#!/usr/bin/env python3
"""Download the design sources referenced by this dataset from their upstream repositories
and verify them against the recorded SHA-256. No design source is redistributed here; every
design remains under the licence of its upstream repository.

    python3 scripts/fetch_sources.py corpus/test.jsonl compositional/designs.jsonl --out sources/

Each record's `source` gives the repository, the commit the dataset was built from (when known),
the path inside the repository and the SHA-256 of the file. The script downloads each repository
archive at that commit (or the default branch when no commit is recorded), extracts the referenced
files, and writes sources/<sha256>.v for every file whose content matches. Records without a
`source` field are ignored. Files are decoded as UTF-8 (undecodable bytes dropped), as when the
dataset was built, and the checksum is computed on that text. Paths that lie inside git
submodules of their repository are not part of the archive and are reported as not found."""
import argparse, collections, hashlib, json, os, sys, tarfile, tempfile, urllib.request
ap = argparse.ArgumentParser(); ap.add_argument("files", nargs="+"); ap.add_argument("--out", default="sources")
a = ap.parse_args(); os.makedirs(a.out, exist_ok=True)
need = collections.defaultdict(dict)
for fn in a.files:
    for line in open(fn):
        if not line.strip():
            continue
        s = json.loads(line).get("source")
        if s and (s.get("repository") or "").startswith("https://github.com/"):
            need[(s["repository"], s.get("commit") or "HEAD")][s["path"]] = s["sha256"]
ok = changed = missing = failed = 0
for (repo, ref), files in sorted(need.items()):
    owner_repo = repo.split("github.com/")[1]
    print(f"{owner_repo}@{ref[:10]}: {len(files)} files", file=sys.stderr)
    with tempfile.NamedTemporaryFile(suffix=".tar.gz") as tmp:
        try:
            with urllib.request.urlopen(f"https://codeload.github.com/{owner_repo}/tar.gz/{ref}", timeout=300) as r:
                while True:
                    chunk = r.read(1 << 20)
                    if not chunk: break
                    tmp.write(chunk)
        except OSError as e:          # repository renamed, removed or unreachable
            print(f"  could not download {owner_repo}@{ref[:10]}: {e}", file=sys.stderr)
            failed += 1; missing += len(files); continue
        tmp.flush()
        found = set()
        try:
            with tarfile.open(tmp.name, mode="r:gz") as t:
                for m in t:
                    rel = m.name.split("/", 1)[1] if "/" in m.name else ""
                    if m.isfile() and rel in files:
                        text = t.extractfile(m).read().decode("utf-8", errors="ignore")
                        h = hashlib.sha256(text.encode()).hexdigest(); found.add(rel)
                        if h == files[rel]:
                            with open(os.path.join(a.out, h + ".v"), "w", encoding="utf-8", newline="") as o: o.write(text)
                            ok += 1
                        else:
                            changed += 1
        except (tarfile.TarError, EOFError, OSError) as e:      # truncated or unreadable archive
            print(f"  could not read the archive of {owner_repo}: {e}", file=sys.stderr)
            failed += 1
        missing += len(set(files) - found)
print(f"verified {ok} files; {changed} differ from the recorded checksum; {missing} not found"
      f" ({failed} repositories could not be downloaded)", file=sys.stderr)
sys.exit(1 if failed or missing or changed else 0)