Tool used on PocketMine-MP to autogenerate Namespace use importing, with automatic collision detection. Abuses PCRE

namespacer.php

<?php

/*
 *
 *  ____            _        _   __  __ _                  __  __ ____  
 * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \ 
 * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
 * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/ 
 * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_| 
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * @author PocketMine Team
 * @link http://www.pocketmine.net/
 * 
 *
*/


function getNamespace($str){
	if(preg_match("/^namespace ([A-Za-z0-9_\\\\]{1,});/m", $str, $matches) > 0){
		return $matches[1];
	}
	return false;
}

function getUse($str, array &$as){
	$use = array();
	if(preg_match_all("/^use ([A-Za-z0-9_\\\\]{1,});/m", $str, $matches) > 0){ //Do not catch traits
		foreach($matches[1] as $m){
			$use[$m] = $m;
		}
	}
	if(preg_match_all("/^use ([A-Za-z0-9_\\\\]{1,}) as ([A-Za-z0-9_\\\\]{1,});/m", $str, $matches) > 0){ 
		foreach($matches[1] as $i => $m){
			$use[$m] = $m;
			$as[$matches[2][$i]] = $m;
		}
	}
	if(preg_match_all("/^(abstract |)(class|interface) ([A-Za-z0-9_]{1,})/m", $str, $matches) > 0){ 
		foreach($matches[3] as $m){
			$as[$m] = $m;
		}
	}
	$use["PocketMine"] = "PocketMine";
	return $use;
}

function getNamespaceUsage($str, $aliases){
	$data = array();
	if(preg_match_all("/[^\\$]([A-Z][A-Za-z0-9_\\\\:]{1,})/m", $str, $matches) > 0){
		foreach($matches[1] as $m){
			if(($static = strpos($m, "::")) !== false or strpos($m, "\\") !== false){
				if($static !== false){
					$m = substr($m, 0, $static);
				}
				if(!isset($aliases[$m])){
					$data[sha1($m, true)] = $m;
				}
			}
		}
	}
	return $data;
}

function getTree($path, array &$tree){
	$dir = dir($path);
	while(false !== ($file = $dir->read())){
		if($file{0} !== "."){
			if(is_dir($dir->path . $file)){
				getTree($dir->path . $file ."/", $tree);
			}else{
				$ext = strtolower(substr($file, -3));
				if($ext === "php" or $ext === "pmf"){
					$ret = null;
					system("php -l " . $dir->path . $file, $ret);
					if($ret !== 0){
						echo("\nERROR on ".$dir->path . $file);
						exit(1);
					}
					$tree[] = $dir->path . $file;
				}
			}
		}
	}
}

$tree = array();

if(is_dir($argv[1])){
	$realpath = $argv[1];
	getTree($argv[1], $tree);
}else{
	$tree[] = $argv[1];
	$realpath = $argv[2];
}

foreach($tree as $file){
	$content = file_get_contents($file);
	echo "[*] $file:".PHP_EOL;
	$namespace = getNamespace($content);
	$aliases = array();
	$uses = getUse($content, $aliases);
	$namespaceUsage = getNamespaceUsage($content, $aliases);
	unset($namespaceUsage[sha1($namespace, true)]);
	$toAdd = array();
	$toReplace = array();
	foreach($namespaceUsage as $nm){
		$path = explode('\\', trim($namespace . "\\" . $nm, '\\'));
		if(($parent = array_shift($path)) === "PocketMine"){ //part of the PocketMine-MP code
			$className = array_pop($path);
			if(count($path) > 0){
				$pathS = implode(DIRECTORY_SEPARATOR, array_map("strtolower", $path)) . DIRECTORY_SEPARATOR;
			}else{
				$pathS = "";
			}
			$fPath = $realpath . DIRECTORY_SEPARATOR . $pathS . $className . ".php";
			
			$nms = implode("\\", array_merge($path, array($className)));
			if(file_exists($fPath) and !isset($toAdd[$hash = sha1("PocketMine\\$nms", true)])){
				while(isset($aliases[$className])){
					if(count($path) > 0){
						$className = array_pop($path) . $className;
					}else{
						$className = "_" . $className;
					}
				}
				$toAdd[$hash] = "PocketMine\\$nms as $className";
				$toReplace[$nm] = $className;
				$aliases[$className] = $nms;
			}
		}
		
		foreach($uses as $use){
			$path = explode('\\', trim($use . "\\" . $nm, '\\'));
			if(($parent = array_shift($path)) === "PocketMine"){ //part of the PocketMine-MP code
				$className = array_pop($path);
				if(count($path) > 0){
					$pathS = implode(DIRECTORY_SEPARATOR, array_map("strtolower", $path)) . DIRECTORY_SEPARATOR;
				}else{
					$pathS = "";
				}
				$fPath = $realpath . DIRECTORY_SEPARATOR . $pathS . $className . ".php";
				$nms = implode("\\", array_merge($path, array($className)));
				if(file_exists($fPath) and !isset($toAdd[$hash = sha1("PocketMine\\$nms", true)])){
					while(isset($aliases[$className])){
						if(count($path) > 0){
							$className = array_pop($path) . $className;
						}else{
							$className = "_" . $className;
						}
					}
					$toAdd[$hash] = "PocketMine\\$nms as $className";
					$toReplace[$nm] = $className;
					$aliases[$className] = $nms;
				}
			}
		}
		
	}
	foreach($uses as $use){
			unset($toAdd[sha1($use, true)]);
	}

	if(count($uses) > 0 and ($final = strrpos($content, "use ".array_pop($uses))) !== false){		
		$final = strpos($content, ";", $final) + 1;
		$header = substr($content, 0, $final);
		$footer = substr($content, $final);
	}elseif(($finalNm = strrpos($content, "namespace $namespace")) !== false){
		$finalNm = strpos($content, ";", $finalNm) + 1;
		$header = substr($content, 0, $finalNm);
		$footer = substr($content, $finalNm);
	}else{
		continue;
	}
	$hash = sha1($content, true);
	$content = $header;
	foreach($toAdd as $nm){
		$content .= "\nuse $nm;";
	}
	foreach($toReplace as $i => $j){
		$footer = str_replace($i, $j, $footer);
	}
	$content .= $footer;
	if(sha1($content, true) !== $hash){
		file_put_contents($file, $content);
	}
	echo PHP_EOL.PHP_EOL;
}