"""Link only files referenced by the selected training manifest into the data package."""
import argparse
import json
from pathlib import Path

DATA_ROOT = Path(__file__).resolve().parents[1]
PREFIX = 'data/source/seamless_interaction/'
FIELDS = ('pose_file', 'audio_file', 'audio_file_listen', 'word_file', 'flame_file')


def link_training_data(manifest, dataset_root, data_root, flame_root=None):
    dataset_root, data_root = Path(dataset_root).resolve(), Path(data_root).resolve()
    rows = json.loads(Path(manifest).read_text())['data']
    sources = {}
    for row in rows:
        for field in FIELDS:
            path = row[field]
            assert path.startswith(PREFIX), f'Unexpected {field} path: {path}'
            name = Path(path[len(PREFIX):])
            assert not name.is_absolute() and '..' not in name.parts, name
            source = (Path(flame_root).resolve() / name.name
                      if field == 'flame_file' and flame_root else dataset_root / name)
            assert name not in sources or sources[name] == source, name
            sources[name] = source
    for source in sources.values():
        assert source.is_file(), source
    for name, source in sorted(sources.items()):
        destination = data_root / 'source/seamless_interaction' / name
        if destination.is_symlink():
            assert destination.resolve() == source.resolve(), destination
        else:
            assert not destination.exists(), destination
            destination.parent.mkdir(parents=True, exist_ok=True)
            destination.symlink_to(source)
    return len(sources)


def main():
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('--input', default=str(DATA_ROOT / 'manifests/train_selected81.json'))
    parser.add_argument('--dataset-root', required=True, help='Downloaded Seamless Interaction root')
    parser.add_argument('--flame-root', help='Directory of freshly extracted <pose_stem>_flame.npz labels')
    parser.add_argument('--data-root', default=str(DATA_ROOT), help='Data package receiving source links')
    args = parser.parse_args()
    count = link_training_data(args.input, args.dataset_root, args.data_root, args.flame_root)
    print(f'Linked {count} unique training files under {Path(args.data_root) / "source/seamless_interaction"}')


if __name__ == '__main__':
    main()