(project, updatedAt: updatedAt)
-
-        return SongProjectUpdateResult(
-            project: updatedProject,
+        SongProjectAIUpdateMerger().apply(
+            snapshot: project,
             changedScopes: changedScopes,
             notes: notes,
-            followUpQuestions: followUpQuestions
+            followUpQuestions: followUpQuestions,
+            to: existingProject,
+            updatedAt: updatedAt
         )
     }
 }

Sources/MusicAssistantCore/Services/ArabicPronunciation/ArabicPronunciationProcessor.swift

@@ -0,0 +1,204 @@
+import Foundation
+
+public struct ArabicPronunciationProcessor: Sendable {
+    public init() {}
+
+    public func process(
+        lyrics: String,
+        settings: ArabicPronunciationSettings
+    ) -> ArabicPronunciationProcessingResult {
+        guard settings.isEnabled else {
+            return ArabicPronunciationProcessingResult(
+                text: lyrics,
+                notes: [.processingDisabled]
+            )
+        }
+
+        let protection = protectPreservedSpellings(
+            in: lyrics,
+            preservedSpellings: settings.preservedSpellings
+        )
+        var processedText = protection.text.precomposedStringWithCanonicalMapping
+        var notes = processingNotes(for: processedText, settings: settings)
+
+        if settings.tanweenPolicy == .removeWhenUnwanted {
+            processedText = removeTanween(from: processedText)
+        }
+
+        if settings.tanweenPolicy == .addWhenPronunciationRequires,
+           containsArabicLetter(in: processedText),
+           !containsTanween(in: processedText) {
+            notes.append(.tanweenAdditionNeedsReview)
+        }
+
+        processedText = restorePreservedSpellings(
+            in: processedText,
+            replacements: protection.replacements
+        )
+
+        if protection.matchCount > 0 {
+            notes.append(.preservedSpellingsProtected(count: protection.matchCount))
+        }
+
+        return ArabicPronunciationProcessingResult(
+            text: processedText,
+            notes: notes
+        )
+    }
+
+    private func processingNotes(
+        for text: String,
+        settings: ArabicPronunciationSettings
+    ) -> [ArabicPronunciationProcessingNote] {
+        guard containsArabicLetter(in: text) else {
+            return []
+        }
+
+        switch settings.diacritizationPolicy {
+        case .unspecified:
+            return [.diacritizationPolicyUnspecified]
+        case .pronunciationTargeted where !containsDiacritics(in: text):
+            return [.pronunciationTargetedDiacriticsNeedReview]
+        case .fullTashkeel where !containsDiacritics(in: text):
+            return [.fullTashkeelNeedsReview]
+        default:
+            return []
+        }
+    }
+
+    private func protectPreservedSpellings(
+        in text: String,
+        preservedSpellings: [String]
+    ) -> PreservedSpellingProtection {
+        let spellings = Set(
+            preservedSpellings.map {
+                $0.trimmingCharacters(in: .whitespacesAndNewlines)
+            }
+        )
+        .filter { !$0.isEmpty }
+        .sorted {
+            if $0.count == $1.count {
+                return $0 < $1
+            }
+            return $0.count > $1.count
+        }
+
+        var protectedText = text
+        var replacements: [PreservedSpellingReplacement] = []
+        var matchCount = 0
+
+        for (index, spelling) in spellings.enumerated() {
+            let occurrenceCount = protectedText.components(separatedBy: spelling).count - 1
+            guard occurrenceCount > 0 else {
+                continue
+            }
+
+            let placeholder = uniquePlaceholder(
+                for: index,
+                in: protectedText
+            )
+            protectedText = protectedText.replacingOccurrences(
+                of: spelling,
+                with: placeholder
+            )
+            replacements.append(
+                PreservedSpellingReplacement(
+                    placeholder: placeholder,
+                    spelling: spelling
+                )
+            )
+            matchCount += occurrenceCount
+        }
+
+        return PreservedSpellingProtection(
+            text: protectedText,
+            replacements: replacements,
+            matchCount: matchCount
+        )
+    }
+
+    private func uniquePlaceholder(for index: Int, in text: String) -> String {
+        var collisionIndex = 0
+        var placeholder = "[[music-assistant-preserved-\(index)]]"
+
+        while text.contains(placeholder) {
+            collisionIndex += 1
+            placeholder = "[[music-assistant-preserved-\(index)-\(collisionIndex)]]"
+        }
+
+        return placeholder
+    }
+
+    private func restorePreservedSpellings(
+        in text: String,
+        replacements: [PreservedSpellingReplacement]
+    ) -> String {
+        replacements.reduce(text) { result, replacement in
+            result.replacingOccurrences(
+                of: replacement.placeholder,
+                with: replacement.spelling
+            )
+        }
+    }
+
+    private func removeTanween(from text: String) -> String {
+        String(text.unicodeScalars.filter { scalar in
+            !isTanween(scalar)
+        })
+    }
+
+    private func containsArabicLetter(in text: String) -> Bool {
+        text.unicodeScalars.contains { scalar in
+            let isArabicBlock = (0x0600...0x06FF).contains(scalar.value)
+                || (0x0750...0x077F).contains(scalar.value)
+                || (0x08A0...0x08FF).contains(scalar.value)
+            return isArabicBlock && CharacterSet.letters.contains(scalar)
+        }
+    }
+
+    private func containsDiacritics(in text: String) -> Bool {
+        text.unicodeScalars.contains(where: isArabicDiacritic)
+    }
+
+    private func containsTanween(in text: String) -> Bool {
+        text.unicodeScalars.contains(where: isTanween)
+    }
+
+    private func isArabicDiacritic(_ scalar: Unicode.Scalar) -> Bool {
+        (0x064B...0x065F).contains(scalar.value) || scalar.value == 0x0670
+    }
+
+    private func isTanween(_ scalar: Unicode.Scalar) -> Bool {
+        (0x064B...0x064D).contains(scalar.value)
+    }
+}
+
+private struct PreservedSpellingProtection {
+    let text: String
+    let replacements: [PreservedSpellingReplacement]
+    let matchCount: Int
+}
+
+private struct PreservedSpellingReplacement {
+    let placeholder: String
+    let spelling: String
+}
+
+public struct ArabicPronunciationProcessingResult: Equatable, Sendable {
+    public var text: String
+    public var notes: [ArabicPronunciationProcessingNote]
+
+    public init(text: String, notes: [ArabicPronunciationProcessingNote] = []) {
+        self.text = text
+        self.notes = notes
+    }
+}
+
+public enum ArabicPronunciationProcessingNote: Equatable, Sendable {
+    case processingDisabled
+    case diacritizationPolicyUnspecified
+    case pronunciationTargetedDiacriticsNeedReview
+    case fullTashkeelNeedsReview
+    case tanweenAdditionNeedsReview
+    case preservedSpellingsProtected(count: Int)
+}

Tests/MusicAssistantCoreTests/AIServiceTests.swift

@@ -24,6 +24,24 @@ final class AIServiceTests: XCTestCase {
         XCTAssertEqual(result.followUpQuestions, ["Should the chorus be bigger?"])
     }
 
+    func testProviderIndependentServiceReturnsDiscussionQuestionsWithoutProjectUpdate() async throws {
+        let service = MockAIService()
+        let project = SongProject(
+            title: "Discussion Project",
+            idea: "Plan the chorus",
+            conversationMode: .discuss
+        )
+        let request = SongProjectDiscussionRequest(
+            context: AIRequestContext(userInstruction: "Ask what is still missing."),
+            project: project
+        )
+
+        let result = try await service.discussSongProject(from: request)
+
+        XCTAssertEqual(result.questions, ["Which vocal delivery should lead the chorus?"])
+        XCTAssertEqual(result.notes, ["Discussion only; no project update was proposed."])
+    }
+
     func testProviderIndependentServiceRevisesLyricsWithStructuredResult() async throws {
         let service = MockAIService()
         let project = SongProject(title: "Lyric Project", idea: "Improve words")
@@ -71,6 +89,13 @@ private struct MockAIService: AIService {
         )
     }
 
+    func discussSongProject(from request: SongProjectDiscussionRequest) async throws -> SongProjectDiscussionResult {
+        SongProjectDiscussionResult(
+            questions: ["Which vocal delivery should lead the chorus?"],
+            notes: ["Discussion only; no project update was proposed."]
+        )
+    }
+
     func reviseLyrics(from request: LyricsRevisionRequest) async throws -> LyricsRevisionResult {
         LyricsRevisionResult(
             lyrics: Lyrics(text: "\(request.sourceLyrics.text)\n\(request.context.userInstruction)"),

Tests/MusicAssistantCoreTests/ApplicationRuleInjectionTests.swift

@@ -17,6 +17,12 @@ final class ApplicationRuleInjectionTests: XCTestCase {
                 context: AIRequestContext(userInstruction: "Generate.")
             )
         )
+        _ = try await service.discussSongProject(
+            from: SongProjectDiscussionRequest(
+                context: AIRequestContext(userInstruction: "Discuss."),
+                project: project
+            )
+        )
         _ = try await service.reviseLyrics(
             from: LyricsRevisionRequest(
                 context: AIRequestContext(userInstruction: "Improve."),
@@ -37,6 +43,7 @@ final class ApplicationRuleInjectionTests: XCTestCase {
         XCTAssertEqual(
             recordedRuleContents,
             [
+                "Use private product rules.",
                 "Use private product rules.",
                 "Use private product rules.",
                 "Use private product rules."
@@ -90,6 +97,11 @@ private actor RecordingAIService: AIService {
         )
     }
 
+    func discussSongProject(from request: SongProjectDiscussionRequest) async throws -> SongProjectDiscussionResult {
+        contexts.append(request.context)
+        return SongProjectDiscussionResult(questions: ["Which direction should we take?"])
+    }
+
     func reviseLyrics(from request: LyricsRevisionRequest) async throws -> LyricsRevisionResult {
         contexts.append(request.context)
         return LyricsRevisionResult(lyrics: request.sourceLyrics)

Tests/MusicAssistantCoreTests/ArabicLyricsFixtures.swift

@@ -0,0 +1,65 @@
+import MusicAssistantCore
+
+struct ArabicLyricsFixture {
+    let dialectName: String
+    let lyrics: String
+    let settings: ArabicPronunciationSettings
+    let expectedLyrics: String
+    let expectedNotes: [ArabicPronunciationProcessingNote]
+}
+
+enum ArabicLyricsFixtures {
+    static let all: [ArabicLyricsFixture] = [
+        levantine,
+        egyptian,
+        gulf,
+        maghrebi
+    ]
+
+    private static let levantine = ArabicLyricsFixture(
+        dialectName: "Levantine Arabic",
+        lyrics: "\u{0634}\u{064F}\u{0648} \u{0628}\u{064E}\u{062F}\u{0651}\u{064E}\u{0643}",
+        settings: ArabicPronunciationSettings(
+            isEnabled: true,
+            diacritizationPolicy: .pronunciationTargeted,
+            tanweenPolicy: .preserveUserInput,
+            preservedSpellings: ["\u{0634}\u{064F}\u{0648}"]
+        ),
+        expectedLyrics: "\u{0634}\u{064F}\u{0648} \u{0628}\u{064E}\u{062F}\u{064E}\u{0651}\u{0643}",
+        expectedNotes: [.preservedSpellingsProtected(count: 1)]
+    )
+
+    private static let egyptian = ArabicLyricsFixture(
+        dialectName: "Egyptian Arabic",
+        lyrics: "\u{0625}\u{0650}\u{0632}\u{0651}\u{064E}\u{0627}\u{064A}\u{064E}\u{0643}",
+        settings: ArabicPronunciationSettings(
+            isEnabled: true,
+            diacritizationPolicy: .pronunciationTargeted
+        ),
+        expectedLyrics: "\u{0625}\u{0650}\u{0632}\u{064E}\u{0651}\u{0627}\u{064A}\u{064E}\u{0643}",
+        expectedNotes: []
+    )
+
+    private static let gulf = ArabicLyricsFixture(
+        dialectName: "Gulf Arabic",
+        lyrics: "\u{0648}\u{064E}\u{064A}\u{0652}\u{0646}\u{064E}\u{0643} \u{0634}\u{064F}\u{0643}\u{0652}\u{0631}\u{064B}\u{0627}",
+        settings: ArabicPronunciationSettings(
+            isEnabled: true,
+            diacritizationPolicy: .pronunciationTargeted,
+            tanweenPolicy: .removeWhenUnwanted
+        ),
+        expectedLyrics: "\u{0648}\u{064E}\u{064A}\u{0652}\u{0646}\u{064E}\u{0643} \u{0634}\u{064F}\u{0643}\u{0652}\u{0631}\u{0627}",
+        expectedNotes: []
+    )
+
+    private static let maghrebi = ArabicLyricsFixture(
+        dialectName: "Maghrebi Arabic",
+        lyrics: "\u{0634}\u{0646}\u{0648} \u{0628}\u{063A}\u{064A}\u{062A}\u{064A}",
+        settings: ArabicPronunciationSettings(
+            isEnabled: true,
+            diacritizationPolicy: .fullTashkeel
+        ),
+        expectedLyrics: "\u{0634}\u{0646}\u{0648} \u{0628}\u{063A}\u{064A}\u{062A}\u{064A}",
+        expectedNotes: [.fullTashkeelNeedsReview]
+    )
+}

Tests/MusicAssistantCoreTests/ArabicPronunciationProcessorTests.swift

@@ -0,0 +1,128 @@
+import MusicAssistantCore
+import XCTest
+
+final class ArabicPronunciationProcessorTests: XCTestCase {
+    private let processor = ArabicPronunciationProcessor()
+
+    func testDisabledProcessingLeavesLyricsUntouched() {
+        let lyrics = "\u{0645}\u{0651}\u{064E}\u{0631}\u{062D}\u{064E}\u{0628}\u{064B}\u{0627}"
+
+        let result = processor.process(
+            lyrics: lyrics,
+            settings: ArabicPronunciationSettings(isEnabled: false)
+        )
+
+        XCTAssertEqual(result.text, lyrics)
+        XCTAssertEqual(result.notes, [.processingDisabled])
+    }
+
+    func testProcessingNormalizesSuppliedDiacritics() {
+        let lyrics = "\u{0645}\u{0651}\u{064E}\u{0631}\u{062D}\u{064E}\u{0628}\u{064B}\u{0627}"
+
+        let result = processor.process(
+            lyrics: lyrics,
+            settings: ArabicPronunciationSettings(
+                isEnabled: true,
+                diacritizationPolicy: .pronunciationTargeted
+            )
+        )
+
+        XCTAssertEqual(
+            result.text,
+            "\u{0645}\u{064E}\u{0651}\u{0631}\u{062D}\u{064E}\u{0628}\u{064B}\u{0627}"
+        )
+        XCTAssertTrue(result.notes.isEmpty)
+    }
+
+    func testRemovingTanweenKeepsOtherDiacritics() {
+        let result = processor.process(
+            lyrics: "\u{0634}\u{064F}\u{0643}\u{0652}\u{0631}\u{064B}\u{0627}",
+            settings: ArabicPronunciationSettings(
+                isEnabled: true,
+                tanweenPolicy: .removeWhenUnwanted
+            )
+        )
+
+        XCTAssertEqual(result.text, "\u{0634}\u{064F}\u{0643}\u{0652}\u{0631}\u{0627}")
+    }
+
+    func testFullTashkeelDoesNotInventMissingMarks() {
+        let lyrics = "\u{0645}\u{0631}\u{062D}\u{0628}\u{0627}"
+
+        let result = processor.process(
+            lyrics: lyrics,
+            settings: ArabicPronunciationSettings(
+                isEnabled: true,
+                diacritizationPolicy: .fullTashkeel,
+                tanweenPolicy: .addWhenPronunciationRequires
+            )
+        )
+
+        XCTAssertEqual(result.text, lyrics)
+        XCTAssertEqual(
+            result.notes,
+            [.fullTashkeelNeedsReview, .tanweenAdditionNeedsReview]
+        )
+    }
+
+    func testPreservedSpellingsKeepTheirTanweenWhileOtherTextIsProcessed() {
+        let protectedSpelling = "\u{0647}\u{064F}\u{062F}\u{064B}\u{0649}"
+        let otherText = "\u{0634}\u{064F}\u{0643}\u{0652}\u{0631}\u{064B}\u{0627}"
+        let lyrics = "\(protectedSpelling) \(otherText) \(protectedSpelling)"
+
+        let result = processor.process(
+            lyrics: lyrics,
+            settings: ArabicPronunciationSettings(
+                isEnabled: true,
+                diacritizationPolicy: .pronunciationTargeted,
+                tanweenPolicy: .removeWhenUnwanted,
+                preservedSpellings: [protectedSpelling]
+            )
+        )
+
+        XCTAssertEqual(
+            result.text,
+            "\(protectedSpelling) \u{0634}\u{064F}\u{0643}\u{0652}\u{0631}\u{0627} \(protectedSpelling)"
+        )
+        XCTAssertEqual(result.notes, [.preservedSpellingsProtected(count: 2)])
+    }
+
+    func testPreservedSpellingsKeepTheirOriginalDiacriticOrder() {
+        let preservedSpelling = "\u{0645}\u{0651}\u{064E}"
+        let otherText = "\u{0628}\u{0651}\u{064E}"
+
+        let result = processor.process(
+            lyrics: "\(preservedSpelling) \(otherText)",
+            settings: ArabicPronunciationSettings(
+                isEnabled: true,
+                diacritizationPolicy: .pronunciationTargeted,
+                preservedSpellings: [preservedSpelling]
+            )
+        )
+
+        XCTAssertEqual(result.text, "\(preservedSpelling) \u{0628}\u{064E}\u{0651}")
+        XCTAssertEqual(result.notes, [.preservedSpellingsProtected(count: 1)])
+    }
+
+    func testArabicDialectFixturesCoverExpectedProcessingBehavior() {
+        XCTAssertEqual(ArabicLyricsFixtures.all.count, 4)
+        XCTAssertEqual(
+            Set(ArabicLyricsFixtures.all.map(\.dialectName)).count,
+            ArabicLyricsFixtures.all.count
+        )
+
+        for fixture in ArabicLyricsFixtures.all {
+            let result = processor.process(
+                lyrics: fixture.lyrics,
+                settings: fixture.settings
+            )
+
+            XCTAssertEqual(
+                result.text.unicodeScalars.map(\.value),
+                fixture.expectedLyrics.unicodeScalars.map(\.value),
+                fixture.dialectName
+            )
+            XCTAssertEqual(result.notes, fixture.expectedNotes, fixture.dialectName)
+        }
+    }
+}

Tests/MusicAssistantCoreTests/AutoSongProjectDecisionsDirectorTests.swift

@@ -0,0 +1,236 @@
+import MusicAssistantCore
+import XCTest
+
+final class AutoSongProjectDecisionsDirectorTests: XCTestCase {
+    func testAutomaticDecisionsRequestEnabledScopesAndPreserveManualChoices() async throws {
+        let currentProject = SongProject(
+            id: "auto-project",
+            title: "Current Project",
+            idea: "Build a cinematic Arabic pop song",
+            bpm: ManualAutoValue(mode: .auto),
+            key: ManualAutoValue(mode: .manual, value: "D"),
+            scale: ManualAutoValue(mode: .auto),
+            maqam: ManualAutoValue(mode: .manual, value: "Hijaz"),
+            structureMode: .manual,
+            sections: [
+                SongSection(id: "verse", type: .verse, title: "Manual Verse", productionDirection: "Dry vocal")
+            ],
+            instruments: [
+                InstrumentTrack(
+                    instrumentId: "piano",
+                    selected: true,
+                    role: "Manual piano role",
+                    autoArrangementEnabled: false,
+                    placements: [InstrumentPlacement(sectionId: "verse", direction: "Manual entry")]
+                ),
+                InstrumentTrack(
+                    instrumentId: "violin",
+                    selected: true,
+                    autoArrangementEnabled: true
+                )
+            ],
+            productionDirections: [ProductionDirection(id: "manual-production", sectionID: "verse", text: "Keep it dry")],
+            productionMode: .manual,
+            createdAt: Date(timeIntervalSince1970: 10),
+            updatedAt: Date(timeIntervalSince1970: 20)
+        )
+        let proposedProject = SongProject(
+            title: "Proposed Project",
+            idea: "Different",
+            bpm: ManualAutoValue(mode: .manual, value: 102),
+            key: ManualAutoValue(mode: .auto, value: "A"),
+            scale: ManualAutoValue(mode: .manual, value: "minor"),
+            maqam: ManualAutoValue(mode: .auto, value: "Bayati"),
+            sections: [
+                SongSection(id: "chorus", type: .chorus, title: "AI Chorus", productionDirection: "Wide synths")
+            ],
+            instruments: [
+                InstrumentTrack(
+                    instrumentId: "piano",
+                    selected: true,
+                    role: "AI piano role",
+                    placements: [InstrumentPlacement(sectionId: "chorus", direction: "AI piano entry")]
+                ),
+                InstrumentTrack(
+                    instrumentId: "violin",
+                    selected: true,
+                    playingStyle: "legato",
+                    role: "AI countermelody",
+                    placements: [InstrumentPlacement(sectionId: "chorus", direction: "Enter at chorus")]
+                )
+            ],
+            productionDirections: [ProductionDirection(id: "ai-production", sectionID: "chorus", text: "Wide synths")]
+        )
+        let aiService = RecordingAutoDecisionsAIService(
+            result: SongProjectUpdateResult(
+                project: proposedProject,
+                changedScopes: [.structure, .arrangement, .musicalParameters, .productionDirections],
+                notes: ["Applied automatic decisions."]
+            )
+        )
+        let director = AutoSongProjectDecisionsDirector(aiService: aiService)
+
+        let result = try await director.applyAutomaticDecisions(
+            to: currentProject,
+            instruction: "  Complete automatic values.  ",
+            localeIdentifier: "en_US",
+            updatedAt: Date(timeIntervalSince1970: 100)
+        )
+        let request = await aiService.recordedRequests.first
+
+        XCTAssertEqual(request?.context.userInstruction, "Complete automatic values.")
+        XCTAssertEqual(request?.context.localeIdentifier, "en_US")
+        XCTAssertEqual(
+            request?.allowedScopes ?? [],
+            [SongProjectUpdateScope.arrangement, .musicalParameters]
+        )
+        XCTAssertEqual(result.project.sections, currentProject.sections)
+        XCTAssertEqual(result.project.productionDirections, currentProject.productionDirections)
+        XCTAssertEqual(result.project.bpm, ManualAutoValue(mode: .auto, value: 102))
+        XCTAssertEqual(result.project.key, currentProject.key)
+        XCTAssertEqual(result.project.scale, ManualAutoValue(mode: .auto, value: "minor"))
+        XCTAssertEqual(result.project.maqam, currentProject.maqam)
+        XCTAssertEqual(result.project.instrumentTrack(for: "piano"), currentProject.instrumentTrack(for: "piano"))
+        XCTAssertEqual(result.project.instrumentTrack(for: "violin")?.role, "AI countermelody")
+        XCTAssertEqual(result.project.instrumentTrack(for: "violin")?.playingStyle, "legato")
+        XCTAssertEqual(result.project.instrumentTrack(for: "violin")?.placements, [InstrumentPlacement(sectionId: "chorus", direction: "Enter at chorus")])
+        XCTAssertEqual(result.project.updatedAt, Date(timeIntervalSince1970: 100))
+        XCTAssertEqual(
+            result.changedScopes,
+            [SongProjectUpdateScope.arrangement, .musicalParameters]
+        )
+        XCTAssertEqual(result.notes, ["Applied automatic decisions."])
+    }
+
+    func testAutomaticDecisionsApplyStructureAndProductionWhenTheirModesAreAutomatic() async throws {
+        let currentProject = SongProject(
+            title: "Auto Project",
+            idea: "Let AI plan it",
+            structureMode: .auto,
+            sections: [SongSection(id: "intro", type: .intro, title: "Current Intro")],
+            productionMode: .auto
+        )
+        let proposedProject = SongProject(
+            title: "Proposed",
+            idea: "Proposed",
+            sections: [SongSection(id: "verse", type: .verse, title: "AI Verse", productionDirection: "Add texture")],
+            productionDirections: [ProductionDirection(id: "production", sectionID: "verse", text: "Add texture")]
+        )
+        let aiService = RecordingAutoDecisionsAIService(
+            result: SongProjectUpdateResult(project: proposedProject)
+        )
+        let director = AutoSongProjectDecisionsDirector(aiService: aiService)
+
+        let result = try await director.applyAutomaticDecisions(to: currentProject, updatedAt: Date(timeIntervalSince1970: 200))
+        let request = await aiService.recordedRequests.first
+
+        XCTAssertEqual(
+            request?.allowedScopes ?? [],
+            [.structure, .musicalParameters, .productionDirections]
+        )
+        XCTAssertEqual(result.project.sections, proposedProject.sections)
+        XCTAssertEqual(result.project.productionDirections, proposedProject.productionDirections)
+        XCTAssertEqual(result.changedScopes, [.structure, .productionDirections])
+    }
+
+    func testAutomaticDecisionsDoNotCallAIWhenEveryDecisionIsManual() async throws {
+        let project = SongProject(
+            title: "Manual Project",
+            idea: "Keep all choices",
+            bpm: ManualAutoValue(mode: .manual, value: 96),
+            key: ManualAutoValue(mode: .manual, value: "C"),
+            scale: ManualAutoValue(mode: .manual, value: "major"),
+            maqam: ManualAutoValue(mode: .manual, value: "Rast"),
+            structureMode: .manual,
+            instruments: [InstrumentTrack(instrumentId: "oud", selected: true, autoArrangementEnabled: false)],
+            productionMode: .manual
+        )
+        let aiService = RecordingAutoDecisionsAIService(
+            result: SongProjectUpdateResult(project: project)
+        )
+        let director = AutoSongProjectDecisionsDirector(aiService: aiService)
+
+        let result = try await director.applyAutomaticDecisions(to: project)
+        let requestCount = await aiService.recordedRequests.count
+
+        XCTAssertEqual(requestCount, 0)
+        XCTAssertEqual(result.project, project)
+        XCTAssertTrue(result.changedScopes.isEmpty)
+        XCTAssertEqual(result.notes, ["No automatic decisions are enabled."])
+    }
+
+    func testAutomaticStructureDoesNotReplaceManualProductionDirections() async throws {
+        let project = SongProject(
+            title: "Mixed Modes",
+            idea: "Change the structure only",
+            bpm: ManualAutoValue(mode: .manual, value: 100),
+            key: ManualAutoValue(mode: .manual, value: "C"),
+            scale: ManualAutoValue(mode: .manual, value: "minor"),
+            maqam: ManualAutoValue(mode: .manual, value: "Rast"),
+            structureMode: .auto,
+            sections: [SongSection(id: "verse", type: .verse, title: "Current Verse", productionDirection: "Keep dry")],
+            productionDirections: [ProductionDirection(id: "manual-production", sectionID: "verse", text: "Keep dry")],
+            productionMode: .manual
+        )
+        let proposedProject = SongProject(
+            title: "Proposed",
+            idea: "Proposed",
+            sections: [SongSection(id: "verse", type: .chorus, title: "AI Chorus", productionDirection: "Add wide synths")],
+            productionDirections: [ProductionDirection(id: "ai-production", sectionID: "verse", text: "Add wide synths")]
+        )
+        let aiService = RecordingAutoDecisionsAIService(result: SongProjectUpdateResult(project: proposedProject))
+        let director = AutoSongProjectDecisionsDirector(aiService: aiService)
+
+        let result = try await director.applyAutomaticDecisions(to: project)
+
+        XCTAssertEqual(result.project.sections.first?.type, .chorus)
+        XCTAssertEqual(result.project.sections.first?.productionDirection, "Keep dry")
+        XCTAssertEqual(result.project.productionDirections, project.productionDirections)
+        XCTAssertEqual(result.changedScopes, [SongProjectUpdateScope.structure])
+    }
+
+    func testAutomaticDecisionsDoNotCallAIForLockedAutomaticScopes() async throws {
+        let project = SongProject(
+            title: "Locked Auto Project",
+            idea: "Do not update the tempo",
+            bpm: ManualAutoValue(mode: .auto),
+            key: ManualAutoValue(mode: .manual, value: "C"),
+            scale: ManualAutoValue(mode: .manual, value: "minor"),
+            maqam: ManualAutoValue(mode: .manual, value: "Rast"),
+            structureMode: .manual,
+            productionMode: .manual,
+            userLocks: SongProjectUserLocks(scopes: [.musicalParameters])
+        )
+        let aiService = RecordingAutoDecisionsAIService(result: SongProjectUpdateResult(project: project))
+        let director = AutoSongProjectDecisionsDirector(aiService: aiService)
+
+        let result = try await director.applyAutomaticDecisions(to: project)
+        let requestCount = await aiService.recordedRequests.count
+
+        XCTAssertEqual(requestCount, 0)
+        XCTAssertEqual(result.project, project)
+        XCTAssertTrue(result.changedScopes.isEmpty)
+    }
+}
+
+private actor RecordingAutoDecisionsAIService: AIService {
+    private(set) var recordedRequests: [SongProjectUpdateRequest] = []
+    private let result: SongProjectUpdateResult
+
+    init(result: SongProjectUpdateResult) {
+        self.result = result
+    }
+
+    func generateSongProject(from request: SongProjectGenerationRequest) async throws -> SongProjectGenerationResult {
+        SongProjectGenerationResult(project: request.seedProject ?? SongProject(title: "Unused", idea: "Unused"))
+    }
+
+    func reviseLyrics(from request: LyricsRevisionRequest) async throws -> LyricsRevisionResult {
+        LyricsRevisionResult(lyrics: request.sourceLyrics)
+    }
+
+    func proposeProjectUpdate(from request: SongProjectUpdateRequest) async throws -> SongProjectUpdateResult {
+        recordedRequests.append(request)
+        return result
+    }
+}

Tests/MusicAssistantCoreTests/ExistingLyricsRevisionDirectorTests.swift

@@ -137,6 +137,30 @@ final class ExistingLyricsRevisionDirectorTests: XCTestCase {
         let requestCount = await aiService.recordedRevisionRequests.count
         XCTAssertEqual(requestCount, 0)
     }
+
+    func testReviseExistingLyricsDoesNotCallAIWhenLyricsAreLocked() async throws {
+        let aiService = RecordingLyricsAIService(
+            revisionResult: LyricsRevisionResult(lyrics: Lyrics(text: "Unused"))
+        )
+        let director = ExistingLyricsRevisionDirector(aiService: aiService)
+        let project = SongProject(
+            title: "Locked Lyrics",
+            idea: "Keep the words",
+            lyrics: Lyrics(text: "User-approved lyrics"),
+            userLocks: SongProjectUserLocks(scopes: [.lyrics])
+        )
+
+        let result = try await director.reviseExistingLyrics(
+            in: project,
+            instruction: "Improve the chorus.",
+            mode: .improve
+        )
+        let requestCount = await aiService.recordedRevisionRequests.count
+
+        XCTAssertEqual(requestCount, 0)
+        XCTAssertEqual(result.project, project)
+        XCTAssertTrue(result.changedScopes.isEmpty)
+    }
 }
 
 private actor RecordingLyricsAIService: AIService {

Tests/MusicAssistantCoreTests/InstrumentCatalogItemTests.swift

@@ -0,0 +1,38 @@
+import MusicAssistantCore
+import XCTest
+
+final class InstrumentCatalogItemTests: XCTestCase {
+    func testCatalogItemStoresStructuredInstrumentMetadata() {
+        let item = InstrumentCatalogItem(
+            id: "oud",
+            name: "Oud",
+            familyCategory: "Plucked strings",
+            regionOrigin: "Middle East",
+            aliases: ["Arabic lute"],
+            searchTerms: ["ud", "عود"]
+        )
+
+        XCTAssertEqual(item.id, "oud")
+        XCTAssertEqual(item.name, "Oud")
+        XCTAssertEqual(item.familyCategory, "Plucked strings")
+        XCTAssertEqual(item.regionOrigin, "Middle East")
+        XCTAssertEqual(item.aliases, ["Arabic lute"])
+        XCTAssertEqual(item.searchTerms, ["ud", "عود"])
+    }
+
+    func testCatalogItemSupportsOptionalMetadataAndRoundTripsThroughJSON() throws {
+        let item = InstrumentCatalogItem(
+            id: "synthesizer",
+            name: "Synthesizer",
+            familyCategory: "Electronic"
+        )
+
+        let data = try JSONEncoder().encode(item)
+        let decodedItem = try JSONDecoder().decode(InstrumentCatalogItem.self, from: data)
+
+        XCTAssertNil(item.regionOrigin)
+        XCTAssertEqual(item.aliases, [])
+        XCTAssertEqual(item.searchTerms, [])
+        XCTAssertEqual(decodedItem, item)
+    }
+}

Tests/MusicAssistantCoreTests/OpenAIClientTests.swift

@@ -68,6 +68,34 @@ final class OpenAIClientTests: XCTestCase {
         XCTAssertEqual(recordedURL, overrideURL)
     }
 
+    func testDiscussSongProjectUsesAdapterAndReturnsQuestions() async throws {
+        let transport = RecordingOpenAITransport(
+            statusCode: 200,
+            responseData: try JSONEncoder().encode(MockOpenAIResponse(text: "Should the chorus be intimate or anthemic?"))
+        )
+        let configuration = OpenAIClientConfiguration(
+            apiKey: "test-api-key",
+            endpointURL: URL(string: "https://api.example.test/v1/configured")!,
+            model: "configured-model"
+        )
+        let client = OpenAIClient(
+            configuration: configuration,
+            adapter: MockOpenAIClientAdapter(),
+            transport: transport
+        )
+
+        let result = try await client.discussSongProject(
+            from: SongProjectDiscussionRequest(
+                context: AIRequestContext(userInstruction: "Ask before deciding."),
+                project: SongProject(title: "Discussion", idea: "Plan this", conversationMode: .discuss)
+            )
+        )
+        let requestBodyString = await transport.requestBodyString
+
+        XCTAssertEqual(result.questions, ["Should the chorus be intimate or anthemic?"])
+        XCTAssertEqual(requestBodyString, "discuss|configured-model|Ask before deciding.")
+    }
+
     func testClientRejectsMissingAPIKeyBeforeSendingRequest() async throws {
         let transport = RecordingOpenAITransport(
             statusCode: 200,
@@ -100,7 +128,7 @@ final class OpenAIClientTests: XCTestCase {
         XCTAssertEqual(recordedRequestCount, 0)
     }
 
-    func testClientReportsUnacceptableStatusWithoutLeakingResponseBody() async throws {
+    func testClientReportsRateLimitWithoutLeakingResponseBody() async throws {
         let transport = RecordingOpenAITransport(
             statusCode: 429,
             responseData: Data("secret server detail".utf8)
@@ -122,7 +150,32 @@ final class OpenAIClientTests: XCTestCase {
             )
             XCTFail("Expected status error to throw.")
         } catch let error as OpenAIClientError {
-            XCTAssertEqual(error, .unacceptableStatusCode(429))
+            XCTAssertEqual(error, .rateLimited(retryAfter: nil))
+        }
+    }
+
+    func testClientReadsRetryAfterForRateLimitedResponses() async throws {
+        let transport = RecordingOpenAITransport(
+            statusCode: 429,
+            responseData: Data(),
+            responseHeaders: ["Retry-After": "3.5"]
+        )
+        let client = OpenAIClient(
+            configuration: OpenAIClientConfiguration(
+                apiKey: "test-api-key",
+                endpointURL: URL(string: "https://api.example.test/v1/configured")!
+            ),
+            adapter: MockOpenAIClientAdapter(),
+            transport: transport
+        )
+
+        do {
+            _ = try await client.generateSongProject(
+                from: SongProjectGenerationRequest(context: AIRequestContext(userInstruction: "Generate."))
+            )
+            XCTFail("Expected rate limit error to throw.")
+        } catch let error as OpenAIClientError {
+            XCTAssertEqual(error, .rateLimited(retryAfter: 3.5))
         }
     }
 }
@@ -131,10 +184,16 @@ private actor RecordingOpenAITransport: OpenAIHTTPTransport {
     private(set) var recordedRequests: [URLRequest] = []
     private let statusCode: Int
     private let responseData: Data
+    private let responseHeaders: [String: String]?
 
-    init(statusCode: Int, responseData: Data) {
+    init(
+        statusCode: Int,
+        responseData: Data,
+        responseHeaders: [String: String]? = nil
+    ) {
         self.statusCode = statusCode
         self.responseData = responseData
+        self.responseHeaders = responseHeaders
     }
 
     var requestBodyString: String? {
@@ -148,7 +207,7 @@ private actor RecordingOpenAITransport: OpenAIHTTPTransport {
             url: request.url!,
             statusCode: statusCode,
             httpVersion: "HTTP/1.1",
-            headerFields: nil
+            headerFields: responseHeaders
         )!
         return (responseData, response)
     }
@@ -175,6 +234,21 @@ private struct MockOpenAIClientAdapter: OpenAIClientAdapter {
         )
     }
 
+    func makeSongProjectDiscussionRequest(
+        _ request: SongProjectDiscussionRequest,
+        configuration: OpenAIClientConfiguration
+    ) throws -> OpenAIClientRequest {
+        OpenAIClientRequest(
+            url: overrideURL,
+            body: Data("discuss|\(configuration.model ?? "")|\(request.context.userInstruction)".utf8)
+        )
+    }
+
+    func decodeSongProjectDiscussionResult(from data: Data) throws -> SongProjectDiscussionResult {
+        let response = try JSONDecoder().decode(MockOpenAIResponse.self, from: data)
+        return SongProjectDiscussionResult(questions: [response.text])
+    }
+
     func makeLyricsRevisionRequest(
         _ request: LyricsRevisionRequest,
         configuration: OpenAIClientConfiguration

Tests/MusicAssistantCoreTests/RetryingAIServiceTests.swift

@@ -0,0 +1,144 @@
+import MusicAssistantCore
+import XCTest
+
+final class RetryingAIServiceTests: XCTestCase {
+    func testRetriesTemporaryServerFailureThenReturnsResult() async throws {
+        let baseService = ScriptedRetryAIService(
+            outcomes: [.serverFailure(503), .serverFailure(503), .success("Generated")]
+        )
+        let scheduler = RecordingRetryScheduler()
+        let service = RetryingAIService(
+            baseService: baseService,
+            policy: AIServiceRetryPolicy(maxAttempts: 3, baseDelay: 0.25, maximumDelay: 2),
+            scheduler: scheduler
+        )
+
+        let result = try await service.generateSongProject(
+            from: SongProjectGenerationRequest(context: AIRequestContext(userInstruction: "Generate."))
+        )
+        let attemptCount = await baseService.generateAttemptCount
+        let delays = await scheduler.delays
+
+        XCTAssertEqual(result.project.title, "Generated")
+        XCTAssertEqual(attemptCount, 3)
+        XCTAssertEqual(delays, [0.25, 0.5])
+    }
+
+    func testHonorsProviderRateLimitDelayBeforeRetrying() async throws {
+        let baseService = ScriptedRetryAIService(
+            outcomes: [.rateLimited(4), .success("Generated")]
+        )
+        let scheduler = RecordingRetryScheduler()
+        let service = RetryingAIService(
+            baseService: baseService,
+            policy: AIServiceRetryPolicy(maxAttempts: 3, baseDelay: 0.25, maximumDelay: 2),
+            scheduler: scheduler
+        )
+
+        _ = try await service.generateSongProject(
+            from: SongProjectGenerationRequest(context: AIRequestContext(userInstruction: "Generate."))
+        )
+        let delays = await scheduler.delays
+
+        XCTAssertEqual(delays, [4])
+    }
+
+    func testDoesNotRetryPermanentFailures() async {
+        let baseService = ScriptedRetryAIService(outcomes: [.missingAPIKey])
+        let scheduler = RecordingRetryScheduler()
+        let service = RetryingAIService(baseService: baseService, scheduler: scheduler)
+
+        do {
+            _ = try await service.generateSongProject(
+                from: SongProjectGenerationRequest(context: AIRequestContext(userInstruction: "Generate."))
+            )
+            XCTFail("Expected missing key error to throw.")
+        } catch let error as OpenAIClientError {
+            XCTAssertEqual(error, .missingAPIKey)
+        } catch {
+            XCTFail("Expected OpenAIClientError.")
+        }
+
+        let attemptCount = await baseService.generateAttemptCount
+        let delays = await scheduler.delays
+        XCTAssertEqual(attemptCount, 1)
+        XCTAssertTrue(delays.isEmpty)
+    }
+
+    func testCancellationWhileWaitingStopsFurtherRetries() async {
+        let baseService = ScriptedRetryAIService(outcomes: [.serverFailure(503), .success("Unused")])
+        let scheduler = RecordingRetryScheduler(shouldCancel: true)
+        let service = RetryingAIService(baseService: baseService, scheduler: scheduler)
+
+        do {
+            _ = try await service.generateSongProject(
+                from: SongProjectGenerationRequest(context: AIRequestContext(userInstruction: "Generate."))
+            )
+            XCTFail("Expected cancellation to throw.")
+        } catch is CancellationError {
+        } catch {
+            XCTFail("Expected CancellationError.")
+        }
+
+        let attemptCount = await baseService.generateAttemptCount
+        XCTAssertEqual(attemptCount, 1)
+    }
+}
+
+private enum RetryOutcome: Sendable {
+    case serverFailure(Int)
+    case rateLimited(TimeInterval?)
+    case missingAPIKey
+    case success(String)
+}
+
+private actor ScriptedRetryAIService: AIService {
+    private var outcomes: [RetryOutcome]
+    private(set) var generateAttemptCount = 0
+
+    init(outcomes: [RetryOutcome]) {
+        self.outcomes = outcomes
+    }
+
+    func generateSongProject(from request: SongProjectGenerationRequest) async throws -> SongProjectGenerationResult {
+        generateAttemptCount += 1
+        guard !outcomes.isEmpty else {
+            return SongProjectGenerationResult(project: SongProject(title: "Unexpected", idea: request.context.userInstruction))
+        }
+
+        switch outcomes.removeFirst() {
+        case let .serverFailure(statusCode):
+            throw OpenAIClientError.serverError(statusCode)
+        case let .rateLimited(retryAfter):
+            throw OpenAIClientError.rateLimited(retryAfter: retryAfter)
+        case .missingAPIKey:
+            throw OpenAIClientError.missingAPIKey
+        case let .success(title):
+            return SongProjectGenerationResult(project: SongProject(title: title, idea: request.context.userInstruction))
+        }
+    }
+
+    func reviseLyrics(from request: LyricsRevisionRequest) async throws -> LyricsRevisionResult {
+        LyricsRevisionResult(lyrics: request.sourceLyrics)
+    }
+
+    func proposeProjectUpdate(from request: SongProjectUpdateRequest) async throws -> SongProjectUpdateResult {
+        SongProjectUpdateResult(project: request.project)
+    }
+}
+
+private actor RecordingRetryScheduler: AIServiceRetryScheduler {
+    private(set) var delays: [TimeInterval] = []
+    private let shouldCancel: Bool
+
+    init(shouldCancel: Bool = false) {
+        self.shouldCancel = shouldCancel
+    }
+
+    func sleep(for interval: TimeInterval) async throws {
+        delays.append(interval)
+        if shouldCancel {
+            throw CancellationError()
+        }
+    }
+}

Tests/MusicAssistantCoreTests/SongProjectDiscussionDirectorTests.swift

@@ -0,0 +1,94 @@
+import MusicAssistantCore
+import XCTest
+
+final class SongProjectDiscussionDirectorTests: XCTestCase {
+    func testDiscussBuildsARequestAndReturnsTrimmedQuestionsWithoutChangingProject() async throws {
+        let project = SongProject(
+            id: "discussion-project",
+            title: "Discussion Project",
+            idea: "Plan a cinematic chorus",
+            conversationMode: .discuss,
+            createdAt: Date(timeIntervalSince1970: 10),
+            updatedAt: Date(timeIntervalSince1970: 20)
+        )
+        let aiService = RecordingDiscussionAIService(
+            result: SongProjectDiscussionResult(
+                questions: ["  Should the chorus use a choir?  ", "   "],
+                notes: ["Awaiting the user's choice."]
+            )
+        )
+        let director = SongProjectDiscussionDirector(aiService: aiService)
+        let conversation = [AIConversationMessage(role: .assistant, content: "What mood should lead?")]
+
+        let result = try await director.discuss(
+            project: project,
+            userMessage: "  Keep the verses intimate.  ",
+            conversation: conversation,
+            localeIdentifier: "en_US"
+        )
+        let request = await aiService.recordedRequests.first
+
+        XCTAssertEqual(request?.context.userInstruction, "Keep the verses intimate.")
+        XCTAssertEqual(request?.context.conversation, conversation)
+        XCTAssertEqual(request?.context.localeIdentifier, "en_US")
+        XCTAssertEqual(request?.project, project)
+        XCTAssertEqual(result.questions, ["Should the chorus use a choir?"])
+        XCTAssertEqual(result.notes, ["Awaiting the user's choice."])
+    }
+
+    func testDiscussRejectsAutoModeAndBlankMessagesBeforeCallingAI() async throws {
+        let aiService = RecordingDiscussionAIService(
+            result: SongProjectDiscussionResult(questions: ["Unused"])
+        )
+        let director = SongProjectDiscussionDirector(aiService: aiService)
+
+        do {
+            _ = try await director.discuss(
+                project: SongProject(title: "Auto", idea: "Auto", conversationMode: .auto),
+                userMessage: "Ask a question."
+            )
+            XCTFail("Expected discussion mode validation to fail.")
+        } catch let error as SongProjectDiscussionDirectorError {
+            XCTAssertEqual(error, .discussionModeNotEnabled)
+        }
+
+        do {
+            _ = try await director.discuss(
+                project: SongProject(title: "Discuss", idea: "Discuss", conversationMode: .discuss),
+                userMessage: " \n "
+            )
+            XCTFail("Expected blank message validation to fail.")
+        } catch let error as SongProjectDiscussionDirectorError {
+            XCTAssertEqual(error, .emptyUserMessage)
+        }
+
+        let requestCount = await aiService.recordedRequests.count
+        XCTAssertEqual(requestCount, 0)
+    }
+}
+
+private actor RecordingDiscussionAIService: AIService {
+    private(set) var recordedRequests: [SongProjectDiscussionRequest] = []
+    private let result: SongProjectDiscussionResult
+
+    init(result: SongProjectDiscussionResult) {
+        self.result = result
+    }
+
+    func generateSongProject(from request: SongProjectGenerationRequest) async throws -> SongProjectGenerationResult {
+        SongProjectGenerationResult(project: request.seedProject ?? SongProject(title: "Unused", idea: "Unused"))
+    }
+
+    func discussSongProject(from request: SongProjectDiscussionRequest) async throws -> SongProjectDiscussionResult {
+        recordedRequests.append(request)
+        return result
+    }
+
+    func reviseLyrics(from request: LyricsRevisionRequest) async throws -> LyricsRevisionResult {
+        LyricsRevisionResult(lyrics: request.sourceLyrics)
+    }
+
+    func proposeProjectUpdate(from request: SongProjectUpdateRequest) async throws -> SongProjectUpdateResult {
+        SongProjectUpdateResult(project: request.project)
+    }
+}

Tests/MusicAssistantCoreTests/SongProjectGenerationDirectorTests.swift

@@ -105,6 +105,42 @@ final class SongProjectGenerationDirectorTests: XCTestCase {
         let requestCount = await aiService.recordedGenerationRequests.count
         XCTAssertEqual(requestCount, 0)
     }
+
+    func testGenerateCompleteProjectPreservesLockedAndManualSeedValues() async throws {
+        let seedProject = SongProject(
+            id: "locked-seed",
+            title: "Seed",
+            idea: "Original",
+            genres: [GenreStyle(id: "arabic-pop", name: "Arabic Pop")],
+            bpm: ManualAutoValue(mode: .manual, value: 96),
+            lyrics: Lyrics(text: "User-approved lyrics"),
+            userLocks: SongProjectUserLocks(scopes: [.genres, .lyrics])
+        )
+        let aiService = RecordingGenerationAIService(
+            generationResult: SongProjectGenerationResult(
+                project: SongProject(
+                    title: "Generated Title",
+                    idea: "Generated idea",
+                    genres: [GenreStyle(id: "rock", name: "Rock")],
+                    bpm: ManualAutoValue(mode: .auto, value: 120),
+                    lyrics: Lyrics(text: "AI lyrics")
+                )
+            )
+        )
+        let director = SongProjectGenerationDirector(aiService: aiService)
+
+        let result = try await director.generateCompleteProject(
+            fromIdea: "Generate around the locked choices",
+            seedProject: seedProject
+        )
+
+        XCTAssertEqual(result.project.title, "Generated Title")
+        XCTAssertEqual(result.project.idea, "Generated idea")
+        XCTAssertEqual(result.project.genres, seedProject.genres)
+        XCTAssertEqual(result.project.lyrics, seedProject.lyrics)
+        XCTAssertEqual(result.project.bpm, seedProject.bpm)
+        XCTAssertEqual(result.project.userLocks, seedProject.userLocks)
+    }
 }
 
 private actor RecordingGenerationAIService: AIService {

Tests/MusicAssistantCoreTests/SongProjectModelTests.swift

@@ -369,6 +369,36 @@ final class SongProjectModelTests: XCTestCase {
         XCTAssertEqual(project.languageIDs, ["english"])
     }
 
+    func testApplyingReviewedArabicLyricsUpdatesMatchingSunoLyrics() {
+        var project = SongProject(
+            id: "project-arabic-review",
+            title: "Arabic Review",
+            idea: "Review pronunciation",
+            lyrics: Lyrics(text: "Original lyrics"),
+            sunoOutput: SunoOutput(lyricsText: "Original lyrics", stylePrompt: "Arabic pop")
+        )
+
+        project.applyReviewedArabicLyrics("Reviewed lyrics")
+
+        XCTAssertEqual(project.lyrics.text, "Reviewed lyrics")
+        XCTAssertEqual(project.sunoOutput?.lyricsText, "Reviewed lyrics")
+    }
+
+    func testApplyingReviewedArabicLyricsPreservesEditedSunoLyrics() {
+        var project = SongProject(
+            id: "project-arabic-review-manual-output",
+            title: "Arabic Review",
+            idea: "Review pronunciation",
+            lyrics: Lyrics(text: "Original lyrics"),
+            sunoOutput: SunoOutput(lyricsText: "Manually edited output", stylePrompt: "Arabic pop")
+        )
+
+        project.applyReviewedArabicLyrics("Reviewed lyrics")
+
+        XCTAssertEqual(project.lyrics.text, "Reviewed lyrics")
+        XCTAssertEqual(project.sunoOutput?.lyricsText, "Manually edited output")
+    }
+
     func testMusicalParametersSupportManualAndAutoModes() {
         var project = SongProject(
             id: "project-8",

Tests/MusicAssistantCoreTests/StructuredAIResponseSchemaTests.swift

@@ -105,10 +105,69 @@ final class StructuredAIResponseSchemaTests: XCTestCase {
         XCTAssertEqual(result.project.createdAt, createdAt)
         XCTAssertEqual(result.project.updatedAt, updatedAt)
         XCTAssertEqual(result.project.versions, [version])
-        XCTAssertEqual(result.project.title, "Updated")
+        XCTAssertEqual(result.project.title, "Original")
         XCTAssertEqual(result.project.lyrics.text, "Updated lyrics")
         XCTAssertEqual(result.changedScopes, [.genres, .lyrics])
         XCTAssertEqual(result.notes, ["Proposed focused update."])
         XCTAssertEqual(result.followUpQuestions, ["Keep it minimal?"])
     }
+
+    func testStructuredResponsePreservesLockedScopesAndManualValues() {
+        let section = SongSection(id: "verse", type: .verse, title: "Manual Verse")
+        let manualInstrument = InstrumentTrack(
+            instrumentId: "oud",
+            selected: true,
+            role: "Manual lead",
+            autoArrangementEnabled: false,
+            placements: [InstrumentPlacement(sectionId: "verse", direction: "Manual entry")]
+        )
+        let existingProject = SongProject(
+            title: "Original Title",
+            idea: "Original Idea",
+            genres: [GenreStyle(id: "arabic-pop", name: "Arabic Pop")],
+            bpm: ManualAutoValue(mode: .manual, value: 96),
+            key: ManualAutoValue(mode: .auto),
+            structureMode: .manual,
+            sections: [section],
+            instruments: [manualInstrument],
+            lyrics: Lyrics(text: "Locked lyrics"),
+            userLocks: SongProjectUserLocks(scopes: [.genres, .lyrics])
+        )
+        let response = StructuredSongProjectUpdateResponse(
+            project: SongProjectSnapshot(
+                title: "AI Title",
+                idea: "AI Idea",
+                genres: [GenreStyle(id: "rock", name: "Rock")],
+                bpm: ManualAutoValue(mode: .auto, value: 120),
+                key: ManualAutoValue(mode: .auto, value: "A"),
+                sections: [SongSection(id: "chorus", type: .chorus, title: "AI Chorus")],
+                instruments: [
+                    InstrumentTrack(
+                        instrumentId: "oud",
+                        selected: true,
+                        role: "AI lead",
+                        placements: [InstrumentPlacement(sectionId: "chorus", direction: "AI entry")]
+                    )
+                ],
+                lyrics: Lyrics(text: "AI lyrics")
+            ),
+            changedScopes: [.genres, .lyrics, .instruments, .musicalParameters, .structure, .arrangement]
+        )
+
+        let result = response.makeUpdateResult(
+            updating: existingProject,
+            updatedAt: Date(timeIntervalSince1970: 500)
+        )
+
+        XCTAssertEqual(result.project.title, "Original Title")
+        XCTAssertEqual(result.project.idea, "Original Idea")
+        XCTAssertEqual(result.project.genres, existingProject.genres)
+        XCTAssertEqual(result.project.lyrics, existingProject.lyrics)
+        XCTAssertEqual(result.project.bpm, existingProject.bpm)
+        XCTAssertEqual(result.project.key, ManualAutoValue(mode: .auto, value: "A"))
+        XCTAssertEqual(result.project.sections, existingProject.sections)
+        XCTAssertEqual(result.project.instruments, existingProject.instruments)
+        XCTAssertEqual(result.project.userLocks, existingProject.userLocks)
+        XCTAssertEqual(result.changedScopes, [.musicalParameters])
+    }
 }

docs/ARCHITECTURE.md

@@ -40,12 +40,38 @@ macOS App
 OpenAI receives the user's intent plus private application rules and
 structured project state. AI output should be requested as structured
 data wherever possible, not treated as an unstructured chat transcript.
+For automatic decisions, the AI Director requests only enabled automatic
+scopes and merges the response into the current project while preserving
+manual structure, arrangement, musical-parameter and production choices.
+When a Song Project uses Discuss mode, the AI Director sends the current
+project and conversation context to the provider and returns follow-up
+questions without applying a project update.
+All structured AI updates pass through a scope-aware merger. It applies only
+the scopes declared by the response, ignores user-locked scopes and preserves
+manual control values.
+AI provider calls can be wrapped by a configurable retry service. It retries only
+temporary network, server and rate-limit failures, honors a provider-supplied
+retry delay when available, and propagates cancellation without retrying.
 
 ## Prompt Compiler
 
 A deterministic layer converts the approved SongProject into the final
 Suno-facing lyrics/style content. User choices override AI suggestions.
 
+## Arabic Pronunciation Processor
+
+The Arabic Pronunciation Processor is a local Application Service. It
+normalizes user-supplied Arabic diacritics and applies the selected
+tanween policy without choosing a diacritization policy for the user.
+It must not invent missing vowel marks or tanween when no reliable
+linguistic source is available; instead, it returns a review note so a
+later user-review flow can present the unresolved text. This processor
+does not use external services or APIs. Before processing, it protects
+the user's exact preserved spellings and dialect phrases so normalization
+or tanween removal cannot alter them. The Presentation layer presents
+both the original and processed lyrics in final review; the user may edit
+and explicitly apply the processed text before any Suno handoff.
+
 ## Security
 
 -   Never commit API keys to source control.

docs/DATA_MODEL.md

@@ -20,11 +20,14 @@ SongProject
 - key
 - scale
 - maqam
+- structureMode: manual | auto
 - sections[]
 - instruments[]
 - vocalists[]
 - lyrics
 - productionDirections[]
+- productionMode: manual | auto
+- userLocks[]
 - sunoOutput
 - versions[]
 - createdAt
@@ -59,6 +62,26 @@ InstrumentTrack
 - autoArrangementEnabled
 - placements[]
 
+Auto-decision behavior
+- The AI may update song sections only when structureMode is auto.
+- The AI may update an instrument's role, playing style and placements only
+  when autoArrangementEnabled is true for that selected instrument.
+- The AI may fill BPM, key, scale and maqam only when their individual
+  ManualAutoValue mode is auto.
+- The AI may update production directions only when productionMode is auto.
+- Manual values remain authoritative when automatic decisions are applied.
+
+Discuss mode behavior
+- When conversationMode is discuss, the AI receives the current Song Project
+  and conversation context, then returns follow-up questions before a project
+  decision is applied.
+- A discussion response does not itself modify the Song Project.
+
+User-lock behavior
+- userLocks records update scopes explicitly locked by the user.
+- AI updates for locked scopes are ignored; every other accepted AI update must
+  still preserve Manual/Auto choices.
+
 InstrumentPlacement
 - sectionId (optional)
 - startTime (optional)

docs/TASKS.md

@@ -59,23 +59,23 @@ requirement is missing and blocks implementation, record it in
 -   [x] Define structured AI response schema for SongProject updates.
 -   [x] Implement idea → complete project generation.
 -   [x] Implement existing lyrics → correction/improvement flow.
--   [ ] Implement Auto mode for structure, arrangement, BPM/key/maqam
+-   [x] Implement Auto mode for structure, arrangement, BPM/key/maqam
     and production decisions.
--   [ ] Implement optional Discuss mode.
--   [ ] Enforce user-lock/manual-value precedence over AI output.
--   [ ] Add error, retry, cancellation and rate-limit handling.
+-   [x] Implement optional Discuss mode.
+-   [x] Enforce user-lock/manual-value precedence over AI output.
+-   [x] Add error, retry, cancellation and rate-limit handling.
 
 ## Phase 5 --- Arabic Lyrics Processing
 
--   [ ] Add Arabic-specific settings UI.
--   [ ] Support diacritics/harakat/tanween processing.
--   [ ] Preserve intentional spelling/dialect choices where possible.
--   [ ] Allow user to compare/edit processed Arabic before Suno handoff.
--   [ ] Add Arabic test fixtures covering multiple dialects.
+-   [x] Add Arabic-specific settings UI.
+-   [x] Support diacritics/harakat/tanween processing.
+-   [x] Preserve intentional spelling/dialect choices where possible.
+-   [x] Allow user to compare/edit processed Arabic before Suno handoff.
+-   [x] Add Arabic test fixtures covering multiple dialects.
 
 ## Phase 6 --- Instrument Selector & Catalog
 
--   [ ] Create structured catalog models for instrument id, name,
+-   [x] Create structured catalog models for instrument id, name,
     family/category, optional region/origin and aliases/search terms.
 -   [ ] Provide large worldwide catalog data covering Western, Middle
     Eastern, African, South Asian, East Asian, Southeast Asian, Latin