Libation/Source/ApplicationServices/BulkSetDownloadStatus.cs

using DataLayer;
using Dinah.Core;
using LibationFileManager;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace ApplicationServices;

public class BulkSetDownloadStatus
{
	private List<(string message, LiberatedStatus newStatus, IEnumerable<LibraryBook> LibraryBooks)> actionSets { get; } = new();

	public int Count => actionSets.Count;

	public IEnumerable<string> Messages => actionSets.Select(a => a.message);
	public string AggregateMessage => $"Are you sure you want to set {Messages.Aggregate((a, b) => $"{a} and {b}")}?";

	private readonly List<LibraryBook> _libraryBooks;
	private readonly bool _setDownloaded;
	private readonly bool _setNotDownloaded;

	public BulkSetDownloadStatus(List<LibraryBook> libraryBooks, bool setDownloaded, bool setNotDownloaded)
	{
		_libraryBooks = libraryBooks;
		_setDownloaded = setDownloaded;
		_setNotDownloaded = setNotDownloaded;
	}

	public int Discover()
	{
		var bookExistsList = _libraryBooks
			.Select(libraryBook => new
			{
				LibraryBook = libraryBook,
				FileExists = AudibleFileStorage.Audio.GetPath(libraryBook.Book.AudibleProductId) is not null
			})
			.ToList();

		if (_setDownloaded)
		{
			var books2change = bookExistsList
				.Where(a => a.FileExists && a.LibraryBook.Book.UserDefinedItem.BookStatus != LiberatedStatus.Liberated)
				.Select(a => a.LibraryBook)
				.ToList();

			if (books2change.Any())
				actionSets.Add((
					$"{"book".PluralizeWithCount(books2change.Count)} to 'Downloaded'",
					LiberatedStatus.Liberated,
					books2change));
		}

		if (_setNotDownloaded)
		{
			var books2change = bookExistsList
				.Where(a => !a.FileExists && a.LibraryBook.Book.UserDefinedItem.BookStatus != LiberatedStatus.NotLiberated)
				.Select(a => a.LibraryBook)
				.ToList();

			if (books2change.Any())
				actionSets.Add((
					$"{"book".PluralizeWithCount(books2change.Count)} to 'Download Pending'",
					LiberatedStatus.NotLiberated,
					books2change));
		}

		return Count;
	}

	public async Task ExecuteAsync()
	{
		foreach (var a in actionSets)
			await a.LibraryBooks.UpdateBookStatusAsync(a.newStatus);
	}
}