<?php
/**
 * 一个小型的PHP模板渲染引擎.
 * {loop $array $key $value}..........{/loop} 循环
 * {loop $array $value}..........{/loop} 循环
 * {if condition}...{elseif condition}..{else}..{/if} if条件语句
 * {$val} 输出变量值
 * {eval echo "ok";} 运行PHP代码
 * {template file} 包含另外一个模版
 * 对象方法:
 * setTplDir($dir)
 * setReal($real)
 * setExtName($ext)
 * setTmpDir($dir)
 * setU(&$dispatcher)
 * assign($name, $value=null)
 * getVal($name)
 * saveHtml($tFile, $html)
 * display($tFile)
 * usage:
 * [code/]
 * require_once('Template.php');
 * $tpl=new Tpl();
 * $tpl->assign('val','test');
 * $tpl->display('tplfile');//不带后缀,默认模板后缀.html
 * [/code]
 * 可配置的项 :TPL_DIR (模板存放目录)和TPL_C_DIR(缓存存放目录),TPL_REAL(bool是否实时编译)
 */
class tpl{

	private $tDir=TPL_DIR; //模版文件目录
	private $tTmpDir=TPL_C_DIR; //编译好后的文件目录
	private $tVal; //模版变量
	private $tFile; //模版文件
	private $tExtName = '.html'; //模板文件的扩展名
	private $tContent; //模版内容
	private $uDispatcher; //URL调度器
	private $real = TPL_REAL; //实时编译

	public function __construct() {
		$this->tVal = array();
	}

	/**
	 * 设置模版文件目录
	 * @param string $dir
	 */
	public function setTplDir($dir) {
		$this->tDir = $dir;
	}

	/**
	 * 是否实时编译
	 * @param bool $real
	 */
	public function setReal($real) {
		$this->real = (bool) $real;
	}

	/**
	 * 设置模板文件的扩展名
	 * @param string $ext 扩展名
	 */
	public function setExtName($ext) {
		$this->tExtName = $ext;
	}

	/**
	 * 临时文件目录
	 * @param string $dir
	 */
	public function setTmpDir($dir) {
		if (!file_exists($dir)) {
			if (!mkdir($dir, 0, true))
				die("tmp dir $dir can't to mkdir");
		}
		$this->tTmpDir = realpath($dir);
	}

	/**
	 * URL调度器
	 * @param Dispatcher $dispatcher
	 */
	public function setU(&$dispatcher) {
		if (is_object($dispatcher) && method_exists($dispatcher, 'U')) {
			$this->uDispatcher = $dispatcher;
		}
	}

	/**
	 * 注册用户自己的函数
	 * 当$function是string时则是方函数，如果是键值对数组时则键是类名，值是类中的静态方法
	 * @param mix $function 函数
	 */
	public function registerFunction($function) {
		if (is_array($function)) {
			foreach ($function as $key => $value) {
				$this->userFunctions['classes'][$key] = $value;
			}
		} else {
			$this->userFunctions['functions'][] = $function;
		}
	}

	/**
	 * 变量赋值
	 * 如果$name是一个键值对的数组，则直接使用对$name数组进行赋值
	 * @param mixed $name 变量名
	 * @param mixed $value 值
	 */
	public function assign($name, $value=null) {
		if (is_array($name)) {
			foreach ($name as $key => $val) {
				$this->tVal[$key] = $val;
			}
		} else {
			$this->tVal[$name] = $value;
		}
	}

	/**
	 * 取得模版的变量
	 * @param string $name
	 */
	public function getVal($name) {
		if (isset($this->tVal[$name])) {
			return $this->tVal[$name];
		}else
			return false;
	}

	/**
	 * 将运行好后的内容，保存到一个html文件中
	 * @param string $tFile
	 * @param string $html
	 */
	public function saveHtml($tFile, $html) {
		ob_start();
		$this->display($tFile);
		$buffer = ob_get_contents();
		ob_end_clean();
		file_put_contents($html, $buffer);
	}

	/**
	 * 运行并显示模版内容
	 * @param string $tfile
	 */
	public function display($tFile) {
		$this->tFile = $this->parseTemplatePath($tFile);
		if (!file_exists($this->getTmpFile()) || $this->real) {
			$this->parse();
		}
		extract($this->tVal, EXTR_OVERWRITE);
		include $this->getTmpFile();
	}

	/**
	 * 编译好后的文件
	 * @return string $filepath
	 */
	private function getTmpFile() {
		$basename = basename($this->tFile);
		$pos = strrpos($basename, '.');
		$tmp = 'tpl_' . substr($basename, 0, $pos) . '.php';
		return $this->tTmpDir . '/' . $tmp;
	}

	private function parse() {
		$this->tContent = file_get_contents($this->tFile);
		$this->parseInclude();
		$this->parseSection();
		$this->parseVal();
		$this->parseEval();

		if (!$this->real) {
			//如果是在非调试环境下，则替换一些没用的内容
			$search = array("/\r?\n/", "/\s{2,}/");
			$repace = array('', '');
			$this->tContent = preg_replace($search, $repace, $this->tContent);
		}

		file_put_contents($this->getTmpFile(), $this->tContent);
	}

	/**
	 * 解析模板中的子模板
	 */
	private function parseInclude() {
		for ($i = 0; $i < 6; $i++) {
			$this->tContent = preg_replace("/\{template\s+([a-zA-z0-9\._]+)\}/ies", "\$this->subtemplate('$1')", $this->tContent);
		}
	}

	/**
	 * 获取只模版
	 * @param string $file
	 */
	private function subtemplate($file) {
		return file_get_contents($this->parseTemplatePath($file));
	}

	/**
	 * 解析模版路径
	 * @param string $file
	 * @return string $filepath
	 */
	private function parseTemplatePath($tFile) {
		$tFile.=$this->tExtName;
		$tFile = $this->tDir ? $this->tDir . '/' . $tFile : $tFile;
		if (!file_exists($tFile)) {
			if($this->real) die("No template file $tFile");
			else die('Something Wrong');
		} else {
			$tFile = realpath($tFile);
		}
		return $tFile;
	}

	/**
	 * 解析变量
	 */
	private function parseVal() {
		$this->tContent = preg_replace("/\{(\\$\S+?)\}/is", "<?php echo \\1 ;?>", $this->tContent);
	}

	/**
	 * 解析段落
	 */
	private function parseSection() {
		//逻辑
		$this->tContent = preg_replace("/\{elseif\s+(.+?)\}/ies", "\$this->stripvtags('<?php } elseif(\\1) { ?>','')", $this->tContent);
		$this->tContent = preg_replace("/\{else\}/is", "<?php } else { ?>", $this->tContent);
		$this->tContent = preg_replace("/\{U\((.+?)\)\}/ies", "\$this->parseUrl('$1')", $this->tContent);
		//循环
		for ($i = 0; $i < 6; $i++) {
			$this->tContent = preg_replace("/\{loop\s+(\S+)\s+(\S+)\}(.+?)\{\/loop\}/ies", "\$this->stripvtags('<?php if(is_array(\\1)) { foreach(\\1 as \\2) { ?>','\\3<?php } } ?>')", $this->tContent);
			$this->tContent = preg_replace("/\{loop\s+(\S+)\s+(\S+)\s+(\S+)\}(.+?)\{\/loop\}/ies", "\$this->stripvtags('<?php if(is_array(\\1)) { foreach(\\1 as \\2 => \\3) { ?>','\\4<?php } } ?>')", $this->tContent);
			$this->tContent = preg_replace("/\{if\s+(.+?)\}(.+?)\{\/if\}/ies", "\$this->stripvtags('<?php if(\\1) { ?>','\\2<?php } ?>')", $this->tContent);
		}
	}

	private function stripvtags($expr, $statement='') {
		$expr = str_replace("\\\"", "\"", preg_replace("/\<\?\=(\\\$.+?)\?\>/s", "\\1", $expr));
		$statement = str_replace("\\\"", "\"", $statement);
		return $expr . $statement;
	}

	/**
	 * 解析PHP语句
	 */
	private function parseEval() {
		$this->tContent = preg_replace("/\{eval\s+(.+?)\}/is", "<?php $1 ?>", $this->tContent);
	}

	/**
	 * 解析URL
	 */
	private function parseUrl($url) {
		if (is_object($this->uDispatcher)) {
			return $this->uDispatcher->U($url);
		} else {
			return $url;
		}
	}

}