import SwiftUI

struct LoginView: View {
    @Bindable var viewModel: AuthViewModel
    var appState: AppState
    @State private var showPairing = false
    @State private var didAttemptBiometric = false

    var body: some View {
        NavigationStack {
            ScrollView {
                VStack(spacing: 20) {
                    Image(systemName: "lock.shield.fill")
                        .font(.system(size: 60))
                        .foregroundStyle(.blue)
                        .padding(.top, 40)

                    Text("Encrypted Chat")
                        .font(.largeTitle.bold())

                    Text("End-to-end encrypted messaging")
                        .font(.subheadline)
                        .foregroundStyle(.secondary)

                    VStack(spacing: 16) {
                        // Server config
                        DisclosureGroup("Server") {
                            TextField("Host", text: $viewModel.serverHost)
                                .textContentType(.URL)
                                .autocapitalization(.none)
                            TextField("Port", text: $viewModel.serverPort)
                                .keyboardType(.numberPad)
                        }
                        .padding(.horizontal)

                        if viewModel.mode == .register {
                            TextField("Username", text: $viewModel.username)
                                .textContentType(.username)
                                .autocapitalization(.none)
                                .textFieldStyle(.roundedBorder)
                        }

                        TextField("Email", text: $viewModel.email)
                            .textContentType(.emailAddress)
                            .keyboardType(.emailAddress)
                            .autocapitalization(.none)
                            .textFieldStyle(.roundedBorder)

                        SecureField("Password", text: $viewModel.password)
                            .textContentType(viewModel.mode == .login ? .password : .oneTimeCode)
                            .autocorrectionDisabled()
                            .textInputAutocapitalization(.never)
                            .textFieldStyle(.roundedBorder)

                        if viewModel.mode == .register {
                            SecureField("Confirm Password", text: $viewModel.confirmPassword)
                                .textContentType(.oneTimeCode)
                                .autocorrectionDisabled()
                                .textInputAutocapitalization(.never)
                                .textFieldStyle(.roundedBorder)
                        }

                        if let error = viewModel.errorMessage {
                            Text(error)
                                .foregroundStyle(.red)
                                .font(.caption)
                                .multilineTextAlignment(.center)
                        }

                        Button(action: {
                            Task {
                                if viewModel.mode == .login {
                                    await viewModel.login(appState: appState)
                                } else {
                                    await viewModel.register(appState: appState)
                                }
                            }
                        }) {
                            if viewModel.isLoading {
                                ProgressView()
                                    .frame(maxWidth: .infinity)
                            } else {
                                Text(viewModel.mode == .login ? "Login" : "Register")
                                    .frame(maxWidth: .infinity)
                            }
                        }
                        .buttonStyle(.borderedProminent)
                        .disabled(viewModel.isLoading)

                        Button(viewModel.mode == .login ? "Don't have an account? Register" : "Already have an account? Login") {
                            viewModel.mode = viewModel.mode == .login ? .register : .login
                            viewModel.errorMessage = nil
                        }
                        .font(.caption)

                        if viewModel.hasSavedCredentials && viewModel.mode == .login {
                            Divider()
                                .padding(.vertical, 4)

                            Button {
                                Task { await viewModel.biometricLogin(appState: appState) }
                            } label: {
                                if viewModel.isBiometricLoading {
                                    ProgressView()
                                        .frame(maxWidth: .infinity)
                                } else {
                                    Label("Sign in with Face ID", systemImage: "faceid")
                                        .frame(maxWidth: .infinity)
                                }
                            }
                            .buttonStyle(.bordered)
                            .disabled(viewModel.isLoading || viewModel.isBiometricLoading)
                        }

                        Divider()
                            .padding(.vertical, 4)

                        Button("Pair from existing device") {
                            showPairing = true
                        }
                        .font(.caption)
                    }
                    .padding(.horizontal, 32)
                }
            }
            .task {
                viewModel.checkSavedCredentials()
                if viewModel.hasSavedCredentials && !didAttemptBiometric {
                    didAttemptBiometric = true
                    await viewModel.biometricLogin(appState: appState)
                }
            }
            .sheet(isPresented: $viewModel.showConfirmation) {
                ConfirmationSheet(viewModel: viewModel, appState: appState)
            }
            .sheet(isPresented: $showPairing) {
                PairingView(appState: appState, authViewModel: viewModel)
            }
        }
    }
}

struct ConfirmationSheet: View {
    @Bindable var viewModel: AuthViewModel
    var appState: AppState

    var body: some View {
        VStack(spacing: 20) {
            Text("Confirm Registration")
                .font(.title2.bold())

            if let msg = viewModel.registrationMessage {
                Text(msg)
                    .font(.subheadline)
                    .foregroundStyle(.secondary)
                    .multilineTextAlignment(.center)
            }

            TextField("Confirmation Code", text: $viewModel.confirmationCode)
                .textFieldStyle(.roundedBorder)
                .keyboardType(.numberPad)

            if let error = viewModel.errorMessage {
                Text(error)
                    .foregroundStyle(.red)
                    .font(.caption)
            }

            Button("Confirm") {
                Task {
                    await viewModel.confirmRegistration(appState: appState)
                }
            }
            .buttonStyle(.borderedProminent)
            .disabled(viewModel.isLoading)
        }
        .padding(32)
    }
}