import hashlib
from pathlib import Path
import sqlite3
import tempfile
import unittest
from sqlite_readonly import inspect_readonly


class PreOpenSchemaGate(unittest.TestCase):
    def test_old_and_unknown_schemas_refuse_without_mutation(self):
        with tempfile.TemporaryDirectory() as folder:
            for version in (0, 1, 2, 3, 4, 6):
                db = Path(folder) / (str(version) + '.sqlite')
                with sqlite3.connect(db) as connection:
                    connection.execute('PRAGMA user_version=' + str(version))
                before = hashlib.sha256(db.read_bytes()).hexdigest()
                with self.assertRaises(ValueError):
                    inspect_readonly(db)
                self.assertEqual(hashlib.sha256(db.read_bytes()).hexdigest(), before)
                with sqlite3.connect(db) as connection:
                    self.assertEqual(connection.execute('PRAGMA user_version').fetchone()[0], version)

    def test_schema5_frozen_snapshot_counts_and_integrity(self):
        with tempfile.TemporaryDirectory() as folder:
            db = Path(folder) / 'snapshot.sqlite'
            with sqlite3.connect(db) as connection:
                connection.executescript('PRAGMA user_version=5; CREATE TABLE lifecycle_records(x); CREATE TABLE lifecycle_events(x); CREATE TABLE lifecycle_pending(x); CREATE TABLE outbox(state); CREATE TABLE submissions(state); INSERT INTO lifecycle_records VALUES(1); INSERT INTO outbox VALUES("pending"); INSERT INTO submissions VALUES("confirmed");')
            before = hashlib.sha256(db.read_bytes()).hexdigest()
            proof = inspect_readonly(db)
            self.assertEqual(proof['schema_version'], 5)
            self.assertEqual(proof['lifecycle']['records'], 1)
            self.assertEqual(proof['outbox'], {'pending': 1})
            self.assertEqual(proof['submissions'], {'confirmed': 1})
            self.assertEqual(proof['integrity'], 'ok')
            self.assertFalse(proof['store_constructed'])
            self.assertEqual(hashlib.sha256(db.read_bytes()).hexdigest(), before)

    def test_missing_database_is_not_created(self):
        with tempfile.TemporaryDirectory() as folder:
            missing = Path(folder) / 'missing.sqlite'
            with self.assertRaises(ValueError):
                inspect_readonly(missing)
            self.assertFalse(missing.exists())


if __name__ == '__main__':
    unittest.main()