import unittest.mock as mock
from unittest.mock import Mock, MagicMock
import unittest

from mlagents.envs.subprocess_environment import *
from mlagents.envs import UnityEnvironmentException, BrainInfo


def mock_env_factory(worker_id: int):
    return mock.create_autospec(spec=BaseUnityEnvironment)


class MockEnvWorker:
    def __init__(self, worker_id):
        self.worker_id = worker_id
        self.process = None
        self.conn = None
        self.send = MagicMock()
        self.recv = MagicMock()


class SubprocessEnvironmentTest(unittest.TestCase):
    def test_environments_are_created(self):
        SubprocessUnityEnvironment.create_worker = MagicMock()
        env = SubprocessUnityEnvironment(mock_env_factory, 2)
        # Creates two processes
        self.assertEqual(
            env.create_worker.call_args_list,
            [mock.call(0, mock_env_factory), mock.call(1, mock_env_factory)],
        )
        self.assertEqual(len(env.envs), 2)

    def test_step_async_fails_when_waiting(self):
        env = SubprocessUnityEnvironment(mock_env_factory, 0)
        env.waiting = True
        with self.assertRaises(UnityEnvironmentException):
            env.step_async(vector_action=[])

    @staticmethod
    def test_step_async_splits_input_by_agent_count():
        env = SubprocessUnityEnvironment(mock_env_factory, 0)
        env.env_agent_counts = {"MockBrain": [1, 3, 5]}
        env.envs = [MockEnvWorker(0), MockEnvWorker(1), MockEnvWorker(2)]
        env_0_actions = [[1.0, 2.0]]
        env_1_actions = [[3.0, 4.0]] * 3
        env_2_actions = [[5.0, 6.0]] * 5
        vector_action = {"MockBrain": env_0_actions + env_1_actions + env_2_actions}
        env.step_async(vector_action=vector_action)
        env.envs[0].send.assert_called_with(
            "step", ({"MockBrain": env_0_actions}, {}, {}, {})
        )
        env.envs[1].send.assert_called_with(
            "step", ({"MockBrain": env_1_actions}, {}, {}, {})
        )
        env.envs[2].send.assert_called_with(
            "step", ({"MockBrain": env_2_actions}, {}, {}, {})
        )

    def test_step_async_sets_waiting(self):
        env = SubprocessUnityEnvironment(mock_env_factory, 0)
        env.step_async(vector_action=[])
        self.assertTrue(env.waiting)

    def test_step_await_fails_if_not_waiting(self):
        env = SubprocessUnityEnvironment(mock_env_factory, 0)
        with self.assertRaises(UnityEnvironmentException):
            env.step_await()

    def test_step_await_combines_brain_info(self):
        all_brain_info_env0 = {
            "MockBrain": BrainInfo(
                [], [[1.0, 2.0], [1.0, 2.0]], [], agents=[1, 2], memory=np.zeros((0, 0))
            )
        }
        all_brain_info_env1 = {
            "MockBrain": BrainInfo(
                [], [[3.0, 4.0]], [], agents=[3], memory=np.zeros((0, 0))
            )
        }
        env_worker_0 = MockEnvWorker(0)
        env_worker_0.recv.return_value = EnvironmentResponse(
            "step", 0, all_brain_info_env0
        )
        env_worker_1 = MockEnvWorker(1)
        env_worker_1.recv.return_value = EnvironmentResponse(
            "step", 1, all_brain_info_env1
        )
        env = SubprocessUnityEnvironment(mock_env_factory, 0)
        env.envs = [env_worker_0, env_worker_1]
        env.waiting = True
        combined_braininfo = env.step_await()["MockBrain"]
        self.assertEqual(
            combined_braininfo.vector_observations.tolist(),
            [[1.0, 2.0], [1.0, 2.0], [3.0, 4.0]],
        )
        self.assertEqual(combined_braininfo.agents, ["0-1", "0-2", "1-3"])

    def test_step_resets_on_global_done(self):
        env_mock = Mock()
        env_mock.reset = Mock(return_value="reset_data")
        env_mock.global_done = True

        def mock_global_done_env_factory(worker_id: int):
            return env_mock

        mock_parent_connection = Mock()
        step_command = EnvironmentCommand("step", (None, None, None, None))
        close_command = EnvironmentCommand("close")
        mock_parent_connection.recv = Mock()
        mock_parent_connection.recv.side_effect = [step_command, close_command]
        mock_parent_connection.send = Mock()

        worker(
            mock_parent_connection, cloudpickle.dumps(mock_global_done_env_factory), 0
        )

        # recv called twice to get step and close command
        self.assertEqual(mock_parent_connection.recv.call_count, 2)

        # worker returns the data from the reset
        mock_parent_connection.send.assert_called_with(
            EnvironmentResponse("step", 0, "reset_data")
        )