import unittest


class TestBackwardCompatibility(unittest.TestCase):
    def test_register_all(self):
        """Tests the old (1.10) way of registering all Trainers.

        Uses the old 1.10 registry.py file and thus makes sure all Trainers can still
        be imported using their old paths (albeit this will create a warning).
        """
        # Try importing old Trainer class (this is just an Alias now to the `Algorithm`
        # class).
        from ray.rllib.agents.trainer import Trainer  # noqa

        # Old registry code.
        from ray.rllib.tests.backward_compat.old_registry import (
            ALGORITHMS,
            _get_trainer_class,
        )
        from ray.rllib.contrib.registry import CONTRIBUTED_ALGORITHMS

        # Test the old `_get_trainer_class()` utility that was used to pull Trainer
        # class and default config.
        for key in (
            list(ALGORITHMS.keys())
            + list(CONTRIBUTED_ALGORITHMS.keys())
            + ["__fake", "__sigmoid_fake_data", "__parameter_tuning"]
        ):
            _get_trainer_class(key)

    def test_old_configs(self):
        """Tests creating various Trainers (Algorithms) using 1.10 config dicts."""
        from ray.rllib.tests.backward_compat.old_ppo import DEFAULT_CONFIG
        from ray.rllib.agents.ppo import PPOTrainer

        config = DEFAULT_CONFIG.copy()
        trainer = PPOTrainer(config=config, env="CartPole-v0")
        trainer.train()
        trainer.stop()


if __name__ == "__main__":
    import pytest
    import sys

    sys.exit(pytest.main(["-v", __file__]))