"""Manually set C000025.IPI back to NULL for one test product, to simulate ERP
drift for the incremental auto-apply test. Guarded the same way as any other
write here (path + allowlist + schema), executed once, by hand, outside the
normal Agent flow — this is test-fixture setup, not something the Agent does.
"""
import importlib.util
import json
import os
import sys
from pathlib import Path

ROOT = Path(__file__).resolve().parent.parent


def load_dotenv(path):
    for line in path.read_text(encoding="utf-8").splitlines():
        line = line.strip()
        if not line or line.startswith("#") or "=" not in line:
            continue
        key, _, value = line.partition("=")
        os.environ[key.strip()] = value.strip()


def load_executor():
    spec = importlib.util.spec_from_file_location("firebird_write_executor", ROOT / "scripts" / "firebird_write_executor.py")
    module = importlib.util.module_from_spec(spec)
    sys.modules[spec.name] = module
    spec.loader.exec_module(module)
    return module


def main():
    code = sys.argv[1] if len(sys.argv) > 1 else "000026"
    load_dotenv(ROOT / ".env")
    executor = load_executor()
    database_path = os.environ["FIREBIRD_DATABASE_PATH"]
    executor.assert_authorized_write_path(database_path)
    executor.assert_allowed_field("C000025", "IPI")

    import fdb
    conn = fdb.connect(
        database=database_path,
        user=os.environ["FB_USER"],
        password=os.environ["FB_PASSWORD"],
        fb_library_name=os.environ.get("FIREBIRD_CLIENT_LIBRARY"),
    )
    try:
        cur = conn.cursor()
        executor.assert_schema_ok(cur, "C000025", "IPI", None)
        cur.execute("SELECT IPI FROM C000025 WHERE CODIGO = ?", (code,))
        row = cur.fetchone()
        before = row[0] if row else None
        cur.execute("UPDATE C000025 SET IPI = NULL WHERE CODIGO = ? AND IPI = ?", (code, before))
        rowcount = cur.rowcount
        if rowcount != 1:
            conn.rollback()
            raise SystemExit(f"expected rowcount 1, got {rowcount}")
        conn.commit()
        cur.execute("SELECT IPI FROM C000025 WHERE CODIGO = ?", (code,))
        after = cur.fetchone()[0]
        print(json.dumps({"product_code": code, "before": before, "after": after, "rowcount": rowcount}, indent=2))
    finally:
        conn.close()


if __name__ == "__main__":
    main()