import pandas as pd
from pathlib import Path
from typing import Optional
try:
    from evidently.report import Report
    from evidently.metric_preset import DataDriftPreset, DataQualityPreset
    EVIDENTLY_AVAILABLE = True
except ImportError:
    EVIDENTLY_AVAILABLE = False


class EvidentlyMonitor:
    def __init__(self, reference_data: pd.DataFrame):
        if not EVIDENTLY_AVAILABLE:
            raise ImportError("Evidently not installed. Run: pip install evidently")
        self.reference_data = reference_data
    
    def generate_drift_report(self, current_data: pd.DataFrame, output_path: Optional[Path] = None):
        """Generate Evidently data drift report"""
        report = Report(metrics=[
            DataDriftPreset(),
            DataQualityPreset()
        ])
        
        report.run(reference_data=self.reference_data, current_data=current_data)
        
        if output_path:
            output_path.parent.mkdir(parents=True, exist_ok=True)
            report.save_html(str(output_path))
        
        return report
    
    def get_drift_metrics(self, current_data: pd.DataFrame) -> dict:
        """Get drift metrics as dictionary"""
        report = Report(metrics=[DataDriftPreset()])
        report.run(reference_data=self.reference_data, current_data=current_data)
        return report.as_dict()