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

// MARK: - 注册根视图
struct RegisterRootView: View {
    @State private var registerModel = RegisterModel()
    
    var body: some View {
        ZStack {
            // 背景毛玻璃
            VisualEffectView(material: .underWindowBackground, blendingMode: .behindWindow)
                .ignoresSafeArea()
            
            Group {
                switch registerModel.stage {
                case .requestVerifyCode:
                    RegisterRequestVerifyCodeView()
                case .submitVerifyCode(let username):
                    RegisterSubmitVerifyCodeView(username: username)
                case .setPassword(let username):
                    RegisterSetPasswordView(username: username)
                }
            }
            .transition(.asymmetric(insertion: .move(edge: .trailing).combined(with: .opacity),
                                   removal: .move(edge: .leading).combined(with: .opacity)))
        }
        .environment(registerModel)
        .frame(width: 400, height: 450)
    }
}

// MARK: - 封装的输入框组件
struct PunchTextField: View {
    let icon: String
    let placeholder: String
    @Binding var text: String
    var isSecure: Bool = false
    var isDisabled: Bool = false

    var body: some View {
        HStack(spacing: 12) {
            Image(systemName: icon)
                .foregroundColor(.secondary)
                .frame(width: 20)
            
            if isSecure {
                SecureField(placeholder, text: $text)
                    .textFieldStyle(.plain)
            } else {
                TextField(placeholder, text: $text)
                    .textFieldStyle(.plain)
                    .disabled(isDisabled)
            }
        }
        .padding(10)
        .background(Color.primary.opacity(isDisabled ? 0.02 : 0.05))
        .cornerRadius(8)
        .overlay(
            RoundedRectangle(cornerRadius: 8)
                .stroke(Color.primary.opacity(0.1), lineWidth: 1)
        )
    }
}

// MARK: - 第一步：获取验证码
struct RegisterRequestVerifyCodeView: View {
    @Environment(RegisterModel.self) var registerModel
    @State private var username: String = ""
    @State private var isProcessing = false
    
    // 错误提示
    @State private var showAlert: Bool = false
    @State private var errorMessage: String = ""

    var body: some View {
        VStack(spacing: 24) {
            headerSection(title: "创建个人网络", subtitle: "输入手机号或邮箱开始注册")

            VStack(spacing: 16) {
                PunchTextField(icon: "person.crop.circle", placeholder: "手机号 / 邮箱", text: $username)
            }
            .frame(width: 280)

            Button(action: {
                self.requestVerifyCode()
            }) {
                if isProcessing {
                    ProgressView()
                        .controlSize(.small)
                } else {
                    Text("获取验证码")
                        .fontWeight(.medium)
                        .frame(maxWidth: .infinity)
                }
            }
            .buttonStyle(.borderedProminent)
            .controlSize(.large)
            .frame(width: 280)
            .disabled(username.isEmpty || isProcessing)

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

    private func requestVerifyCode() {
        self.isProcessing = true
        Task { @MainActor in
            if username.isEmpty {
                self.showAlert = true
                self.errorMessage = "手机号/邮箱为空"
                self.isProcessing = false
                return
            }
            
            switch SDLUtil.identifyContact(username) {
            case .email, .phone:
                do {
                    let result = try await self.registerModel.requestVerifyCode(username: username)
                    print("send verify code result: \(result)")
                    withAnimation(.spring()) {
                        self.registerModel.stage = .submitVerifyCode(username: username)
                    }
                } catch {
                    self.showAlert = true
                    self.errorMessage = error.localizedDescription
                }
            case .invalid:
                self.showAlert = true
                self.errorMessage = "手机号/邮箱格式错误"
            }
            self.isProcessing = false
        }
    }
    
}

// MARK: - 第二步：验证
struct RegisterSubmitVerifyCodeView: View {
    @Environment(RegisterModel.self) var registerModel
    let username: String
    @State private var code: String = ""
    @State private var isProcessing = false
    
    // 错误提示
    @State private var showAlert: Bool = false
    @State private var errorMessage: String = ""

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

            VStack(spacing: 16) {
                PunchTextField(icon: "envelope.badge", placeholder: "输入 4 位验证码", text: $code)
                
                Button("没有收到？重新获取") {
                    // Resend Logic
                }
                .buttonStyle(.link)
                .font(.caption)
            }
            .frame(width: 280)

            VStack(spacing: 12) {
                Button(action: {
                    self.submitVerifyCode()
                }) {
                    if isProcessing {
                        ProgressView()
                            .controlSize(.small)
                    } else {
                        Text("验证并设置密码")
                            .fontWeight(.medium)
                            .frame(maxWidth: .infinity)
                    }
                }
                .buttonStyle(.borderedProminent)
                .controlSize(.large)
                
                Button("返回上一步") {
                    withAnimation {
                        registerModel.stage = .requestVerifyCode
                    }
                }
                .buttonStyle(.plain)
                .foregroundColor(.secondary)
            }
            .frame(width: 280)

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

    private func submitVerifyCode() {
        self.isProcessing = true
        Task { @MainActor in
            if self.code.isEmpty {
                self.showAlert = true
                self.errorMessage = "请输入验证码"
                self.isProcessing = false
                return
            }
            
            if self.code.count != 4 {
                self.showAlert = true
                self.errorMessage = "验证码错误"
                self.isProcessing = false
                return
            }
            
            do {
                let result = try await self.registerModel.submitVerifyCode(username: username, verifyCode: self.code)
                print("submit verify code result: \(result)")
                withAnimation(.spring()) {
                    registerModel.stage = .setPassword(username: username)
                }
            } catch {
                self.showAlert = true
                self.errorMessage = error.localizedDescription
            }
            self.isProcessing = false
        }
    }
}

// MARK: - 第三步：设置密码
struct RegisterSetPasswordView: View {
    @Environment(RegisterModel.self) var registerModel
    let username: String
    @State private var password = ""
    @State private var confirm = ""
    @State private var isProcessing = false
    
    // 错误提示
    @State private var showAlert: Bool = false
    @State private var errorMessage: String = ""

    var body: some View {
        VStack(spacing: 24) {
            headerSection(title: "设置安全密码", subtitle: "最后一步，请确保密码足够强大")

            VStack(spacing: 12) {
                PunchTextField(icon: "lock.shield", placeholder: "新密码", text: $password, isSecure: true)
                PunchTextField(icon: "lock.shield", placeholder: "确认密码", text: $confirm, isSecure: true)
            }
            .frame(width: 280)

            Button(action: {
                self.handleRegister()
            }) {
                if isProcessing {
                    ProgressView()
                        .controlSize(.small)
                } else {
                    Text("完成注册")
                        .fontWeight(.medium)
                        .frame(maxWidth: .infinity)
                }
            }
            .buttonStyle(.borderedProminent)
            .controlSize(.large)
            .frame(width: 280)
            .disabled(password.isEmpty || password != confirm)

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

    private func handleRegister() {
        self.isProcessing = true
        Task { @MainActor in
            if password.isEmpty {
                self.showAlert = true
                self.errorMessage = "请输入新密码"
                self.isProcessing = false
                return
            }
            
            if confirm.isEmpty || confirm != password {
                self.showAlert = true
                self.errorMessage = "两次输入的密码不一致"
                self.isProcessing = false
                return
            }
            
            do {
                let result = try await self.registerModel.register(username: username, password: self.password)
                print("send verify code result: \(result)")
            } catch {
                self.showAlert = true
                self.errorMessage = error.localizedDescription
            }
            self.isProcessing = false
        }
    }
    
}

// MARK: - 辅助视图
extension View {
    
    func headerSection(title: String, subtitle: String) -> some View {
        VStack(spacing: 8) {
            Image(systemName: "shield.lefthalf.filled")
                .font(.system(size: 42))
                .foregroundStyle(.blue.gradient)
            
            Text(title)
                .font(.title2.bold())
            
            Text(subtitle)
                .font(.subheadline)
                .foregroundColor(.secondary)
                .multilineTextAlignment(.center)
        }
    }
    
}