import httpx
import logging
from typing import Optional

logger = logging.getLogger(__name__)

MAX_TEXT_BYTES = 100 * 1024  # 100KB


async def scrape_url(url: str) -> dict:
    """
    Fetch a URL and extract clean text content.
    Returns: {title, text, url} or {error, url}
    """
    try:
        from bs4 import BeautifulSoup

        headers = {
            "User-Agent": "Mozilla/5.0 (compatible; ContextaBot/1.0; +https://contexta.ai)",
        }

        async with httpx.AsyncClient(timeout=30, follow_redirects=True) as client:
            response = await client.get(url, headers=headers)
            response.raise_for_status()

        content_type = response.headers.get("content-type", "")
        if "text/html" not in content_type and "text/plain" not in content_type:
            return {"error": f"Unsupported content type: {content_type}", "url": url}

        html = response.text
        soup = BeautifulSoup(html, "html.parser")

        # Extract title
        title_tag = soup.find("title")
        title = title_tag.get_text(strip=True) if title_tag else ""

        # Remove unwanted tags
        for tag in soup.find_all(["nav", "header", "footer", "script", "style", "noscript", "aside", "advertisement"]):
            tag.decompose()

        # Extract main content (prefer article/main/body)
        main = soup.find("main") or soup.find("article") or soup.find("body") or soup
        text = main.get_text(separator="\n", strip=True)

        # Clean up whitespace
        lines = [line.strip() for line in text.splitlines() if line.strip()]
        text = "\n".join(lines)

        # Limit size
        if len(text.encode("utf-8")) > MAX_TEXT_BYTES:
            text = text[:MAX_TEXT_BYTES].rsplit("\n", 1)[0]

        if not text:
            return {"error": "No text content found on page", "url": url}

        logger.info(f"Scraped {url}: {len(text)} chars, title='{title}'")
        return {"title": title, "text": text, "url": url}

    except httpx.TimeoutException:
        return {"error": "Request timed out", "url": url}
    except httpx.HTTPStatusError as e:
        return {"error": f"HTTP {e.response.status_code}", "url": url}
    except Exception as e:
        logger.error(f"Scrape error for {url}: {e}")
        return {"error": str(e)[:200], "url": url}