import logging
from time import time
from typing import Any, Tuple

import numpy as np
import numpy.typing as npt
from pandas import DataFrame

from freqtrade.freqai.base_models.BasePyTorchModel import BasePyTorchModel
from freqtrade.freqai.data_kitchen import FreqaiDataKitchen


logger = logging.getLogger(__name__)


class BasePyTorchRegressor(BasePyTorchModel):
    """
    A PyTorch implementation of a regressor.
    User must implement fit method
    """
    def __init__(self, **kwargs):
        super().__init__(**kwargs)

    def predict(
        self, unfiltered_df: DataFrame, dk: FreqaiDataKitchen, **kwargs
    ) -> Tuple[DataFrame, npt.NDArray[np.int_]]:
        """
        Filter the prediction features data and predict with it.
        :param unfiltered_df: Full dataframe for the current backtest period.
        :return:
        :pred_df: dataframe containing the predictions
        :do_predict: np.array of 1s and 0s to indicate places where freqai needed to remove
        data (NaNs) or felt uncertain about data (PCA and DI index)
        """

        dk.find_features(unfiltered_df)
        filtered_df, _ = dk.filter_features(
            unfiltered_df, dk.training_features_list, training_filter=False
        )
        dk.data_dictionary["prediction_features"] = filtered_df

        dk.data_dictionary["prediction_features"], outliers, _ = dk.feature_pipeline.transform(
            dk.data_dictionary["prediction_features"], outlier_check=True)

        x = self.data_convertor.convert_x(
            dk.data_dictionary["prediction_features"],
            device=self.device
        )
        self.model.model.eval()
        y = self.model.model(x)
        pred_df = DataFrame(y.detach().tolist(), columns=[dk.label_list[0]])
        pred_df, _, _ = dk.label_pipeline.inverse_transform(pred_df)

        if self.freqai_info.get("DI_threshold", 0) > 0:
            dk.DI_values = dk.feature_pipeline["di"].di_values
        else:
            dk.DI_values = np.zeros(len(outliers.index))
        dk.do_predict = outliers.to_numpy()
        return (pred_df, dk.do_predict)

    def train(
        self, unfiltered_df: DataFrame, pair: str, dk: FreqaiDataKitchen, **kwargs
    ) -> Any:
        """
        Filter the training data and train a model to it. Train makes heavy use of the datakitchen
        for storing, saving, loading, and analyzing the data.
        :param unfiltered_df: Full dataframe for the current training period
        :return:
        :model: Trained model which can be used to inference (self.predict)
        """

        logger.info(f"-------------------- Starting training {pair} --------------------")

        start_time = time()

        features_filtered, labels_filtered = dk.filter_features(
            unfiltered_df,
            dk.training_features_list,
            dk.label_list,
            training_filter=True,
        )

        # split data into train/test data.
        d = dk.make_train_test_datasets(features_filtered, labels_filtered)
        if not self.freqai_info.get("fit_live_predictions", 0) or not self.live:
            dk.fit_labels()

        self.define_data_pipeline(dk)
        self.define_label_pipeline(dk)

        d["train_labels"], _, _ = dk.label_pipeline.fit_transform(d["train_labels"])
        d["test_labels"], _, _ = dk.label_pipeline.transform(d["test_labels"])

        (d["train_features"],
         d["train_labels"],
         d["train_weights"]) = dk.feature_pipeline.fit_transform(d["train_features"],
                                                                 d["train_labels"],
                                                                 d["train_weights"])

        (d["test_features"],
         d["test_labels"],
         d["test_weights"]) = dk.feature_pipeline.transform(d["test_features"],
                                                            d["test_labels"],
                                                            d["test_weights"])

        logger.info(
            f"Training model on {len(dk.data_dictionary['train_features'].columns)} features"
        )
        logger.info(f"Training model on {len(d['train_features'])} data points")

        model = self.fit(d, dk)
        end_time = time()

        logger.info(f"-------------------- Done training {pair} "
                    f"({end_time - start_time:.2f} secs) --------------------")

        return model