<?php
  /**
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements. See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You under the Apache License, Version 2.0
   * (the "License"); you may not use this file except in compliance with
   * the License. You may obtain a copy of the License at
   *
   *	   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  /**
   * LoggerAppenderFile appends log events to a file.
   *
   * This appender uses a layout.
   * 
   * ## Configurable parameters: ##
   * 
   * - **file** - Path to the target file. Relative paths are resolved based on 
   *     the working directory.
   * - **append** - If set to true, the appender will append to the file, 
   *     otherwise the file contents will be overwritten.
   *
   * @version $Revision: 1382274 $
   * @package log4php
   * @subpackage appenders
   * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
   * @link http://logging.apache.org/log4php/docs/appenders/file.html Appender documentation
   */
  class LoggerAppenderFile extends LoggerAppender {
  
  	/**
  	 * If set to true, the file is locked before appending. This allows 
  	 * concurrent access. However, appending without locking is faster so
  	 * it should be used where appropriate.
  	 * 
  	 * TODO: make this a configurable parameter
  	 * 
  	 * @var boolean
  	 */
  	protected $locking = true;
  	
  	/**
  	 * If set to true, appends to file. Otherwise overwrites it.
  	 * @var boolean
  	 */
  	protected $append = true;
  	
  	/**
  	 * Path to the target file.
  	 * @var string 
  	 */
  	protected $file;
  
  	/**
  	 * The file resource.
  	 * @var resource
  	 */
  	protected $fp;
  	
  	/** 
  	 * Helper function which can be easily overriden by daily file appender. 
  	 */
  	protected function getTargetFile() {
  		return $this->file;
  	}
  	
  	/**
  	 * Acquires the target file resource, creates the destination folder if 
  	 * necessary. Writes layout header to file.
  	 * 
  	 * @return boolean FALSE if opening failed
  	 */
  	protected function openFile() {
  		$file = $this->getTargetFile();
  
  		// Create the target folder if needed
  		if(!is_file($file)) {
  			$dir = dirname($file);
  
  			if(!is_dir($dir)) {
  				$success = mkdir($dir, 0777, true);
  				if ($success === false) {
  					$this->warn("Failed creating target directory [$dir]. Closing appender.");
  					$this->closed = true;
  					return false;
  				}
  			}
  		}
  		
  		$mode = $this->append ? 'a' : 'w';
  		$this->fp = fopen($file, $mode);
  		if ($this->fp === false) {
  			$this->warn("Failed opening target file. Closing appender.");
  			$this->fp = null;
  			$this->closed = true;
  			return false;
  		}
  		
  		// Required when appending with concurrent access
  		if($this->append) {
  			fseek($this->fp, 0, SEEK_END);
  		}
  		
  		// Write the header
  		$this->write($this->layout->getHeader());
  	}
  	
  	/**
  	 * Writes a string to the target file. Opens file if not already open.
  	 * @param string $string Data to write.
  	 */
  	protected function write($string) {
  		// Lazy file open
  		if(!isset($this->fp)) {
  			if ($this->openFile() === false) {
  				return; // Do not write if file open failed.
  			}
  		}
  		
  		if ($this->locking) {
  			$this->writeWithLocking($string);
  		} else {
  			$this->writeWithoutLocking($string);
  		}
  	}
  	
  	protected function writeWithLocking($string) {
  		if(flock($this->fp, LOCK_EX)) {
  			if(fwrite($this->fp, $string) === false) {
  				$this->warn("Failed writing to file. Closing appender.");
  				$this->closed = true;				
  			}
  			flock($this->fp, LOCK_UN);
  		} else {
  			$this->warn("Failed locking file for writing. Closing appender.");
  			$this->closed = true;
  		}
  	}
  	
  	protected function writeWithoutLocking($string) {
  		if(fwrite($this->fp, $string) === false) {
  			$this->warn("Failed writing to file. Closing appender.");
  			$this->closed = true;				
  		}
  	}
  	
  	public function activateOptions() {
  		if (empty($this->file)) {
  			$this->warn("Required parameter 'file' not set. Closing appender.");
  			$this->closed = true;
  			return;
  		}
  	}
  	
  	public function close() {
  		if (is_resource($this->fp)) {
  			$this->write($this->layout->getFooter());
  			fclose($this->fp);
  		}
  		$this->fp = null;
  		$this->closed = true;
  	}
  
  	public function append(LoggerLoggingEvent $event) {
  		$this->write($this->layout->format($event));
  	}
  	
  	/**
  	 * Sets the 'file' parameter.
  	 * @param string $file
  	 */
  	public function setFile($file) {
  		$this->setString('file', $file);
  	}
  	
  	/**
  	 * Returns the 'file' parameter.
  	 * @return string
  	 */
  	public function getFile() {
  		return $this->file;
  	}
  	
  	/**
  	 * Returns the 'append' parameter.
  	 * @return boolean
  	 */
  	public function getAppend() {
  		return $this->append;
  	}
  
  	/**
  	 * Sets the 'append' parameter.
  	 * @param boolean $append
  	 */
  	public function setAppend($append) {
  		$this->setBoolean('append', $append);
  	}
  
  	/**
  	 * Sets the 'file' parmeter. Left for legacy reasons.
  	 * @param string $fileName
  	 * @deprecated Use setFile() instead.
  	 */
  	public function setFileName($fileName) {
  		$this->setFile($fileName);
  	}
  	
  	/**
  	 * Returns the 'file' parmeter. Left for legacy reasons.
  	 * @return string
  	 * @deprecated Use getFile() instead.
  	 */
  	public function getFileName() {
  		return $this->getFile();
  	}
  }