import SwiftUI
import ComposableArchitecture
import Perception

// PreferenceKey 用于传递图片高度
struct ImageHeightPreferenceKey: PreferenceKey {
    static let defaultValue: CGFloat = 0
    static func reduce(value: inout CGFloat, nextValue: () -> CGFloat) {
        value = max(value, nextValue())
    }
}

struct LoginView: View {
    let store: StoreOf<LoginFeature>
    let onLoginSuccess: () -> Void  // 新增：登录成功回调
    @State private var topImageHeight: CGFloat = 120 // 默认值
//    @ObservedObject private var localizationManager = LocalizationManager.shared
    @State private var showLanguageSettings = false
    @State private var isAgreedToTerms = true
    @State private var showUserAgreement = false
    @State private var showPrivacyPolicy = false
    @State private var showIDLogin = false  // 使用SwiftUI的@State管理导航
    @State private var showEmailLogin = false  // 新增：邮箱登录导航状态
    
    var body: some View {
        WithViewStore(self.store, observe: { $0.isAnyLoginCompleted }) { viewStore in
            NavigationStack {
                GeometryReader { geometry in
                    WithPerceptionTracking {
                    ZStack {
                        // 使用与 splash 相同的背景图片
                        Image("bg")
                            .resizable()
                            .aspectRatio(contentMode: .fill)
                            .ignoresSafeArea(.all)
                        VStack(spacing: 0) {
                            // 上半部分的"top"图片
                            ZStack {
                                Image("top")
                                    .resizable()
                                    .aspectRatio(contentMode: .fit)
                                    .frame(maxWidth: .infinity)
                                    .padding(.top, -100)
                                    .background(
                                        GeometryReader { topImageGeometry in
                                            Color.clear.preference(key: ImageHeightPreferenceKey.self, value: topImageGeometry.size.height)
                                        }
                                    )
                                // E-PARTI 文本，底部对齐"top"图片底部，间距20
                                HStack {
                                    Text(NSLocalizedString("login.app_title", comment: ""))
                                        .font(FontManager.adaptedFont(.bayonRegular, designSize: 56, for: geometry.size.width))
                                        .foregroundColor(.white)
                                        .padding(.leading, 20)
                                    Spacer()
                                }
                                .padding(.top, max(0, topImageHeight - 100)) // top图片高度 - 140
                                
                                // 语言切换按钮（右上角）- 仅在 Debug 环境下显示
                                #if DEBUG
                                VStack {
                                    HStack {
                                        Spacer()
                                        Button(action: {
                                            showLanguageSettings = true
                                        }) {
                                            Image(systemName: "globe")
                                                .frame(width: 40, height: 40)
                                                .font(.system(size: 20))
                                                .foregroundColor(.white)
                                                .background(Color.black.opacity(0.3))
                                                .clipShape(Circle())
                                        }
                                        .padding(.trailing, 16)
                                    }
                                    Spacer()
                                }
                                #endif
                                
                                VStack(spacing: 24) {
                                    // ID Login 按钮
                                    LoginButton(
                                        iconName: "person.circle.fill",
                                        iconColor: .green,
                                        title: NSLocalizedString("login.id_login", comment: "")
                                    ) {
                                        showIDLogin = true  // 直接设置SwiftUI状态
                                    }
                                    // Email Login 按钮
                                    LoginButton(
                                        iconName: "envelope.fill",
                                        iconColor: .blue,
                                        title: NSLocalizedString("login.email_login", comment: "")
                                    ) {
                                        showEmailLogin = true  // 显示邮箱登录界面
                                    }
                                }.padding(.top, max(0, topImageHeight+140))
                            }
                            .onPreferenceChange(ImageHeightPreferenceKey.self) { imageHeight in
                                topImageHeight = imageHeight
                            }

                            // 间距，使登录按钮区域顶部距离"top"图片底部40pt
                            Spacer()
                                .frame(height: 120)
                            
                            // 用户协议组件
                            UserAgreementView(
                                isAgreed: $isAgreedToTerms,
                                onUserServiceTapped: {
                                    showUserAgreement = true
                                },
                                onPrivacyPolicyTapped: {
                                    showPrivacyPolicy = true
                                }
                            )
                            .padding(.horizontal, 28)
                            .padding(.bottom, 140)
                        }
                        
                        // 移除旧的 NavigationLink，改用 navigationDestination
                    }
                    }
                }
                .navigationBarHidden(true)
                // 新增：适配 iOS 16 的 navigationDestination
                .navigationDestination(isPresented: $showIDLogin) {
                    WithPerceptionTracking {
                        IDLoginView(
                            store: store.scope(
                                state: \.idLoginState,
                                action: \.idLogin
                            ),
                            onBack: {
                                showIDLogin = false
                            },
                            showIDLogin: $showIDLogin // 新增：传递Binding
                        )
                        .navigationBarHidden(true)
                    }
                }
                .navigationDestination(isPresented: $showEmailLogin) {
                    WithPerceptionTracking {
                        EMailLoginView(
                            store: store.scope(
                                state: \.emailLoginState,
                                action: \.emailLogin
                            ),
                            onBack: {
                                showEmailLogin = false
                            },
                            showEmailLogin: $showEmailLogin // 新增：传递Binding
                        )
                        .navigationBarHidden(true)
                    }
                }
                // 移除：HomeView 的 navigationDestination
            }
            .sheet(isPresented: $showLanguageSettings) {
                WithPerceptionTracking {
                    LanguageSettingsView(isPresented: $showLanguageSettings)
                }
            }
            .webView(
                isPresented: $showUserAgreement,
                url: APIConfiguration.webURL(for: .userAgreement)
            )
            .webView(
                isPresented: $showPrivacyPolicy,
                url: APIConfiguration.webURL(for: .privacyPolicy)
            )
            // 新增：监听登录成功，调用回调
            .onChange(of: viewStore.state) { completed in
                if completed {
                    onLoginSuccess()
                }
            }
            // 新增：监听showIDLogin关闭时，若已登录则跳转首页
            .onChange(of: showIDLogin) { newValue in
                if newValue == false && viewStore.state {
                    onLoginSuccess()
                }
            }
            // 新增：监听showEmailLogin关闭时，若已登录则跳转首页
            .onChange(of: showEmailLogin) { newValue in
                if newValue == false && viewStore.state {
                    onLoginSuccess()
                }
            }
        }
    }
}

//#Preview {
//    LoginView(
//        store: Store(
//            initialState: LoginFeature.State()
//        ) {
//            LoginFeature()
//        },
//        onLoginSuccess: {}
//    )
//}