"""
WebSocket manager for real-time communication in Cidadão.AI
Handles investigation streaming, analysis updates, and notifications
"""

from src.core import json_utils
import asyncio
import logging
from typing import Dict, List, Set, Optional
from datetime import datetime
from fastapi import WebSocket, WebSocketDisconnect
from pydantic import BaseModel

logger = logging.getLogger(__name__)

class WebSocketMessage(BaseModel):
    """Standard WebSocket message format"""
    type: str
    data: dict
    timestamp: datetime = None
    user_id: str = None
    
    def __init__(self, **data):
        if 'timestamp' not in data:
            data['timestamp'] = datetime.utcnow()
        super().__init__(**data)

class ConnectionManager:
    """Manages WebSocket connections and message broadcasting"""
    
    def __init__(self):
        # Active connections by user ID
        self.user_connections: Dict[str, Set[WebSocket]] = {}
        
        # Connections by investigation ID
        self.investigation_connections: Dict[str, Set[WebSocket]] = {}
        
        # Connections by analysis ID  
        self.analysis_connections: Dict[str, Set[WebSocket]] = {}
        
        # Global notification connections
        self.notification_connections: Set[WebSocket] = set()
        
        # Connection metadata
        self.connection_metadata: Dict[WebSocket, dict] = {}
    
    async def connect(self, websocket: WebSocket, user_id: str, connection_type: str = "general"):
        """Accept new WebSocket connection"""
        await websocket.accept()
        
        # Store connection metadata
        self.connection_metadata[websocket] = {
            'user_id': user_id,
            'connection_type': connection_type,
            'connected_at': datetime.utcnow(),
            'last_ping': datetime.utcnow()
        }
        
        # Add to user connections
        if user_id not in self.user_connections:
            self.user_connections[user_id] = set()
        self.user_connections[user_id].add(websocket)
        
        # Add to notification connections
        self.notification_connections.add(websocket)
        
        logger.info(f"WebSocket connected: user_id={user_id}, type={connection_type}")
        
        # Send welcome message
        await self.send_personal_message(websocket, WebSocketMessage(
            type="connection_established",
            data={
                "message": "WebSocket connection established",
                "user_id": user_id,
                "connection_type": connection_type
            }
        ))
    
    def disconnect(self, websocket: WebSocket):
        """Remove WebSocket connection"""
        if websocket not in self.connection_metadata:
            return
        
        metadata = self.connection_metadata[websocket]
        user_id = metadata['user_id']
        
        # Remove from all connection sets
        if user_id in self.user_connections:
            self.user_connections[user_id].discard(websocket)
            if not self.user_connections[user_id]:
                del self.user_connections[user_id]
        
        self.notification_connections.discard(websocket)
        
        # Remove from investigation/analysis connections
        for connections in self.investigation_connections.values():
            connections.discard(websocket)
        
        for connections in self.analysis_connections.values():
            connections.discard(websocket)
        
        # Clean up metadata
        del self.connection_metadata[websocket]
        
        logger.info(f"WebSocket disconnected: user_id={user_id}")
    
    async def send_personal_message(self, websocket: WebSocket, message: WebSocketMessage):
        """Send message to specific WebSocket connection"""
        try:
            await websocket.send_text(message.json())
        except Exception as e:
            logger.error(f"Failed to send message to WebSocket: {e}")
            self.disconnect(websocket)
    
    async def send_to_user(self, user_id: str, message: WebSocketMessage):
        """Send message to all connections of a specific user"""
        if user_id not in self.user_connections:
            return
        
        message.user_id = user_id
        disconnected = set()
        
        for websocket in self.user_connections[user_id].copy():
            try:
                await websocket.send_text(message.json())
            except Exception as e:
                logger.error(f"Failed to send message to user {user_id}: {e}")
                disconnected.add(websocket)
        
        # Clean up disconnected sockets
        for websocket in disconnected:
            self.disconnect(websocket)
    
    async def broadcast_to_all(self, message: WebSocketMessage):
        """Broadcast message to all connected users"""
        disconnected = set()
        
        for websocket in self.notification_connections.copy():
            try:
                await websocket.send_text(message.json())
            except Exception as e:
                logger.error(f"Failed to broadcast message: {e}")
                disconnected.add(websocket)
        
        # Clean up disconnected sockets
        for websocket in disconnected:
            self.disconnect(websocket)
    
    async def subscribe_to_investigation(self, websocket: WebSocket, investigation_id: str):
        """Subscribe WebSocket to investigation updates"""
        if investigation_id not in self.investigation_connections:
            self.investigation_connections[investigation_id] = set()
        
        self.investigation_connections[investigation_id].add(websocket)
        
        await self.send_personal_message(websocket, WebSocketMessage(
            type="subscribed_to_investigation",
            data={
                "investigation_id": investigation_id,
                "message": f"Subscribed to investigation {investigation_id}"
            }
        ))
    
    async def unsubscribe_from_investigation(self, websocket: WebSocket, investigation_id: str):
        """Unsubscribe WebSocket from investigation updates"""
        if investigation_id in self.investigation_connections:
            self.investigation_connections[investigation_id].discard(websocket)
            
            if not self.investigation_connections[investigation_id]:
                del self.investigation_connections[investigation_id]
    
    async def send_to_investigation(self, investigation_id: str, message: WebSocketMessage):
        """Send message to all subscribers of an investigation"""
        if investigation_id not in self.investigation_connections:
            return
        
        disconnected = set()
        
        for websocket in self.investigation_connections[investigation_id].copy():
            try:
                await websocket.send_text(message.json())
            except Exception as e:
                logger.error(f"Failed to send investigation update: {e}")
                disconnected.add(websocket)
        
        # Clean up disconnected sockets
        for websocket in disconnected:
            self.disconnect(websocket)
    
    async def subscribe_to_analysis(self, websocket: WebSocket, analysis_id: str):
        """Subscribe WebSocket to analysis updates"""
        if analysis_id not in self.analysis_connections:
            self.analysis_connections[analysis_id] = set()
        
        self.analysis_connections[analysis_id].add(websocket)
        
        await self.send_personal_message(websocket, WebSocketMessage(
            type="subscribed_to_analysis", 
            data={
                "analysis_id": analysis_id,
                "message": f"Subscribed to analysis {analysis_id}"
            }
        ))
    
    async def send_to_analysis(self, analysis_id: str, message: WebSocketMessage):
        """Send message to all subscribers of an analysis"""
        if analysis_id not in self.analysis_connections:
            return
        
        disconnected = set()
        
        for websocket in self.analysis_connections[analysis_id].copy():
            try:
                await websocket.send_text(message.json())
            except Exception as e:
                logger.error(f"Failed to send analysis update: {e}")
                disconnected.add(websocket)
        
        # Clean up disconnected sockets
        for websocket in disconnected:
            self.disconnect(websocket)
    
    async def send_system_notification(self, notification_type: str, data: dict):
        """Send system-wide notification"""
        message = WebSocketMessage(
            type="system_notification",
            data={
                "notification_type": notification_type,
                **data
            }
        )
        
        await self.broadcast_to_all(message)
    
    def get_connection_stats(self) -> dict:
        """Get WebSocket connection statistics"""
        return {
            "total_connections": len(self.connection_metadata),
            "users_connected": len(self.user_connections),
            "active_investigations": len(self.investigation_connections),
            "active_analyses": len(self.analysis_connections),
            "notification_subscribers": len(self.notification_connections)
        }
    
    async def ping_all_connections(self):
        """Send ping to all connections to keep them alive"""
        ping_message = WebSocketMessage(
            type="ping",
            data={"timestamp": datetime.utcnow().isoformat()}
        )
        
        disconnected = set()
        
        for websocket in list(self.connection_metadata.keys()):
            try:
                await websocket.send_text(ping_message.json())
                self.connection_metadata[websocket]['last_ping'] = datetime.utcnow()
            except Exception:
                disconnected.add(websocket)
        
        # Clean up disconnected sockets
        for websocket in disconnected:
            self.disconnect(websocket)

# Global connection manager instance
connection_manager = ConnectionManager()

class WebSocketHandler:
    """Handles WebSocket message processing"""
    
    def __init__(self, connection_manager: ConnectionManager):
        self.connection_manager = connection_manager
    
    async def handle_message(self, websocket: WebSocket, message: dict):
        """Process incoming WebSocket message"""
        message_type = message.get('type')
        data = message.get('data', {})
        
        try:
            if message_type == "subscribe_investigation":
                investigation_id = data.get('investigation_id')
                if investigation_id:
                    await self.connection_manager.subscribe_to_investigation(websocket, investigation_id)
            
            elif message_type == "unsubscribe_investigation":
                investigation_id = data.get('investigation_id')
                if investigation_id:
                    await self.connection_manager.unsubscribe_from_investigation(websocket, investigation_id)
            
            elif message_type == "subscribe_analysis":
                analysis_id = data.get('analysis_id')
                if analysis_id:
                    await self.connection_manager.subscribe_to_analysis(websocket, analysis_id)
            
            elif message_type == "pong":
                # Handle pong response
                if websocket in self.connection_manager.connection_metadata:
                    self.connection_manager.connection_metadata[websocket]['last_ping'] = datetime.utcnow()
            
            else:
                logger.warning(f"Unknown WebSocket message type: {message_type}")
                
        except Exception as e:
            logger.error(f"Error handling WebSocket message: {e}")
            
            error_message = WebSocketMessage(
                type="error",
                data={
                    "message": f"Failed to process message: {str(e)}",
                    "original_type": message_type
                }
            )
            
            await self.connection_manager.send_personal_message(websocket, error_message)

# Global WebSocket handler
websocket_handler = WebSocketHandler(connection_manager)

# Background task for connection maintenance
async def connection_maintenance_task():
    """Background task to maintain WebSocket connections"""
    while True:
        try:
            await connection_manager.ping_all_connections()
            await asyncio.sleep(30)  # Ping every 30 seconds
        except Exception as e:
            logger.error(f"Error in connection maintenance: {e}")
            await asyncio.sleep(60)  # Wait longer on error