<?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

 */

/**

 * This class is specialized in retrieving loggers by name and also maintaining

 * the logger hierarchy. The logger hierarchy is dealing with the several Log-Levels

 * Logger can have. From log4j website:

 *

 * "A logger is said to be an ancestor of another logger if its name followed

 * by a dot is a prefix of the descendant logger name. A logger is said to be

 * a parent of a child logger if there are no ancestors between itself and the

 * descendant logger."

 *

 * Child Loggers do inherit their Log-Levels from their Ancestors. They can

 * increase their Log-Level compared to their Ancestors, but they cannot decrease it.

 *

 * <p>The casual user does not have to deal with this class directly.</p>

 *

 * <p>The structure of the logger hierarchy is maintained by the

 * getLogger method. The hierarchy is such that children link

 * to their parent but parents do not have any pointers to their

 * children. Moreover, loggers can be instantiated in any order, in

 * particular descendant before ancestor.</p>

 *

 * <p>In case a descendant is created before a particular ancestor,

 * then it creates a provision node for the ancestor and adds itself

 * to the provision node. Other descendants of the same ancestor add

 * themselves to the previously created provision node.</p>

 *

 * @version $Revision: 1394956 $

 * @package log4php

 */

class LoggerHierarchy {

    /** Array holding all Logger instances. */

    protected $loggers = array();

    /**

     * The root logger.

     * @var RootLogger

     */

    protected $root;

    /**

     * The logger renderer map.

     * @var LoggerRendererMap

     */

    protected $rendererMap;

    /**

     * Main level threshold. Events with lower level will not be logged by any

     * logger, regardless of it's configuration.

     * @var LoggerLevel

     */

    protected $threshold;

    /**

     * Creates a new logger hierarchy.

     * @param LoggerRoot $root The root logger.

     */

    public function __construct(LoggerRoot $root) {

        $this->root = $root;

        $this->setThreshold(LoggerLevel::getLevelAll());

        $this->rendererMap = new LoggerRendererMap();

    }

    /**

     * Clears all loggers.

     */

    public function clear() {

        $this->loggers = array();

    }

    /**

     * Check if the named logger exists in the hierarchy.

     * @param string $name

     * @return boolean

     */

    public function exists($name) {

        return isset($this->loggers[$name]);

    }

    /**

     * Returns all the currently defined loggers in this hierarchy as an array.

     * @return array

     */

    public function getCurrentLoggers() {

        return array_values($this->loggers);

    }

    /**

     * Returns a named logger instance logger. If it doesn't exist, one is created.

     *

     * @param string $name Logger name

     * @return Logger Logger instance.

     */

    public function getLogger($name) {

        if (!isset($this->loggers[$name])) {

            $logger = new Logger($name);

            $nodes = explode('.', $name);

            $firstNode = array_shift($nodes);

            // if name is not a first node but another first node is their

            if ($firstNode != $name and isset($this->loggers[$firstNode])) {

                $logger->setParent($this->loggers[$firstNode]);

            } else {

                // if there is no father, set root logger as father

                $logger->setParent($this->root);

            }

            // if there are more nodes than one

            if (count($nodes) > 0) {

                // find parent node

                foreach ($nodes as $node) {

                    $parentNode = "$firstNode.$node";

                    if (isset($this->loggers[$parentNode]) and $parentNode != $name) {

                        $logger->setParent($this->loggers[$parentNode]);

                    }

                    $firstNode .= ".$node";

                }

            }

            $this->loggers[$name] = $logger;

        }

        return $this->loggers[$name];

    }

    /**

     * Returns the logger renderer map.

     * @return LoggerRendererMap

     */

    public function getRendererMap() {

        return $this->rendererMap;

    }

    /**

     * Returns the root logger.

     * @return LoggerRoot

     */

    public function getRootLogger() {

        return $this->root;

    }

    /**

     * Returns the main threshold level.

     * @return LoggerLevel

     */

    public function getThreshold() {

        return $this->threshold;

    }

    /**

     * Returns true if the hierarchy is disabled for given log level and false

     * otherwise.

     * @return boolean

     */

    public function isDisabled(LoggerLevel $level) {

        return ($this->threshold->toInt() > $level->toInt());

    }

    /**

     * Reset all values contained in this hierarchy instance to their

     * default.

     *

     * This removes all appenders from all loggers, sets

     * the level of all non-root loggers to <i>null</i>,

     * sets their additivity flag to <i>true</i> and sets the level

     * of the root logger to {@link LOGGER_LEVEL_DEBUG}.

     *

     * <p>Existing loggers are not removed. They are just reset.

     *

     * <p>This method should be used sparingly and with care as it will

     * block all logging until it is completed.</p>

     */

    public function resetConfiguration() {

        $root = $this->getRootLogger();

        $root->setLevel(LoggerLevel::getLevelDebug());

        $this->setThreshold(LoggerLevel::getLevelAll());

        $this->shutDown();

        foreach ($this->loggers as $logger) {

            $logger->setLevel(null);

            $logger->setAdditivity(true);

            $logger->removeAllAppenders();

        }

        $this->rendererMap->reset();

        LoggerAppenderPool::clear();

    }

    /**

     * Sets the main threshold level.

     * @param LoggerLevel $l

     */

    public function setThreshold(LoggerLevel $threshold) {

        $this->threshold = $threshold;

    }

    /**

     * Shutting down a hierarchy will <i>safely</i> close and remove

     * all appenders in all loggers including the root logger.

     *

     * The shutdown method is careful to close nested

     * appenders before closing regular appenders. This is allows

     * configurations where a regular appender is attached to a logger

     * and again to a nested appender.

     *

     * @todo Check if the last paragraph is correct.

     */

    public function shutdown() {

        $this->root->removeAllAppenders();

        foreach ($this->loggers as $logger) {

            $logger->removeAllAppenders();

        }

    }

    /**

     * Prints the current Logger hierarchy tree. Useful for debugging.

     */

    public function printHierarchy() {

        $this->printHierarchyInner($this->getRootLogger(), 0);

    }

    private function printHierarchyInner(Logger $current, $level) {

        for ($i = 0; $i < $level; $i++) {

            echo ($i == $level - 1) ? "|--" : "|  ";

        }

        echo $current->getName() . "\n";

        foreach ($this->loggers as $logger) {

            if ($logger->getParent() == $current) {

                $this->printHierarchyInner($logger, $level + 1);

            }

        }

    }

}