import SwiftUI

/// Account details opened from Settings.
struct ProfileView: View {
    @ObservedObject var authManager: AuthManager = .shared
    
    @State private var showAuthModal = false
    @State private var showLogoutConfirmation = false
    @State private var usernameInput = ""
    @State private var emailInput = ""
    @State private var phoneInput = ""
    @State private var profileMessage: String?
    @State private var profileMessageIsError = false
    
    var body: some View {
        ZStack {
            Color.spaceBlack.ignoresSafeArea()
                
            ScrollView {
                VStack(spacing: 20) {
                    // 1. Account Profile Header
                    accountHeaderCard
                        .padding(.top, 12)
                        
                    // 2. Inline profile editing (if logged in)
                    if authManager.isLoggedIn {
                        profileEditorCard
                    }

                    // Footer
                    footer
                        .padding(.top, 12)
                        .padding(.bottom, 40)
                }
                .padding(.horizontal, 16)
            }
        }
        .navigationTitle("账号")
        .navigationBarTitleDisplayMode(.inline)
        .sheet(isPresented: $showAuthModal) {
            AuthModalView(authManager: authManager)
        }
        .onAppear(perform: loadProfileInputs)
        .confirmationDialog("确定要退出登录吗？", isPresented: $showLogoutConfirmation, titleVisibility: .visible) {
            Button("退出登录", role: .destructive) {
                authManager.logout()
            }
            Button("取消", role: .cancel) {}
        }
    }
    
    // MARK: - 1. Account Header
    
    private var accountHeaderCard: some View {
        VStack(spacing: 16) {
            if let user = authManager.currentUser {
                // Authenticated Profile State
                HStack(spacing: 16) {
                    ZStack {
                        Circle()
                            .fill(Color.primary.opacity(0.12))
                            .frame(width: 60, height: 60)
                        
                        Image(systemName: "person.crop.circle.fill")
                            .font(.system(size: 34))
                            .foregroundStyle(Color.primary)
                    }
                    
                    VStack(alignment: .leading, spacing: 6) {
                        Text(user.username)
                           .font(.system(size: 18, weight: .bold))
                            .foregroundStyle(Color.primary)
                        
                        Text(user.email ?? user.phoneNumber ?? ("用户 ID: " + String(user.id.prefix(12))))
                            .font(.system(size: 12))
                            .foregroundStyle(Color.secondary)
                    }
                    
                    Spacer()
                    
                    Button {
                        showLogoutConfirmation = true
                    } label: {
                        Text("退出")
                            .font(.system(size: 12, weight: .regular))
                            .foregroundStyle(Color.recordingRed)
                            .padding(.horizontal, 10)
                            .padding(.vertical, 5)
                            .overlay(
                                RoundedRectangle(cornerRadius: 6)
                                    .stroke(Color.recordingRed.opacity(0.4), lineWidth: 1)
                            )
                    }
                }
            } else {
                // Guest / Unauthenticated State
                VStack(spacing: 14) {
                    HStack(spacing: 14) {
                        ZStack {
                            Circle()
                                .fill(Color.primary.opacity(0.06))
                                .frame(width: 52, height: 52)
                            
                            Image(systemName: "person.crop.circle.badge.plus")
                                .font(.system(size: 24))
                                .foregroundStyle(Color.secondary)
                        }
                        
                        VStack(alignment: .leading, spacing: 4) {
                            Text("未登录账号")
                                .font(.system(size: 16, weight: .semibold))
                                .foregroundStyle(Color.primary)
                            
                            Text("登录/注册后支持全功能体验与 BLE 硬件绑定")
                                .font(.system(size: 12))
                                .foregroundStyle(Color.secondary)
                        }
                        
                        Spacer()
                    }
                    
                    Button {
                        showAuthModal = true
                    } label: {
                        Text("注册 / 登录账号")
                            .font(.system(size: 14, weight: .semibold))
                            .foregroundStyle(Color.spaceBlack)
                            .frame(maxWidth: .infinity)
                            .padding(.vertical, 11)
                            .background(Color.primary)
                            .cornerRadius(8)
                    }
                }
            }
        }
        .padding(16)
        .background(Color.cardBackground.opacity(0.25))
        .businessBorder(cornerRadius: 12)
    }
    
    // MARK: - 2. Inline Profile Editing
    
    private var profileEditorCard: some View {
        VStack(alignment: .leading, spacing: 14) {
            Text("基本资料")
                .font(.system(size: 15, weight: .semibold))
                .foregroundStyle(Color.primary)

            profileField(label: "账号名", text: $usernameInput, icon: "person")
            profileField(label: "电子邮箱", text: $emailInput, icon: "envelope", keyboard: .emailAddress)
            profileField(label: "手机号码", text: $phoneInput, icon: "phone", keyboard: .phonePad)

            if let profileMessage {
                Text(profileMessage)
                    .font(.system(size: 12))
                    .foregroundStyle(profileMessageIsError ? Color.recordingRed : Color.green)
            }

            Button {
                saveProfile()
            } label: {
                Group {
                    if authManager.isProcessing {
                        ProgressView().tint(Color.spaceBlack)
                    } else {
                        Text("保存基本资料")
                        .font(.system(size: 13, weight: .medium))
                    }
                }
                .foregroundStyle(Color.spaceBlack)
                .frame(maxWidth: .infinity)
                .padding(.vertical, 10)
                .background(Color.primary)
                .cornerRadius(8)
            }
            .disabled(authManager.isProcessing)

            NavigationLink {
                ChangePasswordModalView(authManager: authManager)
            } label: {
                HStack {
                    Image(systemName: "key")
                    Text("修改安全密码")
                    Spacer()
                    Image(systemName: "chevron.right")
                        .font(.system(size: 11, weight: .semibold))
                        .foregroundStyle(Color.secondary)
                }
                .font(.system(size: 13, weight: .medium))
                .foregroundStyle(Color.primary)
                .padding(.vertical, 10)
            }
        }
        .padding(16)
        .background(Color.cardBackground.opacity(0.25))
        .businessBorder(cornerRadius: 12)
    }
    
    // MARK: - Actions

    private func profileField(
        label: String,
        text: Binding<String>,
        icon: String,
        keyboard: UIKeyboardType = .default
    ) -> some View {
        VStack(alignment: .leading, spacing: 6) {
            Text(label)
                .font(.system(size: 12))
                .foregroundStyle(Color.secondary)
            HStack(spacing: 10) {
                Image(systemName: icon)
                    .foregroundStyle(Color.secondary)
                    .frame(width: 18)
                TextField(label, text: text)
                    .textInputAutocapitalization(.never)
                    .autocorrectionDisabled()
                    .keyboardType(keyboard)
            }
            .font(.system(size: 14))
            .padding(.horizontal, 12)
            .padding(.vertical, 11)
            .background(Color.cardBackground.opacity(0.3))
            .businessBorder(cornerRadius: 8)
        }
    }

    private func loadProfileInputs() {
        guard let user = authManager.currentUser else { return }
        usernameInput = user.username
        emailInput = user.email ?? ""
        phoneInput = user.phoneNumber ?? ""
    }

    private func saveProfile() {
        profileMessage = nil
        authManager.updateProfile(
            username: usernameInput,
            email: emailInput,
            phoneNumber: phoneInput,
            avatarURL: nil
        ) { success, error in
            profileMessageIsError = !success
            profileMessage = success ? "基本资料已保存" : (error ?? "保存失败")
            if success {
                loadProfileInputs()
            }
        }
    }
    
    // MARK: - Footer
    
    private var footer: some View {
        VStack(spacing: 4) {
            Text("CELESTIA TRACE USER & DEVICE")
                .font(.system(size: 10, weight: .bold, design: .monospaced))
                .foregroundStyle(Color.secondary.opacity(0.4))
                .tracking(2)
            
            Text("安全本地注册与极简日志空间")
                .font(.system(size: 9))
                .foregroundStyle(Color.secondary.opacity(0.3))
        }
    }
}

#Preview {
    NavigationStack {
        ProfileView()
    }
}