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?
    
    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,
                    selectedStyle: $selectedScanningStyle,
                    detectedCodesCount: scannerViewModel.detectedCodes.count
                )
                
                // 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
                    )
                }
            } 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)
        .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()
        }
    }
    
    // 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")
        
        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)
        // 使用导航返回，不需要手动dismiss
    }
    
    private func pauseForPreview() {
        showPreviewPause = true
    }
    
    private func resetToScanning() {
        logInfo("🔄 ScannerView 开始重置到扫描状态", className: "ScannerView")
        
        // 重置UI状态
        showPreviewPause = false
        
        // 重置扫描状态并重新开始
        scannerViewModel.resetDetection()
        scannerViewModel.restartScanning()
        
        // 延迟检查会话状态
        DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
            logInfo("🔍 检查扫描会话状态", className: "ScannerView")
            self.scannerViewModel.checkSessionStatus()
        }
        
        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) {
            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)
        }
    }
}

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