# app/services/analytics_service.py

import pandas as pd
from data.database import Database

class AnalyticsService:

    def __init__(self):
        self.db = Database()

    def overall_accuracy(self):
        df = pd.read_sql_query("SELECT correct FROM answers", self.db.conn)
        if df.empty:
            return 0
        return df["correct"].mean()