# Copyright 2023 The casbin Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
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# See the License for the specific language governing permissions and
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"""
Unit tests for external session functionality.
"""

import os
import tempfile
import unittest
from unittest import IsolatedAsyncioTestCase

import casbin
from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession, async_sessionmaker

from casbin_async_sqlalchemy_adapter import Adapter
from casbin_async_sqlalchemy_adapter import CasbinRule


def get_fixture(path):
    """Get fixture file path."""
    dir_path = os.path.split(os.path.realpath(__file__))[0] + "/"
    return os.path.abspath(dir_path + path)


class TestExternalSession(IsolatedAsyncioTestCase):
    """Test external session functionality."""

    async def test_external_session_commit(self):
        """Test using external session with commit."""
        # Create a temporary database file
        db_file = tempfile.NamedTemporaryFile(suffix=".db", delete=False)
        db_file.close()

        try:
            # Create async engine
            engine = create_async_engine(f"sqlite+aiosqlite:///{db_file.name}", future=True)

            # Create session factory
            async_session_factory = async_sessionmaker(engine, expire_on_commit=False)

            # Test with external session
            async with async_session_factory() as external_session:
                # Create adapter with external session
                adapter = Adapter(engine, db_session=external_session)

                # Create table
                await adapter.create_table()

                # Create enforcer
                e = casbin.AsyncEnforcer(get_fixture("rbac_model.conf"), adapter)
                await e.load_policy()

                # Add permissions
                await e.add_permission_for_user("alice", "data1", "read")
                await e.add_permission_for_user("alice", "data2", "read")

                # Verify permissions are available in current session
                self.assertTrue(e.enforce("alice", "data1", "read"))
                self.assertTrue(e.enforce("alice", "data2", "read"))

                # Commit the transaction
                await external_session.commit()

            # Verify permissions persist after commit with new session
            async with async_session_factory() as new_session:
                new_adapter = Adapter(engine, db_session=new_session)
                new_enforcer = casbin.AsyncEnforcer(get_fixture("rbac_model.conf"), new_adapter)
                await new_enforcer.load_policy()

                self.assertTrue(new_enforcer.enforce("alice", "data1", "read"))
                self.assertTrue(new_enforcer.enforce("alice", "data2", "read"))

        finally:
            # Clean up
            if os.path.exists(db_file.name):
                os.unlink(db_file.name)

    async def test_external_session_rollback(self):
        """Test using external session with rollback."""
        # Create a temporary database file
        db_file = tempfile.NamedTemporaryFile(suffix=".db", delete=False)
        db_file.close()

        try:
            # Create async engine
            engine = create_async_engine(f"sqlite+aiosqlite:///{db_file.name}", future=True)

            # Create session factory
            async_session_factory = async_sessionmaker(engine, expire_on_commit=False)

            # Test with external session
            async with async_session_factory() as external_session:
                # Create adapter with external session
                adapter = Adapter(engine, db_session=external_session)

                # Create table
                await adapter.create_table()

                # Create enforcer
                e = casbin.AsyncEnforcer(get_fixture("rbac_model.conf"), adapter)
                await e.load_policy()

                # Add permissions
                await e.add_permission_for_user("alice", "data1", "read")
                await e.add_permission_for_user("alice", "data2", "read")

                # Verify permissions are available in current session
                self.assertTrue(e.enforce("alice", "data1", "read"))
                self.assertTrue(e.enforce("alice", "data2", "read"))

                # Rollback the transaction
                await external_session.rollback()

            # Verify permissions do not persist after rollback with new session
            async with async_session_factory() as new_session:
                new_adapter = Adapter(engine, db_session=new_session)
                new_enforcer = casbin.AsyncEnforcer(get_fixture("rbac_model.conf"), new_adapter)
                await new_enforcer.load_policy()

                self.assertFalse(new_enforcer.enforce("alice", "data1", "read"))
                self.assertFalse(new_enforcer.enforce("alice", "data2", "read"))

        finally:
            # Clean up
            if os.path.exists(db_file.name):
                os.unlink(db_file.name)

    async def test_external_session_with_save_policy(self):
        """Test save_policy with external session."""
        # Create a temporary database file
        db_file = tempfile.NamedTemporaryFile(suffix=".db", delete=False)
        db_file.close()

        try:
            # Create async engine
            engine = create_async_engine(f"sqlite+aiosqlite:///{db_file.name}", future=True)

            # Create session factory
            async_session_factory = async_sessionmaker(engine, expire_on_commit=False)

            # Test with external session
            async with async_session_factory() as external_session:
                # Create adapter with external session
                adapter = Adapter(engine, db_session=external_session)

                # Create table
                await adapter.create_table()

                # Create enforcer
                e = casbin.AsyncEnforcer(get_fixture("rbac_model.conf"), adapter)
                await e.load_policy()

                # Add permissions
                await e.add_permission_for_user("alice", "data1", "read")
                await e.add_permission_for_user("bob", "data2", "write")

                # Save policy (should use external session)
                await e.save_policy()

                # Commit the transaction
                await external_session.commit()

            # Verify policies persist after commit with new session
            async with async_session_factory() as new_session:
                new_adapter = Adapter(engine, db_session=new_session)
                new_enforcer = casbin.AsyncEnforcer(get_fixture("rbac_model.conf"), new_adapter)
                await new_enforcer.load_policy()

                self.assertTrue(new_enforcer.enforce("alice", "data1", "read"))
                self.assertTrue(new_enforcer.enforce("bob", "data2", "write"))

        finally:
            # Clean up
            if os.path.exists(db_file.name):
                os.unlink(db_file.name)

    async def test_backward_compatibility(self):
        """Test that existing behavior is preserved."""
        # Create a temporary database file
        db_file = tempfile.NamedTemporaryFile(suffix=".db", delete=False)
        db_file.close()

        try:
            # Create async engine
            engine = create_async_engine(f"sqlite+aiosqlite:///{db_file.name}", future=True)

            # Create adapter without external session (original way)
            adapter = Adapter(engine)

            # Create table
            await adapter.create_table()

            # Create enforcer
            e = casbin.AsyncEnforcer(get_fixture("rbac_model.conf"), adapter)
            await e.load_policy()

            # Add permissions (should auto-commit)
            await e.add_permission_for_user("alice", "data1", "read")
            await e.add_permission_for_user("alice", "data2", "read")

            # Verify permissions are committed automatically
            self.assertTrue(e.enforce("alice", "data1", "read"))
            self.assertTrue(e.enforce("alice", "data2", "read"))

            # Create new adapter to verify persistence
            new_adapter = Adapter(engine)
            new_enforcer = casbin.AsyncEnforcer(get_fixture("rbac_model.conf"), new_adapter)
            await new_enforcer.load_policy()

            self.assertTrue(new_enforcer.enforce("alice", "data1", "read"))
            self.assertTrue(new_enforcer.enforce("alice", "data2", "read"))

        finally:
            # Clean up
            if os.path.exists(db_file.name):
                os.unlink(db_file.name)


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