import ActivityKit
import WidgetKit
import SwiftUI
import AppIntents

struct SkipTrackIntent: AppIntent {
    static let title: LocalizedStringResource = "Skip Track"

    @MainActor
    func perform() async throws -> some IntentResult & OpensIntent {
        let url = URL(string: "tabatago://skipTrack")!
        return .result(opensIntent: OpenURLIntent(url))
    }
}

struct MusicLiveActivity: Widget {
    var body: some WidgetConfiguration {
        ActivityConfiguration(for: MusicActivityAttributes.self) { context in
            @Environment(\.activityFamily) var activityFamily
            @Environment(\.isActivityFullscreen) var isFullscreen
            @Environment(\.isLuminanceReduced) var isLuminanceReduced

            switch activityFamily {
            case .small:
                smallLockScreenView(context: context)
            default:
                lockScreenView(context: context, isFullscreen: isFullscreen, isLuminanceReduced: isLuminanceReduced)
            }
        } dynamicIsland: { context in
            DynamicIsland {
                DynamicIslandExpandedRegion(.leading) {
                    HStack(spacing: 6) {
                        Image(systemName: "music.note")
                            .foregroundStyle(.green)
                            .accessibilityLabel("Music")
                        Text(context.state.title)
                            .font(.caption.weight(.semibold))
                            .lineLimit(1)
                            .accessibilityLabel(context.state.title)
                        if context.state.isPlaying {
                            LiveActivityMusicBars()
                        }
                    }
                }
                DynamicIslandExpandedRegion(.center) {
                    Text(context.state.artist)
                        .font(.caption2)
                        .foregroundStyle(.secondary)
                        .lineLimit(1)
                        .accessibilityLabel(context.state.artist)
                }
                DynamicIslandExpandedRegion(.trailing) {
                    Button(intent: SkipTrackIntent()) {
                        HStack(spacing: 3) {
                            Image(systemName: "forward.fill")
                                .font(.system(size: 10, weight: .semibold))
                            Text("Skip")
                                .font(.caption2.weight(.medium))
                        }
                        .foregroundStyle(.white.opacity(0.6))
                        .padding(.horizontal, 8)
                        .padding(.vertical, 3)
                        .background(.white.opacity(0.15))
                        .clipShape(Capsule())
                    }
                    .buttonStyle(.plain)
                    .accessibilityLabel("Skip track")
                }
            } compactLeading: {
                Image(systemName: "music.note")
                    .foregroundStyle(.green)
                    .font(.system(size: 14))
                    .accessibilityLabel("Music playing")
            } compactTrailing: {
                HStack(spacing: 3) {
                    Image(systemName: "music.note")
                        .font(.system(size: 10))
                        .foregroundStyle(.green)
                        .accessibilityHidden(true)
                    Text(context.state.title)
                        .font(.system(size: 10, weight: .medium))
                        .lineLimit(1)
                        .accessibilityLabel(context.state.title)
                }
                .accessibilityLabel("Now playing: \(context.state.title)")
            } minimal: {
                Image(systemName: "music.note")
                    .foregroundStyle(.green)
                    .font(.system(size: 13))
                    .accessibilityLabel("Music playing")
            }
            .keylineTint(.green)
            .contentMargins(.leading, 8, for: .expanded)
            .contentMargins(.trailing, 8, for: .expanded)
            .widgetURL(URL(string: "tabatago://music")!)
        }
        .supplementalActivityFamilies([.small, .medium])
    }

    // MARK: - Lock Screen / Banner

    @ViewBuilder
    private func lockScreenView(
        context: ActivityViewContext<MusicActivityAttributes>,
        isFullscreen: Bool,
        isLuminanceReduced: Bool
    ) -> some View {
        VStack(spacing: 0) {
            HStack(spacing: 10) {
                Image(systemName: "music.note")
                    .font(isFullscreen ? .title.weight(.semibold) : .title3.weight(.semibold))
                    .foregroundStyle(.green)
                    .accessibilityLabel("Music")

                VStack(alignment: .leading, spacing: 2) {
                    Text(context.state.title)
                        .font(isFullscreen ? .title2 : .headline)
                        .foregroundStyle(.primary)
                        .lineLimit(1)
                        .accessibilityLabel(context.state.title)
                    Text(context.state.artist)
                        .font(.caption)
                        .foregroundStyle(.secondary)
                        .lineLimit(1)
                        .accessibilityLabel(context.state.artist)
                }

                Spacer()

                if context.state.isPlaying, !isLuminanceReduced {
                    LiveActivityMusicBars()
                }
            }
            .padding(.horizontal, 16)
            .padding(.vertical, isFullscreen ? 20 : 12)
        }
        .activityBackgroundTint(.black.opacity(0.9))
        .activitySystemActionForegroundColor(.white)
    }

    // MARK: - Small (Apple Watch / CarPlay)

    @ViewBuilder
    private func smallLockScreenView(context: ActivityViewContext<MusicActivityAttributes>) -> some View {
        HStack(spacing: 6) {
            Image(systemName: "music.note")
                .font(.caption)
                .foregroundStyle(.green)
                .accessibilityLabel("Music")
            Text(context.state.title)
                .font(.caption.weight(.medium))
                .lineLimit(1)
                .accessibilityLabel(context.state.title)
            Spacer()
            Text(context.state.artist)
                .font(.caption2)
                .foregroundStyle(.secondary)
                .lineLimit(1)
        }
        .padding(.horizontal, 12)
        .padding(.vertical, 8)
        .activityBackgroundTint(.black.opacity(0.9))
    }
}

// MARK: - LiveActivityMusicBars

struct LiveActivityMusicBars: View {
    var body: some View {
        TimelineView(.periodic(from: .now, by: 0.45 / Double(barSpeeds.count))) { context in
            HStack(spacing: 2) {
                ForEach(0..<4, id: \.self) { i in
                    let t = context.date.timeIntervalSinceReferenceDate
                    let phase = t * barSpeeds[i] * 2 * .pi
                    let h = barMin + (barMaxHeights[i] - barMin) * abs(sin(phase))
                    Capsule()
                        .fill(.green)
                        .frame(width: 2, height: h)
                }
            }
        }
        .accessibilityHidden(true)
    }
}

private let barMaxHeights: [CGFloat] = [8, 14, 6, 12]
private let barMin: CGFloat = 3
private let barSpeeds: [Double] = [2.2, 1.8, 2.8, 1.5]