import Foundation
#if os(macOS)
import StreamRecorderKit
import AppKit

// MARK: - RecorderState（应用退出保护）

enum RecorderState {
    static nonisolated(unsafe) var isFinalizing: Bool = false
    static nonisolated(unsafe) var pendingTerminate: Bool = false
}

// MARK: - PlayerRecorder（基于 StreamRecorderKit FFmpegRecorder）

/// 使用 FFmpeg 直接从流 URL 下载录制，不再使用 AVAssetWriter + MTAudioProcessingTap 实时捕获方案。
/// 优势：
/// - 直接从源流复制/转码，质量更好
/// - 代码量从 883 行降至 ~150 行
/// - 不再依赖 AVPlayerItemVideoOutput / copyPixelBuffer
/// - 录制与播放完全解耦（暂停播放不影响录制）
@MainActor
final class PlayerRecorder: NSObject {

    private var recorder: FFmpegRecorder?
    private var recordingTask: Task<Void, Never>?
    private var durationTimer: Timer?
    private var startDate: Date?

    @Published var isRecording = false
    @Published var durationText = "00:00"

    var onRecordingSaved: ((URL) -> Void)?
    var onError: ((String) -> Void)?

    private var saveDirectory: URL {
        let movies = FileManager.default.urls(for: .moviesDirectory, in: .userDomainMask).first!
        let dir = movies.appendingPathComponent("MiniPlayer", isDirectory: true)
        try? FileManager.default.createDirectory(at: dir, withIntermediateDirectories: true)
        return dir
    }

    // MARK: - 开始录制

    func startRecording(url: URL) {
        guard !isRecording else { return }

        let recorder = FFmpegRecorder()
        self.recorder = recorder

        let tempFilename = "temp_recording_\(Int(Date().timeIntervalSince1970)).mp4"
        let tempURL = saveDirectory.appendingPathComponent(tempFilename)
        try? FileManager.default.removeItem(at: tempURL)

        isRecording = true
        startDate = Date()
        startDurationTimer()

        NSLog("[Recorder] Starting FFmpeg recording: %@ → %@", url.lastPathComponent, tempFilename)

        recordingTask = Task { [weak self] in
            do {
                try await recorder.start(url: url, outputPath: tempURL.path, duration: 0)
                // duration=0 表示无限录制，直到 stop() 被调用
                // start 在 stop() 后会正常返回
                NSLog("[Recorder] ✓ Recording completed: %@", tempURL.path)
                await MainActor.run {
                    RecorderState.isFinalizing = false
                    self?.stopDurationTimer()
                    self?.showSaveDialog(tempURL: tempURL)
                }
            } catch {
                NSLog("[Recorder] ✗ Recording failed: %@", error.localizedDescription)
                await MainActor.run {
                    RecorderState.isFinalizing = false
                    self?.stopDurationTimer()
                    // 如果文件存在且有内容，仍然允许保存
                    let attrs = try? FileManager.default.attributesOfItem(atPath: tempURL.path)
                    let fileSize = (attrs?[.size] as? Int64) ?? 0
                    NSLog("[Recorder] File exists: %d, size: %lld", FileManager.default.fileExists(atPath: tempURL.path), fileSize)
                    if fileSize > 0 {
                        NSLog("[Recorder] File exists with size %lld, offering save dialog", fileSize)
                        self?.showSaveDialog(tempURL: tempURL)
                    } else {
                        self?.onError?(error.localizedDescription)
                        try? FileManager.default.removeItem(at: tempURL)
                        self?.checkPendingTerminate()
                    }
                }
            }
        }
    }

    // MARK: - 停止录制

    func stopRecording() {
        guard isRecording else { return }
        isRecording = false
        RecorderState.isFinalizing = true
        stopDurationTimer()

        NSLog("[Recorder] Stopping recording...")
        recorder?.stop()
    }

    // MARK: - 录制时长显示

    private func startDurationTimer() {
        startDate = Date()
        durationTimer = Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { [weak self] _ in
            Task { @MainActor in
                self?.updateDuration()
            }
        }
    }

    private func stopDurationTimer() {
        durationTimer?.invalidate()
        durationTimer = nil
    }

    private func updateDuration() {
        guard let start = startDate else { return }
        let elapsed = Int(Date().timeIntervalSince(start))
        let min = elapsed / 60
        let sec = elapsed % 60
        durationText = String(format: "%02d:%02d", min, sec)
    }

    // MARK: - 保存对话框

    private func showSaveDialog(tempURL: URL) {
        let panel = NSSavePanel()
        panel.allowedContentTypes = [.mpeg4Movie]
        // 默认文件名去掉 temp_ 前缀
        let defaultName = tempURL.lastPathComponent.replacingOccurrences(of: "temp_", with: "")
        panel.nameFieldStringValue = defaultName
        panel.directoryURL = saveDirectory

        panel.begin { [weak self] response in
            Task { @MainActor in
                if response == .OK, let url = panel.url {
                    do {
                        if FileManager.default.fileExists(atPath: url.path) {
                            try FileManager.default.removeItem(at: url)
                        }
                        try FileManager.default.moveItem(at: tempURL, to: url)
                        NSLog("[Recorder] ✓ Saved: %@", url.path)
                        self?.onRecordingSaved?(url)
                    } catch {
                        NSLog("[Recorder] ✗ Save failed: %@", error.localizedDescription)
                        self?.onError?("Save failed: \(error.localizedDescription)")
                    }
                } else {
                    try? FileManager.default.removeItem(at: tempURL)
                }
                self?.checkPendingTerminate()
            }
        }
    }

    private func checkPendingTerminate() {
        if RecorderState.pendingTerminate {
            RecorderState.pendingTerminate = false
            NSApp.reply(toApplicationShouldTerminate: true)
        }
    }
}
#endif