// 总结文本
async function summarize(text: string, languageCode: string): Promise<string[] | Error> {
  const lro = await client.beginAnalyzeBatch([
    // 使用AbstractiveSummarization模式
    { kind: "AbstractiveSummarization" },
    // 根据文章的语言指定所使用的语言，实现中文文章输出中文总结，英文文章输出英文总结
  ], [text], languageCode);
 
  // 这是个耗时操作，等待耗时操作结束
  const results = await lro.pollUntilDone();
 
  for await (const actionResult of results) {
    if (actionResult.kind !== "AbstractiveSummarization") {
      return new Error(`Expected extractive summarization results but got: ${actionResult.kind}`);
    }
    if (actionResult.error) {
      const { code, message } = actionResult.error;
      return new Error(`Unexpected error (${code}): ${message}`);
    }
 
    for (const result of actionResult.results) {
      if (result.error) {
        const { code, message } = result.error;
        return new Error(`Unexpected error (${code}): ${message}`);
      }
 
      // 返回输出的结果
      return result.summaries.map((x) => x.text);
    }
  }
 
  throw new Error("No result");
}
 
async function summarizeArticle(articleDir: string) {
  // 获取此文章的所有markdown文件
  const mdFiles = (await readdir(articleDir)).filter((x) => x.endsWith(".md"));
 
  for (const mdFile of mdFiles) {
    const mdFilePath = join(articleDir, mdFile);
 
    // 读取并解析文章内容
    const mdContent = await readFile(mdFilePath, "utf-8");
    const { data: frontMatter, content } = matter(mdContent);
 
    // 计算并更新文章Hash，如果文章内容hash没有变，之后就不要重新生成总结了
    const contentHash = hashContent(content);
 
    const summaryJsonFilePath = join(articleDir, `${frontMatter.lang}.summary.json`);
 
    if (existsSync(summaryJsonFilePath) && (await stat(summaryJsonFilePath)).isFile()) {
      const existingSummaryJson: ArticleSummary = JSON.parse(await readFile(summaryJsonFilePath, "utf-8"));
 
      existingSummaryJson.hash = contentHash;
 
      if (contentHash === existingSummaryJson.hash) {
        log("log", "Content is not changed after the last summarization. Skip summarization.");
        continue;
      }
    }
 
    // 总结文本
    const summary = await summarize(content,
      azureLanguageCodeMap[frontMatter.lang as keyof typeof azureLanguageCodeMap]);
 
    if (summary instanceof Error) {
      log("error", "Error on summarizing %s of lang %s: %s", frontMatter.id, frontMatter.lang, summary.message);
      continue;
    }
 
    // 在文章目录下生成一个[语言id].summary.json文件，存放内容hash、总结以及相关操作信息
    const summaryJson: ArticleSummary = {
      articleId: frontMatter.id,
      lang: frontMatter.lang,
      lastUpdateStartTime: startTime,
      lastUpdateEndTime: new Date().toISOString(),
      summaries: summary,
      hash: contentHash,
    };
 
    log("log", "Write summary of %s of lang %s to %s", frontMatter.id, frontMatter.lang, summaryJsonFilePath);
 
    await writeFile(summaryJsonFilePath, JSON.stringify(summaryJson, null, 2));
  }
}