Summarizer API は、redBus と Miravia が有用なユーザー レビューの要約を作成できるようにします。

//Context to provide a useful summary
const promptContext =
  'Summarize the following reviews in 30 words or less.' +
  'Focus on key positives and negatives, such as comfort, maintenance,' +
  'pricing, and cleanliness. Reviews are separated by {end}.' +
  'Give the summary in just one paragraph.';

// The Summarizer API is available
if ('Summarizer' in self) {
  try {
    const available = await Summarizer.availability();
    let summarizer;
    if (available === 'unavailable') {
      return null;
    }
    if (available === 'available') {
      //model is already available, use immediately
      summarizer = await Summarizer.create();
    } else {
      //trigger model download and wait
      summarizer = await Summarizer.create();
    }

    // Context to provide a useful summary
    const promptContext =
      'Summarize the following reviews in 30 words or less.' +
      'Focus on key positives and negatives, such as comfort, maintenance,' +
      'pricing, and cleanliness. Reviews are separated by {end}.' +
      'Give the summary in just one paragraph.';

    // Retrieve the reviews to be summarized based on user's search query
    let reviews = getIndividualBusReviews();
    if (reviews) {
      const reviewSummary = await summarizer.summarize(reviews, {
        context: promptContext
      });
    }
  } catch (e) {
    console.error("SUMMARIZER_API_ERROR: ", e);
    return null
  }
}

// Compatibility check for device with built-in AI
export const deviceCheck = async () => {
  // Query the browser's AI capabilities
  const availability = await Summarizer.availability();

  // Case 1: Device doesn't support AI summarization
  if (availability === 'unavailable') {
    return {
      summarizationAvailable: false,
      message:
        'AI summarization tools are not supported on this device, or the appropriate permissions have not be set.',
    };
  }

  // Case 2: Device supports AI but requires model download
  if (availability === 'downloadable') {
    // Try to trigger an installation
    Summarizer.create();

    return {
      summarizationAvailable: false,
      message: 'Installing in the background. This may take a few minutes...',
    };
  }

  // Case 3: Device supports AI summarization
  return {
    summarizationAvailable: true,
    message: 'Ready for use.',
  };
};

/**
 * Summarizes a list of reviews using Chrome's Built-in AI
 * @param {Array<string>} reviewContentList - Array of review texts to summarize
 * @returns {Promise<string>} The generated summary text
 * @throws {Error} If summarization is not available or fails
 */
export const reviewSummarize = async (reviewContentList) => {
  // Validate input
  if (!Array.isArray(reviewContentList) || !reviewContentList.length) {
    throw new Error('Please provide a non-empty array of reviews to summarize');
  }

  // Check device compatibility
  const { summarizationAvailable, message } = await deviceCheck();

  if (summarizationAvailable) {
    try {
      // Configure and create the summarizer with appropriate parameters
      const summarizer = await Summarizer.create({
        type: 'tl;dr',
        length: 'short',
        sharedContext:
          'Summarize the given user reviews. Maintain a polite and formal tone.',
      });

      // Generate the summary from the joined review texts
      const summary = await summarizer.summarize(reviewContentList.join('. '));

      // Return the generated summary
      return summary;
    } catch (error) {
      // Handle any errors during summarization
      throw new Error(`Summarization failed: ${error.message}`);
    }
  } else {
    // If unavailable, throw an error with the message from deviceCheck
    throw new Error(
      message ||
        'AI summarization tools are not supported on this device or browser.'
    );
  }
};