"""Writes provenance.json from make_external.sh's logs: every external vector with its
digest, encoder, input and command, and every decode of it with its output's size and
digest. Where several decoders or code paths decode one JPEG XS codestream, it records
whether their outputs are byte-identical.

    python3 -I provenance.py <encodes.jsonl> <decodes.jsonl>
"""

import hashlib
import json
import os
import sys


def main(enc_log, dec_log):
    here = os.path.join(os.path.dirname(os.path.abspath(__file__)), "..", "ext")
    vectors = []
    for line in open(enc_log):
        e = json.loads(line)
        b = open(os.path.join(here, e["file"]), "rb").read()
        e["bytes"] = len(b)
        e["sha256"] = hashlib.sha256(b).hexdigest()
        e["decodes"] = []
        vectors.append(e)
    by_file = {}
    for line in open(dec_log):
        d = json.loads(line)
        by_file.setdefault(d["file"], []).append(d)
    for e in vectors:
        e["decodes"] = [{k: d[k] for k in ("decoder", "bytes", "sha256")} for d in by_file.get(e["file"], [])]
    agreement = []
    for f, ds in sorted(by_file.items()):
        js = [d for d in ds if d["decoder"].startswith("jxs") or d["decoder"] == "source"]
        if len(js) > 1:
            agreement.append({
                "codestream": f,
                "outputs": {d["decoder"]: d["sha256"] for d in js},
                "identical": len({d["sha256"] for d in js}) == 1,
            })
    out = {
        "note": "Written by tools/make_external.sh; each encoder and decoder key is defined, with its repository, revision and licence, in that script's header.",
        "vectors": vectors,
        "jpeg_xs_decodes": agreement,
    }
    json.dump(out, sys.stdout, indent=1, sort_keys=True)
    sys.stdout.write("\n")


if __name__ == "__main__":
    main(*sys.argv[1:])