# drug_interaction_detection/interaction_checker.py
import sqlite3
from config import DB_PATH

class InteractionChecker:
    def __init__(self, db_path: str = DB_PATH):
        self.conn = sqlite3.connect(db_path)
        self.conn.row_factory = sqlite3.Row

    def find(self, cuis: list[str]) -> list[dict]:
        if len(cuis) < 2: return []
        
        # Create a list of all unique pairs
        pairs = []
        for i in range(len(cuis)):
            for j in range(i + 1, len(cuis)):
                # Ensure consistent order for querying (e.g., smaller CUI first)
                pair = tuple(sorted((cuis[i], cuis[j])))
                pairs.append(pair)
        
        if not pairs: return []

        # Query for all pairs at once
        placeholders = ", ".join(["(?, ?)"] * len(pairs))
        flat_params = [item for pair in pairs for item in pair]
        
        query = f"""
            SELECT cui1, cui2, severity, advice 
            FROM interactions 
            WHERE (cui1, cui2) IN ({placeholders})
        """
        
        rows = self.conn.execute(query, flat_params).fetchall()
        return [{"pair": (r["cui1"], r["cui2"]), "severity": r["severity"], "advice": r["advice"]} for r in rows]