import Foundation

public struct SongProject: Codable, Equatable, Identifiable, Sendable {
    public let id: String
    public var title: String
    public var idea: String
    public var duration: SongDuration?
    public var conversationMode: ConversationMode
    public var languages: [LanguageSelection]
    public var dialects: [DialectSelection]
    public var arabicPronunciationSettings: ArabicPronunciationSettings
    public var genres: [GenreStyle]
    public var moods: [MoodTag]
    public var emotionalArc: [EmotionalArcPoint]
    public var bpm: ManualAutoValue<Int>?
    public var key: ManualAutoValue<String>?
    public var scale: ManualAutoValue<String>?
    public var maqam: ManualAutoValue<String>?
    public var sections: [SongSection]
    public var instruments: [InstrumentTrack]
    public var vocalists: [Vocalist]
    public var lyrics: Lyrics
    public var productionDirections: [ProductionDirection]
    public var sunoOutput: SunoOutput?
    public var versions: [SongVersion]
    public let createdAt: Date
    public var updatedAt: Date

    public init(
        id: String = UUID().uuidString,
        title: String,
        idea: String,
        duration: SongDuration? = nil,
        conversationMode: ConversationMode = .auto,
        languages: [LanguageSelection] = [],
        dialects: [DialectSelection] = [],
        arabicPronunciationSettings: ArabicPronunciationSettings = ArabicPronunciationSettings(),
        genres: [GenreStyle] = [],
        moods: [MoodTag] = [],
        emotionalArc: [EmotionalArcPoint] = [],
        bpm: ManualAutoValue<Int>? = nil,
        key: ManualAutoValue<String>? = nil,
        scale: ManualAutoValue<String>? = nil,
        maqam: ManualAutoValue<String>? = nil,
        sections: [SongSection] = [],
        instruments: [InstrumentTrack] = [],
        vocalists: [Vocalist] = [],
        lyrics: Lyrics = Lyrics(),
        productionDirections: [ProductionDirection] = [],
        sunoOutput: SunoOutput? = nil,
        versions: [SongVersion] = [],
        createdAt: Date = Date(),
        updatedAt: Date = Date()
    ) {
        self.id = id
        self.title = title
        self.idea = idea
        self.duration = duration
        self.conversationMode = conversationMode
        self.languages = languages
        self.dialects = dialects
        self.arabicPronunciationSettings = arabicPronunciationSettings
        self.genres = genres
        self.moods = moods
        self.emotionalArc = emotionalArc
        self.bpm = bpm
        self.key = key
        self.scale = scale
        self.maqam = maqam
        self.sections = sections
        self.instruments = instruments
        self.vocalists = vocalists
        self.lyrics = lyrics
        self.productionDirections = productionDirections
        self.sunoOutput = sunoOutput
        self.versions = versions
        self.createdAt = createdAt
        self.updatedAt = updatedAt
    }
}

public extension SongProject {
    var orderedSections: [SongSection] {
        sections
            .enumerated()
            .sorted { left, right in
                if left.element.order == right.element.order {
                    return left.offset < right.offset
                }
                return left.element.order < right.element.order
            }
            .map(\.element)
    }

    var selectedGenreStyleIDs: Set<String> {
        Set(genres.map(\.id))
    }

    func isGenreStyleSelected(_ genreStyle: GenreStyle) -> Bool {
        selectedGenreStyleIDs.contains(genreStyle.id)
    }

    mutating func selectGenreStyle(_ genreStyle: GenreStyle) {
        guard !isGenreStyleSelected(genreStyle) else { return }
        genres.append(genreStyle)
    }

    mutating func deselectGenreStyle(id: String) {
        genres.removeAll { $0.id == id }
    }

    var languageIDs: Set<String> {
        Set(languages.map(\.id))
    }

    var dialectIDs: Set<String> {
        Set(dialects.map(\.id))
    }

    func language(for languageID: String) -> LanguageSelection? {
        languages.first { $0.id == languageID }
    }

    func dialect(for dialectID: String) -> DialectSelection? {
        dialects.first { $0.id == dialectID }
    }

    func dialects(forLanguageID languageID: String) -> [DialectSelection] {
        dialects.filter { $0.languageID == languageID }
    }

    mutating func upsertLanguage(_ language: LanguageSelection) {
        if let index = languages.firstIndex(where: { $0.id == language.id }) {
            languages[index] = language
        } else {
            languages.append(language)
        }
    }

    mutating func removeLanguage(id languageID: String) {
        languages.removeAll { $0.id == languageID }
        dialects.removeAll { $0.languageID == languageID }
    }

    mutating func upsertDialect(_ dialect: DialectSelection) {
        if let index = dialects.firstIndex(where: { $0.id == dialect.id }) {
            dialects[index] = dialect
        } else {
            dialects.append(dialect)
        }
    }

    mutating func removeDialect(id dialectID: String) {
        dialects.removeAll { $0.id == dialectID }
    }

    mutating func setBPMManually(_ value: Int) {
        bpm = ManualAutoValue(mode: .manual, value: value)
    }

    mutating func setBPMAutomatic() {
        bpm = ManualAutoValue(mode: .auto)
    }

    mutating func setKeyManually(_ value: String) {
        key = ManualAutoValue(mode: .manual, value: value)
    }

    mutating func setKeyAutomatic() {
        key = ManualAutoValue(mode: .auto)
    }

    mutating func setScaleManually(_ value: String) {
        scale = ManualAutoValue(mode: .manual, value: value)
    }

    mutating func setScaleAutomatic() {
        scale = ManualAutoValue(mode: .auto)
    }

    mutating func setMaqamManually(_ value: String) {
        maqam = ManualAutoValue(mode: .manual, value: value)
    }

    mutating func setMaqamAutomatic() {
        maqam = ManualAutoValue(mode: .auto)
    }

    func emotionalArcPoint(for pointID: String) -> EmotionalArcPoint? {
        emotionalArc.first { $0.id == pointID }
    }

    func emotionalArcPoints(forSectionID sectionID: String) -> [EmotionalArcPoint] {
        emotionalArc.filter { $0.sectionID == sectionID }
    }

    mutating func upsertEmotionalArcPoint(_ point: EmotionalArcPoint) {
        if let index = emotionalArc.firstIndex(where: { $0.id == point.id }) {
            emotionalArc[index] = point
        } else {
            emotionalArc.append(point)
        }
    }

    mutating func removeEmotionalArcPoint(id pointID: String) {
        emotionalArc.removeAll { $0.id == pointID }
    }

    func productionDirection(for directionID: String) -> ProductionDirection? {
        productionDirections.first { $0.id == directionID }
    }

    func productionDirections(forSectionID sectionID: String) -> [ProductionDirection] {
        productionDirections.filter { $0.sectionID == sectionID }
    }

    mutating func upsertProductionDirection(_ direction: ProductionDirection) {
        if let index = productionDirections.firstIndex(where: { $0.id == direction.id }) {
            productionDirections[index] = direction
        } else {
            productionDirections.append(direction)
        }
    }

    mutating func removeProductionDirection(id directionID: String) {
        productionDirections.removeAll { $0.id == directionID }
    }

    var selectedInstrumentTracks: [InstrumentTrack] {
        instruments.filter(\.selected)
    }

    var selectedInstrumentIDs: Set<String> {
        Set(selectedInstrumentTracks.map(\.instrumentId))
    }

    func instrumentTrack(for instrumentId: String) -> InstrumentTrack? {
        instruments.first { $0.instrumentId == instrumentId }
    }

    func isInstrumentSelected(id instrumentId: String) -> Bool {
        instrumentTrack(for: instrumentId)?.selected == true
    }

    mutating func selectInstrument(_ instrument: InstrumentTrack) {
        var selectedInstrument = instrument
        selectedInstrument.selected = true

        if let index = instruments.firstIndex(where: { $0.instrumentId == instrument.instrumentId }) {
            instruments[index] = selectedInstrument
        } else {
            instruments.append(selectedInstrument)
        }
    }

    mutating func deselectInstrument(id instrumentId: String) {
        guard let index = instruments.firstIndex(where: { $0.instrumentId == instrumentId }) else { return }
        instruments[index].selected = false
    }

    mutating func configureInstrument(
        id instrumentId: String,
        variant: String?,
        playingStyle: String?,
        role: String?,
        autoArrangementEnabled: Bool
    ) {
        guard let index = instruments.firstIndex(where: { $0.instrumentId == instrumentId }) else { return }
        instruments[index].variant = variant
        instruments[index].playingStyle = playingStyle
        instruments[index].role = role
        instruments[index].autoArrangementEnabled = autoArrangementEnabled
    }

    mutating func addInstrumentPlacement(_ placement: InstrumentPlacement, to instrumentId: String) {
        if let index = instruments.firstIndex(where: { $0.instrumentId == instrumentId }) {
            instruments[index].placements.append(placement)
        } else {
            instruments.append(
                InstrumentTrack(
                    instrumentId: instrumentId,
                    selected: true,
                    placements: [placement]
                )
            )
        }
    }

    var vocalistIDs: Set<String> {
        Set(vocalists.map(\.id))
    }

    func vocalist(for vocalistID: String) -> Vocalist? {
        vocalists.first { $0.id == vocalistID }
    }

    func vocalistsAssigned(toSectionID sectionID: String) -> [Vocalist] {
        vocalists.filter { $0.assignedSections.contains(sectionID) }
    }

    mutating func upsertVocalist(_ vocalist: Vocalist) {
        var normalizedVocalist = vocalist
        normalizedVocalist.assignedSections = Self.uniqueOrderedIDs(vocalist.assignedSections)

        if let index = vocalists.firstIndex(where: { $0.id == vocalist.id }) {
            vocalists[index] = normalizedVocalist
        } else {
            vocalists.append(normalizedVocalist)
        }
    }

    mutating func removeVocalist(id vocalistID: String) {
        vocalists.removeAll { $0.id == vocalistID }
    }

    mutating func assignSection(_ sectionID: String, toVocalistID vocalistID: String) {
        guard let index = vocalists.firstIndex(where: { $0.id == vocalistID }) else { return }
        guard !vocalists[index].assignedSections.contains(sectionID) else { return }
        vocalists[index].assignedSections.append(sectionID)
    }

    mutating func unassignSection(_ sectionID: String, fromVocalistID vocalistID: String) {
        guard let index = vocalists.firstIndex(where: { $0.id == vocalistID }) else { return }
        vocalists[index].assignedSections.removeAll { $0 == sectionID }
    }

    mutating func createVersion(
        id: String = UUID().uuidString,
        label: String,
        createdAt: Date = Date()
    ) -> SongVersion {
        let version = SongVersion(
            id: id,
            label: label,
            snapshot: SongProjectSnapshot(project: self),
            createdAt: createdAt
        )
        versions.append(version)
        return version
    }

    func version(id versionID: String) -> SongVersion? {
        versions.first { $0.id == versionID }
    }

    mutating func restoreVersion(id versionID: String, restoredAt: Date = Date()) -> Bool {
        guard let version = version(id: versionID) else { return false }
        restoreSnapshot(version.snapshot, updatedAt: restoredAt)
        return true
    }

    mutating func restoreSnapshot(_ snapshot: SongProjectSnapshot, updatedAt: Date = Date()) {
        title = snapshot.title
        idea = snapshot.idea
        duration = snapshot.duration
        conversationMode = snapshot.conversationMode
        languages = snapshot.languages
        dialects = snapshot.dialects
        arabicPronunciationSettings = snapshot.arabicPronunciationSettings
        genres = snapshot.genres
        moods = snapshot.moods
        emotionalArc = snapshot.emotionalArc
        bpm = snapshot.bpm
        key = snapshot.key
        scale = snapshot.scale
        maqam = snapshot.maqam
        sections = snapshot.sections
        instruments = snapshot.instruments
        vocalists = snapshot.vocalists
        lyrics = snapshot.lyrics
        productionDirections = snapshot.productionDirections
        sunoOutput = snapshot.sunoOutput
        self.updatedAt = updatedAt
    }

    mutating func appendSection(_ section: SongSection) {
        var orderedSection = section
        orderedSection.order = nextSectionOrder
        sections.append(orderedSection)
    }

    mutating func moveSection(id: String, toOrder targetOrder: Int) {
        var ordered = orderedSections
        guard let sourceIndex = ordered.firstIndex(where: { $0.id == id }) else { return }

        let section = ordered.remove(at: sourceIndex)
        let boundedTargetOrder = min(max(targetOrder, 0), ordered.count)
        ordered.insert(section, at: boundedTargetOrder)
        sections = Self.sectionsWithNormalizedOrder(ordered)
    }

    mutating func normalizeSectionOrder() {
        sections = Self.sectionsWithNormalizedOrder(orderedSections)
    }

    private var nextSectionOrder: Int {
        (sections.map(\.order).max() ?? -1) + 1
    }

    private static func sectionsWithNormalizedOrder(_ sections: [SongSection]) -> [SongSection] {
        sections.enumerated().map { index, section in
            var orderedSection = section
            orderedSection.order = index
            return orderedSection
        }
    }

    private static func uniqueOrderedIDs(_ ids: [String]) -> [String] {
        var seenIDs = Set<String>()
        return ids.filter { seenIDs.insert($0).inserted }
    }
}

public enum ConversationMode: String, Codable, Equatable, Sendable {
    case auto
    case discuss
}

public enum ControlMode: String, Codable, Equatable, Sendable {
    case manual
    case auto
}

public struct ManualAutoValue<Value: Codable & Equatable & Sendable>: Codable, Equatable, Sendable {
    public var mode: ControlMode
    public var value: Value?

    public init(mode: ControlMode, value: Value? = nil) {
        self.mode = mode
        self.value = value
    }
}

public struct SongDuration: Codable, Equatable, Sendable {
    public var seconds: Int?
    public var description: String?

    public init(seconds: Int? = nil, description: String? = nil) {
        self.seconds = seconds
        self.description = description
    }
}

public struct LanguageSelection: Codable, Equatable, Identifiable, Sendable {
    public let id: String
    public var name: String

    public init(id: String = UUID().uuidString, name: String) {
        self.id = id
        self.name = name
    }
}

public struct DialectSelection: Codable, Equatable, Identifiable, Sendable {
    public let id: String
    public var name: String
    public var languageID: String?

    public init(id: String = UUID().uuidString, name: String, languageID: String? = nil) {
        self.id = id
        self.name = name
        self.languageID = languageID
    }
}

public struct ArabicPronunciationSettings: Codable, Equatable, Sendable {
    public var isEnabled: Bool
    public var diacritizationPolicy: ArabicDiacritizationPolicy
    public var tanweenPolicy: ArabicTanweenPolicy
    public var userNotes: String?
    public var preservedSpellings: [String]

    public init(
        isEnabled: Bool = false,
        diacritizationPolicy: ArabicDiacritizationPolicy = .unspecified,
        tanweenPolicy: ArabicTanweenPolicy = .unspecified,
        userNotes: String? = nil,
        preservedSpellings: [String] = []
    ) {
        self.isEnabled = isEnabled
        self.diacritizationPolicy = diacritizationPolicy
        self.tanweenPolicy = tanweenPolicy
        self.userNotes = userNotes
        self.preservedSpellings = preservedSpellings
    }
}

public enum ArabicDiacritizationPolicy: String, Codable, Equatable, Sendable {
    case unspecified
    case pronunciationTargeted
    case fullTashkeel
}

public enum ArabicTanweenPolicy: String, Codable, Equatable, Sendable {
    case unspecified
    case preserveUserInput
    case addWhenPronunciationRequires
    case removeWhenUnwanted
}

public struct GenreStyle: Codable, Equatable, Identifiable, Sendable {
    public let id: String
    public var name: String
    public var aliases: [String]

    public init(id: String = UUID().uuidString, name: String, aliases: [String] = []) {
        self.id = id
        self.name = name
        self.aliases = aliases
    }
}

public struct MoodTag: Codable, Equatable, Identifiable, Sendable {
    public let id: String
    public var name: String

    public init(id: String = UUID().uuidString, name: String) {
        self.id = id
        self.name = name
    }
}

public struct EmotionalArcPoint: Codable, Equatable, Identifiable, Sendable {
    public let id: String
    public var sectionID: String?
    public var emotion: String
    public var energy: Int?
    public var direction: String?

    public init(
        id: String = UUID().uuidString,
        sectionID: String? = nil,
        emotion: String,
        energy: Int? = nil,
        direction: String? = nil
    ) {
        self.id = id
        self.sectionID = sectionID
        self.emotion = emotion
        self.energy = energy
        self.direction = direction
    }
}

public struct Lyrics: Codable, Equatable, Sendable {
    public var text: String
    public var sectionTexts: [String: String]

    public init(text: String = "", sectionTexts: [String: String] = [:]) {
        self.text = text
        self.sectionTexts = sectionTexts
    }
}

public struct ProductionDirection: Codable, Equatable, Identifiable, Sendable {
    public let id: String
    public var sectionID: String?
    public var text: String

    public init(id: String = UUID().uuidString, sectionID: String? = nil, text: String) {
        self.id = id
        self.sectionID = sectionID
        self.text = text
    }
}

public struct InstrumentCatalogItem: Codable, Equatable, Identifiable, Sendable {
    public let id: String
    public var name: String
    public var familyCategory: String
    public var regionOrigin: String?
    public var aliases: [String]
    public var searchTerms: [String]

    public init(
        id: String,
        name: String,
        familyCategory: String,
        regionOrigin: String? = nil,
        aliases: [String] = [],
        searchTerms: [String] = []
    ) {
        self.id = id
        self.name = name
        self.familyCategory = familyCategory
        self.regionOrigin = regionOrigin
        self.aliases = aliases
        self.searchTerms = searchTerms
    }
}

public struct SongSection: Codable, Equatable, Identifiable, Sendable {
    public let id: String
    public var type: SongSectionType
    public var title: String
    public var order: Int
    public var startTime: TimeInterval?
    public var endTime: TimeInterval?
    public var lyrics: String
    public var emotion: String?
    public var energy: Int?
    public var vocalDirection: String?
    public var productionDirection: String?

    public init(
        id: String = UUID().uuidString,
        type: SongSectionType,
        title: String,
        order: Int = 0,
        startTime: TimeInterval? = nil,
        endTime: TimeInterval? = nil,
        lyrics: String = "",
        emotion: String? = nil,
        energy: Int? = nil,
        vocalDirection: String? = nil,
        productionDirection: String? = nil
    ) {
        self.id = id
        self.type = type
        self.title = title
        self.order = order
        self.startTime = startTime
        self.endTime = endTime
        self.lyrics = lyrics
        self.emotion = emotion
        self.energy = energy
        self.vocalDirection = vocalDirection
        self.productionDirection = productionDirection
    }
}

public enum SongSectionType: String, Codable, Equatable, Sendable {
    case intro
    case verse
    case preChorus
    case chorus
    case bridge
    case outro
    case custom
}

public struct InstrumentTrack: Codable, Equatable, Sendable {
    public var instrumentId: String
    public var selected: Bool
    public var variant: String?
    public var playingStyle: String?
    public var role: String?
    public var autoArrangementEnabled: Bool
    public var placements: [InstrumentPlacement]

    public init(
        instrumentId: String,
        selected: Bool = true,
        variant: String? = nil,
        playingStyle: String? = nil,
        role: String? = nil,
        autoArrangementEnabled: Bool = true,
        placements: [InstrumentPlacement] = []
    ) {
        self.instrumentId = instrumentId
        self.selected = selected
        self.variant = variant
        self.playingStyle = playingStyle
        self.role = role
        self.autoArrangementEnabled = autoArrangementEnabled
        self.placements = placements
    }
}

public struct InstrumentPlacement: Codable, Equatable, Sendable {
    public var sectionId: String?
    public var startTime: TimeInterval?
    public var endTime: TimeInterval?
    public var direction: String?

    public init(
        sectionId: String? = nil,
        startTime: TimeInterval? = nil,
        endTime: TimeInterval? = nil,
        direction: String? = nil
    ) {
        self.sectionId = sectionId
        self.startTime = startTime
        self.endTime = endTime
        self.direction = direction
    }
}

public struct Vocalist: Codable, Equatable, Identifiable, Sendable {
    public let id: String
    public var label: String
    public var voiceType: String?
    public var genderSelection: String?
    public var performanceStyle: String?
    public var assignedSections: [String]

    public init(
        id: String = UUID().uuidString,
        label: String,
        voiceType: String? = nil,
        genderSelection: String? = nil,
        performanceStyle: String? = nil,
        assignedSections: [String] = []
    ) {
        self.id = id
        self.label = label
        self.voiceType = voiceType
        self.genderSelection = genderSelection
        self.performanceStyle = performanceStyle
        self.assignedSections = assignedSections
    }
}

public struct SunoOutput: Codable, Equatable, Sendable {
    public var lyricsText: String
    public var stylePrompt: String
    public var additionalFields: [String: String]
    public var generatedAt: Date

    public init(
        lyricsText: String,
        stylePrompt: String,
        additionalFields: [String: String] = [:],
        generatedAt: Date = Date()
    ) {
        self.lyricsText = lyricsText
        self.stylePrompt = stylePrompt
        self.additionalFields = additionalFields
        self.generatedAt = generatedAt
    }
}

public struct SongVersion: Codable, Equatable, Identifiable, Sendable {
    public let id: String
    public var label: String
    public var snapshot: SongProjectSnapshot
    public let createdAt: Date

    public init(
        id: String = UUID().uuidString,
        label: String,
        snapshot: SongProjectSnapshot,
        createdAt: Date = Date()
    ) {
        self.id = id
        self.label = label
        self.snapshot = snapshot
        self.createdAt = createdAt
    }
}

public struct SongProjectSnapshot: Codable, Equatable, Sendable {
    public var title: String
    public var idea: String
    public var duration: SongDuration?
    public var conversationMode: ConversationMode
    public var languages: [LanguageSelection]
    public var dialects: [DialectSelection]
    public var arabicPronunciationSettings: ArabicPronunciationSettings
    public var genres: [GenreStyle]
    public var moods: [MoodTag]
    public var emotionalArc: [EmotionalArcPoint]
    public var bpm: ManualAutoValue<Int>?
    public var key: ManualAutoValue<String>?
    public var scale: ManualAutoValue<String>?
    public var maqam: ManualAutoValue<String>?
    public var sections: [SongSection]
    public var instruments: [InstrumentTrack]
    public var vocalists: [Vocalist]
    public var lyrics: Lyrics
    public var productionDirections: [ProductionDirection]
    public var sunoOutput: SunoOutput?

    public init(
        title: String,
        idea: String,
        duration: SongDuration? = nil,
        conversationMode: ConversationMode = .auto,
        languages: [LanguageSelection] = [],
        dialects: [DialectSelection] = [],
        arabicPronunciationSettings: ArabicPronunciationSettings = ArabicPronunciationSettings(),
        genres: [GenreStyle] = [],
        moods: [MoodTag] = [],
        emotionalArc: [EmotionalArcPoint] = [],
        bpm: ManualAutoValue<Int>? = nil,
        key: ManualAutoValue<String>? = nil,
        scale: ManualAutoValue<String>? = nil,
        maqam: ManualAutoValue<String>? = nil,
        sections: [SongSection] = [],
        instruments: [InstrumentTrack] = [],
        vocalists: [Vocalist] = [],
        lyrics: Lyrics = Lyrics(),
        productionDirections: [ProductionDirection] = [],
        sunoOutput: SunoOutput? = nil
    ) {
        self.title = title
        self.idea = idea
        self.duration = duration
        self.conversationMode = conversationMode
        self.languages = languages
        self.dialects = dialects
        self.arabicPronunciationSettings = arabicPronunciationSettings
        self.genres = genres
        self.moods = moods
        self.emotionalArc = emotionalArc
        self.bpm = bpm
        self.key = key
        self.scale = scale
        self.maqam = maqam
        self.sections = sections
        self.instruments = instruments
        self.vocalists = vocalists
        self.lyrics = lyrics
        self.productionDirections = productionDirections
        self.sunoOutput = sunoOutput
    }

    public init(project: SongProject) {
        self.init(
            title: project.title,
            idea: project.idea,
            duration: project.duration,
            conversationMode: project.conversationMode,
            languages: project.languages,
            dialects: project.dialects,
            arabicPronunciationSettings: project.arabicPronunciationSettings,
            genres: project.genres,
            moods: project.moods,
            emotionalArc: project.emotionalArc,
            bpm: project.bpm,
            key: project.key,
            scale: project.scale,
            maqam: project.maqam,
            sections: project.sections,
            instruments: project.instruments,
            vocalists: project.vocalists,
            lyrics: project.lyrics,
            productionDirections: project.productionDirections,
            sunoOutput: project.sunoOutput
        )
    }
}