"""
Tests for encrypted database extended functionality.

Tests cover:
- Thread local engine management
- SQLCipher pragma configuration
- Pool management
"""

from unittest.mock import Mock
import threading
import time


class TestThreadLocalEngineManagement:
    """Tests for thread local engine management."""

    def test_thread_local_engine_creation(self):
        """Thread local engine is created on first access."""
        thread_local = threading.local()

        if not hasattr(thread_local, "engine"):
            thread_local.engine = Mock(name="engine")

        assert hasattr(thread_local, "engine")

    def test_thread_local_engine_isolation(self):
        """Engines are isolated between threads."""
        thread_local = threading.local()
        results = {}

        def set_engine(thread_id, engine_value):
            thread_local.engine = engine_value
            time.sleep(0.01)  # Allow other thread to run
            results[thread_id] = thread_local.engine

        t1 = threading.Thread(target=set_engine, args=(1, "engine_1"))
        t2 = threading.Thread(target=set_engine, args=(2, "engine_2"))

        t1.start()
        t2.start()
        t1.join()
        t2.join()

        assert results[1] == "engine_1"
        assert results[2] == "engine_2"

    def test_thread_local_engine_reuse(self):
        """Engine is reused within same thread."""
        thread_local = threading.local()

        thread_local.engine = Mock(name="engine")
        first_access = thread_local.engine

        second_access = thread_local.engine

        assert first_access is second_access

    def test_thread_local_engine_cleanup(self):
        """Engine is cleaned up on thread exit."""
        cleaned_up = {"value": False}
        thread_local = threading.local()

        def worker():
            thread_local.engine = Mock(name="engine")
            # Simulate cleanup
            del thread_local.engine
            cleaned_up["value"] = True

        t = threading.Thread(target=worker)
        t.start()
        t.join()

        assert cleaned_up["value"]

    def test_thread_local_multiple_threads(self):
        """Multiple threads have independent storage."""
        thread_local = threading.local()
        results = {}

        def worker(thread_id):
            thread_local.value = thread_id * 10
            time.sleep(0.01)
            results[thread_id] = thread_local.value

        threads = [threading.Thread(target=worker, args=(i,)) for i in range(5)]
        for t in threads:
            t.start()
        for t in threads:
            t.join()

        for i in range(5):
            assert results[i] == i * 10

    def test_thread_local_concurrent_access(self):
        """Concurrent access to thread local is safe."""
        thread_local = threading.local()
        errors = []

        def worker():
            try:
                for i in range(100):
                    thread_local.counter = i
                    _ = thread_local.counter
            except Exception as e:
                errors.append(e)

        threads = [threading.Thread(target=worker) for _ in range(10)]
        for t in threads:
            t.start()
        for t in threads:
            t.join()

        assert len(errors) == 0

    def test_thread_local_session_binding(self):
        """Session is bound to thread local engine."""
        thread_local = threading.local()
        thread_local.engine = Mock()
        thread_local.session = Mock()

        thread_local.session.bind = thread_local.engine

        assert thread_local.session.bind is thread_local.engine

    def test_thread_local_transaction_isolation(self):
        """Transactions are isolated between threads."""
        transactions = {}
        lock = threading.Lock()

        def worker(thread_id):
            # Simulate transaction
            transaction = {"id": thread_id, "committed": False}
            time.sleep(0.01)
            transaction["committed"] = True
            with lock:
                transactions[thread_id] = transaction

        threads = [threading.Thread(target=worker, args=(i,)) for i in range(3)]
        for t in threads:
            t.start()
        for t in threads:
            t.join()

        for i in range(3):
            assert transactions[i]["committed"]
            assert transactions[i]["id"] == i

    def test_thread_local_error_recovery(self):
        """Thread local recovers from errors."""
        thread_local = threading.local()

        try:
            thread_local.value = "test"
            raise ValueError("Test error")
        except ValueError:
            pass

        # Thread local should still work
        thread_local.value = "recovered"
        assert thread_local.value == "recovered"

    def test_thread_local_memory_management(self):
        """Thread local doesn't leak memory."""
        thread_local = threading.local()
        large_data = "x" * 10000

        thread_local.data = large_data
        del thread_local.data

        assert not hasattr(thread_local, "data")


class TestSQLCipherPragma:
    """Tests for SQLCipher pragma configuration."""

    def test_sqlcipher_pragma_application(self):
        """Pragma statements are applied to connection."""
        pragmas = [
            "PRAGMA key = 'secret_key'",
            "PRAGMA cipher_page_size = 4096",
        ]

        applied = []
        for pragma in pragmas:
            applied.append(pragma)

        assert len(applied) == 2

    def test_sqlcipher_pragma_key_setting(self):
        """Encryption key pragma is set."""
        key = "my_secret_key"

        pragma = f"PRAGMA key = '{key}'"

        assert "my_secret_key" in pragma

    def test_sqlcipher_pragma_cipher_settings(self):
        """Cipher settings are configured."""
        settings = {
            "cipher": "aes-256-cbc",
            "kdf_iter": 256000,
            "cipher_page_size": 4096,
        }

        pragmas = [
            f"PRAGMA cipher = '{settings['cipher']}'",
            f"PRAGMA kdf_iter = {settings['kdf_iter']}",
            f"PRAGMA cipher_page_size = {settings['cipher_page_size']}",
        ]

        assert len(pragmas) == 3
        assert "256000" in pragmas[1]

    def test_sqlcipher_pragma_kdf_iterations(self):
        """KDF iterations are set correctly."""
        kdf_iter = 256000

        pragma = f"PRAGMA kdf_iter = {kdf_iter}"

        assert "256000" in pragma

    def test_sqlcipher_pragma_page_size(self):
        """Page size pragma is configured."""
        page_size = 4096

        pragma = f"PRAGMA cipher_page_size = {page_size}"

        assert "4096" in pragma

    def test_sqlcipher_pragma_journal_mode(self):
        """Journal mode is set."""
        journal_mode = "WAL"

        pragma = f"PRAGMA journal_mode = {journal_mode}"

        assert journal_mode in pragma

    def test_sqlcipher_pragma_synchronous(self):
        """Synchronous pragma is configured."""
        sync_mode = "NORMAL"

        pragma = f"PRAGMA synchronous = {sync_mode}"

        assert sync_mode in pragma

    def test_sqlcipher_unavailable_fallback(self):
        """Fallback when SQLCipher unavailable."""
        sqlcipher_available = False

        if not sqlcipher_available:
            engine_type = "sqlite3"
            encryption_enabled = False
        else:
            engine_type = "sqlcipher"
            encryption_enabled = True

        assert engine_type == "sqlite3"
        assert not encryption_enabled


class TestPoolManagement:
    """Tests for connection pool management."""

    def test_pool_exhaustion_scenario(self):
        """Pool exhaustion is handled."""
        pool_size = 5
        active_connections = 5

        pool_available = pool_size - active_connections

        if pool_available <= 0:
            wait_for_connection = True
        else:
            wait_for_connection = False

        assert wait_for_connection

    def test_pool_connection_recycling(self):
        """Connections are recycled after use."""
        connections = []
        pool_size = 3

        # Acquire and release
        for _ in range(pool_size):
            conn = Mock()
            connections.append(conn)

        # Return to pool
        for conn in connections:
            conn.close = Mock()

        # Connections should be reusable
        assert len(connections) == pool_size

    def test_pool_timeout_handling(self):
        """Pool timeout raises exception."""
        pool_timeout = 30
        wait_time = 35

        if wait_time > pool_timeout:
            timed_out = True
        else:
            timed_out = False

        assert timed_out

    def test_pool_leak_prevention(self):
        """Connection leaks are detected."""
        checked_out = {"count": 0}
        returned = {"count": 0}

        # Simulate checkout
        checked_out["count"] += 5

        # Simulate return
        returned["count"] += 4

        leaked = checked_out["count"] - returned["count"]

        assert leaked == 1

    def test_pool_max_overflow(self):
        """Max overflow connections are allowed."""
        pool_size = 5
        max_overflow = 10
        current_connections = 12

        within_limits = current_connections <= (pool_size + max_overflow)

        assert within_limits

    def test_pool_pre_ping(self):
        """Pre-ping validates connections."""
        connection = Mock()
        connection.is_valid = Mock(return_value=True)

        # Pre-ping check
        is_valid = connection.is_valid()

        assert is_valid

    def test_pool_connection_invalidation(self):
        """Invalid connections are removed from pool."""
        pool = [Mock(valid=True), Mock(valid=False), Mock(valid=True)]

        valid_connections = [c for c in pool if c.valid]

        assert len(valid_connections) == 2


class TestDatabaseEncryption:
    """Tests for database encryption handling."""

    def test_encryption_key_from_password(self):
        """Encryption key is derived from password."""
        password = "user_password"

        # Simulate key derivation
        import hashlib

        key = hashlib.sha256(password.encode()).hexdigest()

        assert len(key) == 64

    def test_encryption_key_caching(self):
        """Encryption keys are cached per user."""
        key_cache = {}
        username = "testuser"
        password = "password123"

        if username not in key_cache:
            import hashlib

            key_cache[username] = hashlib.sha256(password.encode()).hexdigest()

        cached_key = key_cache.get(username)

        assert cached_key is not None

    def test_encryption_rekey_database(self):
        """Database can be rekeyed."""
        old_key = "old_secret"
        new_key = "new_secret"

        pragmas = [
            f"PRAGMA key = '{old_key}'",
            f"PRAGMA rekey = '{new_key}'",
        ]

        assert len(pragmas) == 2
        assert "rekey" in pragmas[1]

    def test_encryption_verify_key(self):
        """Key verification check."""
        # Simulate key verification by querying
        key_valid = True

        try:
            # Would execute: SELECT count(*) FROM sqlite_master
            result = 1
            key_valid = result >= 0
        except Exception:
            key_valid = False

        assert key_valid

    def test_encryption_wrong_key_handling(self):
        """Wrong encryption key is detected."""
        correct_key = "correct_key"
        provided_key = "wrong_key"

        key_matches = correct_key == provided_key

        assert not key_matches


class TestEncryptedDbExceptionLogging:
    """Tests for improved exception logging in encrypted_db (PR #2006).

    PR #2006 adds logger.debug() to exception handlers for:
    - Temp file cleanup (OSError)
    - Pragma application failures
    - Stale engine disposal
    """

    def test_os_error_is_subclass_hierarchy(self):
        """OSError catches FileNotFoundError and PermissionError."""
        assert issubclass(FileNotFoundError, OSError)
        assert issubclass(PermissionError, OSError)

    def test_pragma_failure_caught_by_exception(self):
        """Pragma execution errors are caught by except Exception."""
        errors = []
        pragmas = ["PRAGMA invalid_pragma = 1", "PRAGMA valid = 1"]

        for pragma in pragmas:
            try:
                if "invalid" in pragma:
                    raise Exception(f"Could not apply pragma '{pragma}'")
            except Exception as e:
                errors.append(str(e))

        assert len(errors) == 1
        assert "invalid" in errors[0]

    def test_engine_dispose_error_caught(self):
        """Engine disposal errors are caught and logged."""
        from unittest.mock import Mock

        mock_engine = Mock()
        mock_engine.dispose.side_effect = Exception("Connection pool error")

        caught = False
        try:
            mock_engine.dispose()
        except Exception:
            caught = True

        assert caught
