feat(video-render): providers/kling.py — Kling AI via PiAPI gateway (SP-7)

POST /api/v1/task (model=kling, task_type=video_generation) →
GET /api/v1/task/{id} 폴링 (10초 × 60) → data.output.video_url 다운로드.
x-api-key 헤더. version 1.5/1.6/2.1/2.5/2.6 지원.
Plan-B-Video Phase 2.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

services/video-render/providers/kling.py

@@ -0,0 +1,133 @@
+"""Kling AI video generation — PiAPI gateway 경유.
+
+POST https://api.piapi.ai/api/v1/task → GET /api/v1/task/{id} 폴링 → data.output.video_url 다운로드.
+"""
+from __future__ import annotations
+
+import logging
+import os
+import time
+from typing import Optional
+
+import requests
+
+from nas_client import webhook_update_task
+
+logger = logging.getLogger(__name__)
+
+PIAPI_BASE_URL = "https://api.piapi.ai/api/v1"
+VIDEO_MEDIA_ROOT = os.getenv("VIDEO_MEDIA_ROOT", "/mnt/nas/webpage/data/video")
+VIDEO_MEDIA_URL_PREFIX = os.getenv("VIDEO_MEDIA_URL_PREFIX", "/media/video")
+
+POLL_INTERVAL = 10   # Kling은 30~180초
+POLL_MAX_ATTEMPTS = 60   # 최대 10분
+
+DEFAULT_VERSION = "2.6"
+
+
+def _headers() -> dict:
+    api_key = os.getenv("PIAPI_API_KEY", "")
+    return {
+        "x-api-key": api_key,
+        "Content-Type": "application/json",
+    }
+
+
+def run_kling_generation(task_id: str, params: dict) -> None:
+    """Kling으로 영상 생성 → mp4 → NAS SMB → webhook."""
+    try:
+        if not os.getenv("PIAPI_API_KEY"):
+            webhook_update_task(task_id, "failed", 0, "", error="PIAPI_API_KEY 미설정")
+            return
+
+        webhook_update_task(task_id, "processing", 5, "Kling API 호출 중...")
+
+        input_obj = {
+            "prompt": params["prompt"][:2500],
+            "duration": params.get("duration", 5),
+            "aspect_ratio": params.get("aspect_ratio", "16:9"),
+            "mode": params.get("mode", "std"),
+            "version": params.get("model") or DEFAULT_VERSION,
+        }
+        if params.get("negative_prompt"):
+            input_obj["negative_prompt"] = params["negative_prompt"][:2500]
+        if params.get("cfg_scale") is not None:
+            input_obj["cfg_scale"] = str(params["cfg_scale"])
+        if params.get("image_url"):
+            input_obj["image_url"] = params["image_url"]
+
+        body = {
+            "model": "kling",
+            "task_type": "video_generation",
+            "input": input_obj,
+            "config": {"service_mode": "public"},
+        }
+
+        resp = requests.post(f"{PIAPI_BASE_URL}/task", headers=_headers(), json=body, timeout=30)
+        if resp.status_code != 200:
+            webhook_update_task(task_id, "failed", 0, "",
+                                error=f"Kling/PiAPI 오류: {resp.status_code} {resp.text[:300]}")
+            return
+
+        body_json = resp.json()
+        if body_json.get("code") != 200:
+            webhook_update_task(task_id, "failed", 0, "",
+                                error=f"Kling/PiAPI 거부: {body_json.get('message', '?')}")
+            return
+
+        piapi_task_id = (body_json.get("data") or {}).get("task_id", "")
+        if not piapi_task_id:
+            webhook_update_task(task_id, "failed", 0, "", error="Kling/PiAPI 응답에 task_id 없음")
+            return
+
+        webhook_update_task(task_id, "processing", 15, "Kling 작업 등록됨")
+
+        # 폴링 — GET /task/{id}
+        video_url = None
+        for attempt in range(POLL_MAX_ATTEMPTS):
+            time.sleep(POLL_INTERVAL)
+            fetch = requests.get(f"{PIAPI_BASE_URL}/task/{piapi_task_id}",
+                                 headers=_headers(), timeout=30)
+            if fetch.status_code != 200:
+                continue
+            fd = fetch.json()
+            data = fd.get("data", {})
+            status = data.get("status", "")
+            scaled = min(15 + int((attempt / POLL_MAX_ATTEMPTS) * 65), 79)
+            webhook_update_task(task_id, "processing", scaled, f"Kling 생성 중... ({status})")
+
+            if status == "Completed":
+                video_url = (data.get("output") or {}).get("video_url", "")
+                break
+            elif status in ("Failed", "failed"):
+                err = (data.get("error") or {}).get("message", "Kling 작업 실패")
+                webhook_update_task(task_id, "failed", 0, "", error=err)
+                return
+            # Pending/Processing/Staged → 계속 폴링
+        else:
+            webhook_update_task(task_id, "failed", 0, "", error="Kling 폴링 timeout (10분)")
+            return
+
+        if not video_url:
+            webhook_update_task(task_id, "failed", 0, "", error="Kling 완료했으나 video_url 없음")
+            return
+
+        webhook_update_task(task_id, "processing", 85, "Kling 결과 다운로드 중...")
+        filename = f"{task_id}.mp4"
+        os.makedirs(VIDEO_MEDIA_ROOT, exist_ok=True)
+        file_path = os.path.join(VIDEO_MEDIA_ROOT, filename)
+
+        dl = requests.get(video_url, stream=True, timeout=300)
+        dl.raise_for_status()
+        with open(file_path, "wb") as f:
+            for chunk in dl.iter_content(chunk_size=8192):
+                f.write(chunk)
+
+        local_url = f"{VIDEO_MEDIA_URL_PREFIX}/{filename}"
+        webhook_update_task(task_id, "succeeded", 100, "Kling 생성 완료", video_url=local_url)
+
+    except requests.Timeout:
+        webhook_update_task(task_id, "failed", 0, "", error="Kling/PiAPI 타임아웃")
+    except Exception as e:
+        logger.exception("Kling generation error task=%s", task_id)
+        webhook_update_task(task_id, "failed", 0, "", error=str(e))