#!/usr/bin/env python3
"""Select CryoAtlas release archives, download them, and verify SHA-256."""
import argparse
import hashlib
import json
from pathlib import Path
from huggingface_hub import HfApi, hf_hub_download

REPO = 'markfaa/CryoAtlas'

def select_archives(manifest, args, entry_map=None):
    if args.part:
        parts = {f'train_part{n:02d}' for n in args.part}
        return [r for r in manifest if r['component'] in parts]
    if args.test:
        components = {'test_benchmark_618', 'test_remaining_534'} if args.test == 'all' else {
            'test_benchmark_618' if args.test == 'benchmark' else 'test_remaining_534'}
        return [r for r in manifest if r['component'] in components]
    if args.resources:
        return [r for r in manifest if r['component'] == 'benchmark_resources']
    emd = args.emd.upper()
    if not emd.startswith('EMD-'):
        emd = 'EMD-' + emd
    if emd not in entry_map:
        raise ValueError(f'{emd} is not in the fixed v1.0 release.')
    return [r for r in manifest if r['path'] == entry_map[emd]]

def main():
    parser = argparse.ArgumentParser(description=__doc__)
    group = parser.add_mutually_exclusive_group(required=True)
    group.add_argument('--part', type=int, choices=(1, 2, 3, 4), nargs='+')
    group.add_argument('--test', choices=('benchmark', 'remaining', 'all'))
    group.add_argument('--resources', action='store_true')
    group.add_argument('--emd', help='Find and download the complete archive containing this EMD ID.')
    parser.add_argument('--destination', type=Path, default=Path('CryoAtlas-downloads'))
    parser.add_argument('--revision', default='main')
    parser.add_argument('--dry-run', action='store_true', help='Show selected archives and sizes without downloading them.')
    args = parser.parse_args()
    # Pin all reads and downloads to one repository revision.
    revision = HfApi().dataset_info(REPO, revision=args.revision).sha
    def read_json(name):
        return json.loads(Path(hf_hub_download(REPO, name, repo_type='dataset', revision=revision)).read_text())
    manifest = read_json('resources/metadata/catalog/archives.json')
    entry_map = read_json('resources/metadata/catalog/entry_archives.json') if args.emd else None
    try:
        selected = select_archives(manifest, args, entry_map)
    except ValueError as exc:
        parser.error(str(exc))
    if not selected:
        parser.error('No matching archives.')
    print(f'Revision: {revision}')
    for row in selected:
        print(f"{row['bytes']/1e9:8.3f} GB  {row['path']}")
    print(f"Total: {sum(r['bytes'] for r in selected)/1e9:.3f} GB")
    if args.emd:
        print('Selection is an entire archive containing this entry, not an individual-entry download.')
    if args.dry_run:
        return
    for row in selected:
        path = Path(hf_hub_download(REPO, row['path'], repo_type='dataset', revision=revision, local_dir=args.destination))
        if path.stat().st_size != row['bytes']:
            raise RuntimeError(f'Size mismatch: {row["path"]}')
        sha = hashlib.sha256()
        with path.open('rb') as stream:
            for block in iter(lambda: stream.read(8 * 1024 * 1024), b''):
                sha.update(block)
        if sha.hexdigest() != row['sha256']:
            raise RuntimeError(f'SHA-256 mismatch: {row["path"]}')
        print(f'Verified: {row["path"]}')

if __name__ == '__main__':
    main()