Restructured the project structure back to the way it was, there's no reasonable way to split the modules

src/NadekoBot/Modules/Music/Services/extractor/YtLoader.cs

@@ -0,0 +1,130 @@
+#nullable disable
+using System.Globalization;
+using System.Text;
+using System.Text.Json;
+
+namespace NadekoBot.Modules.Music.Services;
+
+public sealed partial class YtLoader
+{
+    private static readonly byte[] _ytResultInitialData = Encoding.UTF8.GetBytes("var ytInitialData = ");
+    private static readonly byte[] _ytResultJsonEnd = Encoding.UTF8.GetBytes(";<");
+
+    private static readonly string[] _durationFormats =
+    {
+        @"m\:ss", @"mm\:ss", @"h\:mm\:ss", @"hh\:mm\:ss", @"hhh\:mm\:ss"
+    };
+
+    private readonly IHttpClientFactory _httpFactory;
+
+    public YtLoader(IHttpClientFactory httpFactory)
+        => _httpFactory = httpFactory;
+
+    // public async Task<TrackInfo> LoadTrackByIdAsync(string videoId)
+    // {
+    //     using var http = new HttpClient();
+    //     http.DefaultRequestHeaders.Add("X-YouTube-Client-Name", "1");
+    //     http.DefaultRequestHeaders.Add("X-YouTube-Client-Version", "2.20210520.09.00");
+    //     http.DefaultRequestHeaders.Add("Cookie", "CONSENT=YES+cb.20210530-19-p0.en+FX+071;");
+    //
+    //     var responseString = await http.GetStringAsync($"https://youtube.com?" +
+    //                         $"pbj=1" +
+    //                         $"&hl=en" +
+    //                         $"&v=" + videoId);
+    //
+    //     var jsonDoc = JsonDocument.Parse(responseString).RootElement;
+    //     var elem = jsonDoc.EnumerateArray()
+    //         .FirstOrDefault(x => x.TryGetProperty("page", out var elem) && elem.GetString() == "watch");
+    //
+    //     var formatsJsonArray = elem.GetProperty("streamingdata")
+    //         .GetProperty("formats")
+    //         .GetRawText();
+    //     
+    //     var formats = JsonSerializer.Deserialize<List<YtAdaptiveFormat>>(formatsJsonArray);
+    //     var result = formats
+    //         .Where(x => x.MimeType.StartsWith("audio/"))
+    //         .OrderByDescending(x => x.Bitrate)
+    //         .FirstOrDefault();
+    //
+    //     if (result is null)
+    //         return null;
+    //
+    //     return new YtTrackInfo("1", "2", TimeSpan.Zero);
+    // }
+
+    public async Task<IList<TrackInfo>> LoadResultsAsync(string query)
+    {
+        query = Uri.EscapeDataString(query);
+
+        using var http = _httpFactory.CreateClient();
+        http.DefaultRequestHeaders.Add("Cookie", "CONSENT=YES+cb.20210530-19-p0.en+FX+071;");
+
+        byte[] response;
+        try
+        {
+            response = await http.GetByteArrayAsync($"https://youtube.com/results?hl=en&search_query={query}");
+        }
+        catch (HttpRequestException ex)
+        {
+            Log.Warning("Unable to retrieve data with YtLoader: {ErrorMessage}", ex.Message);
+            return null;
+        }
+
+        // there is a lot of useless html above the script tag, however if html gets significantly reduced
+        // this will result in the json being cut off
+
+        var mem = GetScriptResponseSpan(response);
+        var root = JsonDocument.Parse(mem).RootElement;
+
+        using var tracksJsonItems = root
+                              .GetProperty("contents")
+                              .GetProperty("twoColumnSearchResultsRenderer")
+                              .GetProperty("primaryContents")
+                              .GetProperty("sectionListRenderer")
+                              .GetProperty("contents")[0]
+                              .GetProperty("itemSectionRenderer")
+                              .GetProperty("contents")
+                              .EnumerateArray();
+
+        var tracks = new List<TrackInfo>();
+        foreach (var track in tracksJsonItems)
+        {
+            if (!track.TryGetProperty("videoRenderer", out var elem))
+                continue;
+
+            var videoId = elem.GetProperty("videoId").GetString();
+            // var thumb = elem.GetProperty("thumbnail").GetProperty("thumbnails")[0].GetProperty("url").GetString();
+            var title = elem.GetProperty("title").GetProperty("runs")[0].GetProperty("text").GetString();
+            var durationString = elem.GetProperty("lengthText").GetProperty("simpleText").GetString();
+
+            if (!TimeSpan.TryParseExact(durationString,
+                    _durationFormats,
+                    CultureInfo.InvariantCulture,
+                    out var duration))
+            {
+                Log.Warning("Cannot parse duration: {DurationString}", durationString);
+                continue;
+            }
+
+            tracks.Add(new YtTrackInfo(title, videoId, duration));
+            if (tracks.Count >= 5)
+                break;
+        }
+
+        return tracks;
+    }
+
+    private Memory<byte> GetScriptResponseSpan(byte[] response)
+    {
+        var responseSpan = response.AsSpan()[140_000..];
+        var startIndex = responseSpan.IndexOf(_ytResultInitialData);
+        if (startIndex == -1)
+            return null; // FUTURE try selecting html
+        startIndex += _ytResultInitialData.Length;
+
+        var endIndex =
+            140_000 + startIndex + responseSpan[(startIndex + 20_000)..].IndexOf(_ytResultJsonEnd) + 20_000;
+        startIndex += 140_000;
+        return response.AsMemory(startIndex, endIndex - startIndex);
+    }
+}