"""FFmpeg raw BGRA subprocess pipe encoder producing H.264 High + AAC faststart MP4."""

from __future__ import annotations

import subprocess
from collections.abc import Generator
from pathlib import Path


def encode_silent_mp4(
    frame_generator: Generator[bytes, None, None],
    out_path: Path,
    width: int = 1080,
    height: int = 1920,
    fps: int = 60,
) -> None:
    """Stream raw BGRA frames directly into FFmpeg stdin to produce a silent H.264 MP4."""
    out_path.parent.mkdir(parents=True, exist_ok=True)

    cmd = [
        "ffmpeg",
        "-y",
        "-loglevel",
        "error",
        "-f",
        "rawvideo",
        "-vcodec",
        "rawvideo",
        "-s",
        f"{width}x{height}",
        "-pix_fmt",
        "bgra",
        "-r",
        str(fps),
        "-i",
        "pipe:0",
        "-c:v",
        "libx264",
        "-profile:v",
        "high",
        "-pix_fmt",
        "yuv420p",
        "-preset",
        "fast",
        "-crf",
        "18",
        "-movflags",
        "+faststart",
        str(out_path),
    ]

    log_path = out_path.with_suffix(".ffmpeg.log")
    with open(log_path, "wb") as log_file:
        proc = subprocess.Popen(
            cmd,
            stdin=subprocess.PIPE,
            stdout=subprocess.DEVNULL,
            stderr=log_file,
        )

        try:
            assert proc.stdin is not None
            for frame_bytes in frame_generator:
                proc.stdin.write(frame_bytes)
            proc.stdin.flush()
            proc.stdin.close()
            proc.wait()

            if proc.returncode != 0:
                err_msg = log_path.read_text(errors="replace")
                raise RuntimeError(f"FFmpeg encoding failed with code {proc.returncode}:\n{err_msg}")
        except Exception:
            proc.kill()
            raise
        finally:
            if log_path.exists() and proc.returncode == 0:
                log_path.unlink(missing_ok=True)


def encode_full_mp4(
    frame_generator: Generator[bytes, None, None],
    wav_path: Path,
    out_path: Path,
    width: int = 1080,
    height: int = 1920,
    fps: int = 60,
) -> None:
    """Stream raw BGRA frames directly into FFmpeg stdin and mux with audio to produce final MP4."""
    out_path.parent.mkdir(parents=True, exist_ok=True)

    cmd = [
        "ffmpeg",
        "-y",
        "-loglevel",
        "error",
        "-f",
        "rawvideo",
        "-vcodec",
        "rawvideo",
        "-s",
        f"{width}x{height}",
        "-pix_fmt",
        "bgra",
        "-r",
        str(fps),
        "-i",
        "pipe:0",
        "-i",
        str(wav_path),
        "-c:v",
        "libx264",
        "-profile:v",
        "high",
        "-pix_fmt",
        "yuv420p",
        "-preset",
        "fast",
        "-crf",
        "18",
        "-c:a",
        "aac",
        "-b:a",
        "192k",
        "-shortest",
        "-movflags",
        "+faststart",
        str(out_path),
    ]

    log_path = out_path.with_suffix(".ffmpeg.log")
    with open(log_path, "wb") as log_file:
        proc = subprocess.Popen(
            cmd,
            stdin=subprocess.PIPE,
            stdout=subprocess.DEVNULL,
            stderr=log_file,
        )

        try:
            assert proc.stdin is not None
            for frame_bytes in frame_generator:
                proc.stdin.write(frame_bytes)
            proc.stdin.flush()
            proc.stdin.close()
            proc.wait()

            if proc.returncode != 0:
                err_msg = log_path.read_text(errors="replace")
                raise RuntimeError(f"FFmpeg AV encoding failed with code {proc.returncode}:\n{err_msg}")
        except Exception:
            proc.kill()
            raise
        finally:
            if log_path.exists() and proc.returncode == 0:
                log_path.unlink(missing_ok=True)