mana-swift-ui/Sources/ManaAuthUI/Register/SignUpViewModel.swift

import Foundation
import ManaCore
import Observation

/// State-Maschine für ``ManaSignUpView``. Wraps `AuthClient.register`.
///
/// Bei `requireEmailVerification: true` (Default in mana-auth) ist die
/// erfolgreiche Registrierung kein Login — der Server hat die Verify-
/// Mail verschickt, der User muss klicken. `status` wird in dem Fall
/// `.awaitingVerification(email:)` — die View zeigt den Hinweis-Screen.
@MainActor
@Observable
public final class SignUpViewModel {
    public enum Status: Equatable, Sendable {
        case idle
        case registering
        /// Registrierung erfolgreich, Verify-Mail unterwegs.
        case awaitingVerification(email: String)
        /// Registrierung erfolgreich UND Server hat Tokens geliefert
        /// (z.B. mit `requireEmailVerification: false`). User ist
        /// eingeloggt.
        case signedIn
        case error(String)
    }

    public var email: String = ""
    public var name: String = ""
    public var password: String = ""
    public private(set) var status: Status = .idle

    private let auth: AuthClient
    private let sourceAppUrl: URL?

    public init(auth: AuthClient, sourceAppUrl: URL? = nil) {
        self.auth = auth
        self.sourceAppUrl = sourceAppUrl
    }

    public var canSubmit: Bool {
        guard !trimmedEmail.isEmpty, !password.isEmpty else { return false }
        if case .registering = status { return false }
        return true
    }

    public var isRegistering: Bool {
        if case .registering = status { return true }
        return false
    }

    /// Passwort-Mindest-Check vor dem Server-Call. mana-auth
    /// (Better Auth) gibt heute `WEAK_PASSWORD` zurück wenn das
    /// Passwort < 8 Zeichen ist — wir spiegeln das clientseitig
    /// damit der User keinen Round-Trip braucht.
    public var passwordHint: String? {
        guard !password.isEmpty else { return nil }
        if password.count < 8 {
            return "Passwort muss mindestens 8 Zeichen lang sein."
        }
        return nil
    }

    private var trimmedEmail: String {
        email.trimmingCharacters(in: .whitespacesAndNewlines)
    }

    public func submit() async {
        let emailTrim = trimmedEmail
        let nameTrim = name.trimmingCharacters(in: .whitespacesAndNewlines)
        guard !emailTrim.isEmpty, !password.isEmpty else { return }
        if let hint = passwordHint {
            status = .error(hint)
            return
        }

        status = .registering
        do {
            try await auth.register(
                email: emailTrim,
                password: password,
                name: nameTrim.isEmpty ? nil : nameTrim,
                sourceAppUrl: sourceAppUrl
            )
            password = ""
            switch auth.status {
            case .signedIn:
                status = .signedIn
            default:
                status = .awaitingVerification(email: emailTrim)
            }
        } catch let error as AuthError {
            status = .error(error.errorDescription ?? "Registrierung fehlgeschlagen")
        } catch {
            status = .error(String(describing: error))
        }
    }
}