using System.IO;
using System.Windows;
using System.Windows.Media.Imaging;

using CamBooth.App.Core.AppSettings;
using CamBooth.App.Core.Logging;

using Wpf.Ui.Controls;

namespace CamBooth.App.PictureGallery;

public class PictureGalleryService
{
	private readonly AppSettingsService _appSettings;

	private readonly Logger _logger;

	public List<BitmapImage> ThumbnailsOrderedByNewestDescending =>
		this.thumbnails.OrderByDescending(map => map.Key)
			.Select(ordered => ordered.Value)
			.ToList();

	private Dictionary<DateTime, BitmapImage> thumbnails = new();


	public PictureGalleryService(AppSettingsService appSettings, Logger logger)
	{
		this._appSettings = appSettings;
		this._logger = logger;
	}


	public async Task LoadThumbnailsToCache(int cacheSize = 0)
	{
		this._logger.Info("Start load thumbnails into cache");
		string? pictureLocation = this._appSettings.PictureLocation;
		int loop = 0;

		List<string> picturePaths = Directory.EnumerateFiles(pictureLocation).ToList();

		await Task.Run(
			() =>
			{
				do
				{
					string picturePath = picturePaths[loop];

					DateTime creationTime = File.GetCreationTime(picturePath);

					// add if not exists
					if (!this.thumbnails.ContainsKey(creationTime))
					{
						this.thumbnails.Add(creationTime, CreateThumbnail(picturePath, 244, 200));
						this._logger.Info($"Thumbnail '{picturePath}' successfully created");
					}

					loop++;
				}
				while ((loop < cacheSize || cacheSize == 0) && loop < picturePaths.Count);
			});
		this._logger.Info("Loading thumbnails into cache completed");
	}


	public static BitmapImage CreateThumbnail(string filePath, int maxWidth, int maxHeight)
	{
		var bitmap = new BitmapImage();
		bitmap.BeginInit();
		bitmap.UriSource = new Uri(filePath);
		bitmap.DecodePixelWidth = maxWidth; // Größe des ThumbnailsOrderedByNewestDescending direkt beim Dekodieren festlegen
		bitmap.CacheOption = BitmapCacheOption.OnLoad;
		bitmap.EndInit();
		bitmap.Freeze(); // Threadsicher machen
		return bitmap;
	}
}