eu-regulations

Instructions

Implementation Reference

• src/tools/version-tracking.ts:124-186 (handler)

  The handler implementation for diff_article tool.

  export async function diffArticle(
    db: DatabaseAdapter,
    input: DiffArticleInput,
  ): Promise<ArticleDiff | { premium: false; message: string }> {
    if (!isPremiumEnabled()) {
      return { premium: false, message: PREMIUM_UPGRADE_MESSAGE };
    }
  
    if (!(await hasVersionsTable(db))) {
      throw new Error('Version tracking data not available in this database build.');
    }
  
    const { regulation, article, from_date, to_date } = input;
    const effectiveToDate = to_date ?? new Date().toISOString().slice(0, 10);
  
    const articleResult = await db.query<{ rowid: number }>(
      'SELECT rowid FROM articles WHERE regulation = $1 AND article_number = $2',
      [regulation, article],
    );
  
    if (articleResult.rows.length === 0) {
      throw new Error(`Article ${article} not found in ${regulation}`);
    }
  
    const articleId = articleResult.rows[0].rowid;
  
    // Find the version closest to the to_date that has a diff
    const diffResult = await db.query<{
      diff_from_previous: string | null;
      change_summary: string | null;
      effective_date: string | null;
    }>(
      `SELECT diff_from_previous, change_summary, effective_date
       FROM article_versions
       WHERE article_id = $1
         AND effective_date > $2
         AND effective_date <= $3
       ORDER BY effective_date DESC
       LIMIT 1`,
      [articleId, from_date, effectiveToDate],
    );
  
    if (diffResult.rows.length === 0) {
      return {
        regulation,
        article,
        from_date,
        to_date: effectiveToDate,
        diff: null,
        change_summary: 'No changes found in this date range.',
      };
    }
  
    const row = diffResult.rows[0];
    return {
      regulation,
      article,
      from_date,
      to_date: effectiveToDate,
      diff: row.diff_from_previous,
      change_summary: row.change_summary,
    };
  }

• src/tools/version-tracking.ts:13-18 (schema)

  Input schema definition for diff_article.

  export interface DiffArticleInput {
    regulation: string;
    article: string;
    from_date: string;
    to_date?: string;
  }