import SwiftUI
import AVFoundation
import AudioToolbox
import Combine

// MARK: - 主扫描视图
struct ScannerView: View {
    @StateObject private var scannerViewModel = ScannerViewModel()
    @State private var showPreviewPause = false
    @State private var selectedScanningStyle: ScanningLineStyle = .modern
    @State private var screenOrientation = UIDevice.current.orientation
    @State private var previewLayer: AVCaptureVideoPreviewLayer?
    
    @Environment(\.dismiss) private var dismiss
    
    var body: some View {
        ZStack {
            // 相机预览层
            CameraPreviewView(session: scannerViewModel.captureSession, previewLayer: $previewLayer)
                .ignoresSafeArea()
            
            // 扫描界面覆盖层
            ScanningOverlayView(
                showPreviewPause: showPreviewPause,
                selectedStyle: $selectedScanningStyle,
                detectedCodesCount: scannerViewModel.detectedCodes.count,
                onRescan: resetToScanning,
                onClose: { dismiss() }
            )
            
            // 条码位置标记覆盖层
            if showPreviewPause && !scannerViewModel.detectedCodes.isEmpty {
                CodePositionOverlay(
                    detectedCodes: scannerViewModel.detectedCodes,
                    previewLayer: previewLayer,
                    onCodeSelected: handleCodeSelection
                )
            }
            
            // 测试按钮（调试用）
            if showPreviewPause && scannerViewModel.detectedCodes.count == 1 {
                TestAutoSelectButton(
                    detectedCode: scannerViewModel.detectedCodes[0],
                    onSelect: handleCodeSelection
                )
            }
        }
        .onAppear {
            scannerViewModel.startScanning()
        }
        .onDisappear {
            scannerViewModel.stopScanning()
        }
        .alert("scan_error_title".localized, isPresented: $scannerViewModel.showAlert) {
            Button("OK") { }
        } message: {
            Text("scan_error_message".localized)
        }
        .onReceive(scannerViewModel.$detectedCodes) { codes in
            handleDetectedCodes(codes)
        }
        .onReceive(NotificationCenter.default.publisher(for: UIDevice.orientationDidChangeNotification)) { _ in
            handleOrientationChange()
        }
    }
    
    // MARK: - 私有方法
    
    private func handleDetectedCodes(_ codes: [DetectedCode]) {
        guard !codes.isEmpty else { return }
        
        logInfo("检测到条码数量: \(codes.count)", className: "ScannerView")
        
        if codes.count == 1 {
            logInfo("单个条码，准备自动选择", className: "ScannerView")
            pauseForPreview()
            autoSelectSingleCode(code: codes[0])
        } else {
            logInfo("多个条码，等待用户选择", className: "ScannerView")
            pauseForPreview()
        }
    }
    
    private func handleOrientationChange() {
        screenOrientation = UIDevice.current.orientation
        logInfo("Screen orientation changed to: \(screenOrientation.rawValue)", className: "ScannerView")
    }
    
    private func handleCodeSelection(_ selectedCode: DetectedCode) {
        logInfo("用户选择了条码: \(selectedCode.content)", className: "ScannerView")
        
        let formattedResult = "类型: \(selectedCode.type)\n内容: \(selectedCode.content)"
        NotificationCenter.default.post(name: .scannerDidScanCode, object: formattedResult)
        dismiss()
    }
    
    private func pauseForPreview() {
        showPreviewPause = true
    }
    
    private func resetToScanning() {
        showPreviewPause = false
        scannerViewModel.resetDetection()
        scannerViewModel.startScanning()
    }
    
    private func autoSelectSingleCode(code: DetectedCode) {
        logInfo("开始自动选择定时器，条码类型: \(code.type)", className: "ScannerView")
        
        DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
            guard self.showPreviewPause && self.scannerViewModel.detectedCodes.count == 1 else {
                logInfo("条件不满足，取消自动选择", className: "ScannerView")
                return
            }
            
            logInfo("条件满足，执行自动选择", className: "ScannerView")
            self.handleCodeSelection(code)
        }
    }
}

// MARK: - 扫描界面覆盖层
struct ScanningOverlayView: View {
    let showPreviewPause: Bool
    @Binding var selectedStyle: ScanningLineStyle
    let detectedCodesCount: Int
    let onRescan: () -> Void
    let onClose: () -> Void
    
    var body: some View {
        VStack {
            Spacer()
            
            // 扫描线组件
            if !showPreviewPause {
                ScanningLineView(style: selectedStyle)
            }
            
            // 提示文本
            ScanningInstructionView(
                showPreviewPause: showPreviewPause,
                detectedCodesCount: detectedCodesCount
            )
            
            Spacer()
            
            // 底部按钮区域
            ScanningBottomButtonsView(
                showPreviewPause: showPreviewPause,
                selectedStyle: $selectedStyle,
                onRescan: onRescan,
                onClose: onClose
            )
        }
    }
}

// MARK: - 扫描指令视图
struct ScanningInstructionView: View {
    let showPreviewPause: Bool
    let detectedCodesCount: Int
    
    var body: some View {
        if showPreviewPause {
            VStack(spacing: 8) {
                Text("detected_codes".localized)
                    .foregroundColor(.white)
                    .font(.headline)
                
                if detectedCodesCount == 1 {
                    Text("auto_result_1s".localized)
                        .foregroundColor(.green)
                        .font(.subheadline)
                } else {
                    Text("select_code_instruction".localized)
                        .foregroundColor(.white.opacity(0.8))
                        .font(.subheadline)
                }
            }
            .padding(.top, 20)
        } else {
            Text("scan_instruction".localized)
                .foregroundColor(.white)
                .font(.headline)
                .padding(.top, 20)
        }
    }
}

// MARK: - 扫描底部按钮视图
struct ScanningBottomButtonsView: View {
    let showPreviewPause: Bool
    @Binding var selectedStyle: ScanningLineStyle
    let onRescan: () -> Void
    let onClose: () -> Void
    
    var body: some View {
        VStack(spacing: 15) {
            // 扫描线样式选择器
            if !showPreviewPause {
                ScanningStyleSelectorView(selectedStyle: $selectedStyle)
            }
            
            if showPreviewPause {
                // 预览暂停时的按钮
                Button("rescan_button".localized) {
                    onRescan()
                }
                .foregroundColor(.white)
                .padding(.horizontal, 20)
                .padding(.vertical, 10)
                .background(Color.blue)
                .cornerRadius(20)
            }
            
            // 关闭按钮
            Button("close_button".localized) {
                onClose()
            }
            .foregroundColor(.white)
            .padding()
            .background(Color.black.opacity(0.6))
            .cornerRadius(10)
        }
        .padding(.bottom, 50)
    }
}

// MARK: - 扫描线样式选择器
struct ScanningStyleSelectorView: View {
    @Binding var selectedStyle: ScanningLineStyle
    
    var body: some View {
        HStack(spacing: 10) {
            ForEach(ScanningLineStyle.allCases, id: \.self) { style in
                Button(style.localizedName) {
                    selectedStyle = style
                }
                .foregroundColor(.white)
                .padding(.horizontal, 8)
                .padding(.vertical, 4)
                .background(selectedStyle == style ? Color.green : Color.gray.opacity(0.6))
                .cornerRadius(8)
                .font(.caption)
            }
        }
        .padding(.bottom, 10)
    }
}

// MARK: - 测试自动选择按钮
struct TestAutoSelectButton: View {
    let detectedCode: DetectedCode
    let onSelect: (DetectedCode) -> Void
    
    var body: some View {
        VStack {
            HStack {
                Spacer()
                Button("test_auto_select".localized) {
                    onSelect(detectedCode)
                }
                .foregroundColor(.white)
                .padding(8)
                .background(Color.red)
                .cornerRadius(8)
                .padding(.trailing, 20)
            }
            Spacer()
        }
    }
}

// MARK: - 相机预览视图
struct CameraPreviewView: UIViewRepresentable {
    let session: AVCaptureSession
    @Binding var previewLayer: AVCaptureVideoPreviewLayer?
    
    func makeUIView(context: Context) -> UIView {
        let view = UIView()
        let previewLayer = AVCaptureVideoPreviewLayer(session: session)
        previewLayer.frame = view.bounds
        previewLayer.videoGravity = .resizeAspectFill
        view.layer.addSublayer(previewLayer)
        
        DispatchQueue.main.async {
            self.previewLayer = previewLayer
        }
        
        return view
    }
    
    func updateUIView(_ uiView: UIView, context: Context) {
        if let previewLayer = uiView.layer.sublayers?.first as? AVCaptureVideoPreviewLayer {
            previewLayer.frame = uiView.bounds
            
            DispatchQueue.main.async {
                self.previewLayer = previewLayer
            }
        }
    }
}

// MARK: - 扫描器视图模型
class ScannerViewModel: NSObject, ObservableObject, AVCaptureMetadataOutputObjectsDelegate {
    @Published var detectedCodes: [DetectedCode] = []
    @Published var showAlert = false
    
    var captureSession: AVCaptureSession!
    private var metadataOutput: AVCaptureMetadataOutput?
    
    override init() {
        super.init()
        setupCaptureSession()
    }
    
    // MARK: - 相机设置
    
    private func setupCaptureSession() {
        captureSession = AVCaptureSession()
        
        guard let videoCaptureDevice = AVCaptureDevice.default(for: .video) else {
            showAlert = true
            return
        }
        
        let videoInput: AVCaptureDeviceInput
        
        do {
            videoInput = try AVCaptureDeviceInput(device: videoCaptureDevice)
        } catch {
            showAlert = true
            return
        }
        
        if captureSession.canAddInput(videoInput) {
            captureSession.addInput(videoInput)
        } else {
            showAlert = true
            return
        }
        
        metadataOutput = AVCaptureMetadataOutput()
        
        if let metadataOutput = metadataOutput,
           captureSession.canAddOutput(metadataOutput) {
            captureSession.addOutput(metadataOutput)
            metadataOutput.setMetadataObjectsDelegate(self, queue: DispatchQueue.main)
            metadataOutput.metadataObjectTypes = [.qr, .ean8, .ean13, .code128, .code39, .upce, .pdf417, .aztec]
        } else {
            showAlert = true
            return
        }
    }
    
    // MARK: - 扫描控制
    
    func startScanning() {
        DispatchQueue.global(qos: .background).async { [weak self] in
            self?.captureSession?.startRunning()
        }
    }
    
    func stopScanning() {
        DispatchQueue.global(qos: .background).async { [weak self] in
            self?.captureSession?.stopRunning()
        }
    }
    
    func resetDetection() {
        DispatchQueue.main.async {
            self.detectedCodes = []
        }
    }
    
    // MARK: - AVCaptureMetadataOutputObjectsDelegate
    
    func metadataOutput(_ output: AVCaptureMetadataOutput, 
                       didOutput metadataObjects: [AVMetadataObject], 
                       from connection: AVCaptureConnection) {
        
        logInfo("metadataOutput 被调用，检测到 \(metadataObjects.count) 个对象", className: "ScannerViewModel")
        
        // 震动反馈
        AudioServicesPlaySystemSound(SystemSoundID(kSystemSoundID_Vibrate))
        
        // 停止扫描
        stopScanning()
        
        // 处理所有检测到的条码
        var codes: [DetectedCode] = []
        
        for metadataObject in metadataObjects {
            if let readableObject = metadataObject as? AVMetadataMachineReadableCodeObject,
               let stringValue = readableObject.stringValue {
                
                let codeType = readableObject.type.rawValue
                let bounds = readableObject.bounds
                
                let detectedCode = DetectedCode(
                    type: codeType,
                    content: stringValue,
                    bounds: bounds
                )
                
                codes.append(detectedCode)
                logInfo("创建 DetectedCode: 类型=\(codeType), 内容=\(stringValue)", className: "ScannerViewModel")
            }
        }
        
        logInfo("准备更新 detectedCodes，数量: \(codes.count)", className: "ScannerViewModel")
        
        // 更新检测到的条码列表
        DispatchQueue.main.async {
            logInfo("在主线程更新 detectedCodes", className: "ScannerViewModel")
            self.detectedCodes = codes
        }
    }
}

// MARK: - 条码位置标记覆盖层
struct CodePositionOverlay: View {
    let detectedCodes: [DetectedCode]
    let previewLayer: AVCaptureVideoPreviewLayer?
    let onCodeSelected: (DetectedCode) -> Void
    
    var body: some View {
        GeometryReader { geometry in
            ZStack {
                ForEach(detectedCodes) { code in
                    CodePositionMarker(
                        code: code, 
                        screenSize: geometry.size,
                        previewLayer: previewLayer,
                        onCodeSelected: onCodeSelected
                    )
                }
            }
        }
        .allowsHitTesting(true)
    }
}

// MARK: - 单个条码位置标记
struct CodePositionMarker: View {
    let code: DetectedCode
    let screenSize: CGSize
    let previewLayer: AVCaptureVideoPreviewLayer?
    let onCodeSelected: (DetectedCode) -> Void
    
    var body: some View {
        GeometryReader { geometry in
            let position = calculatePosition(screenSize: geometry.size)
            
            ZStack {
                // 外圈
                Circle()
                    .stroke(Color.green, lineWidth: 3)
                    .frame(width: 40, height: 40)
                
                // 内圈
                Circle()
                    .fill(Color.green.opacity(0.3))
                    .frame(width: 20, height: 20)
                
                // 中心点
                Circle()
                    .fill(Color.green)
                    .frame(width: 6, height: 6)
            }
            .position(x: position.x, y: position.y)
            .background(
                Circle()
                    .fill(Color.clear)
                    .frame(width: 60, height: 60)
            )
            .onTapGesture {
                onCodeSelected(code)
            }
            .onAppear {
                logDebug("CodePositionMarker appeared at: x=\(position.x), y=\(position.y)", className: "CodePositionMarker")
                logDebug("Screen size: \(geometry.size)", className: "CodePositionMarker")
                logDebug("Code bounds: \(code.bounds)", className: "CodePositionMarker")
            }
        }
    }
    
    private func calculatePosition(screenSize: CGSize) -> CGPoint {
        guard let previewLayer = previewLayer else {
            logWarning("No preview layer available, using screen center", className: "CodePositionMarker")
            return CGPoint(x: screenSize.width / 2, y: screenSize.height / 2)
        }
        
        guard previewLayer.session?.isRunning == true else {
            logWarning("Preview layer session not running, using screen center", className: "CodePositionMarker")
            return CGPoint(x: screenSize.width / 2, y: screenSize.height / 2)
        }
        
        let metadataObject = code.bounds
        let convertedPoint = previewLayer.layerPointConverted(fromCaptureDevicePoint: CGPoint(
            x: metadataObject.midX,
            y: metadataObject.midY
        ))
        
        guard convertedPoint.x.isFinite && convertedPoint.y.isFinite else {
            logWarning("Invalid converted point: \(convertedPoint), using screen center", className: "CodePositionMarker")
            return CGPoint(x: screenSize.width / 2, y: screenSize.height / 2)
        }
        
        let clampedX = max(20, min(screenSize.width - 20, convertedPoint.x))
        let clampedY = max(20, min(screenSize.height - 20, convertedPoint.y))
        
        logDebug("AVFoundation bounds: \(code.bounds)", className: "CodePositionMarker")
        logDebug("Converted point: \(convertedPoint)", className: "CodePositionMarker")
        logDebug("Screen size: \(screenSize)", className: "CodePositionMarker")
        logDebug("Clamped: x=\(clampedX), y=\(clampedY)", className: "CodePositionMarker")
        
        return CGPoint(x: clampedX, y: clampedY)
    }
}

// MARK: - 扫描线动画修饰符
struct ScanningLineModifier: ViewModifier {
    @State private var isAnimating = false
    
    func body(content: Content) -> some View {
        content
            .offset(y: isAnimating ? 150 : -150)
            .onAppear {
                withAnimation(
                    Animation.linear(duration: 2)
                        .repeatForever(autoreverses: false)
                ) {
                    isAnimating = true
                }
            }
    }
}

// MARK: - 脉冲动画修饰符
struct PulseAnimationModifier: ViewModifier {
    @State private var isPulsing = false
    
    func body(content: Content) -> some View {
        content
            .scaleEffect(isPulsing ? 1.5 : 1.0)
            .opacity(isPulsing ? 0.0 : 0.8)
            .onAppear {
                withAnimation(
                    Animation.easeInOut(duration: 1.5)
                        .repeatForever(autoreverses: false)
                ) {
                    isPulsing = true
                }
            }
    }
}

// MARK: - 扫描线样式枚举
enum ScanningLineStyle: String, CaseIterable {
    case modern = "style_modern"
    case classic = "style_classic"
    case neon = "style_neon"
    case minimal = "style_minimal"
    case retro = "style_retro"
    
    var localizedName: String {
        switch self {
        case .modern: return "style_modern".localized
        case .classic: return "style_classic".localized
        case .neon: return "style_neon".localized
        case .minimal: return "style_minimal".localized
        case .retro: return "style_retro".localized
        }
    }
}

// MARK: - 扫描线视图
struct ScanningLineView: View {
    let style: ScanningLineStyle
    
    var body: some View {
        Group {
            switch style {
            case .modern:
                ModernScanningLine()
            case .classic:
                ClassicScanningLine()
            case .neon:
                NeonScanningLine()
            case .minimal:
                MinimalScanningLine()
            case .retro:
                RetroScanningLine()
            }
        }
    }
}

// MARK: - 现代扫描线
struct ModernScanningLine: View {
    var body: some View {
        Rectangle()
            .fill(
                LinearGradient(
                    colors: [.blue, .cyan, .blue],
                    startPoint: .leading,
                    endPoint: .trailing
                )
            )
            .frame(width: 200, height: 3)
            .shadow(color: .blue, radius: 5, x: 0, y: 0)
            .modifier(ScanningLineModifier())
    }
}

// MARK: - 经典扫描线
struct ClassicScanningLine: View {
    var body: some View {
        Rectangle()
            .fill(Color.green)
            .frame(width: 150, height: 2)
            .modifier(ScanningLineModifier())
    }
}

// MARK: - 霓虹扫描线
struct NeonScanningLine: View {
    var body: some View {
        Rectangle()
            .fill(Color.purple)
            .frame(width: 180, height: 4)
            .shadow(color: .purple, radius: 8, x: 0, y: 0)
            .modifier(ScanningLineModifier())
    }
}

// MARK: - 极简扫描线
struct MinimalScanningLine: View {
    var body: some View {
        Rectangle()
            .fill(Color.white)
            .frame(width: 100, height: 1)
            .modifier(ScanningLineModifier())
    }
}

// MARK: - 复古扫描线
struct RetroScanningLine: View {
    var body: some View {
        HStack(spacing: 2) {
            ForEach(0..<5, id: \.self) { _ in
                Rectangle()
                    .fill(Color.orange)
                    .frame(width: 2, height: 20)
            }
        }
        .modifier(ScanningLineModifier())
    }
}

// MARK: - 检测到的条码数据结构
struct DetectedCode: Identifiable {
    let id = UUID()
    let type: String
    let content: String
    let bounds: CGRect
}

// MARK: - 通知名称扩展
extension Notification.Name {
    static let scannerDidScanCode = Notification.Name("scannerDidScanCode")
}

#if DEBUG
struct ScannerView_Previews: PreviewProvider {
    static var previews: some View {
        ScannerView()
    }
}
#endif