"""Read-only structural fingerprints; no credentials or row contents in the report."""
import hashlib
import json
import sys
from pathlib import Path

from sqlalchemy import create_engine, text

sys.path.insert(0, str(Path(__file__).resolve().parents[1]))
from app.core.config import get_settings


def fingerprint():
    engine = create_engine(get_settings().mysql_dsn.replace("mysql+asyncmy", "mysql+pymysql"))
    result = {}
    with engine.connect() as connection:
        names = connection.execute(text("""
            SELECT TABLE_NAME FROM information_schema.TABLES WHERE TABLE_SCHEMA=DATABASE()
        """)).scalars().all()
        for name in sorted(names):
            if name == "alembic_version":
                continue
            columns = connection.execute(text("""
                SELECT COLUMN_NAME,COLUMN_TYPE,IS_NULLABLE,COLUMN_DEFAULT,EXTRA,
                       CHARACTER_SET_NAME,COLLATION_NAME,GENERATION_EXPRESSION
                FROM information_schema.COLUMNS
                WHERE TABLE_SCHEMA=DATABASE() AND TABLE_NAME=:name ORDER BY ORDINAL_POSITION
            """), {"name": name}).all()
            canonical = json.dumps([list(row) for row in columns], ensure_ascii=False, default=str)
            result[name] = hashlib.sha256(canonical.encode()).hexdigest()
    engine.dispose()
    return result


if __name__ == "__main__":
    print(json.dumps(fingerprint(), indent=2, ensure_ascii=False))