import ManaCore
import SwiftUI

/// "Passwort vergessen"-Screen: Email-Eingabe + Submit-Button.
/// Bei Erfolg zeigt der View einen generischen Hinweis (User-
/// Enumeration-Schutz).
public struct ManaForgotPasswordView: View {
    @Environment(\.manaBrand) private var brand
    @State private var model: ForgotPasswordViewModel
    private let onDone: () -> Void

    /// - Parameters:
    ///   - auth: gemeinsamer `AuthClient` der App.
    ///   - resetUniversalLink: Universal-Link für den Reset-Klick
    ///     aus der Email (z.B. `https://cardecky.mana.how/auth/reset`).
    ///   - onDone: Callback wenn der User "Fertig" auf dem Hinweis-
    ///     Screen drückt — Apps schließen das Sheet.
    public init(
        auth: AuthClient,
        resetUniversalLink: URL,
        onDone: @escaping () -> Void
    ) {
        _model = State(initialValue: ForgotPasswordViewModel(
            auth: auth,
            resetUniversalLink: resetUniversalLink
        ))
        self.onDone = onDone
    }

    public var body: some View {
        switch model.status {
        case .sent:
            sentView
        default:
            formView
        }
    }

    @ViewBuilder
    private var formView: some View {
        ManaAuthScaffold {
            VStack(spacing: 16) {
                Text("Passwort vergessen?")
                    .font(.title2)
                    .fontWeight(.semibold)
                    .foregroundStyle(brand.foreground)
                    .frame(maxWidth: .infinity, alignment: .leading)

                Text("Gib deine Email-Adresse ein. Wir schicken dir einen Link zum Zurücksetzen.")
                    .font(.subheadline)
                    .foregroundStyle(brand.mutedForeground)
                    .frame(maxWidth: .infinity, alignment: .leading)

                ManaTextField("Email", text: $model.email)
                    .manaEmailField()

                ManaPrimaryButton(
                    "Reset-Link senden",
                    isLoading: model.isSending,
                    isEnabled: model.canSubmit
                ) {
                    Task { await model.submit() }
                }

                if case let .error(message) = model.status {
                    Text(message)
                        .font(.footnote)
                        .foregroundStyle(brand.error)
                        .multilineTextAlignment(.center)
                        .padding(.top, 4)
                }
            }
            .padding(.top, 16)

            Button("Abbrechen", action: onDone)
                .font(.subheadline)
                .foregroundStyle(brand.mutedForeground)
                .padding(.top, 12)
        }
    }

    @ViewBuilder
    private var sentView: some View {
        ManaAuthScaffold {
            VStack(spacing: 16) {
                Image(systemName: "envelope.fill")
                    .font(.system(size: 56, weight: .light))
                    .foregroundStyle(brand.primary)

                Text("Schau in deinen Posteingang")
                    .font(.title2)
                    .fontWeight(.semibold)
                    .foregroundStyle(brand.foreground)
                    .multilineTextAlignment(.center)

                Text(
                    "Wenn ein Account für diese Email existiert, ist eine Mail mit "
                        + "einem Reset-Link unterwegs."
                )
                .font(.subheadline)
                .foregroundStyle(brand.mutedForeground)
                .multilineTextAlignment(.center)

                ManaPrimaryButton("Fertig") {
                    onDone()
                }
                .padding(.top, 16)
            }
        }
    }
}