import argparse
import logging
import subprocess
import pathlib

from tqdm.contrib.concurrent import thread_map

logging.basicConfig(
    filename='flac2alac.log',
    filemode='a',
    format='%(asctime)s - %(levelname)s - %(message)s',
    level=logging.INFO
)

def parse_args():
    parser = argparse.ArgumentParser()
    parser.add_argument('-s', '--source', required=True)
    parser.add_argument('-d', '--destination', required=True)
    parser.add_argument('-j', '--jobs', type=int, default=1)
    return parser.parse_args()

def convert(job):
    job['dst'].parent.mkdir(exist_ok=True)
    try:
        subprocess.run([
            'ffmpeg',
            '-y',  # overwrite if exists
            '-i', str(job['src']),
            '-vn',  # no video
            '-c:a', 'alac',
            str(job['dst'])
        ], check=False, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
        logging.info(f'Converted {job["src"]}')
    except subprocess.CalledProcessError:
        logging.error(f'Failed to convert {job["src"]}')

def main():
    args = parse_args()

    src = pathlib.Path(args.source)
    dst = pathlib.Path(args.destination)
    jobs = list(map(
            lambda s: { 'src': s, 'dst': (dst / s.relative_to(src)).with_suffix('.m4a') },
            sorted(src.glob('**/*.flac'))
    ))

    thread_map(convert, jobs, max_workers=args.jobs)

if __name__ == '__main__':
    main()