from sqlalchemy import select
from sqlalchemy.orm import Session

from app.models.tables import CategoryRule, Transaction


def apply_rules(session: Session, transactions: list[Transaction]) -> int:
    rules = session.execute(
        select(CategoryRule).order_by(CategoryRule.priority)).scalars().all()
    hits = 0
    for tx in transactions:
        if tx.category_id is not None:
            continue
        haystack = f"{tx.purpose} {tx.counterparty}".lower()
        for rule in rules:
            if rule.pattern.lower() in haystack:
                tx.category_id = rule.category_id
                hits += 1
                break
    return hits