import os
from dataclasses import astuple
from typing import Callable, Optional

import gym
from gym.vector.async_vector_env import AsyncVectorEnv
from gym.vector.sync_vector_env import SyncVectorEnv
from gym.wrappers.frame_stack import FrameStack
from gym.wrappers.gray_scale_observation import GrayScaleObservation
from gym.wrappers.resize_observation import ResizeObservation
from stable_baselines3.common.atari_wrappers import MaxAndSkipEnv, NoopResetEnv
from stable_baselines3.common.vec_env.dummy_vec_env import DummyVecEnv
from stable_baselines3.common.vec_env.subproc_vec_env import SubprocVecEnv
from stable_baselines3.common.vec_env.vec_normalize import VecNormalize
from torch.utils.tensorboard.writer import SummaryWriter

from rl_algo_impls.runner.config import Config, EnvHyperparams
from rl_algo_impls.shared.policy.policy import VEC_NORMALIZE_FILENAME
from rl_algo_impls.shared.vec_env.utils import (
    import_for_env_id,
    is_atari,
    is_bullet_env,
    is_car_racing,
    is_gym_procgen,
    is_microrts,
)
from rl_algo_impls.wrappers.action_mask_wrapper import SingleActionMaskWrapper
from rl_algo_impls.wrappers.atari_wrappers import (
    ClipRewardEnv,
    EpisodicLifeEnv,
    FireOnLifeStarttEnv,
)
from rl_algo_impls.wrappers.episode_record_video import EpisodeRecordVideo
from rl_algo_impls.wrappers.episode_stats_writer import EpisodeStatsWriter
from rl_algo_impls.wrappers.hwc_to_chw_observation import HwcToChwObservation
from rl_algo_impls.wrappers.initial_step_truncate_wrapper import (
    InitialStepTruncateWrapper,
)
from rl_algo_impls.wrappers.is_vector_env import IsVectorEnv
from rl_algo_impls.wrappers.no_reward_timeout import NoRewardTimeout
from rl_algo_impls.wrappers.noop_env_seed import NoopEnvSeed
from rl_algo_impls.wrappers.normalize import NormalizeObservation, NormalizeReward
from rl_algo_impls.wrappers.sync_vector_env_render_compat import (
    SyncVectorEnvRenderCompat,
)
from rl_algo_impls.wrappers.vectorable_wrapper import VecEnv
from rl_algo_impls.wrappers.video_compat_wrapper import VideoCompatWrapper


def make_vec_env(
    config: Config,
    hparams: EnvHyperparams,
    training: bool = True,
    render: bool = False,
    normalize_load_path: Optional[str] = None,
    tb_writer: Optional[SummaryWriter] = None,
) -> VecEnv:
    (
        env_type,
        n_envs,
        frame_stack,
        make_kwargs,
        no_reward_timeout_steps,
        no_reward_fire_steps,
        vec_env_class,
        normalize,
        normalize_kwargs,
        rolling_length,
        train_record_video,
        video_step_interval,
        initial_steps_to_truncate,
        clip_atari_rewards,
        normalize_type,
        mask_actions,
        _,  # bots
        _,  # self_play_kwargs
        _,  # selfplay_bots
    ) = astuple(hparams)

    import_for_env_id(config.env_id)

    seed = config.seed(training=training)

    make_kwargs = make_kwargs.copy() if make_kwargs is not None else {}
    if is_bullet_env(config) and render:
        make_kwargs["render"] = True
    if is_car_racing(config):
        make_kwargs["verbose"] = 0
    if is_gym_procgen(config) and not render:
        make_kwargs["render_mode"] = "rgb_array"

    def make(idx: int) -> Callable[[], gym.Env]:
        def _make() -> gym.Env:
            env = gym.make(config.env_id, **make_kwargs)
            env = gym.wrappers.RecordEpisodeStatistics(env)
            env = VideoCompatWrapper(env)
            if training and train_record_video and idx == 0:
                env = EpisodeRecordVideo(
                    env,
                    config.video_prefix,
                    step_increment=n_envs,
                    video_step_interval=int(video_step_interval),
                )
            if training and initial_steps_to_truncate:
                env = InitialStepTruncateWrapper(
                    env, idx * initial_steps_to_truncate // n_envs
                )
            if is_atari(config):  # type: ignore
                env = NoopResetEnv(env, noop_max=30)
                env = MaxAndSkipEnv(env, skip=4)
                env = EpisodicLifeEnv(env, training=training)
                action_meanings = env.unwrapped.get_action_meanings()
                if "FIRE" in action_meanings:  # type: ignore
                    env = FireOnLifeStarttEnv(env, action_meanings.index("FIRE"))
                if clip_atari_rewards:
                    env = ClipRewardEnv(env, training=training)
                env = ResizeObservation(env, (84, 84))
                env = GrayScaleObservation(env, keep_dim=False)
                env = FrameStack(env, frame_stack)
            elif is_car_racing(config):
                env = ResizeObservation(env, (64, 64))
                env = GrayScaleObservation(env, keep_dim=False)
                env = FrameStack(env, frame_stack)
            elif is_gym_procgen(config):
                # env = GrayScaleObservation(env, keep_dim=False)
                env = NoopEnvSeed(env)
                env = HwcToChwObservation(env)
                if frame_stack > 1:
                    env = FrameStack(env, frame_stack)
            elif is_microrts(config):
                env = HwcToChwObservation(env)

            if no_reward_timeout_steps:
                env = NoRewardTimeout(
                    env, no_reward_timeout_steps, n_fire_steps=no_reward_fire_steps
                )

            if seed is not None:
                env.seed(seed + idx)
                env.action_space.seed(seed + idx)
                env.observation_space.seed(seed + idx)

            return env

        return _make

    if env_type == "sb3vec":
        VecEnvClass = {"sync": DummyVecEnv, "async": SubprocVecEnv}[vec_env_class]
    elif env_type == "gymvec":
        VecEnvClass = {"sync": SyncVectorEnv, "async": AsyncVectorEnv}[vec_env_class]
    else:
        raise ValueError(f"env_type {env_type} unsupported")
    envs = VecEnvClass([make(i) for i in range(n_envs)])
    if env_type == "gymvec" and vec_env_class == "sync":
        envs = SyncVectorEnvRenderCompat(envs)
    if env_type == "sb3vec":
        envs = IsVectorEnv(envs)
    if mask_actions:
        envs = SingleActionMaskWrapper(envs)
    if training:
        assert tb_writer
        envs = EpisodeStatsWriter(
            envs, tb_writer, training=training, rolling_length=rolling_length
        )
    if normalize:
        if normalize_type is None:
            normalize_type = "sb3" if env_type == "sb3vec" else "gymlike"
        normalize_kwargs = normalize_kwargs or {}
        if normalize_type == "sb3":
            if normalize_load_path:
                envs = VecNormalize.load(
                    os.path.join(normalize_load_path, VEC_NORMALIZE_FILENAME),
                    envs,  # type: ignore
                )
            else:
                envs = VecNormalize(
                    envs,  # type: ignore
                    training=training,
                    **normalize_kwargs,
                )
            if not training:
                envs.norm_reward = False
        elif normalize_type == "gymlike":
            if normalize_kwargs.get("norm_obs", True):
                envs = NormalizeObservation(
                    envs, training=training, clip=normalize_kwargs.get("clip_obs", 10.0)
                )
            if training and normalize_kwargs.get("norm_reward", True):
                envs = NormalizeReward(
                    envs,
                    training=training,
                    clip=normalize_kwargs.get("clip_reward", 10.0),
                )
        else:
            raise ValueError(
                f"normalize_type {normalize_type} not supported (sb3 or gymlike)"
            )
    return envs