"""
Main MCP Client implementation.
"""

import asyncio
import json
from typing import Any, Dict, Optional, Union

from .exceptions import ConnectionError, ProtocolError, TimeoutError


class MCPClient:
    """
    A client implementation for the Model Context Protocol (MCP).
    
    This client handles communication with MCP servers and provides
    a high-level interface for interacting with MCP services.
    """
    
    def __init__(self, server_url: str, timeout: float = 30.0):
        """
        Initialize the MCP client.
        
        Args:
            server_url: The URL of the MCP server to connect to.
            timeout: Connection and request timeout in seconds.
        """
        self.server_url = server_url
        self.timeout = timeout
        self._connection = None
        self._is_connected = False
    
    async def connect(self) -> None:
        """Connect to the MCP server."""
        try:
            # TODO: Implement actual connection logic
            await asyncio.sleep(0.1)  # Placeholder for connection
            self._is_connected = True
        except Exception as e:
            raise ConnectionError(f"Failed to connect to {self.server_url}: {e}")
    
    async def disconnect(self) -> None:
        """Disconnect from the MCP server."""
        if self._is_connected:
            # TODO: Implement actual disconnection logic
            await asyncio.sleep(0.1)  # Placeholder for disconnection
            self._is_connected = False
    
    @property
    def is_connected(self) -> bool:
        """Check if the client is connected to the server."""
        return self._is_connected
    
    async def send_request(self, method: str, params: Optional[Dict[str, Any]] = None) -> Dict[str, Any]:
        """
        Send a request to the MCP server.
        
        Args:
            method: The MCP method to call.
            params: Optional parameters for the method.
            
        Returns:
            The response from the server.
            
        Raises:
            ProtocolError: If there's an error in the protocol communication.
            TimeoutError: If the request times out.
        """
        if not self._is_connected:
            raise ConnectionError("Not connected to MCP server")
        
        try:
            # TODO: Implement actual request sending logic
            request = {
                "jsonrpc": "2.0",
                "method": method,
                "params": params or {},
                "id": 1  # TODO: Implement proper ID generation
            }
            
            # Placeholder for actual request/response handling
            await asyncio.sleep(0.1)
            response = {"result": f"Mock response for {method}"}
            
            return response
            
        except asyncio.TimeoutError:
            raise TimeoutError(f"Request to {method} timed out")
        except Exception as e:
            raise ProtocolError(f"Protocol error in request {method}: {e}")
    
    async def initialize(self) -> Dict[str, Any]:
        """
        Initialize the MCP session.
        
        Returns:
            The server's capabilities and initialization response.
        """
        return await self.send_request("initialize", {
            "protocolVersion": "2024-11-05",
            "capabilities": {},
            "clientInfo": {
                "name": "mcp-open-client",
                "version": "0.1.0"
            }
        })
    
    async def list_resources(self) -> Dict[str, Any]:
        """
        List available resources from the server.
        
        Returns:
            A list of available resources.
        """
        return await self.send_request("resources/list")
    
    async def list_tools(self) -> Dict[str, Any]:
        """
        List available tools from the server.
        
        Returns:
            A list of available tools.
        """
        return await self.send_request("tools/list")
    
    async def __aenter__(self):
        """Async context manager entry."""
        await self.connect()
        return self
    
    async def __aexit__(self, exc_type, exc_val, exc_tb):
        """Async context manager exit."""
        await self.disconnect()