import logging

_log = logging.getLogger(__name__)


def run_search(search_tool, query: str, max_results: int = 3, max_content: int = 1500) -> str:
    """Invoke a search tool and normalize results to a readable string.

    Handles both formats:
    - dict with 'results' key (TavilySearch from langchain_tavily)
    - list of dicts (older TavilySearchResults / other providers)
    """
    try:
        raw = search_tool.invoke(query)

        if isinstance(raw, dict):
            items = raw.get("results", [])
        elif isinstance(raw, list):
            items = raw
        else:
            return str(raw)[:max_content * max_results]

        lines = [
            f"- {r.get('title', '')}: {r.get('content', '')[:max_content]}"
            for r in items[:max_results]
        ]
        return "\n".join(lines) if lines else "No results found."
    except Exception:
        _log.exception("search failed for query: %s", query[:120])
        return "Search unavailable."