from abc import ABC, abstractmethod
from typing import Union

import numpy as np
import pandas as pd
from sklearn.model_selection import train_test_split

import os

current_directory = os.path.dirname(os.path.abspath(__file__))

print(current_directory)

class DataStrategy(ABC):
    """
    Abstract class defining strategy for handling data
    """

    @abstractmethod
    def handle_data(self, df_movie: pd.DataFrame, df_user: pd.DataFrame, df_rating: pd.DataFrame) -> Union[pd.DataFrame, pd.Series]:
        pass

class DataCombiningBaseline(DataStrategy):
    """
    Baseline method to return data
    """
    def handle_data(self, df_movie: pd.DataFrame, df_user: pd.DataFrame, df_rating: pd.DataFrame) -> Union[pd.DataFrame, pd.Series]:
        result_df = df_rating.pivot(index='movie_id', columns='user_id', values='rating')

        # Reset the index to turn movie_id back into a column
        result_df.reset_index(inplace=True)

        # Fill missing values with NaN (or another value if preferred, like 0)
        result_df.fillna(np.nan, inplace=True)

        # Rename columns to match user_id
        result_df.columns.name = None  # Remove the name of the columns index

        return result_df
        
class DataPreprocessing:
    """
    Class for cleaning data which processes the data and divides it into train and test
    """
    def __init__(self, df_movie: pd.DataFrame, df_user: pd.DataFrame, df_rating: pd.DataFrame, strategy: DataStrategy):
        self.df_movie = df_movie
        self.df_user = df_user
        self.df_rating = df_rating
        self.strategy = strategy

    def handle_data(self) -> Union[pd.DataFrame, pd.Series]:
        """
        Handle data
        """
        try:
            return self.strategy.handle_data(self.df_movie, self.df_user, self.df_rating)
        except Exception as e:
            logging.error(f"Error in handling data: {e}")
            raise e