import SwiftUI
import AVFoundation
import Photos

struct AppPermissionsView: View {
    @EnvironmentObject private var languageManager: LanguageManager
    @State private var cameraPermissionStatus: AVAuthorizationStatus = .notDetermined
    @State private var photoPermissionStatus: PHAuthorizationStatus = .notDetermined
    
    var body: some View {
        NavigationView {
            ZStack {
                // 背景渐变
                LinearGradient(
                    gradient: Gradient(colors: [
                        Color(.systemBackground),
                        Color(.systemGray6).opacity(0.2)
                    ]),
                    startPoint: .top,
                    endPoint: .bottom
                )
                .ignoresSafeArea()
                
                ScrollView {
                    VStack(spacing: 24) {
                        // 顶部图标
                        VStack(spacing: 16) {
                            ZStack {
                                Circle()
                                    .fill(
                                        LinearGradient(
                                            gradient: Gradient(colors: [
                                                Color.blue.opacity(0.1),
                                                Color.blue.opacity(0.05)
                                            ]),
                                            startPoint: .topLeading,
                                            endPoint: .bottomTrailing
                                        )
                                    )
                                    .frame(width: 80, height: 80)
                                
                                Image(systemName: "lock.shield")
                                    .font(.system(size: 36, weight: .light))
                                    .foregroundColor(.blue)
                            }
                            
                            Text("app_permissions".localized)
                                .font(.system(size: 28, weight: .bold, design: .rounded))
                                .foregroundColor(.primary)
                                .id(languageManager.refreshTrigger)
                        }
                        .padding(.top, 20)
                        
                        // 权限说明卡片
                        VStack(alignment: .leading, spacing: 16) {
                            HStack {
                                Image(systemName: "info.circle")
                                    .font(.system(size: 20, weight: .medium))
                                    .foregroundColor(.blue)
                                    .frame(width: 32)
                                
                                Text("permissions_info".localized)
                                    .font(.system(size: 18, weight: .semibold))
                                
                                Spacer()
                            }
                            
                            Text("permissions_description".localized)
                                .font(.system(size: 14))
                                .foregroundColor(.secondary)
                                .lineLimit(nil)
                        }
                        .padding(20)
                        .background(
                            RoundedRectangle(cornerRadius: 16)
                                .fill(Color(.systemBackground))
                                .shadow(color: .black.opacity(0.05), radius: 8, x: 0, y: 2)
                        )
                        .padding(.horizontal, 20)
                        
                        // 相机权限卡片
                        PermissionCard(
                            icon: "camera.fill",
                            iconColor: .blue,
                            title: "camera_permission".localized,
                            description: "camera_permission_description".localized,
                            status: cameraPermissionStatus.displayText,
                            statusColor: cameraPermissionStatus.statusColor,
                            action: {
                                requestCameraPermission()
                            },
                            actionTitle: cameraPermissionStatus.actionTitle
                        )
                        
                        // 相册权限卡片
                        PermissionCard(
                            icon: "photo.fill",
                            iconColor: .green,
                            title: "photo_permission".localized,
                            description: "photo_permission_description".localized,
                            status: photoPermissionStatus.displayText,
                            statusColor: photoPermissionStatus.statusColor,
                            action: {
                                requestPhotoPermission()
                            },
                            actionTitle: photoPermissionStatus.actionTitle
                        )
                        
                        // 系统设置卡片
                        VStack(alignment: .leading, spacing: 16) {
                            HStack {
                                Image(systemName: "gearshape.fill")
                                    .font(.system(size: 20, weight: .medium))
                                    .foregroundColor(.orange)
                                    .frame(width: 32)
                                
                                Text("system_settings".localized)
                                    .font(.system(size: 18, weight: .semibold))
                                
                                Spacer()
                            }
                            
                            Text("system_settings_description".localized)
                                .font(.system(size: 14))
                                .foregroundColor(.secondary)
                                .lineLimit(nil)
                            
                            Button(action: {
                                openSystemSettings()
                            }) {
                                HStack {
                                    Image(systemName: "arrow.up.right.square")
                                        .font(.system(size: 16, weight: .medium))
                                    Text("open_system_settings".localized)
                                        .font(.system(size: 16, weight: .medium))
                                }
                                .foregroundColor(.white)
                                .padding(.horizontal, 20)
                                .padding(.vertical, 12)
                                .background(
                                    RoundedRectangle(cornerRadius: 8)
                                        .fill(Color.blue)
                                )
                            }
                        }
                        .padding(20)
                        .background(
                            RoundedRectangle(cornerRadius: 16)
                                .fill(Color(.systemBackground))
                                .shadow(color: .black.opacity(0.05), radius: 8, x: 0, y: 2)
                        )
                        .padding(.horizontal, 20)
                        
                        Spacer(minLength: 30)
                    }
                }
            }
            .navigationTitle("App Permissions")
            .navigationBarTitleDisplayMode(.inline)
            .onAppear {
                checkPermissions()
            }
        }
    }
    
    // MARK: - 权限检查
    private func checkPermissions() {
        cameraPermissionStatus = AVCaptureDevice.authorizationStatus(for: .video)
        photoPermissionStatus = PHPhotoLibrary.authorizationStatus()
    }
    
    // MARK: - 请求相机权限
    private func requestCameraPermission() {
        AVCaptureDevice.requestAccess(for: .video) { granted in
            DispatchQueue.main.async {
                self.cameraPermissionStatus = granted ? .authorized : .denied
            }
        }
    }
    
    // MARK: - 请求相册权限
    private func requestPhotoPermission() {
        PHPhotoLibrary.requestAuthorization { status in
            DispatchQueue.main.async {
                self.photoPermissionStatus = status
            }
        }
    }
    
    // MARK: - 打开系统设置
    private func openSystemSettings() {
        if let settingsUrl = URL(string: UIApplication.openSettingsURLString) {
            UIApplication.shared.open(settingsUrl)
        }
    }
}

// MARK: - 权限卡片组件
struct PermissionCard: View {
    let icon: String
    let iconColor: Color
    let title: String
    let description: String
    let status: String
    let statusColor: Color
    let action: () -> Void
    let actionTitle: String
    
    var body: some View {
        VStack(alignment: .leading, spacing: 16) {
            HStack {
                Image(systemName: icon)
                    .font(.system(size: 20, weight: .medium))
                    .foregroundColor(iconColor)
                    .frame(width: 32)
                
                VStack(alignment: .leading, spacing: 4) {
                    Text(title)
                        .font(.system(size: 18, weight: .semibold))
                    Text(description)
                        .font(.system(size: 14))
                        .foregroundColor(.secondary)
                }
                
                Spacer()
            }
            
            HStack {
                Text(status)
                    .font(.system(size: 14, weight: .medium))
                    .foregroundColor(statusColor)
                
                Spacer()
                
                Button(action: action) {
                    Text(actionTitle)
                        .font(.system(size: 14, weight: .medium))
                        .foregroundColor(.white)
                        .padding(.horizontal, 16)
                        .padding(.vertical, 8)
                        .background(
                            RoundedRectangle(cornerRadius: 6)
                                .fill(statusColor)
                        )
                }
            }
        }
        .padding(20)
        .background(
            RoundedRectangle(cornerRadius: 16)
                .fill(Color(.systemBackground))
                .shadow(color: .black.opacity(0.05), radius: 8, x: 0, y: 2)
        )
        .padding(.horizontal, 20)
    }
}

// MARK: - 权限状态扩展
extension AVAuthorizationStatus {
    var displayText: String {
        switch self {
        case .notDetermined:
            return "not_determined".localized
        case .restricted:
            return "restricted".localized
        case .denied:
            return "denied".localized
        case .authorized:
            return "authorized".localized
        @unknown default:
            return "unknown".localized
        }
    }
    
    var statusColor: Color {
        switch self {
        case .notDetermined:
            return .orange
        case .restricted, .denied:
            return .red
        case .authorized:
            return .green
        @unknown default:
            return .gray
        }
    }
    
    var actionTitle: String {
        switch self {
        case .notDetermined:
            return "request_permission".localized
        case .restricted, .denied:
            return "open_settings".localized
        case .authorized:
            return "permission_granted".localized
        @unknown default:
            return "unknown".localized
        }
    }
}

extension PHAuthorizationStatus {
    var displayText: String {
        switch self {
        case .notDetermined:
            return "not_determined".localized
        case .restricted:
            return "restricted".localized
        case .denied:
            return "denied".localized
        case .authorized:
            return "authorized".localized
        case .limited:
            return "limited".localized
        @unknown default:
            return "unknown".localized
        }
    }
    
    var statusColor: Color {
        switch self {
        case .notDetermined:
            return .orange
        case .restricted, .denied:
            return .red
        case .authorized, .limited:
            return .green
        @unknown default:
            return .gray
        }
    }
    
    var actionTitle: String {
        switch self {
        case .notDetermined:
            return "request_permission".localized
        case .restricted, .denied:
            return "open_settings".localized
        case .authorized, .limited:
            return "permission_granted".localized
        @unknown default:
            return "unknown".localized
        }
    }
}

#Preview {
    AppPermissionsView()
        .environmentObject(LanguageManager.shared)
}