codesite/lib/util.php

<?php

function mkshield($left_str, $right_str, $color_str) {
	$filename = sprintf(
		"%s-%s-%s.svg", 
		rawurlencode(str_replace('-', '--', $left_str)),
		rawurlencode(str_replace('-', '--', $right_str)),
		rawurlencode($color_str)
	);
	
	$cache_path = SHIELDS_CACHE_DIR.$filename;
	
	if (file_exists($cache_path)) {
		return file_get_contents($cache_path);
		
	} else {
		$retn = file_get_contents('https://img.shields.io/badge/'.$filename);
		
		// We need unique IDs
		$prefix = substr(sha1($filename), 8).'-';
		$retn = str_replace('id="',  'id="'.$prefix,  $retn);
		$retn = str_replace('url(#', 'url(#'.$prefix, $retn);
		
		file_put_contents($cache_path, $retn);
		return $retn;
		
	}
}

/**
 * Create a thumbnail of an image. It overscales, centers, and crops to fit the
 *   target dimensions.
 * 
 * @param string $src_file
 * @param string $dest_file   Null to return an image handle
 * @param int $width
 * @param int $height
 * @return boolean
 */
function mkthumbnail($src_file, $dest_file, $width, $height) {
	list($src_width, $src_height) = getimagesize($src_file);
	
	$im = imagecreatefromstring(file_get_contents($src_file));
	
	$dest = imagecreatetruecolor($width, $height);
	imagefilledrectangle($dest, 0, 0, $width, $height, imagecolorallocate($dest, 0xFF, 0xFF, 0xFF));
	
	$scale = max( $width/$src_width, $height/$src_height ); // overscale + crop
	
	$box_w = $width/$scale;
	$box_h = $height/$scale; 
	
	$box_xoff = floor(($src_width - $box_w)/2);
	$box_yoff = floor(($src_height - $box_h)/2);
	
	imagecopyresampled(
		$dest, $im,
		0, 0,
		$box_xoff, $box_yoff,
		$width, $height, $box_w, $box_h		
	);
	
	imagedestroy($im);
	
	if (is_null($dest_file)) {
		return $dest;
	} else {
		return imagejpeg($dest, $dest_file);
	}
}

function mkspritesheet(array $handles, $dest_file, $width, $height) {
	$im = imagecreatetruecolor($width, $height * count($handles));
	
	for($i = 0, $e = count($handles); $i != $e; ++$i) {
		imagecopy($im, $handles[$i], 0, $i * $height, 0, 0, $width, $height); 
	}
	
	if (is_null($dest_file)) {
		return $dest_file;
	} else {
		return imagejpeg($im, $dest_file);
	}
}

function fbytes($size, $suffixes='B|KiB|MiB|GiB|TiB') {
	$sxlist = explode('|', $suffixes);
	if ($size < 1024) {
		return $size.$sxlist[0];
	}
	
	while ($size > 1024 && count($sxlist) >= 2) {
		array_shift($sxlist);
		$size /= 1024;
	}
	return number_format($size, 2).array_shift($sxlist);
}

function str_ext($sz) {
	$dpos = strrpos($sz, '.');
	return substr($sz, $dpos+1);
}

function is_image($sz) {
	return in_array(strtolower(str_ext($sz)), ['jpg', 'png', 'jpeg']);
}

function hesc($sz) {
	return @htmlentities($sz, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
}

function text2html($sz) {

	$identity = function($sz) {
		return $sz;
	};
	
	$splitInside = function($begin, $end, $sz) {
		$parts = explode($begin, $sz);
		if (count($parts) == 1) return [$sz];
		
		$ret = [$parts[0]];
		for($i = 1, $e = count($parts); $i !== $e; ++$i) {
			$inner = explode($end, $parts[$i], 2);
			$ret = array_merge($ret, $inner);
		}
		return $ret;
	};
	
	$oddEven = function(array $parts, $odd, $even, $join='') {
		$ret = [];
		for($i = 0, $e = count($parts); $i != $e; ++$i) {
			$ret[] = ($i % 2) ? $odd($parts[$i]) : $even($parts[$i]);
		}
		return implode($join, $ret);
	};
	
	$sectionFmt = function($sz) use($oddEven, $identity) {
		$base = hesc($sz);	
		
		$base = preg_replace('~^=+(.+)=+~m', '<strong>\\1</strong>', $base);
		$base = preg_replace('~\\[url=([^\\]]+?)\\](.+?)\\[/url\\]~m', '<a href="\\1">\\2</a>', $base);
		$base = preg_replace('~([^="])(https?://[^ \\r\\n\\t]+)~i', '\\1<a href="\\2">\\2</a>', $base);
		$base = preg_replace('~\\[b\\](.+?)\\[/b\\]~m', '<strong>\\1</strong>', $base);
		$base = preg_replace('~\\[i\\](.+?)\\[/i\\]~m', '<i>\\1</i>', $base);
		$base = preg_replace('~\\[spoiler\\](.+?)\\[/spoiler\\]~m', '<span class="spoiler">\\1</span>', $base);
		$base = preg_replace('~\n- ~ms', "\n&bull; ", $base);
		
		$btparts = explode('`', $base);
		if (count($btparts) > 1 && (count($btparts) % 2)) {
			for ($i = 1, $e = count($btparts); $i < $e; $i += 2) {
				$class = 'code';
				if (strpos($btparts[$i], "\n") !== false) {
					$class .= ' code-multiline';
				}
				$btparts[$i] = '<span class="'.$class.'">'.$btparts[$i].'</span>';
			}
		}
		
		return $oddEven($btparts, $identity, 'nl2br');
	};
	
	$htmlSections = $splitInside('<html>', '</html>', $sz);
	return $oddEven($htmlSections, $identity, $sectionFmt);
}

function array_decimate($array, $total, $partno) {
	$ct = 0;
	$ret = [];
	foreach($array as $k => $v) {
		if (++$ct % $total == ($partno - 1)) {
			$ret[$k] = $v;
		}
	}
	return $ret;
}