import subprocess
import os

def transcode_file(socketio, file_path, codec, resolution, crf, preset, cpu_used):
    width = resolution
    output_file = file_path.replace('.mkv', '_transcoded.mkv')

    if os.path.exists(output_file):  # Проверяем существование файла
        os.remove(output_file)  # Удаляем файл
        print(f"File already exists. {output_file} was deleted.")

    command = [
        "ffmpeg", "-i", file_path,
        "-c:v", codec,
        "-vf", f"scale={width}:-1",
        "-c:a", "copy",
        "-crf", crf
    ]

    if codec == "libaom-av1":
        command.append("-cpu-used")
        command.append(cpu_used)
    elif codec == "libvpx-vp9":
        command.append("-cpu-used")
        command.append(cpu_used)
    else:
        command.append("-preset")
        command.append(preset)    

    command.append(output_file);

    print("\n");
    print(" ".join(command))

    process = subprocess.Popen(command, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, text=True)
    for line in process.stdout:
        # Parse progress from ffmpeg output and send via WebSocket
        if "frame=" in line:
            socketio.emit('progress', {"message": line.strip()})
    process.wait()

    # Step 3: Replace the original file with the transcoded file
    if process.returncode == 0:
        os.replace(output_file, file_path)
        socketio.emit('completed', {"message": f"File {file_path} transcoded successfully"})
        # Optionally delete original
    else:
        socketio.emit('error', {"message": f"Transcoding failed for {file_path}"})