feat(music-lab): cover.py Pexels 이미지 검색 분기 (image_source=pexels)

music-lab/app/pipeline/cover.py

@@ -13,6 +13,7 @@ from .gradient import make_gradient_with_title
 logger = logging.getLogger("music-lab.cover")
 
 DALLE_TIMEOUT_S = 90
+PEXELS_IMG_TIMEOUT_S = 30
 
 
 def _get_api_key() -> str:
@@ -23,13 +24,68 @@ def _get_model() -> str:
     return os.getenv("OPENAI_IMAGE_MODEL", "gpt-image-1")
 
 
+def _get_pexels_key() -> str:
+    return os.getenv("PEXELS_API_KEY", "")
+
+
+async def _generate_with_pexels(genre: str, mood: str, track_title: str,
+                                  out_path: str, keyword_override: str = "") -> bool:
+    """Pexels 이미지 검색·다운로드. 성공 시 True. API key 없거나 0 결과면 False."""
+    api_key = _get_pexels_key()
+    if not api_key:
+        return False
+    keyword = keyword_override or f"{genre} aesthetic background"
+    try:
+        async with httpx.AsyncClient(timeout=PEXELS_IMG_TIMEOUT_S) as client:
+            resp = await client.get(
+                "https://api.pexels.com/v1/search",
+                headers={"Authorization": api_key},
+                params={"query": keyword, "per_page": 5, "orientation": "landscape"},
+            )
+            resp.raise_for_status()
+            data = resp.json()
+            photos = data.get("photos", [])
+            if not photos:
+                return False
+            img_url = photos[0]["src"].get("large2x") or photos[0]["src"].get("original")
+            img_resp = await client.get(img_url)
+            img_resp.raise_for_status()
+            with Image.open(BytesIO(img_resp.content)) as src:
+                img = src.convert("RGB")
+            img.save(out_path, "JPEG", quality=92)
+            return True
+    except (httpx.HTTPError, httpx.TimeoutException, KeyError, ValueError, OSError) as e:
+        logger.warning("Pexels 이미지 검색 실패: %s", e)
+        return False
+
+
 async def generate(*, pipeline_id: int, genre: str, prompt_template: str,
-                   mood: str = "", track_title: str = "", feedback: str = "") -> dict:
+                   mood: str = "", track_title: str = "", feedback: str = "",
+                   image_source: str = "ai",
+                   background_keyword: str = "") -> dict:
     """커버 아트 생성. 성공 시 jpg 저장 + URL 반환. 실패 시 그라데이션 폴백.
 
+    image_source: 'ai' (DALL·E 기본) | 'pexels' (스톡 사진).
     반환: {"url": str, "used_fallback": bool, "error": str | None}
     """
     out_path = os.path.join(storage.pipeline_dir(pipeline_id), "cover.jpg")
+
+    if image_source == "pexels":
+        ok = await _generate_with_pexels(genre, mood, track_title, out_path, background_keyword)
+        if ok:
+            return {
+                "url": storage.media_url(pipeline_id, "cover.jpg"),
+                "used_fallback": False,
+                "error": None,
+            }
+        # Pexels 실패 → 그라데이션 폴백
+        make_gradient_with_title(genre, track_title, out_path)
+        return {
+            "url": storage.media_url(pipeline_id, "cover.jpg"),
+            "used_fallback": True,
+            "error": "Pexels 검색 실패 또는 API 키 없음",
+        }
+
     used_fallback = False
     error = None