import os
import sys
import subprocess

def _remux_video(
    encoded_video_input: str,
    muxed_video_output: str,
):
    # Re-Mux with MKVMerge, as FFmpeg has some kind of bug
    try:
        subprocess.run(f'mkvmerge --output "{muxed_video_output}" "{encoded_video_input}"', shell=True, check=True)
    except subprocess.CalledProcessError as e:
        print(f"\nffmpeg failed with error code {e.returncode}", file=sys.stderr)
        sys.exit(e.returncode)


def _encode_video(
    preset: dict[str, str], 
    source_video: str,
    output_video: str, 
    hentai_title: str, 
    input_aspect: str = "16:9"
):
    print(f'Encoding {preset['h']}p AV1')

    cmd = [
        "ffmpeg",
        "-i", preset['input_video'],
        "-i", source_video,
        "-map", "0:v:0", # Video from upscale or interpolated file
        "-map", "1:a:0", # Audio from source video
        "-map", "1:s:0", # Subtitle from source video
        "-map", "1:t?",  # Attachments from source video (optional)
        "-map", "1:d?",  # Other Data from source video (optional)
        "-disposition:v:0", "default", # Mark video as default in mkv container
        "-metadata", f'Title=\"{hentai_title} [hstream.moe]\"',
        "-c:v", "libsvtav1",
        "-crf", preset['crf'],
        "-preset", "4",
        "-pix_fmt", "yuv420p10le", # 10bit
        "-vf", f"scale=\'min({preset['w']},iw)\':-2,setsar=1:1",
        "-aspect", input_aspect,
        "-c:a", "libopus",
        "-b:a", "160k",
        "-c:s", "copy",
        output_video
    ]

    print(cmd)

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

def encode_downloads(
    folder_name: str,
    hentai_title: str,
    source_video: str,
    upscaled_video: str, 
    interpolated_video: str, 
    interpolated_uhd_video: str | None,
    input_aspect: str = "16:9"
):
    presets = [
        {"w": "1920", "h": "1080", "crf": "22", "name": "[1080p-AV1]",        "input_video": upscaled_video},
        {"w": "1920", "h": "1080", "crf": "22", "name": "[1080p-AV1][48fps]", "input_video": interpolated_video},
        {"w": "3840", "h": "2160", "crf": "24", "name": "[2160p-AV1]",        "input_video": upscaled_video},
    ]

    if interpolated_uhd_video is not None:
        presets.append({"w": "3840", "h": "2160", "crf": "24", "name": "[2160p-AV1][48fps]", "input_video": interpolated_uhd_video})

    for preset in presets:
        file_name = f"{hentai_title} {preset['name']}[hstream.moe].mkv"
        tmp_out = os.path.join('2-Out', folder_name, file_name)
        mux_out = os.path.join('2-Out', folder_name, 'Muxed', file_name)

        if os.path.exists(mux_out):
            print(f'Skipped {preset['h']}p AV1 Encode')
            return

        _encode_video(preset, source_video, tmp_out, hentai_title, input_aspect)
        _remux_video(tmp_out, mux_out)