"""
Rate Limiting Dependencies

Functions for checking and enforcing rate limits on API endpoints.
"""
import logging
from datetime import datetime, timedelta
from sqlalchemy import select, and_
from sqlalchemy.ext.asyncio import AsyncSession

from core.models import RateLimit

logger = logging.getLogger(__name__)


async def check_rate_limit(
    db: AsyncSession,
    identifier: str,
    endpoint: str,
    limit: int,
    window_minutes: int
) -> bool:
    """
    Check if request is within rate limits.
    Returns True if allowed, False if limit exceeded.
    """
    now = datetime.utcnow()
    window_start = now - timedelta(minutes=window_minutes)
    
    # Check existing limit (get most recent if multiple exist)
    query = select(RateLimit).where(
        and_(
            RateLimit.identifier == identifier,
            RateLimit.endpoint == endpoint,
            RateLimit.window_start >= window_start
        )
    ).order_by(RateLimit.window_start.desc())
    result = await db.execute(query)
    rate_limit = result.scalars().first()
    
    if rate_limit:
        if rate_limit.attempts >= limit:
            return False
        
        # Increment attempts
        rate_limit.attempts += 1
        await db.commit()
        return True
    else:
        # Create new rate limit record
        new_limit = RateLimit(
            identifier=identifier,
            endpoint=endpoint,
            attempts=1,
            window_start=now,
            expires_at=now + timedelta(minutes=window_minutes)
        )
        db.add(new_limit)
        await db.commit()
        return True