from mcp.server import Server
from mcp.server.stdio import stdio_server
from mcp import types
import httpx

app = Server("my-tools")

# ── Declare available tools ──────────────────────────────────────────────────

@app.list_tools()
async def list_tools() -> list[types.Tool]:
    """MCP clients call this at startup to discover what the server offers."""
    return [
        types.Tool(
            name="get_weather",
            description="Get current weather for a city. Returns temperature, conditions, and humidity.",
            inputSchema={
                "type": "object",
                "properties": {
                    "city": {"type": "string", "description": "City name, e.g. 'London'"},
                    "units": {"type": "string", "enum": ["celsius", "fahrenheit"], "default": "celsius"},
                },
                "required": ["city"],
            },
        )
    ]

# ── Handle tool calls ────────────────────────────────────────────────────────

@app.call_tool()
async def call_tool(name: str, arguments: dict) -> list[types.TextContent]:
    """MCP clients call this to invoke a tool; return content blocks."""
    if name == "get_weather":
        city = arguments["city"]
        units = arguments.get("units", "celsius")

        async with httpx.AsyncClient() as client:
            response = await client.get(
                "https://api.openweathermap.org/data/2.5/weather",
                params={"q": city, "units": "metric" if units == "celsius" else "imperial", "appid": WEATHER_API_KEY},
            )
        data = response.json()
        return [types.TextContent(
            type="text",
            text=f"Weather in {city}: {data['weather'][0]['description']}, "
                 f"Temp: {data['main']['temp']}°, Humidity: {data['main']['humidity']}%",
        )]

    raise ValueError(f"Unknown tool: {name}")

# ── Run the server ────────────────────────────────────────────────────────────

async def main():
    async with stdio_server() as (read_stream, write_stream):
        await app.run(read_stream, write_stream, app.create_initialization_options())

if __name__ == "__main__":
    import asyncio
    asyncio.run(main())