import { resolveBraveConfig } from "./config.ts";
import { splitDomainFilter } from "./domain-filter.ts";
import type { SearchOptions, SearchResponse, SearchResult } from "./types.ts";

interface BraveSearchResponse {
  web?: { results?: Array<{ title?: string; url?: string; description?: string }> };
}

export async function searchBrave(
  query: string,
  options: SearchOptions = {},
): Promise<SearchResponse> {
  const config = resolveBraveConfig();
  if (!config) throw new Error("Brave API key not found. Set BRAVE_API_KEY or run /websearch-auth");

  const { include, exclude } = splitDomainFilter(options.domainFilter);
  const scopedQuery = [
    query,
    include.length ? `(${include.map((d) => `site:${d}`).join(" OR ")})` : "",
    ...exclude.map((d) => `-site:${d}`),
  ]
    .filter(Boolean)
    .join(" ");
  const url = new URL(config.baseUrl);
  url.searchParams.set("q", scopedQuery);
  url.searchParams.set("count", String(Math.min(options.numResults ?? 8, 20)));
  url.searchParams.set("result_filter", "web");
  // Brave wraps matched terms in <strong> tags unless told otherwise; the
  // snippet goes straight to the model, which wants plain text.
  url.searchParams.set("text_decorations", "false");

  const timeout = AbortSignal.timeout(60_000);
  const res = await fetch(url, {
    headers: { "X-Subscription-Token": config.apiKey, Accept: "application/json" },
    signal: options.signal ? AbortSignal.any([options.signal, timeout]) : timeout,
  });
  if (!res.ok) {
    const detail = await res.text().catch(() => "");
    throw new Error(
      `Brave search failed (${res.status} ${res.statusText}): ${detail.slice(0, 300)}`,
    );
  }
  const data = (await res.json()) as BraveSearchResponse;
  const results: SearchResult[] = (data.web?.results ?? [])
    .flatMap((item) =>
      item.url
        ? [{ title: item.title || item.url, url: item.url, snippet: item.description ?? "" }]
        : [],
    )
    .slice(0, options.numResults ?? 8);
  return { query, results, provider: "brave" };
}