refactor: Update token usage api (#347)

* refactor: Improve token usage api
* refactor: Image recognition to tokens

context/TokenUtils.cpp

@@ -3,6 +3,14 @@
 
 #include "TokenUtils.hpp"
 
+#include <QFileInfo>
+#include <QImageReader>
+#include <QSet>
+#include <QSize>
+
+#include <algorithm>
+#include <cmath>
+
 namespace QodeAssist::Context {
 
 int TokenUtils::estimateTokens(const QString &text)
@@ -15,8 +23,48 @@ int TokenUtils::estimateTokens(const QString &text)
     return text.length() / 4;
 }
 
+bool TokenUtils::isImageFilePath(const QString &filePath)
+{
+    static const QSet<QString> imageExtensions = {"png", "jpg", "jpeg", "gif", "webp", "bmp"};
+    return imageExtensions.contains(QFileInfo(filePath).suffix().toLower());
+}
+
+int TokenUtils::estimateImageAttachmentTokens(const QString &filePath)
+{
+    QImageReader reader(filePath);
+    QSize size = reader.size();
+    if (!size.isValid() || size.isEmpty())
+        return 1500;
+
+    double w = size.width();
+    double h = size.height();
+
+    const double longSide = std::max(w, h);
+    if (longSide > 2048.0) {
+        const double s = 2048.0 / longSide;
+        w *= s;
+        h *= s;
+    }
+
+    const double shortSide = std::min(w, h);
+    if (shortSide > 768.0) {
+        const double s = 768.0 / shortSide;
+        w *= s;
+        h *= s;
+    }
+
+    const int tilesW = static_cast<int>(std::ceil(w / 512.0));
+    const int tilesH = static_cast<int>(std::ceil(h / 512.0));
+    const int tiles = std::max(1, tilesW * tilesH);
+
+    return 85 + tiles * 170;
+}
+
 int TokenUtils::estimateFileTokens(const Context::ContentFile &file)
 {
+    if (isImageFilePath(file.filename))
+        return estimateImageAttachmentTokens(QString());
+
     int total = 0;
 
     total += estimateTokens(file.filename);