"""Cache management API endpoints."""

import logging
from fastapi import APIRouter, HTTPException
from typing import Dict, Any

from app.services import cache

logger = logging.getLogger(__name__)

router = APIRouter(prefix="/api/v1/cache", tags=["Cache Management"])


@router.get("/stats", response_model=Dict[str, Any])
async def get_cache_stats():
    """
    Get cache statistics.
    
    Returns:
    - hits: Number of cache hits
    - misses: Number of cache misses  
    - sets: Number of cache writes
    - total_keys: Current number of cached route keys
    - enabled: Whether Redis cache is enabled
    """
    try:
        stats = cache.get_stats()
        # Calculate hit rate
        total_requests = stats.get("hits", 0) + stats.get("misses", 0)
        if total_requests > 0:
            stats["hit_rate"] = round(stats.get("hits", 0) / total_requests * 100, 2)
        else:
            stats["hit_rate"] = 0.0
        return stats
    except Exception as e:
        logger.error(f"Error getting cache stats: {e}")
        raise HTTPException(status_code=500, detail="Internal server error")


@router.get("/keys")
async def list_cache_keys(pattern: str = "routes:*"):
    """
    List cache keys matching pattern.
    
    - **pattern**: Redis key pattern (default: "routes:*")
    """
    try:
        keys = cache.get_keys(pattern)
        return {
            "pattern": pattern,
            "count": len(keys),
            "keys": keys[:100]  # Limit to first 100 for response size
        }
    except Exception as e:
        logger.error(f"Error listing cache keys: {e}")
        raise HTTPException(status_code=500, detail="Internal server error")


@router.delete("/clear")
async def clear_cache(pattern: str = "routes:*"):
    """
    Clear cache keys matching pattern.
    
    - **pattern**: Redis key pattern to delete (default: "routes:*")
    
    [WARN] **Warning**: This will delete cached route optimizations!
    """
    try:
        deleted_count = cache.delete(pattern)
        logger.info(f"Cleared {deleted_count} cache keys matching pattern: {pattern}")
        return {
            "pattern": pattern,
            "deleted_count": deleted_count,
            "message": f"Cleared {deleted_count} cache keys"
        }
    except Exception as e:
        logger.error(f"Error clearing cache: {e}")
        raise HTTPException(status_code=500, detail="Internal server error")