Libation/FileLiberator/UNTESTED/DownloadBook.cs
2019-12-26 13:04:56 -05:00

82 lines
2.8 KiB
C#

using System;
using System.IO;
using System.Threading.Tasks;
using DataLayer;
using Dinah.Core;
using Dinah.Core.ErrorHandling;
using FileManager;
namespace FileLiberator
{
/// <summary>
/// Download DRM book
///
/// Processes:
/// Download: download aax file: the DRM encrypted audiobook
/// Decrypt: remove DRM encryption from audiobook. Store final book
/// Backup: perform all steps (downloaded, decrypt) still needed to get final book
/// </summary>
public class DownloadBook : DownloadableBase
{
public override bool Validate(LibraryBook libraryBook)
=> !AudibleFileStorage.Audio.Exists(libraryBook.Book.AudibleProductId)
&& !AudibleFileStorage.AAX.Exists(libraryBook.Book.AudibleProductId);
public override async Task<StatusHandler> ProcessItemAsync(LibraryBook libraryBook)
{
var tempAaxFilename = getDownloadPath(libraryBook);
var actualFilePath = await downloadBookAsync(libraryBook, tempAaxFilename);
moveBook(libraryBook, actualFilePath);
return verifyDownload(libraryBook);
}
private static string getDownloadPath(LibraryBook libraryBook)
=> FileUtility.GetValidFilename(
AudibleFileStorage.DownloadsInProgress,
libraryBook.Book.Title,
"aax",
libraryBook.Book.AudibleProductId);
private async Task<string> downloadBookAsync(LibraryBook libraryBook, string tempAaxFilename)
{
var api = await AudibleApi.EzApiCreator.GetApiAsync(AudibleApiStorage.IdentityTokensFile);
var actualFilePath = await PerformDownloadAsync(
tempAaxFilename,
(p) => api.DownloadAaxWorkaroundAsync(libraryBook.Book.AudibleProductId, tempAaxFilename, p));
System.Threading.Thread.Sleep(100);
// if bad file download, a 0-33 byte file will be created
// if service unavailable, a 52 byte string will be saved as file
if (new FileInfo(actualFilePath).Length < 100)
{
var contents = File.ReadAllText(actualFilePath);
File.Delete(actualFilePath);
var unavailable = "Content Delivery Companion Service is not available.";
if (contents.StartsWithInsensitive(unavailable))
throw new Exception(unavailable);
throw new Exception("Error downloading file");
}
return actualFilePath;
}
private void moveBook(LibraryBook libraryBook, string actualFilePath)
{
var newAaxFilename = FileUtility.GetValidFilename(
AudibleFileStorage.DownloadsFinal,
libraryBook.Book.Title,
"aax",
libraryBook.Book.AudibleProductId);
File.Move(actualFilePath, newAaxFilename);
Invoke_StatusUpdate($"Successfully downloaded. Moved to: {newAaxFilename}");
}
private static StatusHandler verifyDownload(LibraryBook libraryBook)
=> !AudibleFileStorage.AAX.Exists(libraryBook.Book.AudibleProductId)
? new StatusHandler { "Downloaded AAX file cannot be found" }
: new StatusHandler();
}
}