import ManaCore
import SwiftUI

/// "Neues Passwort setzen"-Screen. Wird aus dem Universal-Link-Handler
/// der App aufgerufen, sobald der User den Reset-Link aus der Email
/// geklickt hat — die App extrahiert `?token=…` aus der URL und
/// präsentiert diesen View.
///
/// ```swift
/// // In App.handleUniversalLink:
/// if url.path == "/auth/reset", let token = url.queryToken {
///     showResetPasswordSheet(token: token)
/// }
/// ```
public struct ManaResetPasswordView: View {
    @Environment(\.manaBrand) private var brand
    @State private var model: ResetPasswordViewModel
    private let onDone: () -> Void

    /// - Parameters:
    ///   - token: Reset-Token aus der Email (`?token=…`).
    ///   - auth: gemeinsamer `AuthClient` der App.
    ///   - onDone: Callback bei Erfolg oder Abbruch — App schließt
    ///     den Sheet und navigiert zurück zum Login.
    public init(
        token: String,
        auth: AuthClient,
        onDone: @escaping () -> Void
    ) {
        _model = State(initialValue: ResetPasswordViewModel(token: token, auth: auth))
        self.onDone = onDone
    }

    public var body: some View {
        switch model.status {
        case .done:
            doneView
        default:
            formView
        }
    }

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

                Text("Wähle ein neues Passwort. Mindestens 8 Zeichen.")
                    .font(.subheadline)
                    .foregroundStyle(brand.mutedForeground)
                    .frame(maxWidth: .infinity, alignment: .leading)

                ManaSecureField(
                    "Neues Passwort",
                    text: $model.newPassword,
                    textContentType: .newPassword
                )

                ManaSecureField(
                    "Passwort bestätigen",
                    text: $model.confirmPassword,
                    textContentType: .newPassword
                )

                if let hint = model.validationHint {
                    Text(hint)
                        .font(.footnote)
                        .foregroundStyle(brand.mutedForeground)
                        .frame(maxWidth: .infinity, alignment: .leading)
                }

                ManaPrimaryButton(
                    "Passwort setzen",
                    isLoading: model.isSubmitting,
                    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 doneView: some View {
        ManaAuthScaffold {
            VStack(spacing: 16) {
                Image(systemName: "lock.open.fill")
                    .font(.system(size: 56, weight: .light))
                    .foregroundStyle(brand.success)

                Text("Passwort aktualisiert")
                    .font(.title2)
                    .fontWeight(.semibold)
                    .foregroundStyle(brand.foreground)

                Text("Du kannst dich jetzt mit deinem neuen Passwort anmelden.")
                    .font(.subheadline)
                    .foregroundStyle(brand.mutedForeground)
                    .multilineTextAlignment(.center)

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