import re
from typing import Any, Optional
from smolagents.tools import Tool

try:
    from duckduckgo_search import DDGS
except ImportError:
    try:
        from ddgs import DDGS
    except ImportError as e:
        raise ImportError(
            "You must install package `duckduckgo_search` or `ddgs` to run this tool."
        ) from e


class DuckDuckGoSearchTool(Tool):
    name = "web_search"
    description = (
        "Performs a DuckDuckGo web search. Returns titles, links, and text snippets."
    )
    inputs = {
        "query": {
            "type": "string",
            "description": "The search query to perform.",
        }
    }
    output_type = "string"

    def __init__(self, max_results: int = 5, **kwargs: Any) -> None:
        super().__init__(**kwargs)
        self.max_results = max_results

    def _sanitize_query(self, query: str) -> str:
        """Fixes common LLM mistakes like putting URL paths inside site: operators."""
        # Find site:domain.com/path/to/page and trim it to site:domain.com
        def clean_site(match: re.Match) -> str:
            domain_part = match.group(1).split("/")[0].strip()
            return f"site:{domain_part}"

        cleaned = re.sub(r"site:https?://", "site:", query)
        cleaned = re.sub(r"site:([^\s]+)", clean_site, cleaned)
        return cleaned.strip()

    def forward(self, query: str) -> str:
        safe_query = self._sanitize_query(query)
        headers = {
            "User-Agent": (
                "Mozilla/5.0 (Windows NT 10.0; Win64; x64) "
                "AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36"
            )
        }

        results = []
        # Try different backends (html, api, lite) in case one is rate-limited
        for backend in ["api", "html", "lite"]:
            try:
                with DDGS(headers=headers, timeout=10) as ddgs:
                    res = list(
                        ddgs.text(
                            safe_query,
                            region="wt-wt",
                            safesearch="moderate",
                            backend=backend,
                            max_results=self.max_results,
                        )
                    )
                    if res:
                        results = res
                        break
            except Exception:
                continue

        if not results:
            return (
                f"No results found for query: '{safe_query}'. "
                "Instead of retrying generic searches, visit a calendar page directly with `visit_webpage`."
            )

        postprocessed = [
            f"[{r.get('title', 'No Title')}]({r.get('href', '')})\n{r.get('body', '')}"
            for r in results
        ]
        return "## Search Results\n\n" + "\n\n".join(postprocessed)