using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using LehrerApp.Sync;
using LehrerApp.Sync.Models;

namespace LehrerApp.Desktop.ViewModels;

public partial class SyncStatusViewModel : ObservableObject
{
    private readonly SyncEngine? _engine;

    [ObservableProperty] private string _statusText = "Kein Server konfiguriert";
    [ObservableProperty] private string _lastSyncText = "";
    [ObservableProperty] private int _pendingCount;
    [ObservableProperty] private int _conflictCount;
    [ObservableProperty] private bool _isSyncing;
    [ObservableProperty] private bool _hasConflicts;
    [ObservableProperty] private bool _isServerConfigured;

    public SyncStatusViewModel(SyncEngine? engine)
    {
        _engine = engine;
        IsServerConfigured = engine is not null;

        if (_engine is not null)
        {
            _engine.StatusChanged += OnStatusChanged;
            OnStatusChanged(_engine.Status);
        }
    }

    private void OnStatusChanged(SyncStatus status)
    {
        IsSyncing    = status.State == SyncState.Syncing;
        HasConflicts = status.ConflictCount > 0;
        PendingCount = status.PendingEvents;
        ConflictCount = status.ConflictCount;

        StatusText = status.State switch
        {
            SyncState.Idle    => PendingCount > 0
                                    ? $"{PendingCount} ausstehend"
                                    : "Synchronisiert",
            SyncState.Syncing => "Synchronisiere...",
            SyncState.Offline => "Offline",
            SyncState.Error   => $"Fehler: {status.ErrorMessage}",
            _ => "",
        };

        LastSyncText = status.LastSyncAt.HasValue
            ? $"Zuletzt: {status.LastSyncAt:HH:mm}"
            : "Noch nie synchronisiert";
    }

    [RelayCommand(CanExecute = nameof(CanSyncNow))]
    private async Task SyncNow()
    {
        if (_engine is null) return;
        await _engine.SyncNowAsync(isAutomatic: false);
    }

    private bool CanSyncNow() => _engine is not null && !IsSyncing;
}