<?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.
   * 
   * @package log4php
   */
  
  /**
   * Converts ini configuration files to a PHP array.
   * 
   * These used to be called "properties" files (inherited from log4j), and that 
   * file extension is still supported. 
   *
   * @package log4php
   * @subpackage configurators
   * @license http://www.apache.org/licenses/LICENSE-2.0 Apache License, Version 2.0
   * @version $Revision: 1343601 $
   * @since 2.2
   */
  class LoggerConfigurationAdapterINI implements LoggerConfigurationAdapter {
  	
  	/** Name to assign to the root logger. */
  	const ROOT_LOGGER_NAME = "root";
  
  	/** Prefix used for defining logger additivity. */
  	const ADDITIVITY_PREFIX = "log4php.additivity.";
  	
  	/** Prefix used for defining logger threshold. */
  	const THRESHOLD_PREFIX = "log4php.threshold";
  	
  	/** Prefix used for defining the root logger. */
  	const ROOT_LOGGER_PREFIX = "log4php.rootLogger";
  	
  	/** Prefix used for defining a logger. */
  	const LOGGER_PREFIX = "log4php.logger.";
  	
  	/** Prefix used for defining an appender. */
  	const APPENDER_PREFIX = "log4php.appender.";
  	
  	/** Prefix used for defining a renderer. */
  	const RENDERER_PREFIX = "log4php.renderer.";
  	
  	/** Holds the configuration. */
  	private $config = array();
  	
  	/**
  	 * Loads and parses the INI configuration file.
  	 * 
  	 * @param string $url Path to the config file.
  	 * @throws LoggerException
  	 */
  	private function load($url) {
  		if (!file_exists($url)) {
  			throw new LoggerException("File [$url] does not exist.");
  		}
  		
  		$properties = @parse_ini_file($url, true);
  		if ($properties === false) {
  			$error = error_get_last();
  			throw new LoggerException("Error parsing configuration file: {$error['message']}");
  		}
  		
  		return $properties;
  	}
  	
  	/**
  	* Converts the provided INI configuration file to a PHP array config.
  	*
  	* @param string $path Path to the config file.
  	* @throws LoggerException If the file cannot be loaded or parsed.
  	*/
  	public function convert($path) {
  		// Load the configuration
  		$properties = $this->load($path);
  		
  		// Parse threshold
  		if (isset($properties[self::THRESHOLD_PREFIX])) {
  			$this->config['threshold'] = $properties[self::THRESHOLD_PREFIX]; 
  		}
  		
  		// Parse root logger
  		if (isset($properties[self::ROOT_LOGGER_PREFIX])) {
  			$this->parseLogger($properties[self::ROOT_LOGGER_PREFIX], self::ROOT_LOGGER_NAME);
  		}
  		
  		$appenders = array();
  		
  		foreach($properties as $key => $value) {
  			// Parse loggers
  			if ($this->beginsWith($key, self::LOGGER_PREFIX)) {
  				$name = substr($key, strlen(self::LOGGER_PREFIX));
  				$this->parseLogger($value, $name);
  			}
  			
  			// Parse additivity
  			if ($this->beginsWith($key, self::ADDITIVITY_PREFIX)) {
  				$name = substr($key, strlen(self::ADDITIVITY_PREFIX));
  				$this->config['loggers'][$name]['additivity'] = $value;
  			}
  			
  			// Parse appenders
  			else if ($this->beginsWith($key, self::APPENDER_PREFIX)) {
  				$this->parseAppender($key, $value);
  			}
  			
  			// Parse renderers
  			else if ($this->beginsWith($key, self::RENDERER_PREFIX)) {
  				$this->parseRenderer($key, $value);
  			}
  		}
  		
  		return $this->config;
  	}
  	
  	
  	/**
  	 * Parses a logger definition.
  	 * 
  	 * Loggers are defined in the following manner:
  	 * <pre>
  	 * log4php.logger.<name> = [<level>], [<appender-ref>, <appender-ref>, ...] 
  	 * </pre>
  	 * 
  	 * @param string $value The configuration value (level and appender-refs).
  	 * @param string $name Logger name. 
  	 */
  	private function parseLogger($value, $name) {
  		// Value is divided by commas
  		$parts = explode(',', $value);
  		if (empty($value) || empty($parts)) {
  			return;
  		}
  
  		// The first value is the logger level 
  		$level = array_shift($parts);
  		
  		// The remaining values are appender references 
  		$appenders = array();
  		while($appender = array_shift($parts)) {
  			$appender = trim($appender);
  			if (!empty($appender)) {
  				$appenders[] = trim($appender);
  			}
  		}
  
  		// Find the target configuration 
  		if ($name == self::ROOT_LOGGER_NAME) {
  			$this->config['rootLogger']['level'] = trim($level);
  			$this->config['rootLogger']['appenders'] = $appenders;
  		} else {
  			$this->config['loggers'][$name]['level'] = trim($level);
  			$this->config['loggers'][$name]['appenders'] = $appenders;
  		}
  	}
  	
  	/**
  	 * Parses an configuration line pertaining to an appender.
  	 * 
  	 * Parses the following patterns:
  	 * 
  	 * Appender class:
  	 * <pre>
  	 * log4php.appender.<name> = <class>
  	 * </pre>
  	 * 
  	 * Appender parameter:
  	 * <pre>
  	 * log4php.appender.<name>.<param> = <value>
  	 * </pre>
  	 * 
   	 * Appender threshold:
  	 * <pre>
  	 * log4php.appender.<name>.threshold = <level>
  	 * </pre>
  	 * 
   	 * Appender layout:
  	 * <pre>
  	 * log4php.appender.<name>.layout = <layoutClass>
  	 * </pre>
  	 * 
  	 * Layout parameter:
  	 * <pre>
  	 * log4php.appender.<name>.layout.<param> = <value>
  	 * </pre> 
  	 * 
  	 * For example, a full appender config might look like:
  	 * <pre>
  	 * log4php.appender.myAppender = LoggerAppenderConsole
  	 * log4php.appender.myAppender.threshold = info
  	 * log4php.appender.myAppender.target = stdout
  	 * log4php.appender.myAppender.layout = LoggerLayoutPattern
  	 * log4php.appender.myAppender.layout.conversionPattern = "%d %c: %m%n"
  	 * </pre>
  	 * 
  	 * After parsing all these options, the following configuration can be 
  	 * found under $this->config['appenders']['myAppender']:
  	 * <pre>
  	 * array(
  	 * 	'class' => LoggerAppenderConsole,
  	 * 	'threshold' => info,
  	 * 	'params' => array(
  	 * 		'target' => 'stdout'
  	 * 	),
  	 * 	'layout' => array(
  	 * 		'class' => 'LoggerAppenderConsole',
  	 * 		'params' => array(
  	 * 			'conversionPattern' => '%d %c: %m%n'
  	 * 		)
  	 * 	)
  	 * )
  	 * </pre>
  	 * 
  	 * @param string $key
  	 * @param string $value
  	 */
  	private function parseAppender($key, $value) {
  
  		// Remove the appender prefix from key
  		$subKey = substr($key, strlen(self::APPENDER_PREFIX));
  		
  		// Divide the string by dots
  		$parts = explode('.', $subKey);
  		$count = count($parts);
  		
  		// The first part is always the appender name
  		$name = trim($parts[0]);
  		
  		// Only one part - this line defines the appender class 
  		if ($count == 1) {
  			$this->config['appenders'][$name]['class'] = $value;
  			return;
  		}
  		
  		// Two parts - either a parameter, a threshold or layout class
  		else if ($count == 2) {
  			
  			if ($parts[1] == 'layout') {
  				$this->config['appenders'][$name]['layout']['class'] = $value;
  				return;
  			} else if ($parts[1] == 'threshold') {
  				$this->config['appenders'][$name]['threshold'] = $value;
  				return;
  			} else {
  				$this->config['appenders'][$name]['params'][$parts[1]] = $value;
  				return;
  			}
  		}
  		
  		// Three parts - this can only be a layout parameter
  		else if ($count == 3) {
  			if ($parts[1] == 'layout') {
  				$this->config['appenders'][$name]['layout']['params'][$parts[2]] = $value;
  				return;
  			}
  		}
  		
  		trigger_error("log4php: Don't know how to parse the following line: \"$key = $value\". Skipping.");
  	}
  
  	/**
  	 * Parses a renderer definition.
  	 * 
  	 * Renderers are defined as:
  	 * <pre>
  	 * log4php.renderer.<renderedClass> = <renderingClass> 
  	 * </pre>
  	 * 
  	 * @param string $key log4php.renderer.<renderedClass>
  	 * @param string $value <renderingClass>
  	 */
  	private function parseRenderer($key, $value) {
  		// Remove the appender prefix from key
  		$renderedClass = substr($key, strlen(self::APPENDER_PREFIX));
  		$renderingClass = $value;
  		
  		$this->config['renderers'][] = compact('renderedClass', 'renderingClass');
  	}
  	
  	/** Helper method. Returns true if $str begins with $sub. */
  	private function beginsWith($str, $sub) {
  		return (strncmp($str, $sub, strlen($sub)) == 0);
  	}
  	
  	
  }