/// <summary>
/// Sync tasks that are currently in the queue.
/// </summary>
/// <exception cref="ApiFormatException">if the request times out.</exception>
/// <remarks>The SyncStart, SyncStop, and SyncError events send error message or success indicators!</remarks>
public async Task <bool> Sync()
{
var remote = await _client.PullAnimeList();
/* CASES
* 0. A queued anime is in neither the remote or the list.
* It has likely been manually deleted after a list error.
* 1. The anime is in remote, but not in list
* a. The anime is enqueued for deletion - delete from server
* b. The anime is not enqueued for deletion - it was added to the server; add it to the list
* 2. The anime is in the list, but not in remote
* a. The anime is enqueued for addition - add it to the server
* b. The anime is not enqueued for addition - it was deleted; remove it from the list
* 3. The anime is in the list, and in remote.
* a. The anime is enqueued for updating - update it on the server and keep our copy.
* b. The anime is not enqueued for updating - keep the server's copy; the values could have changed.
*/
// First lets partition our lists.
var remoteUnique = remote.Except(_entries).ToList(); // remote - entries
var clientUnique = _entries.Except(remote).ToList(); // entries - remote
var common = _entries.Except(remoteUnique).Except(clientUnique).ToList(); // entries u remote
// Case 0: empty the queue of expired values
foreach (var e in _queue)
{
if (!remote.Contains(e) && !_entries.Contains(e))
{
_queue.Remove(e);
}
}
// Case 1: unique to server
foreach (var a in remoteUnique)
{
if (!_queue.Contains(a))
{
_entries.Add(a);
}
else if (_queue.First(x => x.Id == a.Id).ListStatus == ApiEntry.ListStatuses.NotInList)
{
await _client.RemoveAnime(a.Id);
_queue.Remove(a);
}
}
// Case 2: unique to client
foreach (var a in clientUnique)
{
if (!_queue.Contains(a))
{
_entries.Remove(a);
}
else if (_queue.First(x => x.Id == a.Id).ListStatus != ApiEntry.ListStatuses.NotInList)
{
if (!await _client.AddAnime(a.Id, a.ListStatus))
{
Debug.WriteLine($"Failed to add {a.Id} {a.Title}");
}
else if (!await _client.UpdateAnime(a))
{
Debug.WriteLine($"Failed to update{a.Id} {a.Title}");
}
else
{
_queue.Remove(a);
}
}
else
{
_entries.Remove(a);
_queue.Remove(a);
}
}
// Case 3: common to both
foreach (var a in common)
{
if (!_queue.Contains(a))
{
a.Replace(remote.First(x => x.Id == a.Id)); // take the server values
}
else if (_queue.First(x => x.Id == a.Id).ListStatus != ApiEntry.ListStatuses.NotInList)
{
if (!await _client.UpdateAnime(a))
{
Debug.WriteLine($"Failed to update {a.Id} {a.Title}");
}
else
{
_queue.Remove(a);
}
}
}
if (_queue.Count != 0)
{
// Something may have gone wrong here
Debug.WriteLine("Queue is not empty! Something failed to sync..");
_queue.ForEach(x => Debug.WriteLine($"{x.Title}, {x.ListStatus}, {x.CurrentEpisode}"));
}
else
{
Debug.WriteLine("Queue is empty");
}
return(_queue.Count == 0);
}