import logging
import asyncio
import time
from typing import List, Dict, Any
from fastapi import APIRouter, HTTPException, WebSocket, WebSocketDisconnect, Depends
from fastapi.responses import JSONResponse
from pydantic import BaseModel
from cryptography.fernet import Fernet
from cryptography.hazmat.primitives import hashes
from ..services.task_queue import distribute_task, task_retry, validate_task_parameters
from ..auth import JWTBearer
from ..utils import get_node_id, get_peers, register_node, check_peer_health
from ..services.health_check import SystemHealthMonitor
from ..services.anomaly_detection import AnomalyDetector

# Set up logging
logger = logging.getLogger(__name__)

# Initialize WebSocket clients dictionary to track active connections
active_connections = {}

# P2P Router Setup
router = APIRouter()

# Encryption key for secure communications
encryption_key = Fernet.generate_key()
cipher = Fernet(encryption_key)

# Add new system components
health_monitor = SystemHealthMonitor()
anomaly_detector = AnomalyDetector()

# --- P2P Node Models ---
class P2PNode(BaseModel):
    """Schema for P2P Node registration."""
    node_id: str
    ip_address: str
    port: int

class TaskRequest(BaseModel):
    """Schema for task request in P2P network."""
    task_name: str
    parameters: Dict[str, Any]
    target_node_id: str

class TaskResponse(BaseModel):
    """Schema for task response in P2P network."""
    task_name: str
    result: Dict[str, Any]
    success: bool
    message: str


# --- P2P Node Management ---
@router.post("/register-node", response_model=Dict[str, Any])
async def register_p2p_node(node: P2PNode):
    """
    Register a new node in the P2P network and notify other peers.
    
    This allows nodes to join the network and be discovered by others.
    """
    try:
        # Register the node locally and broadcast to other peers
        register_node(node.node_id, node.ip_address, node.port)
        logger.info(f"Node {node.node_id} registered successfully.")
        return {"success": True, "message": f"Node {node.node_id} registered successfully."}
    except Exception as e:
        logger.error(f"Node registration failed: {str(e)}")
        raise HTTPException(status_code=500, detail=f"Node registration failed: {str(e)}")


@router.get("/discover-peers", response_model=List[P2PNode])
async def discover_peers():
    """
    Discover all available peers in the P2P network.
    
    Returns:
    - List of P2PNode objects representing other peers in the network.
    """
    try:
        peers = get_peers()  # Retrieve peer list from the node registry
        return peers
    except Exception as e:
        logger.error(f"Peer discovery failed: {str(e)}")
        raise HTTPException(status_code=500, detail="Failed to discover peers.")


@router.get("/check-peer-health/{node_id}", response_model=Dict[str, Any])
async def check_peer_health_status(node_id: str):
    """
    Check the health status of a peer node.
    
    Parameters:
    - node_id: The ID of the node to check.
    
    Returns:
    - Health status of the peer node.
    """
    try:
        is_healthy = await check_peer_health(node_id)
        return {"node_id": node_id, "status": "healthy" if is_healthy else "unhealthy"}
    except Exception as e:
        logger.error(f"Error checking health of node {node_id}: {str(e)}")
        raise HTTPException(status_code=500, detail="Failed to check peer health.")


@router.get("/node-health/{node_id}", response_model=Dict[str, Any])
async def get_node_health(node_id: str):
    """Get comprehensive health metrics for a node."""
    try:
        health_metrics = health_monitor.get_node_health(node_id)
        anomalies = anomaly_detector.check_node(node_id)
        
        return {
            "node_id": node_id,
            "health_metrics": health_metrics,
            "anomalies": anomalies,
            "timestamp": time.time()
        }
    except Exception as e:
        logger.error(f"Error checking node health: {str(e)}")
        raise HTTPException(status_code=500, detail="Failed to check node health")

@router.post("/report-anomaly")
async def report_anomaly(node_id: str, anomaly_data: Dict[str, Any]):
    """Report an anomaly in the network."""
    try:
        # Verify the reporting node's signature
        if not verify_node_signature(node_id, anomaly_data):
            raise HTTPException(status_code=403, detail="Invalid node signature")
            
        consensus = await get_anomaly_consensus(anomaly_data)
        if consensus:
            await redistribute_workload(node_id)
        
        return {"status": "Anomaly reported and handled"}
    except Exception as e:
        logger.error(f"Error reporting anomaly: {str(e)}")
        raise HTTPException(status_code=500, detail="Failed to process anomaly report")


# --- Task Distribution and Management ---
@router.websocket("/task-distribution")
async def task_distribution_socket(websocket: WebSocket, task_request: TaskRequest, jwt_token: str = Depends(JWTBearer())):
    """
    WebSocket for handling task distribution in the P2P network.
    
    This endpoint listens for task requests and distributes them across available nodes.
    """
    await websocket.accept()
    
    # Decrypt task request for secure transmission
    decrypted_task_request = cipher.decrypt(task_request.encode()).decode()
    logger.info(f"Task request received: {decrypted_task_request}")

    try:
        # Validate task parameters before distributing
        validate_task_parameters(task_request.task_name, task_request.parameters)
        
        # Check if the target node is active
        if not await check_peer_health(task_request.target_node_id):
            raise HTTPException(status_code=404, detail="Target node is not reachable.")
        
        # Assign task to the specified peer
        task_result = await distribute_task(task_request, task_request.target_node_id)
        
        # Send back the task response
        response = TaskResponse(task_name=task_request.task_name, result=task_result, success=True, message="Task successfully distributed.")
        await websocket.send_json(response.dict())
    
    except WebSocketDisconnect:
        logger.info("WebSocket disconnected.")
    
    except HTTPException as e:
        logger.error(f"Error during task distribution: {str(e)}")
        await websocket.send_json({"success": False, "message": str(e.detail)})
    
    except Exception as e:
        logger.error(f"Unexpected error: {str(e)}")
        await websocket.send_json({"success": False, "message": "An unexpected error occurred."})


@router.post("/retry-task")
async def retry_task(task_id: str):
    """
    Retry a failed task on the P2P network.
    
    Parameters:
    - task_id: The ID of the task to retry.
    
    Returns:
    - Success message or error.
    """
    try:
        result = await task_retry(task_id)
        return {"success": True, "message": f"Task {task_id} retried successfully."}
    
    except Exception as e:
        logger.error(f"Task retry failed for {task_id}: {str(e)}")
        raise HTTPException(status_code=500, detail=f"Task retry failed: {str(e)}")


# --- Utility Functions for P2P Network ---
async def register_node(node_id: str, ip_address: str, port: int):
    """Register a new node to the network."""
    # Placeholder: Implement node registration in a database or distributed ledger
    logger.info(f"Registering node {node_id} at {ip_address}:{port}")
    pass

async def get_peers() -> List[P2PNode]:
    """Retrieve a list of available peers in the P2P network."""
    # Placeholder: Fetch list of peers from a database or distributed registry
    return [
        P2PNode(node_id="node_1", ip_address="192.168.1.1", port=8001),
        P2PNode(node_id="node_2", ip_address="192.168.1.2", port=8002),
    ]

async def check_peer_health(node_id: str) -> bool:
    """Check if a specific peer node is healthy and responsive."""
    # Placeholder: Implement peer health check (ping test, monitoring system, etc.)
    if node_id == "node_1":
        return True  # Node_1 is healthy
    return False  # Node_2 is not healthy for example


# --- Example of Broadcasting Messages to Peers ---
async def broadcast_message(message: Dict[str, Any], exclude_node_id: str = None):
    """Broadcast a message to all peers except the specified one."""
    peers = await get_peers()
    
    for peer in peers:
        if peer.node_id != exclude_node_id:
            try:
                # Here, send the message to the peer's WebSocket or HTTP endpoint
                logger.info(f"Broadcasting message to node {peer.node_id}")
                pass  # Placeholder for actual communication method (e.g., WebSocket/HTTP)
            except Exception as e:
                logger.error(f"Failed to broadcast message to {peer.node_id}: {str(e)}")

    # Next Steps
    """
    Implement the underlying distributed storage or database mechanism to track node states and tasks.
    Improve security and fault tolerance, including encrypted communication for all traffic between nodes.
    """
