import SwiftUI
import AVFoundation
import AudioToolbox
import Combine
import CoreData
import QRCode
import Vision

// MARK: - 主扫描视图
struct ScannerView: View {
    @StateObject private var scannerViewModel = ScannerViewModel()
    @State private var showPreviewPause = false
    @State private var screenOrientation = UIDevice.current.orientation
    @State private var previewLayer: AVCaptureVideoPreviewLayer?
    @State private var navigateToDetail = false
    @State private var selectedHistoryItem: HistoryItem?
    
    // 图片解码相关状态
    @State private var showImagePicker = false
    @State private var isDecodingImage = false
    @State private var decodedImageCodes: [DetectedCode] = []
    @State private var showDecodeFailure = false
    @State private var decodeFailureMessage = ""
    
    var body: some View {
        ZStack {
            // 相机权限检查
            if scannerViewModel.cameraAuthorizationStatus == .authorized {
                // 相机预览层
                CameraPreviewView(session: scannerViewModel.captureSession, previewLayer: $previewLayer)
                    .ignoresSafeArea()
                
                            // 扫描界面覆盖层
            ScanningOverlayView(
                showPreviewPause: showPreviewPause && 
                    ((scannerViewModel.detectedCodes.count > 1) || (decodedImageCodes.count > 1)),
                detectedCodesCount: scannerViewModel.detectedCodes.count + decodedImageCodes.count,
                onImageDecode: { showImagePicker = true }
            )
                
                // 条码位置标记覆盖层 - 只在需要用户选择时显示
                if showPreviewPause && 
                   ((!scannerViewModel.detectedCodes.isEmpty && scannerViewModel.detectedCodes.count > 1) || 
                    (!decodedImageCodes.isEmpty && decodedImageCodes.count > 1)) {
                    CodePositionOverlay(
                        detectedCodes: scannerViewModel.detectedCodes + decodedImageCodes,
                        previewLayer: previewLayer,
                        onCodeSelected: handleCodeSelection
                    )
                }
                
                // 测试按钮（调试用）- 只在需要用户选择时显示
                if showPreviewPause && 
                   ((scannerViewModel.detectedCodes.count > 1) || (decodedImageCodes.count > 1)) {
                    let singleCode = scannerViewModel.detectedCodes.first ?? decodedImageCodes.first
                    if let code = singleCode {
                        TestAutoSelectButton(
                            detectedCode: code,
                            onSelect: handleCodeSelection
                        )
                    }
                }
                
                // 解码失败提示
                if showDecodeFailure {
                    DecodeFailureOverlay(
                        message: decodeFailureMessage,
                        onDismiss: {
                            showDecodeFailure = false
                        }
                    )
                }
            } else {
                // 权限未授权时的UI
                CameraPermissionView(
                    authorizationStatus: scannerViewModel.cameraAuthorizationStatus,
                    onRequestPermission: {
                        scannerViewModel.refreshCameraPermission()
                    },
                    onOpenSettings: {
                        scannerViewModel.openSettings()
                    }
                )
            }
        }
        .navigationTitle("扫描器")
        .navigationBarTitleDisplayMode(.inline)
        .navigationBarBackButtonHidden(false)
        .sheet(isPresented: $showImagePicker) {
            ImagePicker(onImageSelected: handleImageDecodeResult)
        }
        .toolbar {
            ToolbarItem(placement: .navigationBarLeading) {
                // 手电筒按钮 - 只在相机权限已授权时显示
                if scannerViewModel.cameraAuthorizationStatus == .authorized && scannerViewModel.isTorchAvailable {
                    Button(action: {
                        logInfo("🔦 用户点击手电筒按钮", className: "ScannerView")
                        
                        // 添加触觉反馈
                        let impactFeedback = UIImpactFeedbackGenerator(style: .medium)
                        impactFeedback.impactOccurred()
                        
                        scannerViewModel.toggleTorch()
                    }) {
                        Image(systemName: scannerViewModel.isTorchOn ? "bolt.fill" : "bolt")
                            .font(.system(size: 18, weight: .semibold))
                            .foregroundColor(scannerViewModel.isTorchOn ? .yellow : .blue)
                    }
                }
            }
            
            ToolbarItem(placement: .navigationBarTrailing) {
                // 重新扫描按钮 - 只在预览暂停状态时显示
                if showPreviewPause {
                    Button(action: {
                        logInfo("🔄 用户点击工具栏重新扫描按钮", className: "ScannerView")
                        
                        // 添加触觉反馈
                        let impactFeedback = UIImpactFeedbackGenerator(style: .medium)
                        impactFeedback.impactOccurred()
                        
                        resetToScanning()
                    }) {
                        HStack(spacing: 6) {
                            Image(systemName: "arrow.clockwise")
                                .font(.system(size: 16, weight: .semibold))
                            
                            Text("rescan_button".localized)
                                .font(.system(size: 14, weight: .medium))
                        }
                        .foregroundColor(.blue)
                    }
                }
            }
        }
        .onAppear {
            // 只有在相机权限已授权时才启动扫描
            if scannerViewModel.cameraAuthorizationStatus == .authorized {
                scannerViewModel.startScanning()
            }
        }
        .onDisappear {
            scannerViewModel.stopScanning()
            // 确保退出时关闭手电筒
            if scannerViewModel.isTorchOn {
                scannerViewModel.turnOffTorch()
            }
        }
        .alert("scan_error_title".localized, isPresented: $scannerViewModel.showAlert) {
            Button("OK") { }
        } message: {
            Text("scan_error_message".localized)
        }
        .onReceive(scannerViewModel.$detectedCodes) { codes in
            handleDetectedCodes(codes)
        }
        .onReceive(scannerViewModel.$cameraAuthorizationStatus) { status in
            if status == .authorized {
                logInfo("🎯 相机权限已授权，启动扫描", className: "ScannerView")
                scannerViewModel.startScanning()
            }
        }
        .onReceive(NotificationCenter.default.publisher(for: UIDevice.orientationDidChangeNotification)) { _ in
            handleOrientationChange()
        }
        .background(
            NavigationLink(
                destination: Group {
                    if let historyItem = selectedHistoryItem {
                        // 根据数据类型跳转到相应的详情页
                        if historyItem.dataType == DataType.qrcode.rawValue {
                            QRCodeDetailView(historyItem: historyItem)
                                .onDisappear {
                                    // 从详情页返回时，重新开始扫描
                                    logInfo("🔄 从二维码详情页返回，重新开始扫描", className: "ScannerView")
                                    resetToScanning()
                                }
                        } else {
                            BarcodeDetailView(historyItem: historyItem)
                                .onDisappear {
                                    // 从详情页返回时，重新开始扫描
                                    logInfo("🔄 从条形码详情页返回，重新开始扫描", className: "ScannerView")
                                    resetToScanning()
                                }
                        }
                    }
                },
                isActive: $navigateToDetail
            ) {
                EmptyView()
            }
        )
    }
    
    // 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("🎯 ScannerView 收到条码选择回调", className: "ScannerView")
        logInfo("  选择的条码ID: \(selectedCode.id)", className: "ScannerView")
        logInfo("  选择的条码类型: \(selectedCode.type)", className: "ScannerView")
        logInfo("  选择的条码内容: \(selectedCode.content)", className: "ScannerView")
        logInfo("  选择的条码位置: \(selectedCode.bounds)", className: "ScannerView")
        
        // 停止扫描功能，避免在详情页面继续扫描
        scannerViewModel.stopScanning()
        logInfo("🛑 已停止扫描功能", className: "ScannerView")
        
        // 创建 HistoryItem 并保存到 Core Data
        let historyItem = createHistoryItem(from: selectedCode)
        
        // 延迟一小段时间确保扫描完全停止后再跳转
        DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
            // 设置选中的历史记录项并导航到详情页
            self.selectedHistoryItem = historyItem
            self.navigateToDetail = true
        }
        
        // 发送通知（保持向后兼容）
        let formattedResult = "类型: \(selectedCode.type)\n内容: \(selectedCode.content)"
        logInfo("  格式化结果: \(formattedResult)", className: "ScannerView")
        NotificationCenter.default.post(name: .scannerDidScanCode, object: formattedResult)
    }
    
    private func createHistoryItem(from detectedCode: DetectedCode) -> HistoryItem {
        let context = CoreDataManager.shared.container.viewContext
        let historyItem = HistoryItem(context: context)
        
        historyItem.id = UUID()
        historyItem.content = detectedCode.content
        historyItem.dataSource = DataSource.scanned.rawValue
        historyItem.createdAt = Date()
        historyItem.isFavorite = false
        
        // 根据条码类型设置相应的类型字段
        let isQRCode = detectedCode.type.lowercased().contains("qr") || 
                      detectedCode.type.lowercased().contains("二维码") ||
                      detectedCode.type.lowercased().contains("data matrix") ||
                      detectedCode.type.lowercased().contains("aztec")
        
        if isQRCode {
            // 二维码类型
            historyItem.dataType = DataType.qrcode.rawValue
            // 尝试解析二维码类型
            let parsedData = QRCodeParser.parseQRCode(detectedCode.content)
            historyItem.qrCodeType = parsedData.type.rawValue
            historyItem.barcodeType = nil // 清空条形码类型
            logInfo("📱 创建二维码历史记录，类型: \(detectedCode.type)", className: "ScannerView")
        } else {
            // 条形码类型
            historyItem.dataType = DataType.barcode.rawValue
            historyItem.barcodeType = detectedCode.type
            historyItem.qrCodeType = nil // 清空二维码类型
            logInfo("📊 创建条形码历史记录，类型: \(detectedCode.type)", className: "ScannerView")
        }
        
        // 保存到 Core Data
        CoreDataManager.shared.addHistoryItem(historyItem)
        
        logInfo("✅ 已创建并保存历史记录项", className: "ScannerView")
        return historyItem
    }
    
    private func pauseForPreview() {
        showPreviewPause = true
        // 暂停相机功能，防止在预览暂停时继续拍照
        scannerViewModel.pauseCamera()
    }
    
    private func resetToScanning() {
        logInfo("🔄 ScannerView 开始重置到扫描状态", className: "ScannerView")
        
        // 重置UI状态
        showPreviewPause = false
        
        // 重置扫描状态
        scannerViewModel.resetDetection()
        
        // 重置图片解码状态
        resetImageDecodeState()
        
        // 恢复相机功能并重新开始扫描
        scannerViewModel.resumeCamera()
        
        logInfo("✅ ScannerView 已重置到扫描状态", className: "ScannerView")
    }
    
    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) {
            let totalCodes = self.scannerViewModel.detectedCodes.count + self.decodedImageCodes.count
            guard self.showPreviewPause && totalCodes == 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: - 图片解码相关方法
    
    /// 处理图片解码结果
    private func handleImageDecodeResult(_ image: UIImage) {
        isDecodingImage = true
        decodedImageCodes.removeAll()
        showDecodeFailure = false
        decodeFailureMessage = ""
        
        logInfo("🔍 开始解码图片", className: "ScannerView")
        
        // 在后台线程进行解码
        DispatchQueue.global(qos: .userInitiated).async { [self] in
            var allResults: [DetectedCode] = []
            
            // 使用Vision框架检测所有条码（包括二维码和条形码）
            if let cgImage = image.cgImage {
                let barcodeResults = detectBarcodes(in: cgImage)
                if !barcodeResults.isEmpty {
                    logInfo("✅ 检测到 \(barcodeResults.count) 个条码", className: "ScannerView")
                    allResults.append(contentsOf: barcodeResults)
                }
            }
            
            // 如果没有检测到条码，尝试使用QRCode库作为备用方案
            if allResults.isEmpty {
                let detectedQR = QRCode.DetectQRCodes(in: image)
                if detectedQR.count > 0 {
                    logInfo("✅ 使用QRCode库检测到 \(detectedQR.count) 个二维码", className: "ScannerView")
                    
                    let qrResults = detectedQR.enumerated().map { index, qrCode in
                        DetectedCode(
                            type: "QR Code",
                            content: qrCode.messageString ?? "未知内容",
                            bounds: qrCode.bounds
                        )
                    }
                    allResults.append(contentsOf: qrResults)
                }
            }
            
            DispatchQueue.main.async {
                if !allResults.isEmpty {
                    // 去重：移除相同内容的重复条码
                    let uniqueResults = self.removeDuplicateCodes(allResults)
                    self.decodedImageCodes = uniqueResults
                    self.isDecodingImage = false
                    logInfo("✅ 图片解码完成，去重后共 \(uniqueResults.count) 个结果", className: "ScannerView")
                    
                    // 图片解码结果直接跳转，不显示选择点
                    if uniqueResults.count == 1 {
                        // 直接处理单个条码，跳转到结果页
                        DispatchQueue.main.asyncAfter(deadline: .now() + 0.3) {
                            self.handleCodeSelection(uniqueResults[0])
                        }
                    } else if uniqueResults.count > 1 {
                        // 多个条码时，显示选择点让用户选择
                        self.pauseForPreview()
                        logInfo("📱 检测到多个条码，显示选择点", className: "ScannerView")
                    }
                } else {
                    self.isDecodingImage = false
                    self.decodeFailureMessage = "图片中未检测到二维码或条形码"
                    self.showDecodeFailure = true
                    logWarning("❌ 图片中未检测到二维码或条形码", className: "ScannerView")
                }
            }
        }
    }
    
    /// 重置图片解码状态
    private func resetImageDecodeState() {
        decodedImageCodes.removeAll()
        showDecodeFailure = false
        decodeFailureMessage = ""
    }
    
    /// 使用Vision框架检测条形码
    private func detectBarcodes(in cgImage: CGImage) -> [DetectedCode] {
        let request = VNDetectBarcodesRequest { request, error in
            if let error = error {
                logWarning("条形码检测错误: \(error.localizedDescription)", className: "ScannerView")
                return
            }
        }
        
        // 设置条形码类型
        request.symbologies = [
            .ean8,
            .ean13,
            .upce,
            .code39,
            .code39Checksum,
            .code39FullASCII,
            .code39FullASCIIChecksum,
            .code93,
            .code93i,
            .code128,
            .itf14,
            .pdf417,
            .qr,
            .dataMatrix,
            .aztec
        ]
        
        let handler = VNImageRequestHandler(cgImage: cgImage, options: [:])
        
        do {
            try handler.perform([request])
            
            let results = request.results ?? []
            guard !results.isEmpty else {
                return []
            }
            
            return results.enumerated().map { index, observation in
                let barcodeType = getBarcodeTypeString(from: observation.symbology)
                let content = observation.payloadStringValue ?? "未知内容"
                
                logInfo("检测到条形码 #\(index + 1): 类型=\(barcodeType), 内容=\(content)", className: "ScannerView")
                
                return DetectedCode(
                    type: barcodeType,
                    content: content,
                    bounds: observation.boundingBox
                )
            }
        } catch {
            logWarning("条形码检测请求失败: \(error.localizedDescription)", className: "ScannerView")
            return []
        }
    }
    
    /// 获取条形码类型的可读字符串
    private func getBarcodeTypeString(from symbology: VNBarcodeSymbology) -> String {
        switch symbology {
        case .ean8:
            return "EAN-8"
        case .ean13:
            return "EAN-13"
        case .upce:
            return "UPC-E"
        case .code39:
            return "Code 39"
        case .code39Checksum:
            return "Code 39 (Checksum)"
        case .code39FullASCII:
            return "Code 39 (Full ASCII)"
        case .code39FullASCIIChecksum:
            return "Code 39 (Full ASCII + Checksum)"
        case .code93:
            return "Code 93"
        case .code93i:
            return "Code 93i"
        case .code128:
            return "Code 128"
        case .itf14:
            return "ITF-14"
        case .pdf417:
            return "PDF417"
        case .qr:
            return "QR Code"
        case .dataMatrix:
            return "Data Matrix"
        case .aztec:
            return "Aztec"
        default:
            return "Unknown Barcode"
        }
    }
    
    /// 移除重复的条码（基于内容去重）
    private func removeDuplicateCodes(_ codes: [DetectedCode]) -> [DetectedCode] {
        var uniqueCodes: [DetectedCode] = []
        var seenContents: Set<String> = []
        
        for code in codes {
            if !seenContents.contains(code.content) {
                seenContents.insert(code.content)
                uniqueCodes.append(code)
            } else {
                logInfo("🔄 发现重复条码，内容: \(code.content)，已跳过", className: "ScannerView")
            }
        }
        
        return uniqueCodes
    }
}

// MARK: - 图片选择器（兼容iOS 15）
struct ImagePicker: UIViewControllerRepresentable {
    let onImageSelected: (UIImage) -> Void
    
    func makeUIViewController(context: Context) -> UIImagePickerController {
        let picker = UIImagePickerController()
        picker.delegate = context.coordinator
        picker.sourceType = .photoLibrary
        picker.allowsEditing = false
        return picker
    }
    
    func updateUIViewController(_ uiViewController: UIImagePickerController, context: Context) {}
    
    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }
    
    class Coordinator: NSObject, UIImagePickerControllerDelegate, UINavigationControllerDelegate {
        let parent: ImagePicker
        
        init(_ parent: ImagePicker) {
            self.parent = parent
        }
        
        func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
            if let image = info[.originalImage] as? UIImage {
                parent.onImageSelected(image)
            }
            picker.dismiss(animated: true)
        }
        
        func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
            picker.dismiss(animated: true)
        }
    }
}

// MARK: - 解码失败提示覆盖层
struct DecodeFailureOverlay: View {
    let message: String
    let onDismiss: () -> Void
    
    var body: some View {
        ZStack {
            // 半透明背景
            Color.black.opacity(0.7)
                .ignoresSafeArea()
                .onTapGesture {
                    onDismiss()
                }
            
            // 失败提示卡片
            VStack(spacing: 20) {
                // 失败图标
                Image(systemName: "exclamationmark.triangle.fill")
                    .font(.system(size: 50))
                    .foregroundColor(.orange)
                
                // 失败标题
                Text("解码失败")
                    .font(.title2)
                    .fontWeight(.bold)
                    .foregroundColor(.white)
                
                // 失败消息
                Text(message)
                    .font(.body)
                    .foregroundColor(.white.opacity(0.8))
                    .multilineTextAlignment(.center)
                    .padding(.horizontal, 20)
                
                // 重试按钮
                Button(action: {
                    onDismiss()
                }) {
                    HStack(spacing: 8) {
                        Image(systemName: "arrow.clockwise")
                            .font(.system(size: 16, weight: .semibold))
                        
                        Text("重新选择图片")
                            .font(.headline)
                            .fontWeight(.medium)
                    }
                    .foregroundColor(.white)
                    .padding(.horizontal, 20)
                    .padding(.vertical, 12)
                    .background(
                        RoundedRectangle(cornerRadius: 12)
                            .fill(Color.blue.opacity(0.8))
                            .overlay(
                                RoundedRectangle(cornerRadius: 12)
                                    .stroke(Color.blue, lineWidth: 1)
                            )
                    )
                }
                .buttonStyle(PlainButtonStyle())
            }
            .padding(30)
            .background(
                RoundedRectangle(cornerRadius: 20)
                    .fill(Color(.systemGray6).opacity(0.9))
                    .overlay(
                        RoundedRectangle(cornerRadius: 20)
                            .stroke(Color.white.opacity(0.2), lineWidth: 1)
                    )
            )
            .shadow(color: .black.opacity(0.3), radius: 20, x: 0, y: 10)
        }
        .zIndex(2000) // 确保在最上层
        .transition(.opacity.combined(with: .scale))
    }
}

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