"""自由创作·上传素材探测(移植自 jimeng-clone utils/media_utils.py)。

ffprobe 取视频/音频时长、ffmpeg 抽视频首帧缩略图。生产镜像已带 ffmpeg
(_generate_video_poster 在用)。全部 best-effort:探测失败返回 None,由调用方决定拒绝或放行。
"""
import subprocess
import tempfile
from pathlib import Path


# 参考视频/音频对外仍写「2-15 秒」。15 秒成片常被探测成 15.01–15.04（帧率取整 / AAC 对齐），给半秒容差。
REF_DURATION_MIN = 1.95
REF_DURATION_MAX = 15.5


def duration_in_ref_range(seconds: float) -> bool:
    return REF_DURATION_MIN <= seconds <= REF_DURATION_MAX


def probe_duration(file_path: str) -> float | None:
    """ffprobe 取媒体时长(秒)。失败返回 None。"""
    try:
        proc = subprocess.run(
            [
                "ffprobe", "-v", "error",
                "-show_entries", "format=duration",
                "-of", "default=noprint_wrappers=1:nokey=1",
                str(file_path),
            ],
            capture_output=True,
            timeout=30,
        )
        if proc.returncode != 0:
            return None
        return float(proc.stdout.decode().strip())
    except Exception:  # noqa: BLE001
        return None


def extract_video_poster(file_path: str) -> bytes | None:
    """ffmpeg 抽视频首帧 jpg 字节。失败返回 None。"""
    try:
        with tempfile.TemporaryDirectory(prefix="airshelf-freeprobe-") as tmp:
            poster_path = Path(tmp) / "poster.jpg"
            proc = subprocess.run(
                ["ffmpeg", "-y", "-ss", "0", "-i", str(file_path), "-frames:v", "1", "-q:v", "3", str(poster_path)],
                capture_output=True,
                timeout=60,
            )
            if proc.returncode != 0 or not poster_path.exists():
                return None
            data = poster_path.read_bytes()
            return data or None
    except Exception:  # noqa: BLE001
        return None