"""Digests of every image record's stored workflow and prompt graph text.

Proves the workflow storage rewrite (#249 S6) kept every text byte for byte.
Run it from this repository on the database before the rewrite (or on its
``prompts.db.pre-workflow-storage_*`` backup) and again after, then compare::

    python3 tools/workflow_text_digests.py prompts.db.pre-workflow-storage_<stamp> \\
        before.sha
    python3 tools/workflow_text_digests.py prompts.db after.sha
    diff before.sha after.sha        # prints nothing when every text is identical

Each line is ``<image id> <sha256 of workflow_data> <sha256 of prompt_metadata>``
(``-`` for none), hashing the exact stored bytes: the inline column before the
rewrite, the document read through the one accessor after it. Read-only: the
database is opened with ``mode=ro`` and nothing is written to it.
"""

import argparse
import hashlib
import os
import sqlite3
import sys
from pathlib import Path

sys.path.insert(0, str(Path(__file__).resolve().parents[1]))

from database.workflow_documents import (  # noqa: E402
    DocumentReader,
    resolve_image_row,
)


def _digest(value):
    if value is None:
        return "-"
    raw = value if isinstance(value, bytes) else value.encode("utf-8")
    return hashlib.sha256(raw).hexdigest()


def write_digests(db_path, out):
    """Write one digest line per image record of ``db_path`` to ``out``."""
    uri = Path(os.path.abspath(db_path)).as_uri() + "?mode=ro"
    conn = sqlite3.connect(uri, uri=True)
    try:
        conn.row_factory = sqlite3.Row
        conn.text_factory = bytes  # inline text exactly as stored, even undecodable
        reader = DocumentReader(conn)
        count = 0
        with open(out, "w", encoding="utf-8") as handle:
            for row in conn.execute("SELECT * FROM generated_images ORDER BY id"):
                texts = resolve_image_row(reader, row)
                handle.write(
                    f"{row['id']} {_digest(texts.get('workflow_data'))} "
                    f"{_digest(texts.get('prompt_metadata'))}\n"
                )
                count += 1
        return count
    finally:
        conn.close()


def main(argv=None):
    parser = argparse.ArgumentParser(description=__doc__.splitlines()[0])
    parser.add_argument("database", help="prompts.db or one of its backups")
    parser.add_argument("out", help="file to write the digests to")
    args = parser.parse_args(argv)
    count = write_digests(args.database, args.out)
    print(f"{count} image records")
    return 0


if __name__ == "__main__":
    sys.exit(main())