import re
from typing import Any

import httpx

from app.tools.base import Tool


class WebFetchTool(Tool):
    name = "web_fetch"
    description = "Fetch a webpage and return simplified content."

    def parameters_schema(self) -> dict[str, Any]:
        return {
            "type": "object",
            "properties": {
                "url": {
                    "type": "string",
                    "description": "The http or https URL to fetch.",
                }
            },
            "required": ["url"],
            "additionalProperties": False,
        }

    async def run(self, payload: dict[str, Any]) -> dict[str, Any]:
        url = str(payload.get("url", "")).strip()
        if not url.startswith(("http://", "https://")):
            return {
                "tool": self.name,
                "status": "error",
                "url": url,
                "message": "Only http and https URLs are allowed.",
            }

        try:
            async with httpx.AsyncClient(timeout=15.0, follow_redirects=True) as client:
                response = await client.get(url)
                response.raise_for_status()
        except httpx.HTTPError as exc:
            return {
                "tool": self.name,
                "status": "error",
                "url": url,
                "message": str(exc),
            }

        text = self._simplify_content(response.text)
        return {
            "tool": self.name,
            "status": "ok",
            "url": url,
            "content_type": response.headers.get("content-type", ""),
            "content": text[:12000],
            "truncated": len(text) > 12000,
        }

    def _simplify_content(self, content: str) -> str:
        text = re.sub(r"(?is)<script.*?>.*?</script>", " ", content)
        text = re.sub(r"(?is)<style.*?>.*?</style>", " ", text)
        text = re.sub(r"(?s)<[^>]+>", " ", text)
        text = re.sub(r"&nbsp;", " ", text)
        text = re.sub(r"&amp;", "&", text)
        text = re.sub(r"\s+", " ", text)
        return text.strip()