"""
MongoDB Database Connection Manager
Author: AI Generated
Created: 2025-11-24
Purpose: Handle MongoDB connection and collection access
"""

from pymongo import MongoClient
from pymongo.database import Database
from pymongo.collection import Collection
from config import settings


class DatabaseManager:
    """Singleton MongoDB connection manager"""
    
    _instance = None
    _client: MongoClient = None
    _db: Database = None
    
    def __new__(cls):
        if cls._instance is None:
            cls._instance = super().__new__(cls)
        return cls._instance
    
    def __init__(self):
        if self._client is None:
            self.connect()
    
    @property
    def client(self):
        """Get MongoDB client"""
        return self._client
    
    @property
    def db_name(self):
        """Get database name"""
        return settings.DB_NAME
    
    def connect(self):
        """Establish connection to MongoDB"""
        self._client = MongoClient(settings.MONGODB_URI)
        self._db = self._client[settings.DB_NAME]
        print(f"✓ Connected to MongoDB: {settings.DB_NAME}")
    
    def get_collection(self, collection_name: str) -> Collection:
        """Get a MongoDB collection"""
        return self._db[collection_name]
    
    def close(self):
        """Close MongoDB connection"""
        if self._client:
            self._client.close()
            print("✓ MongoDB connection closed")
    
    # ACTUAL Collections (matching models.txt)
    @property
    def users(self) -> Collection:
        """User collection (contains embedded UserFollows array)"""
        return self.get_collection(settings.COLLECTION_USERS)
    
    @property
    def payments(self) -> Collection:
        """Payment collection"""
        return self.get_collection(settings.COLLECTION_PAYMENTS)
    
    @property
    def event_versions(self) -> Collection:
        """EventVersion collection"""
        return self.get_collection(settings.COLLECTION_EVENT_VERSIONS)
    
    @property
    def post_social_media(self) -> Collection:
        """PostSocialMedia collection (contains nested Images.UserCommentPosts)"""
        return self.get_collection(settings.COLLECTION_POST_SOCIAL_MEDIA)
    
    # AI Result Collections
    @property
    def audience_segments(self) -> Collection:
        """AudienceSegment collection (DEPRECATED - use event_audience_segments)"""
        return self.get_collection(settings.COLLECTION_AUDIENCE_SEGMENTS)
    
    @property
    def user_segment_assignments(self) -> Collection:
        """UserSegmentAssignment collection"""
        return self.get_collection(settings.COLLECTION_USER_SEGMENT_ASSIGNMENTS)
    
    @property
    def sentiment_results(self) -> Collection:
        """SentimentAnalysisResult collection"""
        return self.get_collection(settings.COLLECTION_SENTIMENT_RESULTS)
    
    @property
    def event_insights(self) -> Collection:
        """EventInsightReport collection"""
        return self.get_collection(settings.COLLECTION_EVENT_INSIGHTS)
    
    # NEW: Event-centric collections
    @property
    def event_audience_segments(self) -> Collection:
        """EventAudienceSegment collection"""
        return self.get_collection("EventAudienceSegment")
    
    @property
    def event_sentiment_summary(self) -> Collection:
        """EventSentimentSummary collection"""
        return self.get_collection("EventSentimentSummary")


# Global database instance
db = DatabaseManager()