[CHANGE] WIP YouTubeClient & HTML parsing

Manager.YouTube/Manager.YouTube.csproj

@@ -6,4 +6,9 @@
         <Nullable>enable</Nullable>
     </PropertyGroup>
 
+    <ItemGroup>
+      <PackageReference Include="DotBased" Version="1.0.0" />
+      <PackageReference Include="HtmlAgilityPack" Version="1.12.2" />
+    </ItemGroup>
+
 </Project>

Manager.YouTube/Models/Innertube/ClientState.cs

@@ -0,0 +1,18 @@
+using System.Text.Json.Serialization;
+
+namespace Manager.YouTube.Models.Innertube;
+
+public class ClientState
+{
+    [JsonExtensionData]
+    public Dictionary<string, object> AdditionalData { get; set; } = [];
+
+    [JsonPropertyName("INNERTUBE_API_KEY")]
+    public string? InnertubeApiKey { get; set; }
+    
+    [JsonPropertyName("SIGNIN_URL")]
+    public string? SigninUrl { get; set; }
+
+    [JsonPropertyName("SBOX_SETTINGS")]
+    public SBoxSettings? SBoxSettings { get; set; }
+}

Manager.YouTube/Models/Innertube/SBoxSettings.cs

@@ -0,0 +1,12 @@
+using System.Text.Json.Serialization;
+
+namespace Manager.YouTube.Models.Innertube;
+
+public class SBoxSettings
+{
+    [JsonExtensionData]
+    public Dictionary<string, object> AdditionalData { get; set; } = [];
+
+    [JsonPropertyName("VISITOR_DATA")]
+    public string? VisitorData { get; set; }
+}

Manager.YouTube/NetworkService.cs

@@ -0,0 +1,59 @@
+using System.Text.Json;
+using DotBased.Monads;
+using Manager.YouTube.Models.Innertube;
+using Manager.YouTube.Parsers;
+using Manager.YouTube.Util;
+
+namespace Manager.YouTube;
+
+public static class NetworkService
+{
+    public static async Task<Result<ClientState>> GetClientStateAsync(YouTubeClient client)
+    {
+        var origin = "https://www.youtube.com/";
+        var httpRequest = new HttpRequestMessage
+        {
+            Method = HttpMethod.Get,
+            RequestUri = new Uri(origin)
+        };
+        httpRequest.Headers.IfModifiedSince = new DateTimeOffset(DateTime.UtcNow);
+        httpRequest.Headers.UserAgent.ParseAdd(client.UserAgent);
+        
+        if (client.SapisidCookie != null)
+        {
+            httpRequest.Headers.Authorization = AuthenticationUtilities.GetSapisidHashHeader(client.SapisidCookie.Value, origin);
+            httpRequest.Headers.Add("Origin", origin);
+        }
+        
+        var http = client.GetHttpClient();
+        if (http == null)
+        {
+            return ResultError.Fail("Unable to get http client!");
+        }
+        
+        var response = await http.SendAsync(httpRequest);
+        if (!response.IsSuccessStatusCode)
+        {
+            var responseResult = await response.Content.ReadAsStringAsync();
+            return Result<ClientState>.Fail(ResultError.Fail(responseResult));
+        }
+        var responseHtml = await response.Content.ReadAsStringAsync();
+        var clientStateResult = HtmlParser.GetJsonFromScriptFunction(responseHtml, "ytcfg.set");
+        if (clientStateResult is { IsSuccess: false, Error: not null })
+        {
+            return clientStateResult.Error;
+        }
+
+        ClientState? clientState;
+        try
+        {
+            clientState = JsonSerializer.Deserialize<ClientState>(clientStateResult.Value);
+        }
+        catch (Exception e)
+        {
+            return ResultError.Error(e, "Error while parsing JSON!");
+        }
+        
+        return clientState == null ? ResultError.Fail("Unable to parse client state!") : clientState;
+    }
+}

Manager.YouTube/Parsers/HtmlParser.cs

@@ -0,0 +1,39 @@
+using System.Text.RegularExpressions;
+using DotBased.Monads;
+using HtmlAgilityPack;
+
+namespace Manager.YouTube.Parsers;
+
+public static class HtmlParser
+{
+    public static Result<string> GetJsonFromScriptFunction(string html, string functionName)
+    {
+        if (string.IsNullOrWhiteSpace(html))
+        {
+            return ResultError.Fail("html cannot be empty!");
+        }
+        
+        if (string.IsNullOrWhiteSpace(functionName))
+        {
+            return ResultError.Fail("No function names provided!");
+        }
+
+        var htmlDocument = new HtmlDocument();
+        htmlDocument.LoadHtml(html);
+        
+        var scriptNode = htmlDocument.DocumentNode.SelectSingleNode($"//script[contains(., '{functionName}')]");
+        if (string.IsNullOrWhiteSpace(scriptNode.InnerText))
+            return ResultError.Fail($"Could not find {functionName} in html script nodes!");
+        
+        var regexPattern = $@"{Regex.Escape(functionName)}\(([^)]+)\);";
+        var match = Regex.Match(scriptNode.InnerText, regexPattern);
+
+        if (match.Success)
+        {
+            var jsonString = match.Groups[1].Value.Trim();
+            return jsonString;
+        }
+
+        return ResultError.Fail($"Unable to parse {functionName} JSON!");
+    }
+}

Manager.YouTube/Util/AuthenticationUtilities.cs

@@ -0,0 +1,37 @@
+using System.Globalization;
+using System.Net.Http.Headers;
+using System.Security.Cryptography;
+using System.Text;
+
+namespace Manager.YouTube.Util;
+
+public static class AuthenticationUtilities
+{
+    private const string HeaderScheme = "SAPISIDHASH";
+    
+    // Dave Thomas @ https://stackoverflow.com/a/32065323/9948300
+    public static AuthenticationHeaderValue? GetSapisidHashHeader(string sapisid, string origin)
+    {
+        if (string.IsNullOrWhiteSpace(sapisid) || string.IsNullOrWhiteSpace(origin))
+            return null;
+        var time = GetTime();
+        var sha1 = HashString($"{time} {sapisid} {origin}");
+        var completeHash = $"{time}_{sha1}";
+        return new AuthenticationHeaderValue(HeaderScheme, completeHash);
+    }
+    
+    private static string HashString(string stringData)
+    {
+        var dataBytes = Encoding.ASCII.GetBytes(stringData);
+        var hashData = SHA1.HashData(dataBytes);
+        return hashData.Aggregate(string.Empty, (current, item) => current + item.ToString("x2"));
+    }
+    
+    private static string GetTime()
+    {
+        var st = new DateTime(1970, 1, 1);
+        var t = DateTime.Now.ToUniversalTime() - st;
+        var time = (t.TotalMilliseconds + 0.5).ToString(CultureInfo.InvariantCulture);
+        return time[..10];
+    }
+}

Manager.YouTube/YouTubeClient.cs

@@ -1,6 +1,54 @@
+using System.Net;
+using DotBased.Logging;
+using Manager.YouTube.Models.Innertube;
+
 namespace Manager.YouTube;
 
 public sealed class YouTubeClient
 {
-    
+    public string Id { get; private set; }
+    public string AccountName { get; private set; }
+    public string? UserAgent { get; private set; }
+    public CookieContainer CookieContainer { get; }
+    public ClientState? ClientState { get; private set; }
+    public Cookie? SapisidCookie => CookieContainer.GetAllCookies()["SAPISID"];
+    public HttpClient? GetHttpClient() => _httpClient;
+
+    private readonly ILogger? _logger;
+    private HttpClient? _httpClient;
+
+    public YouTubeClient(CookieContainer cookieContainer, string userAgent, ILogger? logger = null)
+    {
+        CookieContainer = cookieContainer;
+        _logger = logger;
+        UserAgent = userAgent;
+        SetupClient();
+    }
+
+    private void SetupClient()
+    {
+        _logger?.Information("Building http client...");
+        _httpClient?.Dispose();
+
+        var clientHandler = new HttpClientHandler
+        {
+            AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip,
+            UseCookies = true,
+            CookieContainer = CookieContainer
+        };
+        _httpClient = new HttpClient(clientHandler);
+    }
+
+    private async Task GetStateAsync()
+    {
+        var state = await NetworkService.GetClientStateAsync(this);
+        if (!state.IsSuccess)
+        {
+            _logger?.Warning($"Error getting client state: {state.Error}");
+            return;
+        }
+        
+        ClientState = state.Value;
+        _logger?.Information("Client state retrieved. With API key: {InnertubeApiKey}", ClientState.InnertubeApiKey);
+    }
 }