haixunMaster/lib/services/web-search.ts

/**
 * 巡樓網路搜尋 — 委派至 lib/search（Brave Search API）。
 *
 * 允許的搜尋來源（全專案）：
 * 1. Threads API（lib/threads-api / lib/search）
 * 2. Brave Search API（lib/search）
 * 3. 瀏覽器爬蟲（lib/threads-browser）
 *
 * 以下 provider 已移除，不得再接入：
 * SerpAPI, Google Search API, Google Custom Search, Bing Search API,
 * Serper, Tavily, Exa, DuckDuckGo wrapper, SearXNG, 其他第三方 SERP。
 */
import {
  detectLegacySearchEnvKeys,
  executeBraveSearch,
  getSearchConfig,
  LEGACY_SEARCH_ENV_KEYS,
} from "@/lib/search";

export type SearchProvider = "brave";

export { detectLegacySearchEnvKeys, LEGACY_SEARCH_ENV_KEYS };

export interface WebSearchResult {
  title: string;
  snippet: string;
  link: string;
  provider: SearchProvider;
}

const PROVIDER_LABELS: Record<SearchProvider, string> = {
  brave: "Brave Search",
};

export function getProviderLabel(provider: SearchProvider): string {
  return PROVIDER_LABELS[provider];
}

function toWebResults(
  results: Array<{ title: string; snippet: string; url: string }>
): WebSearchResult[] {
  return results.map((item) => ({
    title: item.title,
    snippet: item.snippet,
    link: item.url,
    provider: "brave" as const,
  }));
}

export interface BraveWebSearchOptions {
  limit?: number;
  /** 巡邏模式：檢查 high priority + 每日額度（預設依 context） */
  patrolMode?: boolean;
  priority?: "high" | "medium" | "low";
  /** 僅保留 threads.com 結果 */
  threadsOnly?: boolean;
}

/** Brave Search API（需 BRAVE_SEARCH_API_KEY） */
export async function searchBrave(
  query: string,
  limit = 5,
  options?: BraveWebSearchOptions
): Promise<WebSearchResult[]> {
  const cfg = getSearchConfig().brave;
  if (!cfg.enabled || !cfg.apiKey) return [];

  const patrolMode = options?.patrolMode ?? true;
  const executed = await executeBraveSearch({
    keyword: query,
    query,
    limit,
    priority: options?.priority ?? (patrolMode ? "high" : undefined),
    patrolMode,
    threadsOnly: options?.threadsOnly ?? true,
  });

  if (executed.status === "skipped" && executed.skipReason !== "cache_hit") {
    return [];
  }

  return toWebResults(executed.results);
}

/** 單一查詢（Brave） */
export async function searchWeb(
  query: string,
  limit = 5,
  options?: BraveWebSearchOptions
): Promise<{
  results: WebSearchResult[];
  provider: SearchProvider;
  providerLabel: string;
}> {
  const results = await searchBrave(query, limit, options);
  return {
    results,
    provider: "brave",
    providerLabel: results.length > 0 ? PROVIDER_LABELS.brave : "無搜尋結果",
  };
}

/** 網路搜尋入口（僅 Brave） */
export async function searchWebThorough(
  query: string,
  limit = 6,
  options?: BraveWebSearchOptions
): Promise<{
  results: WebSearchResult[];
  provider: SearchProvider;
  providerLabel: string;
  sources: SearchProvider[];
}> {
  const results = await searchBrave(query, limit, options);
  return {
    results,
    provider: "brave",
    sources: results.length > 0 ? ["brave"] : [],
    providerLabel: results.length > 0 ? PROVIDER_LABELS.brave : "無搜尋結果",
  };
}

export function isBraveSearchConfigured(): boolean {
  const cfg = getSearchConfig().brave;
  return cfg.enabled && !!cfg.apiKey;
}