import SwiftUI
import Combine

// MARK: - Splash ViewModel

@MainActor
class SplashViewModel: ObservableObject {
    // MARK: - Published Properties
    @Published var isLoading = true
    @Published var shouldShowMainApp = false
    @Published var authenticationStatus: UserInfoManager.AuthenticationStatus = .notFound
    @Published var isCheckingAuthentication = false
    @Published var navigationDestination: NavigationDestination?
    
    // MARK: - Private Properties
    private var cancellables = Set<AnyCancellable>()
    
    // MARK: - Navigation Destination
    enum NavigationDestination: Equatable {
        case login
        case main
    }
    
    // MARK: - Initialization
    init() {
        setupBindings()
    }
    
    // MARK: - Public Methods
    func onAppear() {
        isLoading = true
        shouldShowMainApp = false
        authenticationStatus = .notFound
        isCheckingAuthentication = false
        navigationDestination = nil
        
        // 1秒延迟后显示主应用
        Task {
            try await Task.sleep(nanoseconds: 1_000_000_000)
            await MainActor.run {
                self.splashFinished()
            }
        }
    }
    
    func splashFinished() {
        isLoading = false
        checkAuthentication()
    }
    
    func checkAuthentication() {
        isCheckingAuthentication = true
        
        Task {
            let authStatus = await UserInfoManager.checkAuthenticationStatus()
            await MainActor.run {
                self.authenticationChecked(authStatus)
            }
        }
    }
    
    func authenticationChecked(_ status: UserInfoManager.AuthenticationStatus) {
        isCheckingAuthentication = false
        authenticationStatus = status
        
        if status.canAutoLogin {
            debugInfoSync("🎉 自动登录成功，开始获取用户信息")
            fetchUserInfo()
        } else {
            debugInfoSync("🔑 需要手动登录")
            navigateToLogin()
        }
    }
    
    func fetchUserInfo() {
        Task {
            let success = await UserInfoManager.autoFetchUserInfoOnAppLaunch(apiService: LiveAPIService())
            await MainActor.run {
                self.userInfoFetched(success)
            }
        }
    }
    
    func userInfoFetched(_ success: Bool) {
        if success {
            debugInfoSync("✅ 用户信息获取成功，进入主页")
        } else {
            debugInfoSync("⚠️ 用户信息获取失败，但仍进入主页")
        }
        navigateToMain()
    }
    
    func navigateToLogin() {
        navigationDestination = .login
    }
    
    func navigateToMain() {
        navigationDestination = .main
        shouldShowMainApp = true
    }
    
    // MARK: - Private Methods
    private func setupBindings() {
        // 可以在这里设置 Combine 绑定
    }
}

// MARK: - Splash View

struct Splash: View {
    @StateObject private var viewModel = SplashViewModel()
    
    var body: some View {
        ZStack {
            Group {
                // 根据导航目标显示不同页面
                if let navigationDestination = viewModel.navigationDestination {
                    switch navigationDestination {
                    case .login:
                        // 显示登录页面
                        LoginPage(
                            onLoginSuccess: {
                                // 登录成功后导航到主页面
                                viewModel.navigateToMain()
                            }
                        )
                    case .main:
                        // 显示主应用页面
                        MainPage(
                            onLogout: {
                                viewModel.navigateToLogin()
                            }
                        )
                    }
                } else {
                    // 显示启动画面
                    splashContent
                }
            }
            .onAppear {
                viewModel.onAppear()
            }
            
            // API Loading 效果视图 - 显示在所有内容之上
            APILoadingEffectView()
        }
    }
    
    // 启动画面内容
    private var splashContent: some View {
        ZStack {
            // 背景图片 - 全屏显示
            LoginBackgroundView()
            
            VStack(spacing: 32) {
                Spacer()
                    .frame(height: 200) // 与 storyboard 中的约束对应
                
                // Logo 图片 - 100x100
                Image("logo")
                    .resizable()
                    .aspectRatio(contentMode: .fit)
                    .frame(width: 100, height: 100)
                
                // 应用标题 - 白色，40pt字体
                Text(LocalizedString("splash.title", comment: "E-Parti"))
                    .font(.system(size: 40, weight: .regular))
                    .foregroundColor(.white)
                
                Spacer()
            }
        }
    }
}

//#Preview {
//    Splash()
//}

#Preview {
    Splash()
}