adding generic tag cards

src/inc/routes/tag_image.mjs

@@ -0,0 +1,41 @@
+import crypto from 'crypto';
+
+export default (router, tpl) => {
+  router.get(/^\/tag_image\/(?<tag>.+)$/, async (req, res) => {
+    const tag = req.params.tag;
+
+    // Create a deterministic hash from the tag
+    const hash = crypto.createHash('md5').update(tag).digest('hex');
+
+    // Generate colors from hash
+    const c1 = '#' + hash.substring(0, 6);
+    const c2 = '#' + hash.substring(6, 12);
+    const c3 = '#' + hash.substring(12, 18);
+
+    // Generate some deterministic numbers for shapes
+    const n1 = parseInt(hash.substring(18, 20), 16);
+    const n2 = parseInt(hash.substring(20, 22), 16);
+
+    const svg = `
+      <svg width="300" height="150" viewBox="0 0 300 150" xmlns="http://www.w3.org/2000/svg">
+        <defs>
+          <linearGradient id="grad" x1="0%" y1="0%" x2="100%" y2="100%">
+            <stop offset="0%" style="stop-color:${c1};stop-opacity:1" />
+            <stop offset="100%" style="stop-color:${c2};stop-opacity:1" />
+          </linearGradient>
+        </defs>
+        <rect width="300" height="150" fill="url(#grad)" />
+        <circle cx="${n1}%" cy="${n2}%" r="${(n1 + n2) / 4}" fill="${c3}" fill-opacity="0.3" />
+        <circle cx="${100 - n1}%" cy="${100 - n2}%" r="${(n1 + n2) / 3}" fill="${c3}" fill-opacity="0.2" />
+        <text x="50%" y="50%" dominant-baseline="middle" text-anchor="middle" font-family="sans-serif" font-size="24" fill="#fff" fill-opacity="0.9" font-weight="bold">${tag}</text>
+      </svg>
+    `.trim();
+
+    res.writeHead(200, {
+      'Content-Type': 'image/svg+xml',
+      'Cache-Control': 'public, max-age=86400'
+    });
+    res.end(svg);
+  });
+  return router;
+};