import SwiftUI

struct LoginView: View {
    @Environment(AppState.self) private var app

    @State private var serverURL: String = ""
    @State private var username: String = ""
    @State private var password: String = ""
    @State private var remember: Bool = true
    @State private var isLoading: Bool = false

    var body: some View {
        VStack(spacing: 16) {
            Spacer()
            Image(systemName: "books.vertical.fill")
                .font(.system(size: 48))
                .foregroundStyle(.tint)
            Text("ABS Client")
                .font(.largeTitle).bold()
            Text("Verbinde dich mit deinem Audiobookshelf-Server")
                .foregroundStyle(.secondary)

            VStack(alignment: .leading, spacing: 12) {
                LabeledField(label: "Server-URL", placeholder: "https://abs.example.com") {
                    TextField("", text: $serverURL)
                        .textFieldStyle(.roundedBorder)
                        .disableAutocorrection(true)
                }
                LabeledField(label: "Benutzername", placeholder: "user") {
                    TextField("", text: $username)
                        .textFieldStyle(.roundedBorder)
                        .disableAutocorrection(true)
                }
                LabeledField(label: "Passwort", placeholder: "••••••") {
                    SecureField("", text: $password)
                        .textFieldStyle(.roundedBorder)
                }
                Toggle("Anmeldung merken", isOn: $remember)
                    .toggleStyle(.checkbox)
            }
            .frame(maxWidth: 380)

            if let err = app.auth.errorMessage {
                Text(err)
                    .foregroundStyle(.red)
                    .font(.callout)
                    .multilineTextAlignment(.center)
                    .frame(maxWidth: 380)
            }

            Button(action: doLogin) {
                if isLoading {
                    ProgressView().controlSize(.small)
                } else {
                    Text("Einloggen")
                        .frame(maxWidth: 200)
                }
            }
            .buttonStyle(.borderedProminent)
            .controlSize(.large)
            .disabled(isLoading || serverURL.isEmpty || username.isEmpty || password.isEmpty)
            .keyboardShortcut(.defaultAction)

            Spacer()
        }
        .padding(32)
    }

    private func doLogin() {
        isLoading = true
        Task {
            await app.auth.login(
                serverURL: serverURL,
                username: username,
                password: password,
                remember: remember
            )
            isLoading = false
        }
    }
}

private struct LabeledField<Content: View>: View {
    let label: String
    let placeholder: String
    @ViewBuilder let content: Content

    var body: some View {
        VStack(alignment: .leading, spacing: 4) {
            Text(label).font(.subheadline).foregroundStyle(.secondary)
            content
        }
    }
}