"""Provides a generic testing environment for use in tests with custom reset, step and render functions."""
from __future__ import annotations

import types
from collections.abc import Callable
from typing import Any

import gymnasium as gym
from gymnasium import spaces
from gymnasium.core import ActType, ObsType
from gymnasium.envs.registration import EnvSpec


def basic_reset_func(
    self,
    *,
    seed: int | None = None,
    options: dict | None = None,
) -> tuple[ObsType, dict]:
    """A basic reset function that will pass the environment check using random actions from the observation space."""
    super(GenericTestEnv, self).reset(seed=seed)
    self.observation_space.seed(seed)
    return self.observation_space.sample(), {"options": options}


def old_reset_func(self) -> ObsType:
    """An old reset function that will pass the environment check using random actions from the observation space."""
    super(GenericTestEnv, self).reset()
    return self.observation_space.sample()


def basic_step_func(self, action: ActType) -> tuple[ObsType, float, bool, bool, dict]:
    """A step function that follows the basic step api that will pass the environment check using random actions from the observation space."""
    return self.observation_space.sample(), 0, False, False, {}


def old_step_func(self, action: ActType) -> tuple[ObsType, float, bool, dict]:
    """A step function that follows the old step api that will pass the environment check using random actions from the observation space."""
    return self.observation_space.sample(), 0, False, {}


def basic_render_func(self):
    """Basic render fn that does nothing."""
    pass


# todo: change all testing environment to this generic class
class GenericTestEnv(gym.Env):
    """A generic testing environment for use in testing with modified environments are required."""

    def __init__(
        self,
        action_space: spaces.Space = spaces.Box(0, 1, (1,)),
        observation_space: spaces.Space = spaces.Box(0, 1, (1,)),
        reset_func: Callable = basic_reset_func,
        step_func: Callable = basic_step_func,
        render_func: Callable = basic_render_func,
        metadata: dict[str, Any] = {"render_modes": []},
        render_mode: str | None = None,
        spec: EnvSpec = EnvSpec(
            "TestingEnv-v0", "testing-env-no-entry-point", max_episode_steps=100
        ),
    ):
        """Generic testing environment constructor.

        Args:
            action_space: The environment action space
            observation_space: The environment observation space
            reset_func: The environment reset function
            step_func: The environment step function
            render_func: The environment render function
            metadata: The environment metadata
            render_mode: The render mode of the environment
            spec: The environment spec
        """
        self.metadata = metadata
        self.render_mode = render_mode
        self.spec = spec

        if observation_space is not None:
            self.observation_space = observation_space
        if action_space is not None:
            self.action_space = action_space

        if reset_func is not None:
            self.reset = types.MethodType(reset_func, self)
        if step_func is not None:
            self.step = types.MethodType(step_func, self)
        if render_func is not None:
            self.render = types.MethodType(render_func, self)

    def reset(
        self,
        *,
        seed: int | None = None,
        options: dict | None = None,
    ) -> ObsType | tuple[ObsType, dict]:
        """Resets the environment."""
        # If you need a default working reset function, use `basic_reset_fn` above
        raise NotImplementedError("TestingEnv reset_fn is not set.")

    def step(self, action: ActType) -> tuple[ObsType, float, bool, dict[str, Any]]:
        """Steps through the environment."""
        raise NotImplementedError("TestingEnv step_fn is not set.")

    def render(self):
        """Renders the environment."""
        raise NotImplementedError("testingEnv render_fn is not set.")