#!/usr/bin/env python
"""
Standalone FastAPI MCP server for Hyper-V management.
Server will be available at http://localhost:8000
"""
import asyncio
import json
import logging
import subprocess
import sys
import platform
from typing import Dict, Any, List, Optional
from dataclasses import dataclass, asdict
from fastapi import FastAPI, HTTPException
from pydantic import BaseModel
import uvicorn

# Ensure SelectorEventLoopPolicy on Windows
if platform.system() == "Windows":
    try:
        asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())
    except AttributeError:
        pass

# Setup logging
logging.basicConfig(level=logging.INFO)
logger = logging.getLogger("hyperv_mcp_server")

# Pydantic models for API
class ToolCallRequest(BaseModel):
    name: str
    arguments: Dict[str, Any] = {}

class ToolInfo(BaseModel):
    name: str
    description: str
    inputSchema: Dict[str, Any]

class ToolsListResponse(BaseModel):
    tools: List[ToolInfo]

class ToolCallResponse(BaseModel):
    success: bool
    result: Any = None
    error: str = None

@dataclass
class VirtualMachine:
    name: str
    state: str
    status: str

class HyperVManager:
    def __init__(self, host: str = "localhost", username: Optional[str] = None, password: Optional[str] = None):
        self.host = host
        self.username = username
        self.password = password

    def _run_powershell(self, command: str) -> str:
        """Execute PowerShell command and return output"""
        try:
            if self.host == "localhost":
                proc = subprocess.run(
                    ["powershell", "-Command", command],
                    capture_output=True, text=True, shell=True, timeout=30
                )
                if proc.returncode != 0:
                    raise RuntimeError(f"PowerShell error: {proc.stderr}")
                return proc.stdout.strip()
            else:
                raise NotImplementedError("Remote host not supported in this server")
        except subprocess.TimeoutExpired:
            raise RuntimeError("PowerShell command timed out")
        except Exception as e:
            logger.error(f"PowerShell execution error: {e}")
            raise

    async def list_vms(self) -> List[Dict[str, Any]]:
        """List all virtual machines"""
        try:
            cmd = (
                "Get-VM | Select-Object Name,State,Status | "
                "ConvertTo-Json -Depth 2"
            )
            output = await asyncio.get_event_loop().run_in_executor(
                None, self._run_powershell, cmd
            )
            
            if not output:
                return []
                
            data = json.loads(output)
            if isinstance(data, dict):
                data = [data]
            
            vms = []
            for item in data:
                vm = VirtualMachine(
                    name=item.get('Name', ''),
                    state=item.get('State', ''),
                    status=item.get('Status', ''),
                )
                vms.append(asdict(vm))
            
            return vms
        except Exception as e:
            logger.error(f"Failed to list VMs: {e}")
            raise

    async def get_vm_status(self, vm_name: str) -> Dict[str, Any]:
        """Get status of a specific virtual machine"""
        try:
            cmd = (
                f"$vm = Get-VM -Name '{vm_name}' -ErrorAction Stop; "
                "$vm | Select-Object Name,State,Status | "
                "ConvertTo-Json -Depth 2"
            )
            output = await asyncio.get_event_loop().run_in_executor(
                None, self._run_powershell, cmd
            )
            
            if not output:
                return {}
                
            return json.loads(output)
        except Exception as e:
            logger.error(f"Failed to get VM status for {vm_name}: {e}")
            raise

    async def start_vm(self, vm_name: str) -> Dict[str, Any]:
        """Start a virtual machine"""
        try:
            cmd = f"Start-VM -Name '{vm_name}' -ErrorAction Stop"
            await asyncio.get_event_loop().run_in_executor(
                None, self._run_powershell, cmd
            )
            return {"success": True, "message": f"VM '{vm_name}' started successfully"}
        except Exception as e:
            logger.error(f"Failed to start VM {vm_name}: {e}")
            raise

    async def stop_vm(self, vm_name: str, force: bool = False) -> Dict[str, Any]:
        """Stop a virtual machine"""
        try:
            force_flag = "-Force" if force else ""
            cmd = f"Stop-VM -Name '{vm_name}' {force_flag} -ErrorAction Stop"
            await asyncio.get_event_loop().run_in_executor(
                None, self._run_powershell, cmd
            )
            return {"success": True, "message": f"VM '{vm_name}' stopped successfully"}
        except Exception as e:
            logger.error(f"Failed to stop VM {vm_name}: {e}")
            raise

    async def restart_vm(self, vm_name: str, force: bool = False) -> Dict[str, Any]:
        """Restart a virtual machine"""
        try:
            force_flag = "-Force" if force else ""
            cmd = f"Restart-VM -Name '{vm_name}' {force_flag} -ErrorAction Stop"
            await asyncio.get_event_loop().run_in_executor(
                None, self._run_powershell, cmd
            )
            return {"success": True, "message": f"VM '{vm_name}' restarted successfully"}
        except Exception as e:
            logger.error(f"Failed to restart VM {vm_name}: {e}")
            raise


# Initialize FastAPI app and Hyper-V manager
app = FastAPI(title="Hyper-V MCP Server", version="1.0.0")
hyperv_manager = HyperVManager()

# Tool definitions
TOOLS = {
    "list_vms": {
        "name": "list_vms",
        "description": "List all virtual machines on the Hyper-V host",
        "inputSchema": {
            "type": "object",
            "properties": {},
            "required": []
        }
    },
    "get_vm_status": {
        "name": "get_vm_status",
        "description": "Get detailed status information for a specific virtual machine",
        "inputSchema": {
            "type": "object",
            "properties": {
                "vm_name": {"type": "string", "description": "Name of the virtual machine"}
            },
            "required": ["vm_name"]
        }
    },
    "start_vm": {
        "name": "start_vm",
        "description": "Start a virtual machine",
        "inputSchema": {
            "type": "object",
            "properties": {
                "vm_name": {"type": "string", "description": "Name of the virtual machine to start"}
            },
            "required": ["vm_name"]
        }
    },
    "stop_vm": {
        "name": "stop_vm",
        "description": "Stop a virtual machine",
        "inputSchema": {
            "type": "object",
            "properties": {
                "vm_name": {"type": "string", "description": "Name of the virtual machine to stop"},
                "force": {"type": "boolean", "description": "Force stop the VM", "default": False}
            },
            "required": ["vm_name"]
        }
    },
    "restart_vm": {
        "name": "restart_vm",
        "description": "Restart a virtual machine",
        "inputSchema": {
            "type": "object",
            "properties": {
                "vm_name": {"type": "string", "description": "Name of the virtual machine to restart"},
                "force": {"type": "boolean", "description": "Force restart the VM", "default": False}
            },
            "required": ["vm_name"]
        }
    },
}

# API Endpoints
@app.get("/")
async def root():
    """Health check endpoint"""
    return {"status": "Hyper-V MCP Server is running", "version": "1.0.0"}

@app.get("/tools", response_model=ToolsListResponse)
async def list_tools():
    """List all available tools"""
    tools = [ToolInfo(**tool_info) for tool_info in TOOLS.values()]
    return ToolsListResponse(tools=tools)

@app.post("/tools/call", response_model=ToolCallResponse)
async def call_tool(request: ToolCallRequest):
    """Execute a tool with given arguments"""
    try:
        tool_name = request.name
        arguments = request.arguments
        
        if tool_name not in TOOLS:
            raise HTTPException(status_code=404, detail=f"Tool '{tool_name}' not found")
        
        # Get the corresponding method from HyperVManager
        if not hasattr(hyperv_manager, tool_name):
            raise HTTPException(status_code=500, detail=f"Method '{tool_name}' not implemented")
        
        method = getattr(hyperv_manager, tool_name)
        
        # Call the method with arguments
        if arguments:
            result = await method(**arguments)
        else:
            result = await method()
        
        return ToolCallResponse(success=True, result=result)
        
    except Exception as e:
        logger.error(f"Tool execution error: {e}")
        return ToolCallResponse(success=False, error=str(e))

# Additional convenience endpoints
@app.get("/vms")
async def get_vms():
    """Convenience endpoint to list VMs"""
    try:
        result = await hyperv_manager.list_vms()
        return {"success": True, "vms": result}
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.get("/vms/{vm_name}")
async def get_vm(vm_name: str):
    """Convenience endpoint to get VM status"""
    try:
        result = await hyperv_manager.get_vm_status(vm_name)
        return {"success": True, "vm": result}
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.post("/vms/{vm_name}/start")
async def start_vm_endpoint(vm_name: str):
    """Convenience endpoint to start a VM"""
    try:
        result = await hyperv_manager.start_vm(vm_name)
        return result
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

@app.post("/vms/{vm_name}/stop")
async def stop_vm_endpoint(vm_name: str, force: bool = False):
    """Convenience endpoint to stop a VM"""
    try:
        result = await hyperv_manager.stop_vm(vm_name, force)
        return result
    except Exception as e:
        raise HTTPException(status_code=500, detail=str(e))

if __name__ == "__main__":
    print("Starting Hyper-V MCP Server...")
    print("Server will be available at: http://localhost:8000")
    print("API documentation at: http://localhost:8000/docs")
    
    uvicorn.run(
        app, 
        host="0.0.0.0", 
        port=8000,
        log_level="info"
    )