src/monitoring/drift.py

import pandas as pd
from evidently.report import Report
from evidently.metric_preset import DataDriftPreset
import os
import sys

sys.path.append(os.path.abspath(os.path.join(os.path.dirname(__file__), "..")))
from src.monitoring.db import load_data_from_db

def detect_drift(reference_path):
    # Load reference (original training data)
    reference_data = pd.read_csv(reference_path).drop("Class", axis=1)

    # Load current data from live DB
    current_data = load_data_from_db()

    # Drop tracking columns so we only compare the raw features (V1-V28, Time, Amount)
    current_data = current_data.drop(["id", "prediction", "probability", "Actual_Class"], axis=1)

    if len(current_data) < 50:
        print("⚠️ Not enough live data for drift detection")
        return None

    # Run statistical tests via Evidently AI
    report = Report(metrics=[DataDriftPreset()])
    report.run(reference_data=reference_data, current_data=current_data)

    BASE_DIR = os.path.abspath(os.path.join(os.path.dirname(__file__), "../../"))
    REPORT_PATH = os.path.join(BASE_DIR, "reports")
    os.makedirs(REPORT_PATH, exist_ok=True)

    path = os.path.join(REPORT_PATH, "drift_report.html")
    report.save_html(path)

    return path