"""
TranscodeHandler — executes transcode/trim jobs using FFmpeg.

Extracted from the old tasks.py Celery task logic.
"""

import logging
import os
import tempfile
from pathlib import Path
from typing import Any, Callable, Dict, Optional

from core.ffmpeg.transcode import TranscodeConfig, transcode
from core.storage import BUCKET_IN, BUCKET_OUT, download_to_temp, upload_file

from .base import Handler

logger = logging.getLogger(__name__)


class TranscodeHandler(Handler):
    """Handle transcode and trim jobs via FFmpeg."""

    def process(
        self,
        job_id: str,
        payload: Dict[str, Any],
        progress_callback: Optional[Callable[[int, Dict[str, Any]], None]] = None,
    ) -> Dict[str, Any]:
        source_key = payload["source_key"]
        output_key = payload["output_key"]
        preset = payload.get("preset")
        trim_start = payload.get("trim_start")
        trim_end = payload.get("trim_end")
        duration = payload.get("duration")

        logger.info(f"TranscodeHandler: {source_key} -> {output_key}")

        # Download source
        tmp_source = download_to_temp(BUCKET_IN, source_key)

        ext = Path(output_key).suffix or ".mp4"
        fd, tmp_output = tempfile.mkstemp(suffix=ext)
        os.close(fd)

        try:
            if preset:
                config = TranscodeConfig(
                    input_path=tmp_source,
                    output_path=tmp_output,
                    video_codec=preset.get("video_codec", "libx264"),
                    video_bitrate=preset.get("video_bitrate"),
                    video_crf=preset.get("video_crf"),
                    video_preset=preset.get("video_preset"),
                    resolution=preset.get("resolution"),
                    framerate=preset.get("framerate"),
                    audio_codec=preset.get("audio_codec", "aac"),
                    audio_bitrate=preset.get("audio_bitrate"),
                    audio_channels=preset.get("audio_channels"),
                    audio_samplerate=preset.get("audio_samplerate"),
                    container=preset.get("container", "mp4"),
                    extra_args=preset.get("extra_args", []),
                    trim_start=trim_start,
                    trim_end=trim_end,
                )
            else:
                config = TranscodeConfig(
                    input_path=tmp_source,
                    output_path=tmp_output,
                    video_codec="copy",
                    audio_codec="copy",
                    trim_start=trim_start,
                    trim_end=trim_end,
                )

            def wrapped_callback(percent: float, details: Dict[str, Any]) -> None:
                if progress_callback:
                    progress_callback(int(percent), details)

            success = transcode(
                config,
                duration=duration,
                progress_callback=wrapped_callback if progress_callback else None,
            )

            if not success:
                raise RuntimeError("Transcode returned False")

            # Upload result
            logger.info(f"Uploading {output_key} to {BUCKET_OUT}")
            upload_file(tmp_output, BUCKET_OUT, output_key)

            return {
                "status": "completed",
                "job_id": job_id,
                "output_key": output_key,
            }

        finally:
            for f in [tmp_source, tmp_output]:
                try:
                    os.unlink(f)
                except OSError:
                    pass