Persist selections and compile song output

2026-09-14 21:56:26 +02:00
parent 35703f89a8
commit 7bf4df79f9
10 changed files with 490 additions and 11 deletions
@@ -0,0 +1,171 @@
+import Foundation
+
+public struct SongGenerationContext: Codable, Equatable, Sendable {
+    public static let empty = SongGenerationContext(selectedInstruments: [])
+
+    public var selectedInstruments: [SelectedInstrumentContext]
+
+    public init(selectedInstruments: [SelectedInstrumentContext]) {
+        self.selectedInstruments = selectedInstruments
+    }
+
+    public init(project: SongProject) {
+        let sectionsByID = Dictionary(uniqueKeysWithValues: project.sections.map { ($0.id, $0) })
+        selectedInstruments = project.selectedInstrumentTracks.map { track in
+            SelectedInstrumentContext(
+                instrumentId: track.instrumentId,
+                displayName: Self.displayName(for: track),
+                playingStyle: Self.normalized(track.playingStyle),
+                role: Self.normalized(track.role),
+                autoArrangementEnabled: track.autoArrangementEnabled,
+                placements: track.placements.map { placement in
+                    SelectedInstrumentPlacementContext(
+                        sectionId: placement.sectionId,
+                        sectionTitle: placement.sectionId.flatMap { sectionsByID[$0]?.title },
+                        sectionType: placement.sectionId.flatMap { sectionsByID[$0]?.type },
+                        startTime: placement.startTime,
+                        endTime: placement.endTime,
+                        direction: Self.normalized(placement.direction)
+                    )
+                }
+            )
+        }
+    }
+
+    public var hasSelectedInstruments: Bool {
+        !selectedInstruments.isEmpty
+    }
+
+    public var sunoStyleInstrumentPhrase: String {
+        selectedInstruments
+            .map(\.stylePromptPhrase)
+            .joined(separator: ", ")
+    }
+
+    private static func displayName(for track: InstrumentTrack) -> String {
+        normalized(track.variant) ?? track.instrumentId
+    }
+
+    private static func normalized(_ value: String?) -> String? {
+        let trimmedValue = value?.trimmingCharacters(in: .whitespacesAndNewlines)
+        return trimmedValue?.isEmpty == false ? trimmedValue : nil
+    }
+}
+
+public struct SelectedInstrumentContext: Codable, Equatable, Sendable {
+    public var instrumentId: String
+    public var displayName: String
+    public var playingStyle: String?
+    public var role: String?
+    public var autoArrangementEnabled: Bool
+    public var placements: [SelectedInstrumentPlacementContext]
+
+    public init(
+        instrumentId: String,
+        displayName: String,
+        playingStyle: String? = nil,
+        role: String? = nil,
+        autoArrangementEnabled: Bool = true,
+        placements: [SelectedInstrumentPlacementContext] = []
+    ) {
+        self.instrumentId = instrumentId
+        self.displayName = displayName
+        self.playingStyle = playingStyle
+        self.role = role
+        self.autoArrangementEnabled = autoArrangementEnabled
+        self.placements = placements
+    }
+
+    public var stylePromptPhrase: String {
+        var details: [String] = []
+
+        if let role {
+            details.append(role)
+        }
+
+        if let playingStyle {
+            details.append(playingStyle)
+        }
+
+        let timingPhrase = placements
+            .map(\.stylePromptPhrase)
+            .filter { !$0.isEmpty }
+            .joined(separator: "; ")
+
+        if !timingPhrase.isEmpty {
+            details.append(timingPhrase)
+        }
+
+        guard !details.isEmpty else {
+            return displayName
+        }
+
+        return "\(displayName) (\(details.joined(separator: ", ")))"
+    }
+}
+
+public struct SelectedInstrumentPlacementContext: Codable, Equatable, Sendable {
+    public var sectionId: String?
+    public var sectionTitle: String?
+    public var sectionType: SongSectionType?
+    public var startTime: TimeInterval?
+    public var endTime: TimeInterval?
+    public var direction: String?
+
+    public init(
+        sectionId: String? = nil,
+        sectionTitle: String? = nil,
+        sectionType: SongSectionType? = nil,
+        startTime: TimeInterval? = nil,
+        endTime: TimeInterval? = nil,
+        direction: String? = nil
+    ) {
+        self.sectionId = sectionId
+        self.sectionTitle = sectionTitle
+        self.sectionType = sectionType
+        self.startTime = startTime
+        self.endTime = endTime
+        self.direction = direction
+    }
+
+    public var stylePromptPhrase: String {
+        var parts: [String] = []
+
+        if let sectionTitle, !sectionTitle.isEmpty {
+            parts.append(sectionTitle)
+        } else if let sectionType {
+            parts.append(sectionType.rawValue)
+        }
+
+        if let timing = timingPhrase {
+            parts.append(timing)
+        }
+
+        if let direction, !direction.isEmpty {
+            parts.append(direction)
+        }
+
+        return parts.joined(separator: " ")
+    }
+
+    private var timingPhrase: String? {
+        switch (startTime, endTime) {
+        case let (start?, end?):
+            return "\(Self.formattedTime(start))-\(Self.formattedTime(end))"
+        case let (start?, nil):
+            return "from \(Self.formattedTime(start))"
+        case let (nil, end?):
+            return "until \(Self.formattedTime(end))"
+        case (nil, nil):
+            return nil
+        }
+    }
+
+    private static func formattedTime(_ time: TimeInterval) -> String {
+        let roundedTime = time.rounded()
+        if roundedTime == time {
+            return "\(Int(roundedTime))s"
+        }
+        return String(format: "%.1fs", time)
+    }
+}