"""
Web search tool — DuckDuckGo backend.

Uses the duckduckgo-search library. Set DDG_API_KEY in .env for a paid account
(higher rate limits). The free unauthenticated tier works for moderate usage.
"""

import asyncio
import logging
from config import settings

logger = logging.getLogger(__name__)


async def search(query: str, max_results: int | None = None) -> str:
    """Search DuckDuckGo and return results as a formatted string.

    Returns a markdown-formatted list of results: title, URL, and snippet.
    The orchestrator includes this in the context it passes to Claude.
    """
    n = min(max_results or settings.ddg_max_results, 10)
    results = await asyncio.to_thread(_sync_search, query, n)
    if not results:
        return f"No results found for: {query}"

    lines = [f"Search results for: **{query}**\n"]
    for i, r in enumerate(results, 1):
        lines.append(f"{i}. [{r['title']}]({r['href']})")
        if r.get("body"):
            lines.append(f"   {r['body']}")
        lines.append("")

    return "\n".join(lines).strip()


def _sync_search(query: str, max_results: int) -> list[dict]:
    """Synchronous DuckDuckGo search — run via asyncio.to_thread."""
    from ddgs import DDGS

    kwargs = {}
    if settings.ddg_api_key:
        # Paid account — pass token for higher rate limits
        kwargs["headers"] = {"Authorization": f"Bearer {settings.ddg_api_key}"}

    try:
        with DDGS(**kwargs) as ddgs:
            return list(ddgs.text(query, max_results=max_results))
    except Exception as e:
        logger.warning("DuckDuckGo search error: %s", e)
        return []