import MusicAssistantCore
import SwiftUI

struct ProjectInspectorView: View {
    @Binding var project: SongProject
    let saveProject: (SongProject) async -> Bool

    @State private var newGenreName = ""
    @State private var newInstrumentName = ""
    @State private var newVocalistLabel = ""
    @State private var newLanguageName = ""
    @State private var isInstrumentBrowserPresented = false
    @State private var isSaving = false
    @State private var saveStatus: SaveStatus?

    var body: some View {
        VStack(spacing: 0) {
            HStack {
                Label("Inspector", systemImage: "slider.horizontal.3")
                    .font(.headline)

                Spacer()

                Button {
                    Task {
                        await save()
                    }
                } label: {
                    Label("Save", systemImage: "tray.and.arrow.down")
                }
                .disabled(isSaving)
            }
            .padding(16)

            Divider()

            Form {
                Section("Overview") {
                    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)
                }

                Section("Genres") {
                    EditableTokenList(
                        values: project.genres.map(\.name),
                        removeAction: { index in
                            project.deselectGenreStyle(id: project.genres[index].id)
                        }
                    )
                    AddTextRow(
                        placeholder: "Add genre",
                        text: $newGenreName,
                        addAction: addGenre
                    )
                }

                Section("Instruments") {
                    Button {
                        isInstrumentBrowserPresented = true
                    } label: {
                        Label("Browse catalog", systemImage: "magnifyingglass")
                    }

                    ForEach($project.instruments, id: \.instrumentId) { $instrument in
                        Toggle(isOn: $instrument.selected) {
                            Text(instrument.variant?.isEmpty == false ? instrument.variant ?? instrument.instrumentId : instrument.instrumentId)
                                .lineLimit(1)
                        }
                    }
                    AddTextRow(
                        placeholder: "Add instrument",
                        text: $newInstrumentName,
                        addAction: addInstrument
                    )
                }

                Section("Vocalists") {
                    EditableTokenList(
                        values: project.vocalists.map(\.label),
                        removeAction: { index in
                            project.removeVocalist(id: project.vocalists[index].id)
                        }
                    )
                    AddTextRow(
                        placeholder: "Add vocalist",
                        text: $newVocalistLabel,
                        addAction: addVocalist
                    )
                }

                Section("Languages") {
                    EditableTokenList(
                        values: project.languages.map(\.name),
                        removeAction: { index in
                            project.removeLanguage(id: project.languages[index].id)
                        }
                    )
                    AddTextRow(
                        placeholder: "Add language",
                        text: $newLanguageName,
                        addAction: addLanguage
                    )
                }

                Section("Arabic Pronunciation") {
                    ArabicPronunciationSettingsView(
                        settings: $project.arabicPronunciationSettings
                    )
                }

                Section("Song Structure") {
                    SongStructureEditorView(project: $project)
                }

                Section("Musical Parameters") {
                    MusicalParametersEditorView(project: $project)
                }

                Section("Arrangement") {
                    ArrangementEditorView(project: $project)
                }

                Section("Final Review") {
                    FinalReviewView(project: $project)
                }
            }
            .formStyle(.grouped)

            if let saveStatus {
                Divider()
                Label(saveStatus.title, systemImage: saveStatus.systemImage)
                    .font(.caption)
                    .foregroundStyle(saveStatus.foregroundStyle)
                    .padding(.horizontal, 16)
                    .padding(.vertical, 10)
                    .frame(maxWidth: .infinity, alignment: .leading)
            }
        }
        .background(Color(nsColor: .windowBackgroundColor))
        .sheet(isPresented: $isInstrumentBrowserPresented) {
            InstrumentBrowserView(project: $project)
        }
    }

    private var durationSecondsBinding: Binding<String> {
        Binding {
            project.duration?.seconds.map(String.init) ?? ""
        } set: { newValue in
            var duration = project.duration ?? SongDuration()
            duration.seconds = Int(newValue.trimmingCharacters(in: .whitespacesAndNewlines))
            project.duration = duration.isEmpty ? nil : duration
        }
    }

    private var durationDescriptionBinding: Binding<String> {
        Binding {
            project.duration?.description ?? ""
        } set: { newValue in
            let trimmedValue = newValue.trimmingCharacters(in: .whitespacesAndNewlines)
            var duration = project.duration ?? SongDuration()
            duration.description = trimmedValue.isEmpty ? nil : trimmedValue
            project.duration = duration.isEmpty ? nil : duration
        }
    }

    private func addGenre() {
        let name = trimmed(newGenreName)
        guard !name.isEmpty else { return }
        project.selectGenreStyle(GenreStyle(id: stableID(from: name), name: name))
        newGenreName = ""
    }

    private func addInstrument() {
        let name = trimmed(newInstrumentName)
        guard !name.isEmpty else { return }
        project.selectInstrument(InstrumentTrack(instrumentId: stableID(from: name), variant: name))
        newInstrumentName = ""
    }

    private func addVocalist() {
        let label = trimmed(newVocalistLabel)
        guard !label.isEmpty else { return }
        project.upsertVocalist(Vocalist(id: stableID(from: label), label: label))
        newVocalistLabel = ""
    }

    private func addLanguage() {
        let name = trimmed(newLanguageName)
        guard !name.isEmpty else { return }
        project.upsertLanguage(LanguageSelection(id: stableID(from: name), name: name))
        newLanguageName = ""
    }

    private func save() async {
        isSaving = true
        let didSave = await saveProject(project)
        isSaving = false
        saveStatus = didSave ? .saved : .failed
    }

    private func trimmed(_ value: String) -> String {
        value.trimmingCharacters(in: .whitespacesAndNewlines)
    }

    private func stableID(from value: String) -> String {
        let allowedCharacters = CharacterSet.alphanumerics.union(CharacterSet(charactersIn: "-"))
        let lowercasedValue = value.lowercased()
        let scalars = lowercasedValue.unicodeScalars.map { scalar in
            allowedCharacters.contains(scalar) ? String(scalar) : "-"
        }
        let collapsed = scalars.joined()
            .split(separator: "-")
            .joined(separator: "-")
        return collapsed.isEmpty ? UUID().uuidString : collapsed
    }
}

private struct EditableTokenList: View {
    let values: [String]
    let removeAction: (Int) -> Void

    var body: some View {
        if values.isEmpty {
            Text("None yet")
                .foregroundStyle(.secondary)
        } else {
            ForEach(Array(values.enumerated()), id: \.offset) { index, value in
                HStack {
                    Text(value)
                        .lineLimit(1)

                    Spacer()

                    Button {
                        removeAction(index)
                    } label: {
                        Label("Remove", systemImage: "minus.circle")
                            .labelStyle(.iconOnly)
                    }
                    .buttonStyle(.borderless)
                    .help("Remove")
                }
            }
        }
    }
}

private struct AddTextRow: View {
    let placeholder: String
    @Binding var text: String
    let addAction: () -> Void

    var body: some View {
        HStack {
            TextField(placeholder, text: $text)
                .onSubmit(addAction)

            Button(action: addAction) {
                Label("Add", systemImage: "plus.circle.fill")
                    .labelStyle(.iconOnly)
            }
            .buttonStyle(.borderless)
            .disabled(text.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty)
            .help("Add")
        }
    }
}

private enum SaveStatus {
    case saved
    case failed

    var title: String {
        switch self {
        case .saved:
            return "Saved"
        case .failed:
            return "Save failed"
        }
    }

    var systemImage: String {
        switch self {
        case .saved:
            return "checkmark.circle.fill"
        case .failed:
            return "exclamationmark.triangle.fill"
        }
    }

    var foregroundStyle: Color {
        switch self {
        case .saved:
            return .green
        case .failed:
            return .red
        }
    }
}

private extension SongDuration {
    var isEmpty: Bool {
        seconds == nil && (description?.isEmpty ?? true)
    }
}

#Preview {
    ProjectInspectorPreview()
}

private struct ProjectInspectorPreview: View {
    @State private var project = SongProject(
        title: "Inspector Preview",
        idea: "A compact editor for the current song project.",
        duration: SongDuration(seconds: 180, description: "about three minutes"),
        languages: [LanguageSelection(id: "english", name: "English")],
        genres: [GenreStyle(id: "pop", name: "Pop")],
        bpm: ManualAutoValue(mode: .manual, value: 96),
        key: ManualAutoValue(mode: .auto),
        scale: ManualAutoValue(mode: .manual, value: "minor"),
        maqam: ManualAutoValue(mode: .auto),
        sections: [
            SongSection(type: .intro, title: "Intro"),
            SongSection(type: .verse, title: "Verse", order: 1)
        ],
        instruments: [
            InstrumentTrack(
                instrumentId: "piano",
                variant: "Piano",
                placements: [
                    InstrumentPlacement(sectionId: nil, startTime: 0, endTime: 12)
                ]
            )
        ],
        vocalists: [Vocalist(id: "lead", label: "Lead vocalist")],
        lyrics: Lyrics(text: "Draft lyric idea"),
        sunoOutput: SunoOutput(
            lyricsText: "Draft lyric idea",
            stylePrompt: "Pop with piano"
        )
    )

    var body: some View {
        ProjectInspectorView(project: $project, saveProject: { _ in true })
    }
}