import SwiftUI
import Combine

// MARK: - EMailLogin ViewModel

@MainActor
class EMailLoginViewModel: ObservableObject {
    // MARK: - Published Properties
    @Published var email: String = ""
    @Published var verificationCode: String = ""
    @Published var codeCountdown: Int = 0
    @Published var isLoading: Bool = false
    @Published var isCodeLoading: Bool = false
    @Published var errorMessage: String?
    @Published var loginStep: LoginStep = .input
    
    // MARK: - Callbacks
    var onBack: (() -> Void)?
    var onLoginSuccess: (() -> Void)?
    
    // MARK: - Private Properties
    private var cancellables = Set<AnyCancellable>()
    private var timerCancellable: AnyCancellable?
    
    // MARK: - Enums
    enum LoginStep: Equatable {
        case input
        case completed
    }
    
    // MARK: - Computed Properties
    var isLoginButtonEnabled: Bool {
        return !isLoading && !email.isEmpty && !verificationCode.isEmpty
    }
    
    var getCodeButtonText: String {
        if codeCountdown > 0 {
            return "\(codeCountdown)s"
        } else {
            return "Get"
        }
    }
    
    var isCodeButtonEnabled: Bool {
        return !isCodeLoading && codeCountdown == 0 && !email.isEmpty
    }
    
    // MARK: - Public Methods
    func onBackTapped() {
        onBack?()
    }
    
    func onEmailChanged(_ newEmail: String) {
        email = newEmail
    }
    
    func onVerificationCodeChanged(_ newCode: String) {
        verificationCode = newCode
    }
    
    func onGetVerificationCodeTapped() {
        guard isCodeButtonEnabled else { return }
        
        isCodeLoading = true
        errorMessage = nil
        
        Task {
            do {
                let result = try await requestVerificationCode()
                await MainActor.run {
                    self.handleCodeRequestResult(result)
                }
            } catch {
                await MainActor.run {
                    self.handleCodeRequestError(error)
                }
            }
        }
    }
    
    func onLoginTapped() {
        guard isLoginButtonEnabled else { return }
        
        isLoading = true
        errorMessage = nil
        
        Task {
            do {
                let result = try await performLogin()
                await MainActor.run {
                    self.handleLoginResult(result)
                }
            } catch {
                await MainActor.run {
                    self.handleLoginError(error)
                }
            }
        }
    }
    
    func resetState() {
        email = ""
        verificationCode = ""
        codeCountdown = 0
        isLoading = false
        isCodeLoading = false
        errorMessage = nil
        loginStep = .input
        stopCountdown()
    }
    
    // MARK: - Private Methods
    private func requestVerificationCode() async throws -> Bool {
        return false
//        let request = EmailVerificationCodeRequest(email: email)
//        let apiService = LiveAPIService()
//        let response: EmailVerificationCodeResponse = try await apiService.request(request)
//        
//        if response.code == 200 {
//            return true
//        } else {
//            throw APIError.serverError(response.message ?? "Failed to send verification code")
//        }
    }
    
    private func performLogin() async throws -> Bool {
        return false
//        let request = EmailLoginRequest(
//            email: email,
//            verificationCode: verificationCode
//        )
//        
//        let apiService = LiveAPIService()
//        let response: EmailLoginResponse = try await apiService.request(request)
//        
//        if response.code == 200, let data = response.data {
//            // 保存用户信息
//            await UserInfoManager.saveUserInfo(data)
//            
//            // 创建并保存账户模型
//            let accountModel = AccountModel(
//                uid: data.uid,
//                accessToken: data.accessToken,
//                tokenType: data.tokenType,
//                refreshToken: data.refreshToken,
//                expiresIn: data.expiresIn
//            )
//            await UserInfoManager.saveAccountModel(accountModel)
//            
//            // 获取用户详细信息
//            if let userInfo = await UserInfoManager.fetchUserInfoFromServer(
//                uid: String(data.uid),
//                apiService: apiService
//            ) {
//                await UserInfoManager.saveUserInfo(userInfo)
//            }
//            
//            return true
//        } else {
//            throw APIError.serverError(response.message ?? "Login failed")
//        }
    }
    
    private func handleCodeRequestResult(_ success: Bool) {
        isCodeLoading = false
        if success {
            startCountdown()
        }
    }
    
    private func handleCodeRequestError(_ error: Error) {
        isCodeLoading = false
        errorMessage = error.localizedDescription
    }
    
    private func handleLoginResult(_ success: Bool) {
        isLoading = false
        if success {
            loginStep = .completed
            onLoginSuccess?()
        }
    }
    
    private func handleLoginError(_ error: Error) {
        isLoading = false
        errorMessage = error.localizedDescription
    }
    
    private func startCountdown() {
        stopCountdown()
        codeCountdown = 60
        timerCancellable = Timer.publish(every: 1.0, on: .main, in: .common)
            .autoconnect()
            .sink { _ in
                if self.codeCountdown > 0 {
                    self.codeCountdown -= 1
                } else {
                    self.stopCountdown()
                }
            }
    }
    
    private func stopCountdown() {
        timerCancellable?.cancel()
        timerCancellable = nil
    }
}

// MARK: - EMailLogin View

struct EMailLoginPage: View {
    @StateObject private var viewModel = EMailLoginViewModel()
    let onBack: () -> Void
    let onLoginSuccess: () -> Void
    
    @FocusState private var focusedField: Field?
    
    enum Field {
        case email
        case verificationCode
    }
    
    var body: some View {
        GeometryReader { geometry in
            ZStack {
                LoginBackgroundView()
                
                VStack(spacing: 0) {
                    LoginHeaderView(onBack: {
                        viewModel.onBackTapped()
                    })
                    
                    Spacer().frame(height: 60)
                    
                    Text("Email Login")
                        .font(.system(size: 28, weight: .bold))
                        .foregroundColor(.white)
                        .padding(.bottom, 60)
                    
                    VStack(spacing: 24) {
                        // 邮箱输入框
                        emailInputField
                        
                        // 验证码输入框（带获取按钮）
                        verificationCodeInputField
                    }
                    .padding(.horizontal, 32)
                    
                    Spacer()
                        .frame(height: 80)
                    
                    // 登录按钮
                    LoginButtonView(
                        isLoading: viewModel.isLoading,
                        isEnabled: viewModel.isLoginButtonEnabled,
                        onTap: {
                            viewModel.onLoginTapped()
                        }
                    )
                    .padding(.horizontal, 32)
                    
                    Spacer()
                }
            }
        }
        .navigationBarHidden(true)
        .onAppear {
            viewModel.onBack = onBack
            viewModel.onLoginSuccess = onLoginSuccess
            viewModel.resetState()
            
            #if DEBUG
            viewModel.email = "exzero@126.com"
            #endif
        }
        .onDisappear {
//            viewModel.stopCountdown()
        }
        .onChange(of: viewModel.email) { _, newEmail in
            viewModel.onEmailChanged(newEmail)
        }
        .onChange(of: viewModel.verificationCode) { _, newCode in
            viewModel.onVerificationCodeChanged(newCode)
        }
        .onChange(of: viewModel.isCodeLoading) { _, isCodeLoading in
            if !isCodeLoading && viewModel.errorMessage == nil {
                DispatchQueue.main.asyncAfter(deadline: .now() + 0.1) {
                    focusedField = .verificationCode
                }
            }
        }
        .onChange(of: viewModel.loginStep) { _, newStep in
            debugInfoSync("🔄 EMailLoginView: loginStep 变化为 \(newStep)")
            if newStep == .completed {
                debugInfoSync("✅ EMailLoginView: 登录成功，准备关闭自身")
            }
        }
    }
    
    // MARK: - UI Components
    
    private var emailInputField: some View {
        CustomInputField(
            type: .text,
            placeholder: "Please enter email",
            text: $viewModel.email
        )
        .focused($focusedField, equals: .email)
    }
    
    private var verificationCodeInputField: some View {
        CustomInputField(
            type: .verificationCode,
            placeholder: "Please enter verification code",
            text: $viewModel.verificationCode,
            onGetCode: {
                viewModel.onGetVerificationCodeTapped()
            },
            isCodeButtonEnabled: viewModel.isCodeButtonEnabled,
            isCodeLoading: viewModel.isCodeLoading,
            getCodeButtonText: viewModel.getCodeButtonText
        )
        .focused($focusedField, equals: .verificationCode)
    }
}

#Preview {
    EMailLoginPage(
        onBack: {},
        onLoginSuccess: {}
    )
}