import SwiftUI
import AVFoundation
import Combine

/// Vault 内一段问诊录音的回放控件(2026-06-28)。播放/暂停 + 进度条 + 时间。
/// 录音存在加密 Vault 里,App 前台即解锁可读;读不到(损坏/异常)显示占位,不崩。
/// 不做拖拽 seek(降复杂度):进度条只读,demo 够用。
struct ConsultationAudioPlayer: View {
    let asset: Asset

    @State private var player: AVAudioPlayer?
    @State private var isPlaying = false
    @State private var currentTime: Double = 0
    @State private var duration: Double = 0
    @State private var loadFailed = false

    /// 播放时刷新进度/时间;不播放时空转(开销可忽略)。AVAudioPlayer 播完 isPlaying 自然转 false。
    private let ticker = Timer.publish(every: 0.2, on: .main, in: .common).autoconnect()

    var body: some View {
        VStack(alignment: .leading, spacing: 10) {
            HStack(spacing: 6) {
                Image(systemName: "waveform")
                    .font(.tjScaled( 12, weight: .semibold))
                    .foregroundStyle(Tj.Palette.ink2)
                Text(String(appLoc: "问诊录音"))
                    .font(.tjScaled( 12, weight: .semibold))
                    .foregroundStyle(Tj.Palette.text2)
                Spacer()
                Text(String(appLoc: "本机存储"))
                    .font(.tjScaled( 11)).foregroundStyle(Tj.Palette.text3)
            }

            if loadFailed {
                Text("录音无法读取")
                    .font(.tjScaled( 13)).foregroundStyle(Tj.Palette.text3)
                    .frame(maxWidth: .infinity, alignment: .leading)
            } else {
                HStack(spacing: 12) {
                    Button(action: togglePlay) {
                        Image(systemName: isPlaying ? "pause.fill" : "play.fill")
                            .font(.tjScaled( 16, weight: .bold))
                            .foregroundStyle(Tj.Palette.paper)
                            .frame(width: 40, height: 40)
                            .background(Circle().fill(Tj.Palette.ink2))
                    }
                    .buttonStyle(.plain)

                    VStack(alignment: .leading, spacing: 6) {
                        GeometryReader { geo in
                            ZStack(alignment: .leading) {
                                Capsule().fill(Tj.Palette.sand2)
                                Capsule().fill(Tj.Palette.ink2)
                                    .frame(width: geo.size.width * progressFraction)
                            }
                        }
                        .frame(height: 5)
                        HStack {
                            Text(Self.timeText(currentTime))
                            Spacer()
                            Text(Self.timeText(duration))
                        }
                        .font(.tjScaled( 11, design: .monospaced))
                        .foregroundStyle(Tj.Palette.text3)
                    }
                }
            }
        }
        .padding(14)
        .frame(maxWidth: .infinity, alignment: .leading)
        .background(
            RoundedRectangle(cornerRadius: Tj.Radius.md, style: .continuous)
                .fill(Tj.Palette.paper)
        )
        .overlay(
            RoundedRectangle(cornerRadius: Tj.Radius.md, style: .continuous)
                .strokeBorder(Tj.Palette.lineSoft, lineWidth: 1)
        )
        .onAppear(perform: load)
        .onDisappear {
            player?.stop()
            isPlaying = false
        }
        .onReceive(ticker) { _ in
            guard let p = player, isPlaying else { return }
            currentTime = p.currentTime
            if !p.isPlaying {        // 播完:复位
                isPlaying = false
                currentTime = 0
                p.currentTime = 0
            }
        }
    }

    private var progressFraction: CGFloat {
        guard duration > 0 else { return 0 }
        return CGFloat(min(max(currentTime / duration, 0), 1))
    }

    private func load() {
        guard player == nil, !loadFailed else { return }
        do {
            let url = try FileVault.shared.absoluteURL(forReading: asset.relativePath)
            let p = try AVAudioPlayer(contentsOf: url)
            p.prepareToPlay()
            player = p
            duration = p.duration
        } catch {
            loadFailed = true
        }
    }

    private func togglePlay() {
        guard let p = player else { return }
        if isPlaying {
            p.pause()
            isPlaying = false
        } else {
            try? AVAudioSession.sharedInstance().setCategory(.playback, options: [])
            try? AVAudioSession.sharedInstance().setActive(true)
            p.play()
            isPlaying = true
        }
    }

    private static func timeText(_ seconds: Double) -> String {
        let s = Int(seconds.rounded())
        return String(format: "%d:%02d", s / 60, s % 60)
    }
}