import os
import sys
import subprocess

from utils.mediainfo import get_framerate

MAX_INPUT_WIDTH  = '720'

def _re_encode(
    source_video: str, 
    temp_out_video: str,
    input_aspect: str = "16:9"
):
    """
    Re-Encodes the source video to avoid nasty video bugs
    
    :param source_video: Video Input
    :type source_video: str
    :param input_aspect: Aspect Ratio of Video
    :type input_aspect: str
    """

    fps = get_framerate(source_video)

    vf_filter = f"fps={fps},scale=-1:min({MAX_INPUT_WIDTH}\\,ih)"

    cmd = [
        "ffmpeg", "-v", "quiet", "-stats",
        "-i", source_video,
        "-c:v", "ffv1",
        "-level", "3",
        "-vf", vf_filter,
        "-aspect", input_aspect,
        "-pix_fmt", "yuv420p",
        "-color_primaries", "1",
        "-color_trc", "1",
        "-colorspace", "1",
        "-an",
        "-sn",
        "-map_metadata", "-1",
        temp_out_video
    ]

    try:
        subprocess.run(cmd, check=True)
    except subprocess.CalledProcessError as e:
        print(f"\nffmpeg failed with error code {e.returncode} at _re_encode()", file=sys.stderr)
        sys.exit(e.returncode)

def _upscale(
    upscale_output: str,
    input_aspect: str = "16:9"
):
    print('Started Upscale')

    vapoursynth_script = os.path.join('utils', 'vs-realesrgan.vpy')

    try:
        # First process (vspipe)
        vspipe = subprocess.Popen(
            [
                "vspipe",
                "-c", "y4m",
                vapoursynth_script,
                "-"
            ],
            stdout=subprocess.PIPE
        )

        # Second process (ffmpeg), reading from vspipe
        ffmpeg = subprocess.Popen(
            [
                "ffmpeg",
                "-v", "quiet", "-stats",
                "-f", "yuv4mpegpipe",
                "-i", "-",
                "-c:v", "hevc_nvenc",
                "-qp", "5",
                "-aspect", input_aspect,
                upscale_output
            ],
            stdin=vspipe.stdout
        )

        # Important: allow vspipe to receive SIGPIPE if ffmpeg exits
        vspipe.stdout.close()

        ffmpeg.wait()
        vspipe.wait()

        if ffmpeg.returncode != 0:
            raise subprocess.CalledProcessError(ffmpeg.returncode, "ffmpeg")

    except subprocess.CalledProcessError as e:
        print(f"\nffmpeg failed with error code {e.returncode}", file=sys.stderr)
        sys.exit(e.returncode)


def upscale(
    source_video: str, 
    upscaled_video_output: str, 
    input_aspect: str,
):
    if os.path.exists(upscaled_video_output):
        print('Skipped Upscale')
        return
    
    temp_out_video = os.path.join('1-Temp', 'source.mkv')

    _re_encode(source_video, temp_out_video, input_aspect)
    _upscale(upscaled_video_output, input_aspect)
    
    # Remove Temp Files
    os.remove(temp_out_video)
    os.remove(f'{temp_out_video}.ffindex')