"""
Data Analyzer class for causal inference pipelines.

This module provides the DataAnalyzer class for analyzing datasets
and extracting relevant information for causal inference.
"""

import pandas as pd
import numpy as np
from typing import Dict, List, Any, Optional


class DataAnalyzer:
    """
    Data analyzer for causal inference datasets.
    
    This class provides methods for analyzing datasets to extract
    relevant information for causal inference, such as variables,
    relationships, and temporal structures.
    """
    
    def __init__(self, verbose=False):
        """
        Initialize the data analyzer.
        
        Args:
            verbose: Whether to print verbose information
        """
        self.verbose = verbose
    
    def analyze_dataset(self, dataset_path: str) -> Dict[str, Any]:
        """
        Analyze a dataset and extract relevant information.
        
        Args:
            dataset_path: Path to the dataset file
            
        Returns:
            Dictionary with dataset analysis results
        """
        try:
            # Load the dataset
            df = pd.read_csv(dataset_path)
            
            # Get basic statistics
            n_rows, n_cols = df.shape
            columns = list(df.columns)
            
            # Get column types and categories
            column_types = {col: str(df[col].dtype) for col in columns}
            column_categories = self._categorize_columns(df)
            
            # Check for temporal structure
            temporal_structure = self._check_temporal_structure(df)
            
            # Identify potential confounders
            variable_relationships = self._identify_relationships(df)
            
            # Look for potential instruments
            potential_instruments = self._identify_potential_instruments(df)
            
            # Check for discontinuities
            discontinuities = self._check_discontinuities(df)
            
            # Construct the analysis result
            analysis = {
                "filepath": dataset_path,
                "n_rows": n_rows,
                "n_cols": n_cols,
                "columns": columns,
                "column_types": column_types,
                "column_categories": column_categories,
                "temporal_structure": temporal_structure,
                "variable_relationships": variable_relationships,
                "potential_instruments": potential_instruments,
                "discontinuities": discontinuities
            }
            
            if self.verbose:
                print(f"Dataset analysis completed: {n_rows} rows, {n_cols} columns")
            
            return analysis
            
        except Exception as e:
            if self.verbose:
                print(f"Error analyzing dataset: {str(e)}")
            
            return {
                "error": str(e),
                "filepath": dataset_path,
                "n_rows": 0,
                "n_cols": 0,
                "columns": [],
                "column_types": {},
                "column_categories": {},
                "temporal_structure": {"has_temporal_structure": False},
                "variable_relationships": {"potential_confounders": []},
                "potential_instruments": [],
                "discontinuities": {"has_discontinuities": False}
            }
    
    def _categorize_columns(self, df: pd.DataFrame) -> Dict[str, str]:
        """
        Categorize columns by data type.
        
        Args:
            df: Pandas DataFrame
            
        Returns:
            Dictionary mapping column names to categories
        """
        categories = {}
        for col in df.columns:
            if df[col].dtype == 'bool':
                categories[col] = 'binary'
            elif pd.api.types.is_numeric_dtype(df[col]):
                if len(df[col].unique()) <= 2:
                    categories[col] = 'binary'
                else:
                    categories[col] = 'continuous'
            else:
                unique_values = df[col].nunique()
                if unique_values <= 2:
                    categories[col] = 'binary'
                elif unique_values <= 10:
                    categories[col] = 'categorical'
                else:
                    categories[col] = 'high_cardinality'
        
        return categories
    
    def _check_temporal_structure(self, df: pd.DataFrame) -> Dict[str, Any]:
        """
        Check for temporal structure in the dataset.
        
        Args:
            df: Pandas DataFrame
            
        Returns:
            Dictionary with temporal structure information
        """
        # Look for date/time columns
        date_cols = [col for col in df.columns if 
                    any(keyword in col.lower() for keyword in 
                        ['date', 'time', 'year', 'month', 'day', 'period'])]
        
        # Check for panel data structure
        id_cols = [col for col in df.columns if 
                  any(keyword in col.lower() for keyword in 
                      ['id', 'group', 'entity', 'unit'])]
        
        return {
            "has_temporal_structure": len(date_cols) > 0,
            "is_panel_data": len(date_cols) > 0 and len(id_cols) > 0,
            "time_variables": date_cols,
            "id_variables": id_cols
        }
    
    def _identify_relationships(self, df: pd.DataFrame) -> Dict[str, List[str]]:
        """
        Identify potential variable relationships.
        
        Args:
            df: Pandas DataFrame
            
        Returns:
            Dictionary with relationship information
        """
        # This is a simplified implementation
        # A real implementation would use statistical tests or causal discovery
        
        return {
            "potential_confounders": []
        }
    
    def _identify_potential_instruments(self, df: pd.DataFrame) -> List[str]:
        """
        Identify potential instrumental variables.
        
        Args:
            df: Pandas DataFrame
            
        Returns:
            List of potential instrumental variables
        """
        # This is a simplified implementation
        # A real implementation would use statistical tests
        
        # Look for variables that might be instruments based on naming
        potential_instruments = [col for col in df.columns if 
                               any(keyword in col.lower() for keyword in 
                                   ['instrument', 'random', 'assignment', 'iv'])]
        
        return potential_instruments
    
    def _check_discontinuities(self, df: pd.DataFrame) -> Dict[str, Any]:
        """
        Check for potential discontinuities for RDD.
        
        Args:
            df: Pandas DataFrame
            
        Returns:
            Dictionary with discontinuity information
        """
        # This is a simplified implementation
        # A real implementation would use statistical tests
        
        return {
            "has_discontinuities": False,
            "potential_running_variables": []
        }