import SwiftUI

// MARK: - VoiceSelectionView
// Sheet for selecting TTS voice. Loads voices from the API, plays sample audio, and
// saves the selection back to user settings on confirm.
// VoiceSelectionViewModel is defined in PlayerViews.swift (shared with the full player).

struct VoiceSelectionView: View {
    @EnvironmentObject private var authStore: AuthStore
    @Environment(\.dismiss) private var dismiss

    @State private var selectedVoice: String
    @State private var vm = VoiceSelectionViewModel()

    init(currentVoice: String) {
        _selectedVoice = State(initialValue: currentVoice)
    }

    var body: some View {
        NavigationStack {
            Group {
                if vm.isLoading {
                    loadingState
                } else if let error = vm.error {
                    errorState(error)
                } else {
                    voiceList
                }
            }
            .background(Color(uiColor: UIColor(red: 0.094, green: 0.094, blue: 0.106, alpha: 1)))
            .navigationTitle("Select Voice")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .cancellationAction) {
                    Button("Cancel") {
                        vm.stopSample()
                        dismiss()
                    }
                }
                ToolbarItem(placement: .confirmationAction) {
                    Button("Done") { saveAndDismiss() }
                        .fontWeight(.semibold)
                        .foregroundStyle(Color.amber)
                        .disabled(selectedVoice == authStore.settings.voice)
                }
            }
            .task { await vm.loadVoices() }
            .onDisappear { vm.stopSample() }
        }
    }

    // MARK: - States

    private var loadingState: some View {
        VStack(spacing: 16) {
            ProgressView()
                .scaleEffect(1.3)
            Text("Loading voices…")
                .font(.subheadline)
                .foregroundStyle(.secondary)
        }
        .frame(maxWidth: .infinity, maxHeight: .infinity)
    }

    private func errorState(_ message: String) -> some View {
        VStack(spacing: 16) {
            Image(systemName: "exclamationmark.triangle")
                .font(.system(size: 48))
                .foregroundStyle(Color.amber)
                .symbolEffect(.pulse)
            Text(message)
                .font(.subheadline)
                .multilineTextAlignment(.center)
                .foregroundStyle(.secondary)
                .padding(.horizontal, 32)
            Button("Retry") { Task { await vm.loadVoices() } }
                .font(.subheadline.bold())
                .foregroundStyle(Color.amber)
        }
        .frame(maxWidth: .infinity, maxHeight: .infinity)
    }

    // MARK: - Voice list

    private var voiceList: some View {
        List {
            Section {
                ForEach(vm.voices, id: \.self) { voice in
                    VoiceSelectionRow(
                        voice: voice,
                        isSelected: voice == selectedVoice,
                        isPlaying: vm.playingVoice == voice,
                        voiceLabel: vm.voiceLabel(voice),
                        voiceId: vm.voiceId(voice),
                        onSelect: {
                            UIImpactFeedbackGenerator(style: .light).impactOccurred()
                            vm.stopSample()
                            selectedVoice = voice
                        },
                        onPlaySample: {
                            UIImpactFeedbackGenerator(style: .light).impactOccurred()
                            Task { await vm.playSample(voice) }
                        }
                    )
                }
            } header: {
                Text("Available Voices")
                    .font(.subheadline.bold())
                    .foregroundStyle(.secondary)
                    .textCase(nil)
            } footer: {
                if selectedVoice != authStore.settings.voice {
                    Text("New voice will apply to the next audio playback.")
                        .font(.caption)
                        .foregroundStyle(.secondary)
                }
            }
        }
        .scrollContentBackground(.hidden)
        .listStyle(.insetGrouped)
    }

    // MARK: - Save

    private func saveAndDismiss() {
        vm.stopSample()
        Task {
            var s = authStore.settings
            s.voice = selectedVoice
            await authStore.saveSettings(s)
            dismiss()
        }
    }
}

// MARK: - VoiceSelectionRow

private struct VoiceSelectionRow: View {
    let voice: String
    let isSelected: Bool
    let isPlaying: Bool
    let voiceLabel: String
    let voiceId: String
    let onSelect: () -> Void
    let onPlaySample: () -> Void

    var body: some View {
        HStack(spacing: 12) {
            // Selection indicator
            Image(systemName: isSelected ? "checkmark.circle.fill" : "circle")
                .font(.system(size: 22))
                .foregroundStyle(isSelected ? Color.amber : Color.secondary.opacity(0.4))
                .frame(width: 28)
                .contentTransition(.symbolEffect(.replace.downUp))
                .accessibilityHidden(true)

            // Voice name + id
            VStack(alignment: .leading, spacing: 3) {
                Text(voiceLabel)
                    .font(.body)
                    .fontWeight(isSelected ? .semibold : .regular)
                Text(voiceId)
                    .font(.caption)
                    .fontDesign(.monospaced)
                    .foregroundStyle(.secondary)
            }

            Spacer()

            // Play sample button
            Button {
                onPlaySample()
            } label: {
                Image(systemName: isPlaying ? "stop.circle.fill" : "play.circle.fill")
                    .font(.system(size: 28))
                    .foregroundStyle(isPlaying ? Color.red : Color.amber)
                    .contentTransition(.symbolEffect(.replace.downUp))
            }
            .buttonStyle(.plain)
            .frame(minWidth: 44, minHeight: 44)
            .accessibilityLabel(isPlaying ? "Stop sample for \(voiceLabel)" : "Play sample for \(voiceLabel)")
        }
        .padding(.vertical, 4)
        .contentShape(Rectangle())
        .onTapGesture { onSelect() }
        .accessibilityElement(children: .combine)
        .accessibilityAddTraits(isSelected ? [.isSelected] : [])
    }
}