import os
import pickle
from typing import Any, Union

import numpy as np
from pytorch_lightning.callbacks import ModelCheckpoint
from torch.optim import Optimizer
from torch.optim.lr_scheduler import LRScheduler

from navsim.agents.vadv2.vadv2_config import Vadv2Config
from navsim.agents.vadv2.vadv2_features import (
    Vadv2FeatureBuilder,
    Vadv2TargetBuilder,
)
from navsim.agents.vadv2.vadv2_loss import vadv2_loss_pdm_w_progress
from navsim.agents.vadv2.vadv2_pdm_model_progress import Vadv2ModelPDMProgress
from navsim.common.dataclasses import SensorConfig
from navsim.planning.training.abstract_feature_target_builder import (
    AbstractFeatureBuilder,
    AbstractTargetBuilder,
)

DEVKIT_ROOT = os.getenv('NAVSIM_DEVKIT_ROOT')
TRAJ_PDM_ROOT = os.getenv('NAVSIM_TRAJPDM_ROOT')

from typing import Dict, List

import pytorch_lightning as pl
import torch
from nuplan.planning.simulation.trajectory.trajectory_sampling import TrajectorySampling

from navsim.agents.abstract_agent import AbstractAgent
from navsim.common.dataclasses import Trajectory


class Vadv2AgentPDMProgress(AbstractAgent):
    def __init__(
            self,
            config: Vadv2Config,
            lr: float,
            checkpoint_path: str = None,
            pdm_split=None,
            metrics=None,
    ):
        super().__init__()
        config.trajectory_pdm_weight = {
            'noc': 3.0,
            'da': 3.0,
            'ttc': 2.0,
            'progress': config.progress_weight,
            'comfort': 1.0,
        }
        self._config = config
        self._lr = lr
        self.metrics = metrics
        self._checkpoint_path = checkpoint_path
        self.vadv2_model = Vadv2ModelPDMProgress(config)
        self.vocab_size = config.vocab_size
        self.backbone_wd = config.backbone_wd
        new_pkl_dir = f'vocab_score_full_{self.vocab_size}_navtrain'
        self.vocab_pdm_score_full = pickle.load(
            open(f'{TRAJ_PDM_ROOT}/{new_pkl_dir}/{pdm_split}.pkl', 'rb'))

    def name(self) -> str:
        """Inherited, see superclass."""

        return self.__class__.__name__

    def initialize(self) -> None:
        """Inherited, see superclass."""
        # if torch.cuda.is_available():
        #     state_dict: Dict[str, Any] = torch.load(self._checkpoint_path)["state_dict"]
        # else:
        #     state_dict: Dict[str, Any] = torch.load(self._checkpoint_path, map_location=torch.device("cpu"))[
        #         "state_dict"]
        state_dict: Dict[str, Any] = torch.load(self._checkpoint_path, map_location=torch.device("cpu"))["state_dict"]
        self.load_state_dict({k.replace("agent.", ""): v for k, v in state_dict.items()})

    def get_sensor_config(self) -> SensorConfig:
        """Inherited, see superclass."""
        return SensorConfig.build_mm_sensors()

    def get_target_builders(self) -> List[AbstractTargetBuilder]:
        return [Vadv2TargetBuilder(config=self._config)]

    def get_feature_builders(self) -> List[AbstractFeatureBuilder]:
        return [Vadv2FeatureBuilder(config=self._config)]

    def forward(self, features: Dict[str, torch.Tensor]) -> Dict[str, torch.Tensor]:
        return self.vadv2_model(features)

    def forward_train(self, features, interpolated_traj):
        return self.vadv2_model(features, interpolated_traj)

    def compute_loss(
            self,
            features: Dict[str, torch.Tensor],
            targets: Dict[str, torch.Tensor],
            predictions: Dict[str, torch.Tensor],
            tokens=None
    ) -> Union[torch.Tensor, Dict[str, torch.Tensor]]:
        # get the pdm score by tokens
        scores = {}
        for k in self.metrics:
            tmp = [self.vocab_pdm_score_full[token][k][None] for token in tokens]
            scores[k] = (torch.from_numpy(np.concatenate(tmp, axis=0))
                         .to(predictions['trajectory'].device))
        return vadv2_loss_pdm_w_progress(targets, predictions, self._config, scores)

    def get_optimizers(self) -> Union[Optimizer, Dict[str, Union[Optimizer, LRScheduler]]]:
        if self._config.backbone_type == 'moe':
            backbone_params_eva = '_backbone.image_encoder.eva'
            backbone_params_da = '_backbone.image_encoder.davit'
            img_backbone_params = list(
                filter(lambda kv: backbone_params_eva in kv[0] or backbone_params_da in kv[0], self.vadv2_model.named_parameters())
            )
            default_params = list(filter(lambda kv: backbone_params_da not in kv[0] and backbone_params_eva not in kv[0], self.vadv2_model.named_parameters()))
            params_lr_dict = [
                {'params': [tmp[1] for tmp in default_params]},
                {
                    'params': [tmp[1] for tmp in img_backbone_params],
                    'lr': self._lr * self._config.lr_mult_backbone,
                    'weight_decay': self.backbone_wd
                }
            ]
            return torch.optim.Adam(params_lr_dict, lr=self._lr)
        backbone_params_name = '_backbone.image_encoder'
        img_backbone_params = list(
            filter(lambda kv: backbone_params_name in kv[0], self.vadv2_model.named_parameters()))
        default_params = list(filter(lambda kv: backbone_params_name not in kv[0], self.vadv2_model.named_parameters()))
        params_lr_dict = [
            {'params': [tmp[1] for tmp in default_params]},
            {
                'params': [tmp[1] for tmp in img_backbone_params],
                'lr': self._lr * self._config.lr_mult_backbone,
                'weight_decay': self.backbone_wd
            }
        ]
        return torch.optim.Adam(params_lr_dict, lr=self._lr)

    def get_training_callbacks(self) -> List[pl.Callback]:
        return [
            # TransfuserCallback(self._config),
            ModelCheckpoint(
                save_top_k=30,
                monitor="val/loss_epoch",
                mode="min",
                dirpath=f"{os.environ.get('NAVSIM_EXP_ROOT')}/{self._config.ckpt_path}/",
                filename="{epoch:02d}-{step:04d}",
            )
        ]

    def compute_trajectory(self, agent_input):
        """
        Submission
        """
        self.eval()
        features: Dict[str, torch.Tensor] = {}
        # build features
        for builder in self.get_feature_builders():
            features.update(builder.compute_features(agent_input))

        # add batch dimension
        features = {k: v.unsqueeze(0).cuda() for k, v in features.items()}
        vocab = self.vadv2_model._trajectory_head.vocab
        self.vadv2_model = self.vadv2_model.cuda()
        # forward pass
        with torch.no_grad():
            predictions = self.vadv2_model(features)

        imis = predictions["imi"].softmax(-1).log().cpu().numpy()
        nocs = predictions["noc"].log().cpu().numpy()
        das = predictions["da"].log().cpu().numpy()
        ttcs = predictions["ttc"].log().cpu().numpy()
        comforts = predictions["comfort"].log().cpu().numpy()
        progresses = predictions["progress"].log().cpu().numpy()

        imi_weight = 0.1
        noc_weight = 0.25
        da_weight = 2.0
        ttc_weight = 3.0
        progress_weight = 5.0
        comfort_weight = 1.0
        tpc_weight = 2.25

        # A temporary trajectory for choosing the best epoch -> for grid search
        score = (
                imi_weight * imis +
                noc_weight * nocs +
                da_weight * das +
                tpc_weight * (
                        ttc_weight * ttcs +
                        comfort_weight * comforts +
                        progress_weight * progresses
                )
        )[0].argmax(0)
        traj = vocab[score].cpu().numpy()
        return Trajectory(traj,
                          TrajectorySampling(time_horizon=4, interval_length=0.1))