Added tool calling support (#731)

Co-authored-by: krut_ni <nils.kruthoff@dlr.de>
Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/MindWork AI Studio/Tools/Web/HttpContentReader.cs

@@ -0,0 +1,65 @@
+using System.Text;
+
+namespace AIStudio.Tools.Web;
+
+/// <summary>
+/// Reads an HTTP response body as text, without trusting what it claims about its size.
+/// </summary>
+public static class HttpContentReader
+{
+    private const int CHUNK_SIZE = 8192;
+
+    /// <summary>
+    /// Reads the body as text, refusing anything beyond the given limit.
+    /// </summary>
+    /// <remarks>
+    /// The declared content length is checked first, and the actual bytes are counted while
+    /// reading — a server may understate the length or omit it entirely. Counting happens after
+    /// decompression, so a small compressed body that expands into a large one is caught too.
+    /// </remarks>
+    /// <param name="content">The response body.</param>
+    /// <param name="maxResponseBytes">The most that may be read.</param>
+    /// <param name="token">The cancellation token.</param>
+    /// <returns>The body as text, decoded by its declared charset or UTF-8.</returns>
+    /// <exception cref="HttpRequestException">The body exceeds the limit.</exception>
+    public static async Task<string> ReadAsStringWithLimitAsync(HttpContent content, int maxResponseBytes, CancellationToken token)
+    {
+        if (content.Headers.ContentLength is { } contentLength && contentLength > maxResponseBytes)
+            throw new HttpRequestException($"The response body is too large. Maximum allowed size is {maxResponseBytes} bytes.");
+
+        await using var stream = await content.ReadAsStreamAsync(token);
+        await using var buffer = new MemoryStream();
+        var chunk = new byte[CHUNK_SIZE];
+        while (true)
+        {
+            var read = await stream.ReadAsync(chunk, token);
+            if (read is 0)
+                break;
+
+            if (buffer.Length + read > maxResponseBytes)
+                throw new HttpRequestException($"The response body is too large. Maximum allowed size is {maxResponseBytes} bytes.");
+
+            buffer.Write(chunk, 0, read);
+        }
+
+        return (TryGetContentEncoding(content) ?? Encoding.UTF8).GetString(buffer.ToArray());
+    }
+
+    private static Encoding? TryGetContentEncoding(HttpContent content)
+    {
+        var charset = content.Headers.ContentType?.CharSet?.Trim();
+        if (string.IsNullOrWhiteSpace(charset))
+            return null;
+
+        try
+        {
+            return Encoding.GetEncoding(charset.Trim('"'));
+        }
+        catch
+        {
+            // An unknown or malformed charset is not worth failing the request over; the caller
+            // falls back to UTF-8, which is what such a server almost always meant.
+            return null;
+        }
+    }
+}