first commit

Co-authored-by: Cursor <cursoragent@cursor.com>

api/src/icons.ts

@@ -0,0 +1,65 @@
+import fs from 'node:fs/promises';
+import path from 'node:path';
+import { config } from './config.ts';
+import { log } from './log.ts';
+import type { MintRow } from './mints.ts';
+
+const EXT_BY_TYPE: Record<string, string> = {
+  'image/png': '.png',
+  'image/jpeg': '.jpg',
+  'image/webp': '.webp',
+  'image/svg+xml': '.svg',
+  'image/gif': '.gif',
+  'image/x-icon': '.ico',
+  'image/vnd.microsoft.icon': '.ico',
+};
+
+const MAX_ICON_BYTES = 512 * 1024;
+
+/**
+ * Cache a mint's icon to disk so offline mints keep theirs.
+ * Re-fetches only when the icon_url changed, per BACKEND.md.
+ * Returns the stored filename, or the existing one if nothing needed doing.
+ */
+export async function cacheIcon(row: MintRow, iconUrl: string | null): Promise<string | null> {
+  if (!iconUrl) return row.icon_file;
+  if (iconUrl === row.icon_url && row.icon_file) return row.icon_file;
+
+  // Some mints inline the icon as a data URI. Nothing to fetch, and nothing worth storing.
+  if (iconUrl.startsWith('data:')) return row.icon_file;
+
+  try {
+    const absolute = new URL(iconUrl, `${row.url}/`).toString();
+    if (!absolute.startsWith('https://') && !absolute.startsWith('http://')) return row.icon_file;
+
+    const controller = new AbortController();
+    const timer = setTimeout(() => controller.abort(), config.probeTimeoutMs);
+    let res: Response;
+    try {
+      res = await fetch(absolute, {
+        signal: controller.signal,
+        headers: { 'User-Agent': config.userAgent },
+      });
+    } finally {
+      clearTimeout(timer);
+    }
+    if (!res.ok) return row.icon_file;
+
+    const type = (res.headers.get('content-type') ?? '').split(';')[0]?.trim() ?? '';
+    const ext = EXT_BY_TYPE[type];
+    if (!ext) return row.icon_file;
+
+    const buf = Buffer.from(await res.arrayBuffer());
+    if (buf.byteLength === 0 || buf.byteLength > MAX_ICON_BYTES) return row.icon_file;
+
+    const filename = `${row.host}${ext}`;
+    await fs.writeFile(path.join(config.iconDir, filename), buf);
+    return filename;
+  } catch (err) {
+    log.warn('icon fetch failed', {
+      url: row.url,
+      reason: err instanceof Error ? err.message : String(err),
+    });
+    return row.icon_file;
+  }
+}