Genesis

src/queries/image.js

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+import sql from 'mssql';
+import { getPool } from '../db.js';
+
+const IMAGE_BY_HASH_SQL = `
+SELECT bBild, bVorschauBild, nBreite, nHoehe, nVorschauBreite, nVorschauHoehe, cQuelle
+FROM dbo.tBild
+WHERE cHash = @hash;
+`;
+
+function contentTypeFor(cQuelle) {
+  const extension = (cQuelle || '').split('.').pop()?.toLowerCase();
+  switch (extension) {
+    case 'png':
+      return 'image/png';
+    case 'gif':
+      return 'image/gif';
+    case 'webp':
+      return 'image/webp';
+    case 'jpg':
+    case 'jpeg':
+    default:
+      return 'image/jpeg';
+  }
+}
+
+export async function getImageByHash(hash, size) {
+  const result = await getPool().request().input('hash', sql.NVarChar, hash).query(IMAGE_BY_HASH_SQL);
+
+  const row = result.recordset[0];
+  if (!row) {
+    return null;
+  }
+
+  const previewMaxDimension = Math.max(row.nVorschauBreite || 0, row.nVorschauHoehe || 0);
+  const useFull = !previewMaxDimension || Number(size) > previewMaxDimension;
+  const buffer = useFull ? row.bBild : row.bVorschauBild;
+
+  if (!buffer) {
+    return null;
+  }
+
+  return { buffer, contentType: contentTypeFor(row.cQuelle) };
+}