PlaylistShared/PlaylistShared.Api/Services/YandexMusicService.cs

using Microsoft.AspNetCore.DataProtection;
using PlaylistShared.Api.Entities;
using PlaylistShared.Shared.DTO;
using YandexMusic;
using YandexMusic.API.Extensions.API;
using YandexMusic.API.Models.Playlist;
using YandexMusic.API.Models.Track;

namespace PlaylistShared.Api.Services;

public class YandexMusicService
{
    private readonly IDataProtector _dataProtector;

    public YandexMusicService(IDataProtectionProvider provider)
    {
        _dataProtector = provider.CreateProtector("YandexTokens");
    }

    private async Task<YandexMusicClient?> CreateClientAsync(ApplicationUser user)
    {
        if (string.IsNullOrEmpty(user.YandexAccessToken))
            return null;

        string decryptedToken;
        try
        {
            decryptedToken = _dataProtector.Unprotect(user.YandexAccessToken);
        }
        catch
        {
            return null;
        }

        var client = new YandexMusicClient();
        var success = await client.Authorize(decryptedToken);
        return success ? client : null;
    }

    public async Task<YPlaylist?> GetPlaylistAsync(ApplicationUser user, string ownerUid, string kind)
    {
        var client = await CreateClientAsync(user);
        if (client == null) return null;
        return await client.GetPlaylistAsync(ownerUid, kind);
    }

    public async Task<YPlaylist?> CreatePlaylistAsync(ApplicationUser user, string title)
    {
        var client = await CreateClientAsync(user);
        if (client == null) return null;
        return await client.CreatePlaylistAsync(title);
    }

    public async Task<YPlaylist?> AddTracksAsync(ApplicationUser user, string ownerUid, string kind, IEnumerable<string> trackIds)
    {
        var client = await CreateClientAsync(user);
        if (client == null) return null;

        var playlist = await client.GetPlaylistAsync(ownerUid, kind);
        if (playlist == null) return null;

        var tracks = await client.GetTracksAsync(trackIds);
        if (tracks == null || !tracks.Any()) return null;

        var insertedTracks = tracks.Where(t => !playlist.Tracks.Any(p => p.Track.Id == t.Id)).ToArray();

        return await playlist.InsertTracksAsync(insertedTracks);
    }

    public async Task<YPlaylist?> RemoveTracksAsync(ApplicationUser user, string ownerUid, string kind, IEnumerable<string> trackIds)
    {
        var client = await CreateClientAsync(user);
        if (client == null) return null;
        var tracks = await client.GetTracksAsync(trackIds);
        if (tracks == null || !tracks.Any()) return null;
        var playlist = await client.GetPlaylistAsync(ownerUid, kind);
        if (playlist == null) return null;
        return await playlist.RemoveTracksAsync(tracks.ToArray());
    }

    public async Task<string?> GetTrackFileUrlAsync(ApplicationUser user, string trackId)
    {
        var track = await GetYTrackAsync(user, trackId);
        if (track == null) return null;
        return await track.GetLinkAsync();
    }

    public async Task<YTrack?> GetYTrackAsync(ApplicationUser user, string trackId)
    {
        using var client = await CreateClientAsync(user);
        if (client == null) return null;
        var track = await client.GetTrackAsync(trackId);
        return track;
    }

    public string EncryptToken(string token) => _dataProtector.Protect(token);

    public string DecryptToken(string encryptedToken)
    {
        try
        {
            return _dataProtector.Unprotect(encryptedToken);
        }
        catch
        {
            return null;
        }
    }

    public async Task<List<YandexTrack>> SearchTracksAsync(ApplicationUser user, string query, int limit = 20)
    {
        var client = await CreateClientAsync(user);
        if (client == null) return new List<YandexTrack>();

        var searchResult = await client.SearchAsync(query, YandexMusic.API.Models.Common.YSearchType.Track, page: 0, pageSize: limit);
        if (searchResult?.Tracks?.Results == null) return new List<YandexTrack>();

        return searchResult.Tracks.Results.Select(t => new YandexTrack
        {
            TrackId = t.Id,
            Title = t.Title,
            Artists = t.Artists?.Select(a => a.Name).ToList() ?? new List<string>(),
            CoverUri = t.CoverUri ?? string.Empty,
            DurationMs = t.DurationMs,
        }).ToList();
    }
}