<?php

// This will deal with text formating (Markdown etc.)
// TODO: we need to escape some URLs and some values
// PCRE modifiers: m = work at line level (else at file level)
function rg_format_markdown($a)
{
	$k = array();
	$v = array();

	// 2 spaces at the end of the line
	$k[] = '/ {2}$/mu';
	$v[] = '<br />';

	// blockquote
	$k[] = '/^>\s(.*)$/mu';
	$v[] = '<blockquote><p>\1</p></blockquote>';

	// strikethrough
	$k[] = '/~~(.*?)~~/uD';
	$v[] = '<strike>\1</strike>';

	// hr
	$k[] = '/^---$/mu';
	$v[] = '<hr />';

	// bold
	$k[] = '/\*\*(.*?)\*\*/uD'; // note '?' for non-greedy
	$v[] = '<strong>\1</strong>';
	$k[] = '/__(.*?)__/uD';
	$v[] = '<strong>\1</strong>';

	// italic
	$k[] = '/\*(.*?)\*/uD';
	$v[] = '<em>\1</em>';
	$k[] = '/_(.*?)_/uD';
	$v[] = '<em>\1</em>';

	// image
	$k[] = '/!\[(.*?)\]\((.*?)\s"(.*?)"\)/uD';
	$v[] = '<img alt="\1" title="\3" src="\2" />';

	// link
	$k[] = '/\[(.*?)\]\((.*?)\)/uD';
	$v[] = '<a href="\2" target="_blank">\1</a>';
	$k[] = '#(http[s]://.*?)\s#uD';
	$v[] = '<a href="\1" target="_blank">\1</a>';

	// Headers
	$k[] = '/^######\s(.*)/mu';
	$v[] = '<h6>\1</h6>';
	$k[] = '/^#####\s(.*)/mu';
	$v[] = '<h5>\1</h5>';
	$k[] = '/^####\s(.*)/mu';
	$v[] = '<h4>\1</h4>';
	$k[] = '/^###\s(.*)/mu';
	$v[] = '<h3>\1</h3>';
	$k[] = '/^##\s(.*)/mu';
	$v[] = '<h2>\1</h2>';
	$k[] = '/^#\s(.*)/mu';
	$v[] = '<h1>\1</h1>';

	// Syntax highlighting (not there yet)
	$k[] = '/`(.*?)`/mu';
	$v[] = '<code>\1</code>';
	$k[] = '/```(.*?)```/uD';
	$v[] = '<code>\1</code>';

	$a = preg_replace($k, $v, $a);

	// tables
	$ret = array(); $j = 0;
	$table_started = FALSE;
	$f = explode("\n", $a); unset($a);
	foreach ($f as $i => $line) {
		rg_log('DEBUG: line=' . $line);

		if (preg_match('/^=+$/u', $line) === 1) {
			rg_log('Found a h1 with = sign');
			if (($j > 0) && (strlen($line) == strlen($ret[$j - 1]))) {
				$ret[$j - 1] = '<h1>' . $ret[$j - 1] . '</h1>';
				continue;
			}
		}

		if (preg_match('/^-+$/u', $line) === 1) {
			rg_log('Found a h2 with - sign');
			if (($j > 0) && (strlen($line) == strlen($ret[$j - 1]))) {
				$ret[$j - 1] = '<h2>' . $ret[$j - 1] . '</h2>';
				continue;
			}
		}

		// table line
		$cont = FALSE;
		while (1) {
			$r = preg_split($p = '/\s*\|\s*/u', $line);
			if (($r === FALSE) || !isset($r[1]))
				break;

			rg_log_ml('DEBUG: found a table row: ' . print_r($r, TRUE));
			if ($table_started !== TRUE) {
				rg_log('DEBUG: But table was not started.');
				if ($j == 0) {
					rg_log('DEBUG: this is first line; ship');
					break;
				}
				rg_log('DEBUG: Check previous line [' . $ret[$j - 1] . '] to contain \s|\s');
				$r2 = preg_split($p = '/\s*\|\s*/u', $ret[$j - 1]);
				if (($r2 === FALSE) || !isset($r2[1]))
					break;

				rg_log_ml('DEBUG: header match: ' . print_r($r2, TRUE));
				rg_log('  DEBUG: Found a table in the previous line!');
				$ret[$j - 1] = '<table>';
				$ret[$j++] = '<tr><th>'
					. implode('</th><th>', $r2)
					. '</th></tr>';
				$table_started = TRUE;
				$cont = TRUE;
				break;
			}

			$ret[$j++] = '<tr><td>' . implode('</td><td>', $r)
				. '</td></tr>';
			$cont = TRUE;
			break;
		}
		if ($cont)
			continue;

		if ($table_started) {
			rg_log('DEBUG: we have a normal line but table is in progress; stop table');
			$ret[$j++] = '</table>';
			$table_started = FALSE;
		}

		$ret[$j++] = $line;
	}
	if ($table_started) {
		rg_log('DEBUG: we have a normal line but table is in progress; stop table');
		$ret[$j++] = '</table>';
		$table_started = FALSE;
	}

	$a = implode("\n", $ret); unset($ret);

	$k = array();
	$v = array();

	$k[] = '/' . "\n\n" . '(.*)' . '(' . "\n\n" . '|$)/uD';
	$v[] = "\n\n" . '<p>' . "\n" . '\1' . "\n" . '</p>' . '\2';

	return preg_replace($k, $v, $a);
}