import asyncio
import json
import aiohttp
from typing import Callable, Any, List, Optional


class EventEmitter:
    def __init__(self, event_emitter: Optional[Callable[[dict], Any]] = None):
        self.event_emitter = event_emitter

    async def emit(self, event_type: str, data: dict):
        if self.event_emitter:
            await self.event_emitter({"type": event_type, "data": data})

    async def update_status(
        self, description: str, done: bool, action: str, urls: List[str]
    ):
        await self.emit(
            "status",
            {"done": done, "action": action, "description": description, "urls": urls},
        )

    async def send_citation(self, title: str, url: str, content: str):
        await self.emit(
            "citation",
            {
                "document": [content],
                "metadata": [{"name": title, "source": url, "html": False}],
            },
        )


class Tools:
    @staticmethod
    async def web_scrape(
        urls: List[str], __event_emitter__: Optional[Callable[[dict], Any]] = None
    ) -> str:
        """
        Scrapes content from provided URLs and returns a summary.
        Only call this function for explicit web search requests or when URLs are provided.

        :param urls: List of URLs to scrape. Each URL must include http or https.
        :param __event_emitter__: Optional event emitter for status updates.
        :return: Combined scraped and processed contents, or error messages.
        """
        emitter = EventEmitter(__event_emitter__)
        api_url = "https://gpts.webpilot.ai/api/read"
        headers = {"Content-Type": "application/json", "WebPilot-Friend-UID": "0"}

        await emitter.update_status(
            f"开始读取 {len(urls)} 个网页", False, "web_search", urls
        )

        async def process_url(url: str) -> str:
            try:
                async with aiohttp.ClientSession() as session:
                    async with session.post(
                        api_url,
                        headers=headers,
                        json={
                            "link": url,
                            "ur": "summary of the page",
                            "lp": True,
                            "rt": False,
                            "l": "en",
                        },
                    ) as response:
                        response.raise_for_status()
                        result = await response.json()

                result.pop("rules", None)
                content = json.dumps(result, ensure_ascii=False)
                title = result.get("title") or url
                await emitter.send_citation(title, url, content)
                return f"{content}\n"

            except Exception as e:
                error_message = f"读取网页 {url} 时出错: {str(e)}"
                await emitter.update_status(error_message, False, "web_scrape", [url])
                await emitter.send_citation(f"Error from {url}", url, str(e))
                return f"URL: {url}\n错误: {error_message}\n"

        results = await asyncio.gather(*[process_url(url) for url in urls])
        await emitter.update_status(
            f"已完成 {len(urls)} 个网页的读取", True, "web_search", urls
        )

        return "\n".join(results)