import os
import time
import requests
from fastapi import FastAPI, Response
from fastapi.responses import StreamingResponse
from datetime import datetime, timedelta
from starlette.routing import Mount  # 用于挂载
from mcp.server.fastmcp import FastMCP  # 导入MCP SDK

app = FastAPI()

# 缓存最新获取的热门项目
cached_trending = []
last_updated = None

async def fetch_github_trending():
    """获取 GitHub 热门项目"""
    global cached_trending, last_updated
    
    url = "https://api.github.com/search/repositories"
    params = {
        "q": "stars:>1000",
        "sort": "stars",
        "order": "desc",
        "per_page": 10
    }
    
    headers = {}
    github_token = os.getenv("GITHUB_TOKEN")
    if github_token:
        headers["Authorization"] = f"token {github_token}"
    
    try:
        response = requests.get(url, params=params, headers=headers)
        response.raise_for_status()
        items = response.json().get("items", [])
        
        # 简化项目信息
        trending_projects = []
        for item in items:
            trending_projects.append({
                "name": item["full_name"],
                "url": item["html_url"],
                "stars": item["stargazers_count"],
                "description": item["description"],
                "language": item["language"]
            })
        
        cached_trending = trending_projects
        last_updated = datetime.now()
        return trending_projects
    except Exception as e:
        print(f"Error fetching GitHub trending: {e}")
        return cached_trending if cached_trending else []

# 定义MCP服务器和工具
mcp_server = FastMCP(name="GithubTrending", stateless_http=True)

@mcp_server.tool()
def get_trending_repos(num: int = 10) -> dict:
    """Tool to get top GitHub trending repositories with stars >1000"""
    if not last_updated or (datetime.now() - last_updated) > timedelta(minutes=5):
        fetch_github_trending()
    return {"trending": cached_trending[:num]}

# 挂载MCP到FastAPI（使用/mcp路径）
app.mount("/mcp", app=mcp_server.streamable_http_app())

async def trending_generator():
    """SSE 事件生成器"""
    while True:
        if not last_updated or (datetime.now() - last_updated) > timedelta(minutes=5):
            await fetch_github_trending()
        yield f"data: {cached_trending}\n\n"
        time.sleep(30)

@app.get("/trending")
async def get_trending():
    """原有端点"""
    if not cached_trending or (datetime.now() - last_updated) > timedelta(minutes=5):
        await fetch_github_trending()
    return {"trending": cached_trending, "last_updated": last_updated.isoformat() if last_updated else None}

@app.get("/trending-sse")
async def get_trending_sse():
    """原有SSE端点"""
    return StreamingResponse(
        trending_generator(),
        media_type="text/event-stream",
        headers={"Cache-Control": "no-cache", "Connection": "keep-alive"}
    )

@app.on_event("startup")
async def startup_event():
    """启动时初始化数据"""
    await fetch_github_trending()