from pathlib import Path

backend = Path(r'C:\kefu\wechat_rpa\admin_backend.py')
source = backend.read_text(encoding='utf-8')
anchor = '''        with self.connect() as db:
            db.execute("BEGIN")
            before = db.total_changes
'''
replacement = '''        with self.connect() as db:
            # Metering must not hold up an otherwise completed model reply.
            # Keep the normal 10s busy timeout for all other application writes.
            db.execute("PRAGMA busy_timeout = 250")
            db.execute("BEGIN")
            before = db.total_changes
'''
assert source.count(anchor) == 1
backend.write_text(source.replace(anchor, replacement, 1), encoding='utf-8', newline='')

tests = Path(r'C:\kefu\wechat_rpa\test_model_usage_ledger.py')
source = tests.read_text(encoding='utf-8').replace('import tempfile\n', 'import tempfile\nimport time\n', 1)
anchor = '    def test_invalid_metadata_and_noninteger_tokens_are_rejected(self):'
addition = '''    def test_usage_write_lock_has_short_budget_without_changing_other_connections(self):
        record = event()
        with self.db.connect() as locker:
            self.assertEqual(locker.execute('PRAGMA busy_timeout').fetchone()[0], 10000)
            locker.execute('BEGIN IMMEDIATE')
            started = time.monotonic()
            with self.assertRaises(sqlite3.OperationalError) as raised:
                self.db.record_model_usage_batch([record])
            elapsed = time.monotonic() - started
            self.assertIn('locked', str(raised.exception))
            self.assertGreaterEqual(elapsed, .15)
            self.assertLess(elapsed, 1.5, 'metering must not inherit the normal 10s lock wait')
        self.assertTrue(self.db.record_model_usage(record))
        with self.db.connect() as other:
            self.assertEqual(other.execute('PRAGMA busy_timeout').fetchone()[0], 10000)

'''
assert source.count(anchor) == 1
tests.write_text(source.replace(anchor, addition + anchor, 1), encoding='utf-8', newline='')
print('usage transaction busy timeout limited to 250ms; real-lock regression added')