"""Seedance 2.0 video generation — ByteDance Volcano Engine (BytePlus 국제 endpoint).

POST https://api.byteplus.com/seedance/v1/videos → GET /videos/{id} 폴링 → 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__)

SEEDANCE_BASE_URL = "https://api.byteplus.com/seedance/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 = 8   # Seedance는 30~120초
POLL_MAX_ATTEMPTS = 60

DEFAULT_MODEL = "seedance-2.0"


def _headers() -> dict:
    api_key = os.getenv("SEEDANCE_API_KEY", "")
    return {
        "Authorization": f"Bearer {api_key}",
        "Content-Type": "application/json",
    }


def run_seedance_generation(task_id: str, params: dict) -> None:
    """Seedance로 영상 생성 → mp4 → NAS SMB → webhook."""
    try:
        if not os.getenv("SEEDANCE_API_KEY"):
            webhook_update_task(task_id, "failed", 0, "", error="SEEDANCE_API_KEY 미설정")
            return

        webhook_update_task(task_id, "processing", 5, "Seedance API 호출 중...")

        body = {
            "model": params.get("model") or DEFAULT_MODEL,
            "prompt": params["prompt"][:2000],
            "resolution": params.get("resolution", "1080p"),
            "duration": params.get("duration", 5),
            "aspect_ratio": params.get("aspect_ratio", "16:9"),
        }
        if params.get("negative_prompt"):
            body["negative_prompt"] = params["negative_prompt"]
        if params.get("image_url"):
            body["references"] = [{"type": "image", "data": params["image_url"], "role": "subject"}]
        if params.get("audio") is not None:
            body["audio"] = bool(params["audio"])
        if params.get("seed") is not None:
            body["seed"] = int(params["seed"])

        resp = requests.post(f"{SEEDANCE_BASE_URL}/videos", headers=_headers(), json=body, timeout=30)
        if resp.status_code not in (200, 201):
            webhook_update_task(task_id, "failed", 0, "",
                                error=f"Seedance API 오류: {resp.status_code} {resp.text[:300]}")
            return

        body_json = resp.json()
        job_id = body_json.get("id", "")
        if not job_id:
            webhook_update_task(task_id, "failed", 0, "", error="Seedance 응답에 id 없음")
            return

        webhook_update_task(task_id, "processing", 15, "Seedance 작업 등록됨")

        # 폴링
        video_url = None
        for attempt in range(POLL_MAX_ATTEMPTS):
            time.sleep(POLL_INTERVAL)
            fetch = requests.get(f"{SEEDANCE_BASE_URL}/videos/{job_id}",
                                 headers=_headers(), timeout=30)
            if fetch.status_code != 200:
                continue
            fd = fetch.json()
            status = fd.get("status", "")
            scaled = min(15 + int((attempt / POLL_MAX_ATTEMPTS) * 65), 79)
            webhook_update_task(task_id, "processing", scaled, f"Seedance 생성 중... ({status})")

            if status == "completed":
                video_url = (fd.get("output") or {}).get("video_url", "")
                break
            elif status == "failed":
                err = fd.get("error") or "Seedance 작업 실패"
                webhook_update_task(task_id, "failed", 0, "", error=str(err)[:300])
                return
        else:
            webhook_update_task(task_id, "failed", 0, "", error="Seedance 폴링 timeout (10분)")
            return

        if not video_url:
            webhook_update_task(task_id, "failed", 0, "", error="Seedance 완료했으나 video_url 없음")
            return

        webhook_update_task(task_id, "processing", 85, "Seedance 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, "Seedance 생성 완료", video_url=local_url)

    except requests.Timeout:
        webhook_update_task(task_id, "failed", 0, "", error="Seedance API 타임아웃")
    except Exception as e:
        logger.exception("Seedance generation error task=%s", task_id)
        webhook_update_task(task_id, "failed", 0, "", error=str(e))