import WidgetKit
import SwiftUI

// ──────────────────────────────────────────────────────────────────────
// NowPlayingWidget.swift
// TARGET: Widget extension only.
//
// Defines the widget bundle, timeline provider, and timeline entry.
// The provider reads from WidgetSharedState (App Group UserDefaults)
// and generates entries with projected playback positions so the
// progress bar advances even between reloads.
// ──────────────────────────────────────────────────────────────────────

// MARK: - Widget Bundle

@main
struct NavidromeWidgetBundle: WidgetBundle {
    var body: some Widget {
        NowPlayingWidget()
    }
}

// MARK: - Timeline Entry

struct NowPlayingEntry: TimelineEntry {
    let date: Date

    // Song metadata
    let songTitle: String
    let artist: String
    let album: String

    // Playback state
    let isPlaying: Bool
    let currentTime: TimeInterval
    let duration: TimeInterval

    // Images (raw JPEG data — decoded in the view)
    let coverArtData: Data?
    let blurredArtData: Data?

    // Up Next queue
    let queueNext: [WidgetQueueItem]

    // v2: waveform, adaptive colors, crossfade
    let waveformSamples: [Float]    // 40 peaks 0.0–1.0
    let accentColorHex: String?     // dominant color e.g. "E74C3C"
    let secondaryColorHex: String?  // lighter variant for text
    let crossfadeAt: TimeInterval   // 0 = no crossfade data

    // Whether any data has ever been written
    let hasData: Bool

    // MARK: - Computed

    var progress: Double {
        guard duration > 0 else { return 0 }
        return min(max(currentTime / duration, 0), 1)
    }

    var currentTimeFormatted: String { formatTime(currentTime) }

    var remainingTimeFormatted: String {
        "-\(formatTime(max(duration - currentTime, 0)))"
    }

    /// Seconds until crossfade triggers. Nil if no crossfade data or already past.
    var crossfadeCountdown: TimeInterval? {
        guard crossfadeAt > 0, crossfadeAt > currentTime else { return nil }
        let remaining = crossfadeAt - currentTime
        return remaining < 120 ? remaining : nil  // only show if < 2 min
    }

    var crossfadeCountdownFormatted: String? {
        guard let cd = crossfadeCountdown else { return nil }
        return "in \(formatTime(cd))"
    }

    private func formatTime(_ t: TimeInterval) -> String {
        let total = Int(max(t, 0))
        return String(format: "%d:%02d", total / 60, total % 60)
    }

    // MARK: - Placeholder

    static let placeholder = NowPlayingEntry(
        date: .now,
        songTitle: "Not Playing",
        artist: "NavidromePlayer",
        album: "",
        isPlaying: false,
        currentTime: 0,
        duration: 1,
        coverArtData: nil,
        blurredArtData: nil,
        queueNext: [],
        waveformSamples: [],
        accentColorHex: nil,
        secondaryColorHex: nil,
        crossfadeAt: 0,
        hasData: false
    )
}

// MARK: - Timeline Provider

struct NowPlayingProvider: TimelineProvider {

    func placeholder(in context: Context) -> NowPlayingEntry { .placeholder }

    func getSnapshot(in context: Context, completion: @escaping (NowPlayingEntry) -> Void) {
        completion(buildEntry(at: .now))
    }

    func getTimeline(in context: Context, completion: @escaping (Timeline<NowPlayingEntry>) -> Void) {
        let state = WidgetSharedState.shared
        let now = Date()

        if state.isPlaying && state.duration > 0 {
            var entries: [NowPlayingEntry] = []
            let elapsed = now.timeIntervalSince(state.lastUpdatedDate)
            let baseTime = state.currentTime + elapsed

            for i in 0..<10 {
                let offset = Double(i) * 30.0
                let entryDate = now.addingTimeInterval(offset)
                let projectedTime = min(baseTime + offset, state.duration)
                entries.append(makeEntry(at: entryDate, projectedTime: projectedTime, state: state))
            }

            completion(Timeline(entries: entries, policy: .after(now.addingTimeInterval(300))))
        } else {
            let entry = buildEntry(at: now)
            completion(Timeline(entries: [entry], policy: .after(now.addingTimeInterval(15 * 60))))
        }
    }

    private func buildEntry(at date: Date) -> NowPlayingEntry {
        let state = WidgetSharedState.shared
        var projectedTime = state.currentTime
        if state.isPlaying && state.duration > 0 {
            let elapsed = date.timeIntervalSince(state.lastUpdatedDate)
            projectedTime = min(state.currentTime + elapsed, state.duration)
        }
        return makeEntry(at: date, projectedTime: projectedTime, state: state)
    }

    private func makeEntry(at date: Date, projectedTime: TimeInterval, state: WidgetSharedState) -> NowPlayingEntry {
        NowPlayingEntry(
            date: date,
            songTitle: state.songTitle.isEmpty ? "Not Playing" : state.songTitle,
            artist: state.artist.isEmpty ? "NavidromePlayer" : state.artist,
            album: state.album,
            isPlaying: state.isPlaying,
            currentTime: projectedTime,
            duration: state.duration,
            coverArtData: state.coverArtData,
            blurredArtData: state.blurredArtData,
            queueNext: state.queueNext,
            waveformSamples: state.waveformSamples,
            accentColorHex: state.accentColorHex,
            secondaryColorHex: state.secondaryColorHex,
            crossfadeAt: state.crossfadeAt,
            hasData: state.hasData
        )
    }
}

// MARK: - Widget Definition

struct NowPlayingWidget: Widget {
    let kind = "NowPlayingWidget"

    var body: some WidgetConfiguration {
        StaticConfiguration(kind: kind, provider: NowPlayingProvider()) { entry in
            NowPlayingWidgetView(entry: entry)
                .containerBackground(.clear, for: .widget)
        }
        .configurationDisplayName("Now Playing")
        .description("Control playback and see what's playing.")
        .supportedFamilies([.systemSmall, .systemMedium, .systemLarge])
        .contentMarginsDisabled()
    }
}