WooNooW/includes/Core/Notifications/MarkdownParser.php

<?php
/**
 * Markdown to Email HTML Parser
 * 
 * PHP port of the TypeScript markdown parser from admin-spa
 * 
 * Supports:
 * - Standard Markdown (headings, bold, italic, lists, links, horizontal rules)
 * - Card blocks with ::: syntax
 * - Button blocks with [button url="..."]Text[/button] syntax
 * - Variables with {variable_name}
 * - Checkmarks (✓) and bullet points (•)
 * - Proper newline handling
 * 
 * @package WooNooW\Core\Notifications
 */

namespace WooNooW\Core\Notifications;

class MarkdownParser {
	
	/**
	 * Parse markdown to email HTML
	 * 
	 * @param string $markdown
	 * @return string
	 */
	public static function parse($markdown) {
		$html = $markdown;
		
		// Parse card blocks first (:::card or :::card[type])
		$html = preg_replace_callback(
			'/:::card(?:\[(\w+)\])?\n([\s\S]*?):::/s',
			function($matches) {
				$type = $matches[1] ?? '';
				$content = trim($matches[2]);
				$parsed_content = self::parse_basics($content);
				return '[card' . ($type ? ' type="' . $type . '"' : '') . "]\n" . $parsed_content . "\n[/card]";
			},
			$html
		);
		
		// Parse button blocks [button url="..."]Text[/button] - already in correct format
		// Also support legacy [button](url){text} syntax
		$html = preg_replace_callback(
			'/\[button(?:\s+style="(solid|outline)")?\]\((.*?)\)\s*\{([^}]+)\}/',
			function($matches) {
				$style = $matches[1] ?? '';
				$url = $matches[2];
				$text = $matches[3];
				return '[button url="' . $url . '"' . ($style ? ' style="' . $style . '"' : '') . ']' . $text . '[/button]';
			},
			$html
		);
		
		// Horizontal rules
		$html = preg_replace('/^---$/m', '<hr>', $html);
		
		// Parse remaining markdown (outside cards)
		$html = self::parse_basics($html);
		
		return $html;
	}
	
	/**
	 * Parse basic markdown syntax
	 * 
	 * @param string $text
	 * @return string
	 */
	private static function parse_basics($text) {
		$html = $text;
		
		// Headings (must be done in order from h4 to h1 to avoid conflicts)
		$html = preg_replace('/^#### (.*)$/m', '<h4>$1</h4>', $html);
		$html = preg_replace('/^### (.*)$/m', '<h3>$1</h3>', $html);
		$html = preg_replace('/^## (.*)$/m', '<h2>$1</h2>', $html);
		$html = preg_replace('/^# (.*)$/m', '<h1>$1</h1>', $html);
		
		// Bold
		$html = preg_replace('/\*\*(.*?)\*\*/s', '<strong>$1</strong>', $html);
		$html = preg_replace('/__(.*?)__/s', '<strong>$1</strong>', $html);
		
		// Italic
		$html = preg_replace('/\*([^\*]+?)\*/', '<em>$1</em>', $html);
		$html = preg_replace('/_([^_]+?)_/', '<em>$1</em>', $html);
		
		// Links (but not button syntax)
		$html = preg_replace('/\[(?!button)([^\]]+)\]\(([^)]+)\)/', '<a href="$2">$1</a>', $html);
		
		// Unordered lists (including checkmarks and bullets)
		$html = preg_replace('/^[\*\-•✓✔] (.*)$/m', '<li>$1</li>', $html);
		
		// Wrap consecutive <li> in <ul>
		$html = preg_replace('/(<li>.*?<\/li>\s*)+/s', '<ul>$0</ul>', $html);
		
		// Ordered lists
		$html = preg_replace('/^\d+\. (.*)$/m', '<li>$1</li>', $html);
		
		// Paragraphs (lines not already in tags)
		$lines = explode("\n", $html);
		$processed_lines = [];
		
		foreach ($lines as $line) {
			$trimmed = trim($line);
			
			// Skip empty lines
			if (empty($trimmed)) {
				$processed_lines[] = '';
				continue;
			}
			
			// Skip lines that are already HTML tags or shortcodes
			if (preg_match('/^</', $trimmed) || preg_match('/^\[/', $trimmed)) {
				$processed_lines[] = $line;
				continue;
			}
			
			// Wrap in paragraph
			$processed_lines[] = '<p>' . $line . '</p>';
		}
		
		$html = implode("\n", $processed_lines);
		
		// Clean up extra newlines in HTML
		$html = preg_replace('/\n{3,}/', "\n\n", $html);
		
		return $html;
	}
	
	/**
	 * Convert newlines to <br> tags for email rendering
	 * 
	 * @param string $html
	 * @return string
	 */
	public static function nl2br_email($html) {
		// Don't convert newlines inside HTML tags
		$html = preg_replace('/(?<!>)\n(?!<)/', '<br>', $html);
		return $html;
	}
}