blockquoteCitations.js

/**
 * Automatically adds <cite> tags to blockquotes by parsing citation patterns.
 * Replicates Hugo partial logic for extracting citations from blockquote text.
 * Uses regex-based string manipulation for SSR compatibility.
 */

/**
 * Post-processor function that can be chained after marked processing
 * @param {string} html - HTML output from marked
 * @returns {string} - HTML with processed blockquote citations
 */
export function postProcessCitations(html) {
    const dashPatterns = ['~ '];
    const citationLengthLimit = 2048;
    
    // Match blockquote tags and their content
    const blockquoteRegex = /<blockquote>([\s\S]*?)<\/blockquote>/g;
    
    return html.replace(blockquoteRegex, (match, content) => {
        let modifiedContent = content;
        let cite = '';
        
        // Try each dash pattern to find a citation
        for (const dashPattern of dashPatterns) {
            if (!cite && content.includes(dashPattern)) {
                const parts = content.split(dashPattern);
                
                if (parts.length > 1) {
                    let lastPart = parts[parts.length - 1];
                    
                    // Remove closing </p> tag if present
                    lastPart = lastPart.replace(/<\/p>\s*$/, '');
                    
                    // Trim whitespace
                    lastPart = lastPart.trim();
                    
                    // Check if this looks like a valid citation
                    if (lastPart && lastPart.length < citationLengthLimit) {
                        cite = lastPart;
                        
                        // Rebuild content without the citation
                        const contentParts = parts.slice(0, -1);
                        modifiedContent = contentParts.join(dashPattern);
                        
                        // Ensure content ends with </p> if it doesn't already
                        if (!modifiedContent.trim().endsWith('</p>')) {
                            modifiedContent = modifiedContent + '</p>';
                        }
                        
                        break;
                    }
                }
            }
        }
        
        // If we found a citation, rebuild the blockquote
        if (cite) {
            return `<blockquote>${modifiedContent}\n<cite>${cite}</cite></blockquote>`;
        }
        
        return match;
    });
}