"""
Data Manager Module
Handles in-memory storage, persistence, and data operations.
"""

import json
import logging
from typing import List, Dict, Any, Set
from datetime import datetime
from pathlib import Path

logging.basicConfig(level=logging.INFO)
logger = logging.getLogger(__name__)

DATA_DIR = Path("data")
LISTINGS_FILE = DATA_DIR / "listings.json"
FAVORITES_FILE = DATA_DIR / "favorites.json"


class DataManager:
    """Manages in-memory and persistent storage of listings."""
    
    def __init__(self):
        self.listings: Dict[str, Dict[str, Any]] = {}
        self.favorites: Set[str] = set()
        self.seen_ids: Set[str] = set()
        self._ensure_data_dir()
        self._load_data()
    
    def _ensure_data_dir(self):
        """Ensure data directory exists."""
        DATA_DIR.mkdir(exist_ok=True)
    
    def _load_data(self):
        """Load persisted data from files."""
        try:
            if LISTINGS_FILE.exists():
                with open(LISTINGS_FILE, "r", encoding="utf-8") as f:
                    data = json.load(f)
                    self.listings = data.get("listings", {})
                    self.seen_ids = set(self.listings.keys())
                logger.info(f"Loaded {len(self.listings)} listings from disk")
        except Exception as e:
            logger.error(f"Error loading listings: {e}")
        
        try:
            if FAVORITES_FILE.exists():
                with open(FAVORITES_FILE, "r", encoding="utf-8") as f:
                    data = json.load(f)
                    self.favorites = set(data.get("favorites", []))
                logger.info(f"Loaded {len(self.favorites)} favorites from disk")
        except Exception as e:
            logger.error(f"Error loading favorites: {e}")
    
    def _save_listings(self):
        """Persist listings to disk."""
        try:
            with open(LISTINGS_FILE, "w", encoding="utf-8") as f:
                json.dump({"listings": self.listings}, f, ensure_ascii=False, indent=2)
        except Exception as e:
            logger.error(f"Error saving listings: {e}")
    
    def _save_favorites(self):
        """Persist favorites to disk."""
        try:
            with open(FAVORITES_FILE, "w", encoding="utf-8") as f:
                json.dump({"favorites": list(self.favorites)}, f, ensure_ascii=False, indent=2)
        except Exception as e:
            logger.error(f"Error saving favorites: {e}")
    
    def add_listings(self, listings: List[Dict[str, Any]]) -> int:
        """
        Add new listings to storage.
        
        Args:
            listings: List of listing dictionaries
            
        Returns:
            Number of new listings added
        """
        new_count = 0
        for listing in listings:
            divar_id = listing.get("divar_id")
            if divar_id and divar_id not in self.seen_ids:
                self.listings[divar_id] = listing
                self.seen_ids.add(divar_id)
                new_count += 1
        
        if new_count > 0:
            self._save_listings()
            logger.info(f"Added {new_count} new listings")
        
        return new_count
    
    def get_all_listings(self) -> List[Dict[str, Any]]:
        """Get all listings."""
        return list(self.listings.values())
    
    def get_listings_by_neighborhood(self, neighborhood: str) -> List[Dict[str, Any]]:
        """Get listings for a specific neighborhood."""
        return [l for l in self.listings.values() if l.get("neighborhood") == neighborhood]
    
    def get_budget_fit_listings(self) -> List[Dict[str, Any]]:
        """Get listings that fit the budget."""
        return [l for l in self.listings.values() if l.get("budget_fit") == "fits_budget"]
    
    def get_listing(self, divar_id: str) -> Dict[str, Any]:
        """Get a specific listing by ID."""
        return self.listings.get(divar_id, {})
    
    def add_favorite(self, divar_id: str) -> bool:
        """Add a listing to favorites (max 3)."""
        if len(self.favorites) >= 3 and divar_id not in self.favorites:
            logger.warning("Favorites limit (3) reached")
            return False
        
        self.favorites.add(divar_id)
        self._save_favorites()
        logger.info(f"Added {divar_id} to favorites")
        return True
    
    def remove_favorite(self, divar_id: str) -> bool:
        """Remove a listing from favorites."""
        if divar_id in self.favorites:
            self.favorites.remove(divar_id)
            self._save_favorites()
            logger.info(f"Removed {divar_id} from favorites")
            return True
        return False
    
    def get_favorites(self) -> List[Dict[str, Any]]:
        """Get all favorite listings."""
        return [self.listings[fid] for fid in self.favorites if fid in self.listings]
    
    def is_favorite(self, divar_id: str) -> bool:
        """Check if a listing is in favorites."""
        return divar_id in self.favorites
    
    def clear_all(self):
        """Clear all data (for testing)."""
        self.listings.clear()
        self.favorites.clear()
        self.seen_ids.clear()
        self._save_listings()
        self._save_favorites()
        logger.info("Cleared all data")
    
    def get_statistics(self) -> Dict[str, Any]:
        """Get statistics about stored listings."""
        listings = self.get_all_listings()
        budget_fit = len(self.get_budget_fit_listings())
        
        return {
            "total_listings": len(listings),
            "budget_fit_count": budget_fit,
            "favorites_count": len(self.favorites),
            "neighborhoods": list(set(l.get("neighborhood", "") for l in listings)),
            "last_updated": datetime.now().isoformat()
        }


# Global instance
_data_manager = None


def get_data_manager() -> DataManager:
    """Factory function to get or create data manager instance."""
    global _data_manager
    if _data_manager is None:
        _data_manager = DataManager()
    return _data_manager


if __name__ == "__main__":
    manager = get_data_manager()
    print(f"Statistics: {manager.get_statistics()}")