feat(api): POST /api/recipes/extract-from-photo

src/routes/api/recipes/extract-from-photo/+server.ts

@@ -0,0 +1,155 @@
+import type { RequestHandler } from './$types';
+import { json } from '@sveltejs/kit';
+import { extractRecipeFromImage, GeminiError } from '$lib/server/ai/gemini-client';
+import { preprocessImage } from '$lib/server/ai/image-preprocess';
+import { pickRandomPhrase } from '$lib/server/ai/description-phrases';
+import { createRateLimiter } from '$lib/server/ai/rate-limit';
+import type { Ingredient, Step } from '$lib/types';
+
+const MAX_BYTES = 8 * 1024 * 1024;
+const ALLOWED_MIME = new Set([
+  'image/jpeg',
+  'image/png',
+  'image/webp',
+  'image/heic',
+  'image/heif'
+]);
+
+// Singleton-Limiter: 10 Requests/Minute pro IP. Verhindert Kosten-Runaways
+// bei versehentlichem Dauer-Tappen.
+const limiter = createRateLimiter({ windowMs: 60_000, max: 10 });
+
+function errJson(status: number, code: string, message: string) {
+  return json({ code, message }, { status });
+}
+
+function buildRawText(q: number | null, u: string | null, name: string): string {
+  const parts: string[] = [];
+  if (q !== null) parts.push(String(q).replace('.', ','));
+  if (u) parts.push(u);
+  parts.push(name);
+  return parts.join(' ');
+}
+
+export const POST: RequestHandler = async ({ request, getClientAddress }) => {
+  const ip = getClientAddress();
+  if (!limiter.check(ip)) {
+    return errJson(
+      429,
+      'RATE_LIMITED',
+      'Zu viele Anfragen — bitte einen Moment warten.'
+    );
+  }
+
+  let form: FormData;
+  try {
+    form = await request.formData();
+  } catch {
+    return errJson(400, 'BAD_REQUEST', 'Multipart body erwartet.');
+  }
+  const photo = form.get('photo');
+  if (!(photo instanceof Blob)) {
+    return errJson(400, 'BAD_REQUEST', 'Feld "photo" fehlt.');
+  }
+  if (photo.size > MAX_BYTES) {
+    return errJson(
+      413,
+      'PAYLOAD_TOO_LARGE',
+      `Foto zu groß (max ${MAX_BYTES / 1024 / 1024} MB).`
+    );
+  }
+  if (!ALLOWED_MIME.has(photo.type)) {
+    return errJson(
+      415,
+      'UNSUPPORTED_MEDIA_TYPE',
+      `MIME "${photo.type}" nicht unterstützt.`
+    );
+  }
+
+  const rawBuffer = Buffer.from(await photo.arrayBuffer());
+  let preprocessed: { buffer: Buffer; mimeType: 'image/jpeg' };
+  try {
+    preprocessed = await preprocessImage(rawBuffer);
+  } catch (e) {
+    return errJson(
+      415,
+      'UNSUPPORTED_MEDIA_TYPE',
+      `Bild konnte nicht gelesen werden: ${(e as Error).message}`
+    );
+  }
+
+  const startedAt = Date.now();
+  let extracted;
+  try {
+    extracted = await extractRecipeFromImage(
+      preprocessed.buffer,
+      preprocessed.mimeType
+    );
+  } catch (e) {
+    if (e instanceof GeminiError) {
+      const status =
+        e.code === 'AI_RATE_LIMITED'
+          ? 429
+          : e.code === 'AI_TIMEOUT'
+            ? 503
+            : e.code === 'AI_NOT_CONFIGURED'
+              ? 503
+              : 503;
+      // Nur Code + Meta loggen, niemals Prompt/Response-Inhalt.
+      console.warn(
+        `[extract-from-photo] ${e.code} after ${Date.now() - startedAt}ms, ${preprocessed.buffer.byteLength} bytes`
+      );
+      return errJson(status, e.code, 'Die Bild-Analyse ist fehlgeschlagen.');
+    }
+    console.warn(`[extract-from-photo] UNEXPECTED ${(e as Error).message}`);
+    return errJson(503, 'AI_FAILED', 'Die Bild-Analyse ist fehlgeschlagen.');
+  }
+
+  // Minimum-Gültigkeit: Titel + (mind. 1 Zutat ODER mind. 1 Schritt).
+  if (
+    !extracted.title.trim() ||
+    (extracted.ingredients.length === 0 && extracted.steps.length === 0)
+  ) {
+    return errJson(
+      422,
+      'NO_RECIPE_IN_IMAGE',
+      'Ich konnte kein Rezept im Bild erkennen.'
+    );
+  }
+
+  const ingredients: Ingredient[] = extracted.ingredients.map((i, idx) => ({
+    position: idx + 1,
+    quantity: i.quantity,
+    unit: i.unit,
+    name: i.name,
+    note: i.note,
+    raw_text: buildRawText(i.quantity, i.unit, i.name),
+    section_heading: null
+  }));
+
+  const steps: Step[] = extracted.steps.map((s, idx) => ({
+    position: idx + 1,
+    text: s.text
+  }));
+
+  return json({
+    recipe: {
+      id: null,
+      title: extracted.title,
+      description: pickRandomPhrase(),
+      source_url: null,
+      source_domain: null,
+      image_path: null,
+      servings_default: extracted.servings_default,
+      servings_unit: extracted.servings_unit,
+      prep_time_min: extracted.prep_time_min,
+      cook_time_min: extracted.cook_time_min,
+      total_time_min: extracted.total_time_min,
+      cuisine: null,
+      category: null,
+      ingredients,
+      steps,
+      tags: []
+    }
+  });
+};