"""WebSocket routes for agent real-time communication"""
import asyncio
import json
import logging
import threading
from typing import Any, Dict, Optional, Set
from datetime import datetime
from fastapi import APIRouter, WebSocket, WebSocketDisconnect, Depends
import uuid

from luxx.agents.core import Agent, AgentConfig, AgentType, AgentStatus
from luxx.agents.dag import DAG, TaskNode, TaskNodeStatus, TaskResult
from luxx.agents.supervisor import SupervisorAgent
from luxx.agents.worker import WorkerAgent
from luxx.agents.dag_scheduler import DAGScheduler, SchedulerPool
from luxx.agents.registry import AgentRegistry
from luxx.services.llm_client import llm_client
from luxx.tools.executor import ToolExecutor

logger = logging.getLogger(__name__)

router = APIRouter()


class ConnectionManager:
    """
    WebSocket Connection Manager
    
    Manages WebSocket connections for real-time agent progress updates.
    Features:
    - Connection tracking by task_id
    - Heartbeat mechanism
    - Progress broadcasting
    """
    
    def __init__(self):
        # task_id -> set of websocket connections
        self._connections: Dict[str, Set[WebSocket]] = {}
        # websocket -> task_id mapping
        self._ws_to_task: Dict[WebSocket, str] = {}
        # heartbeat tasks
        self._heartbeat_tasks: Dict[WebSocket, asyncio.Task] = {}
        # lock for thread safety
        self._lock = threading.Lock()
        # heartbeat interval in seconds
        self._heartbeat_interval = 30
    
    def connect(self, websocket: WebSocket, task_id: str) -> None:
        """
        Accept and register a WebSocket connection
        
        Args:
            websocket: WebSocket connection
            task_id: Task ID to subscribe to
        """
        websocket.accept()
        
        with self._lock:
            if task_id not in self._connections:
                self._connections[task_id] = set()
            self._connections[task_id].add(websocket)
            self._ws_to_task[websocket] = task_id
        
        logger.info(f"WebSocket connected for task {task_id}")
    
    def disconnect(self, websocket: WebSocket) -> None:
        """
        Unregister a WebSocket connection
        
        Args:
            websocket: WebSocket connection
        """
        with self._lock:
            task_id = self._ws_to_task.pop(websocket, None)
            if task_id and task_id in self._connections:
                self._connections[task_id].discard(websocket)
                if not self._connections[task_id]:
                    del self._connections[task_id]
            
            # Cancel heartbeat task
            if websocket in self._heartbeat_tasks:
                self._heartbeat_tasks[websocket].cancel()
                del self._heartbeat_tasks[websocket]
        
        if task_id:
            logger.info(f"WebSocket disconnected for task {task_id}")
    
    async def send_to_task(self, task_id: str, message: Dict[str, Any]) -> None:
        """
        Send message to all connections subscribed to a task
        
        Args:
            task_id: Task ID
            message: Message to send
        """
        with self._lock:
            connections = self._connections.get(task_id, set()).copy()
        
        if not connections:
            return
        
        dead_connections = set()
        
        for websocket in connections:
            try:
                await websocket.send_json(message)
            except Exception as e:
                logger.warning(f"Failed to send to websocket: {e}")
                dead_connections.add(websocket)
        
        # Clean up dead connections
        for ws in dead_connections:
            self.disconnect(ws)
    
    async def broadcast(self, message: Dict[str, Any]) -> None:
        """
        Broadcast message to all connections
        
        Args:
            message: Message to broadcast
        """
        with self._lock:
            all_connections = list(self._ws_to_task.keys())
        
        for websocket in all_connections:
            try:
                await websocket.send_json(message)
            except Exception as e:
                logger.warning(f"Failed to broadcast: {e}")
    
    async def send_personal(self, websocket: WebSocket, message: Dict[str, Any]) -> None:
        """
        Send message to a specific connection
        
        Args:
            websocket: Target WebSocket
            message: Message to send
        """
        try:
            await websocket.send_json(message)
        except Exception as e:
            logger.warning(f"Failed to send personal message: {e}")
    
    def start_heartbeat(self, websocket: WebSocket) -> None:
        """
        Start heartbeat for a connection
        
        Args:
            websocket: WebSocket connection
        """
        async def heartbeat_loop():
            while True:
                await asyncio.sleep(self._heartbeat_interval)
                try:
                    await websocket.send_json({
                        "type": "heartbeat",
                        "interval": self._heartbeat_interval
                    })
                except Exception:
                    break
        
        task = asyncio.create_task(heartbeat_loop())
        with self._lock:
            self._heartbeat_tasks[websocket] = task
    
    @property
    def connection_count(self) -> int:
        """Total number of connections"""
        with self._lock:
            return len(self._ws_to_task)
    
    def get_task_connections(self, task_id: str) -> int:
        """Get number of connections for a task"""
        with self._lock:
            return len(self._connections.get(task_id, set()))


# Global connection manager
connection_manager = ConnectionManager()

# Global scheduler pool
scheduler_pool = SchedulerPool(max_concurrent=10)

# Global tool executor
tool_executor = ToolExecutor()


class ProgressEmitter:
    """
    Progress emitter that sends updates via WebSocket
    
    Wraps DAGScheduler progress callback to emit WebSocket messages.
    """
    
    def __init__(self, task_id: str, connection_manager: ConnectionManager):
        self.task_id = task_id
        self.connection_manager = connection_manager
    
    def __call__(self, node_id: str, progress: float, message: str = "") -> None:
        """Progress callback"""
        if node_id == "dag":
            # DAG-level progress
            asyncio.create_task(self.connection_manager.send_to_task(
                self.task_id,
                {
                    "type": "dag_progress",
                    "data": {
                        "progress": progress,
                        "message": message
                    }
                }
            ))
        else:
            # Node-level progress
            asyncio.create_task(self.connection_manager.send_to_task(
                self.task_id,
                {
                    "type": "node_progress",
                    "data": {
                        "node_id": node_id,
                        "progress": progress,
                        "message": message
                    }
                }
            ))


@router.websocket("/ws/dag/{task_id}")
async def dag_websocket(websocket: WebSocket, task_id: str):
    """
    WebSocket endpoint for DAG progress updates
    
    Protocol:
    - Client sends: subscribe, get_status, ping, cancel_task
    - Server sends: subscribed, heartbeat, dag_start, node_start, node_progress, 
                    node_complete, node_error, dag_complete, pong
    """
    # Accept connection
    connection_manager.connect(websocket, task_id)
    
    # Send subscribed confirmation
    await connection_manager.send_personal(websocket, {
        "type": "subscribed",
        "task_id": task_id
    })
    
    # Start heartbeat
    connection_manager.start_heartbeat(websocket)
    
    # Get scheduler if exists
    scheduler = scheduler_pool.get(task_id)
    if scheduler:
        # Send current DAG state
        await connection_manager.send_personal(websocket, {
            "type": "dag_status",
            "data": scheduler.dag.to_dict()
        })
    
    try:
        while True:
            # Receive message
            data = await websocket.receive_text()
            
            try:
                message = json.loads(data)
            except json.JSONDecodeError:
                await connection_manager.send_personal(websocket, {
                    "type": "error",
                    "message": "Invalid JSON"
                })
                continue
            
            msg_type = message.get("type")
            
            if msg_type == "subscribe":
                # Already subscribed on connect
                await connection_manager.send_personal(websocket, {
                    "type": "subscribed",
                    "task_id": task_id
                })
            
            elif msg_type == "get_status":
                scheduler = scheduler_pool.get(task_id)
                if scheduler:
                    await connection_manager.send_personal(websocket, {
                        "type": "dag_status",
                        "data": scheduler.dag.to_dict()
                    })
                else:
                    await connection_manager.send_personal(websocket, {
                        "type": "dag_status",
                        "data": None
                    })
            
            elif msg_type == "ping":
                await connection_manager.send_personal(websocket, {
                    "type": "pong"
                })
            
            elif msg_type == "cancel_task":
                if scheduler_pool.cancel(task_id):
                    await connection_manager.send_personal(websocket, {
                        "type": "task_cancelled",
                        "task_id": task_id
                    })
                else:
                    await connection_manager.send_personal(websocket, {
                        "type": "error",
                        "message": "Task not found or already completed"
                    })
            
            else:
                await connection_manager.send_personal(websocket, {
                    "type": "error",
                    "message": f"Unknown message type: {msg_type}"
                })
    
    except WebSocketDisconnect:
        connection_manager.disconnect(websocket)
    except Exception as e:
        logger.error(f"WebSocket error: {e}")
        connection_manager.disconnect(websocket)


# Helper functions to emit progress from scheduler

def create_progress_emitter(task_id: str) -> ProgressEmitter:
    """Create a progress emitter for a task"""
    return ProgressEmitter(task_id, connection_manager)


async def emit_dag_start(task_id: str, dag: DAG) -> None:
    """Emit DAG start event"""
    await connection_manager.send_to_task(task_id, {
        "type": "dag_start",
        "data": {
            "graph": dag.to_dict()
        }
    })


async def emit_node_start(task_id: str, node: TaskNode) -> None:
    """Emit node start event"""
    await connection_manager.send_to_task(task_id, {
        "type": "node_start",
        "data": {
            "node_id": node.id,
            "name": node.name,
            "status": node.status.value
        }
    })


async def emit_node_complete(task_id: str, node: TaskNode) -> None:
    """Emit node complete event"""
    await connection_manager.send_to_task(task_id, {
        "type": "node_complete",
        "data": {
            "node_id": node.id,
            "result": node.result.to_dict() if node.result else None,
            "output_data": node.output_data
        }
    })


async def emit_node_error(task_id: str, node: TaskNode, error: str) -> None:
    """Emit node error event"""
    await connection_manager.send_to_task(task_id, {
        "type": "node_error",
        "data": {
            "node_id": node.id,
            "error": error
        }
    })


async def emit_dag_complete(task_id: str, success: bool, results: Dict) -> None:
    """Emit DAG complete event"""
    await connection_manager.send_to_task(task_id, {
        "type": "dag_complete",
        "data": {
            "success": success,
            "results": results
        }
    })