"""Clip extraction service using FFmpeg."""

import asyncio
import logging
import os

from app.config import settings

logger = logging.getLogger(__name__)


async def extract_clip(
    video_path: str,
    start_time: float,
    end_time: float,
    output_path: str,
) -> str:
    """Extract a clip from video using FFmpeg stream copy (instant, no re-encode).

    Args:
        video_path: path to source video
        start_time: clip start in seconds
        end_time: clip end in seconds
        output_path: where to write the clip

    Returns:
        output_path
    """
    os.makedirs(os.path.dirname(output_path), exist_ok=True)

    duration = end_time - start_time

    # Use stream copy for speed - seek before input for accuracy
    cmd = [
        "ffmpeg",
        "-ss", str(start_time),
        "-i", video_path,
        "-t", str(duration),
        "-c", "copy",
        "-avoid_negative_ts", "make_zero",
        "-y",
        output_path,
    ]

    logger.info(
        f"Extracting clip: {start_time:.1f}s - {end_time:.1f}s -> {output_path}"
    )

    proc = await asyncio.create_subprocess_exec(
        *cmd,
        stdout=asyncio.subprocess.PIPE,
        stderr=asyncio.subprocess.PIPE,
    )
    _, stderr = await proc.communicate()

    if proc.returncode != 0:
        raise RuntimeError(f"FFmpeg clip extraction failed: {stderr.decode()}")

    size_mb = os.path.getsize(output_path) / (1024 * 1024)
    logger.info(f"Extracted clip: {output_path} ({size_mb:.1f} MB)")
    return output_path


async def extract_thumbnail(
    video_path: str,
    timestamp: float,
    output_path: str,
) -> str:
    """Extract a single frame as thumbnail."""
    os.makedirs(os.path.dirname(output_path), exist_ok=True)

    cmd = [
        "ffmpeg",
        "-ss", str(timestamp),
        "-i", video_path,
        "-vframes", "1",
        "-q:v", "2",
        "-y",
        output_path,
    ]

    proc = await asyncio.create_subprocess_exec(
        *cmd,
        stdout=asyncio.subprocess.PIPE,
        stderr=asyncio.subprocess.PIPE,
    )
    _, stderr = await proc.communicate()

    if proc.returncode != 0:
        raise RuntimeError(f"FFmpeg thumbnail extraction failed: {stderr.decode()}")

    return output_path


async def get_video_duration(video_path: str) -> float:
    """Get video duration in seconds using ffprobe."""
    cmd = [
        "ffprobe",
        "-v", "quiet",
        "-print_format", "json",
        "-show_format",
        video_path,
    ]

    proc = await asyncio.create_subprocess_exec(
        *cmd,
        stdout=asyncio.subprocess.PIPE,
        stderr=asyncio.subprocess.PIPE,
    )
    stdout, _ = await proc.communicate()

    if proc.returncode != 0:
        return 0.0

    import json
    data = json.loads(stdout.decode())
    return float(data.get("format", {}).get("duration", 0))