//
//  ResetPasswordView.swift
//  punchnet
//
//  Created by 安礼成 on 2026/3/9.
//
import SwiftUI
import Observation

// MARK: - 1. 根视图
struct ResetPasswordRootView: View {
    @State private var resetPasswordModel = ResetPasswordModel()
    @Environment(AppContext.self) private var appContext: AppContext
    
    var body: some View {
        ZStack(alignment: .center) {
            switch resetPasswordModel.stage {
            case .requestVerifyCode:
                GetVerifyCodeView()
            case .submitVerifyCode:
                SubmitVerifyCodeView()
            case .resetPassword:
                ResetPasswordView()
            case .success:
                ResetPasswordSuccessView()
            }
        }
        .transition(.asymmetric(
            insertion: .move(edge: resetPasswordModel.transitionEdge).combined(with: .opacity),
            removal: .move(edge: resetPasswordModel.transitionEdge == .trailing ? .leading : .trailing).combined(with: .opacity)
        ))
        .environment(resetPasswordModel)
        .overlay(alignment: .topLeading) {
            // 仅在非成功页面显示返回按钮
            if resetPasswordModel.stage != .success {
                Button(action: {
                    // 执行返回逻辑，例如重置到登录
                    withAnimation(.spring(duration: 0.6, bounce: 0.2)) {
                        self.appContext.appScene = .login(username: nil)
                    }
                }) {
                    HStack {
                        Image(systemName: "chevron.left")
                            .font(.system(size: 16, weight: .semibold))
                            .padding(5)
                        
                        Text("首页")
                            .font(.system(size: 16, weight: .regular))
                    }
                    .contentShape(Rectangle()) // 扩大点击热区
                }
                .buttonStyle(.plain)
                .padding([.top, .leading], 16) // 控制距离窗口边缘的边距
                .transition(.opacity) // 按钮出现的动画
            }
        }
    }
}

// MARK: - 2. 第一步：获取验证码
struct GetVerifyCodeView: View {
    @Environment(ResetPasswordModel.self) var resetPasswordModel
    @State private var isProcessing = false
    @State private var showAlert = false
    @State private var errorMessage = ""

    var body: some View {
        @Bindable var model = resetPasswordModel
        
        VStack(spacing: 24) {
            headerSection(title: "重置密码", subtitle: "请输入关联的邮箱来验证身份")

            PunchTextField(icon: "person.crop.circle", placeholder: "邮箱", text: $model.username)
                .frame(width: 280)

            Button {
                Task { @MainActor in
                    await self.sendVerifyCode(username: model.username)
                }
            } label: {
                Text("获取验证码")
                    .fontWeight(.medium)
                    .frame(maxWidth: .infinity)
            }
            .buttonStyle(.borderedProminent)
            .controlSize(.large)
            .frame(width: 280)
            .disabled(!SDLUtil.isValidIdentifyContact(model.username) || isProcessing)

            Spacer()
        }
        .padding(40)
        .alert(isPresented: $showAlert) {
            Alert(title: Text("提示"), message: Text(errorMessage))
        }
    }

    // 发送验证码
    private func sendVerifyCode(username: String) async {
        self.isProcessing = true
        defer {
            self.isProcessing = false
        }
        
        do {
            let resetSession = try await resetPasswordModel.requestVerifyCode(username: username)
            withAnimation(.spring(duration: 0.6, bounce: 0.2)) {
                self.resetPasswordModel.stage = .submitVerifyCode
                self.resetPasswordModel.sessionId = resetSession.sessionId
                
                self.resetPasswordModel.transitionEdge = .trailing
            }
        } catch {
            self.errorMessage = error.localizedDescription
            self.showAlert = true
        }
    }
    
}

// MARK: - 3. 第二步：验证验证码
struct SubmitVerifyCodeView: View {
    @Environment(ResetPasswordModel.self) var resetPasswordModel: ResetPasswordModel
    
    @State private var code: String = ""
    @State private var isProcessing = false
    
    // 重发逻辑
    @State private var remainingSeconds = 60
    @State private var isResendEnabled = false
    
    // 错误逻辑处理
    @State private var showAlert = false
    @State private var errorMessage = ""
    
    var validInputCode: Bool {
        return !self.code.isEmpty && self.code.count == 6 && self.code.allSatisfy {$0.isNumber}
    }

    var body: some View {
        VStack(spacing: 24) {
            headerSection(title: "身份验证", subtitle: "验证码已发送至 \(self.resetPasswordModel.username)")

            VStack(alignment: .trailing, spacing: 16) {
                PunchTextField(icon: "envelope.badge", placeholder: "输入 6 位验证码", text: $code)
                
                Button(isResendEnabled ? "重新获取" : "重新获取 (\(remainingSeconds)s)") {
                    Task { @MainActor in
                        await self.resendAction(username: self.resetPasswordModel.username)
                    }
                }
                .buttonStyle(.link)
                .font(.caption)
                .disabled(!isResendEnabled)
            }
            .frame(width: 280)

            VStack(spacing: 12) {
                Button {
                    Task { @MainActor in
                        await self.submitAction(sessionId: self.resetPasswordModel.sessionId)
                    }
                } label: {
                    Text("验证并继续")
                        .fontWeight(.medium)
                        .frame(maxWidth: .infinity)
                }
                .buttonStyle(.borderedProminent)
                .controlSize(.large)
                .disabled(!validInputCode)
                
                Button("返回上一步") {
                    withAnimation(.spring(duration: 0.6, bounce: 0.2)) {
                        self.resetPasswordModel.stage = .requestVerifyCode
                        self.resetPasswordModel.transitionEdge = .leading
                    }
                }
                .buttonStyle(.plain)
                .foregroundColor(.secondary)
            }
            .frame(width: 280)

            Spacer()
        }
        .padding(40)
        .task {
            await startCountdown()
        }
        .alert(isPresented: $showAlert) {
            Alert(title: Text("提示"), message: Text(self.errorMessage))
        }
    }

    private func resendAction(username: String) async {
        _ = try? await resetPasswordModel.requestVerifyCode(username: username)
        await startCountdown()
    }

    private func startCountdown() async {
        self.isResendEnabled = false
        self.remainingSeconds = 60
        while remainingSeconds > 0 {
            try? await Task.sleep(nanoseconds: 1_000_000_000)
            self.remainingSeconds -= 1
        }
        self.isResendEnabled = true
    }

    private func submitAction(sessionId: Int) async {
        self.isProcessing = true
        defer {
            self.isProcessing = false
        }
        
        do {
            let result = try await resetPasswordModel.submitVerifyCode(sessionId: sessionId, verifyCode: code)
            NSLog("reset password submit verify code result: \(result)")
            withAnimation(.spring(duration: 0.6, bounce: 0.2)) {
                self.resetPasswordModel.stage = .resetPassword
                self.resetPasswordModel.transitionEdge = .trailing
            }
        } catch let err as SDLAPIError {
            self.showAlert = true
            self.errorMessage = err.message
        } catch let err {
            self.showAlert = true
            self.errorMessage = err.localizedDescription
        }
    }
    
}

// MARK: - 4. 第三步：重置密码
struct ResetPasswordView: View {
    @Environment(ResetPasswordModel.self) var resetPasswordModel: ResetPasswordModel
    
    @State private var password = ""
    @State private var confirm = ""
    @State private var isProcessing = false
    
    // 错误逻辑处理
    @State private var showAlert = false
    @State private var errorMessage = ""
    
    // 判断输入是否合法
    var isInputValid: Bool {
        !password.isEmpty && password == confirm && password.count >= 8
    }
    
    // 提示错误信息
    var passwordError: String? {
        if password.isEmpty || confirm.isEmpty {
            return nil
        }
        
        if password != confirm {
            return "两次输入的密码不一致"
        }
        
        if password.count < 8 {
            return "密码至少需要 8 位"
        }
        
        return nil
    }

    var body: some View {
        VStack(spacing: 24) {
            headerSection(title: "设置新密码", subtitle: "请为账号 \(self.resetPasswordModel.username) 设置一个强密码")

            VStack(spacing: 12) {
                PunchTextField(icon: "lock.shield", placeholder: "新密码 (至少8位)", text: $password, isSecure: true)
                PunchTextField(icon: "lock.shield", placeholder: "确认新密码", text: $confirm, isSecure: true)
                
                if let passwordError = self.passwordError {
                    Text(passwordError)
                        .font(.caption)
                        .foregroundColor(.red)
                        .frame(width: 280, alignment: .leading)
                }
            }
            .frame(width: 280)
            
            Button {
                Task { @MainActor in
                    await self.handleReset(sessionId: self.resetPasswordModel.sessionId)
                }
            } label: {
                Text("重置密码并登录")
                    .fontWeight(.medium)
                    .frame(maxWidth: .infinity)
            }
            .buttonStyle(.borderedProminent)
            .controlSize(.large)
            .frame(width: 280)
            .disabled(!isInputValid || isProcessing)

            Spacer()
        }
        .padding(40)
        .alert(isPresented: $showAlert) {
            Alert(title: Text("提示"), message: Text(self.errorMessage))
        }
    }

    private func handleReset(sessionId: Int) async {
        self.isProcessing = true
        defer {
            self.isProcessing = false
        }
        
        do {
            let result = try await resetPasswordModel.resetPassword(sessionId: sessionId, newPassword: password)
            print("密码重置成功: \(result)")
            withAnimation(.spring(duration: 0.6, bounce: 0.2)) {
                self.resetPasswordModel.stage = .success
                self.resetPasswordModel.transitionEdge = .trailing
            }
        } catch {
            self.showAlert = true
            self.errorMessage = "重置失败, 请稍后重试"
        }
    }
    
}

struct ResetPasswordSuccessView: View {
    @Environment(AppContext.self) var appContext: AppContext
    @Environment(ResetPasswordModel.self) var resetPasswordModel: ResetPasswordModel

    // 动画状态
    @State private var animateIcon = false
    @State private var animateText = false

    var body: some View {
        VStack(spacing: 32) {
            Spacer()
            
            // 成功图标 (使用蓝紫色调区别于注册的绿色)
            ZStack {
                Circle()
                    .fill(Color.blue.opacity(0.1))
                    .frame(width: 100, height: 100)
                    .scaleEffect(animateIcon ? 1.1 : 0.95)
                    .opacity(animateIcon ? 0.8 : 1.0)
                
                Image(systemName: "lock.circle.fill")
                    .font(.system(size: 56))
                    .foregroundStyle(.blue.gradient)
                    .scaleEffect(animateIcon ? 1.05 : 1.0)
            }
            .transition(.move(edge: .bottom).combined(with: .opacity))
            
            VStack(spacing: 32) {
                VStack(spacing: 12) {
                    Text("密码重置成功")
                        .font(.title2.bold())
                    
                    Text("您的新密码已生效。\n为了安全，建议您立即尝试使用新密码登录。")
                        .font(.subheadline)
                        .foregroundColor(.secondary)
                        .multilineTextAlignment(.center)
                }
                
                Button(action: {
                    withAnimation(.spring(duration: 0.6, bounce: 0.2)) {
                        self.appContext.appScene = .login(username: self.resetPasswordModel.username)
                    }
                }) {
                    Text("返回登录")
                        .fontWeight(.bold)
                        .frame(width: 200)
                }
                .buttonStyle(.borderedProminent)
                .controlSize(.large)
                .tint(.blue)
            }
            .opacity(animateText ? 1.0 : 0.0)
            .offset(y: animateText ? 0 : 20)
            
            Spacer()
        }
        .padding(40)
        .frame(maxWidth: .infinity, maxHeight: .infinity)
        .onAppear {
            withAnimation(.easeInOut(duration: 1.5).repeatForever(autoreverses: true)) {
                animateIcon = true
            }
            withAnimation(.spring(duration: 0.6, bounce: 0.3).delay(0.4)) {
                animateText = true
            }
        }
    }
}