namespace UtopiaCanteenSystem.Services;

/// <summary>
/// Navigates between main views (AdminLogin, Scanner, Dashboard, Settings).
/// </summary>
public interface INavigationService
{
    /// <summary>Current view model to display in the main content area.</summary>
    object? CurrentViewModel { get; }

    /// <summary>Raised when CurrentViewModel changes.</summary>
    event EventHandler? CurrentViewModelChanged;

    void NavigateToAdminLogin();
    void NavigateToScanner();
    void NavigateToDashboard();
    void NavigateToAdminSettingsAuth();
    void NavigateToSettings();
    /// <summary>Opens Meal Schedules admin screen (Phase 2.5).</summary>
    void NavigateToMealSchedules();

    /// <summary>Starts a new dashboard session (used after scan).</summary>
    void StartDashboardSession();

    /// <summary>Returns true when the dashboard session is expired for the given timeout.</summary>
    bool IsDashboardSessionExpired(TimeSpan timeout);

    /// <summary>Navigates back from Settings based on dashboard session expiry.</summary>
    void NavigateBackFromSettings(TimeSpan timeout);

    /// <summary>Returns elapsed time since dashboard session start.</summary>
    TimeSpan GetDashboardSessionElapsed();
}