<?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

 */

/**

 * Manages defined renderers and determines which renderer to use for a given

 * input.

 *

 * @version $Revision: 1394956 $

 * @package log4php

 * @subpackage renderers

 * @since 0.3

 */

class LoggerRendererMap {

    /**

     * Maps class names to appropriate renderers.

     * @var array

     */

    private $map = array();

    /**

     * The default renderer to use if no specific renderer is found.

     * @var LoggerRenderer

     */

    private $defaultRenderer;

    public function __construct() {

        // Set default config

        $this->reset();

    }

    /**

     * Adds a renderer to the map.

     *

     * If a renderer already exists for the given <var>$renderedClass</var> it

     * will be overwritten without warning.

     *

     * @param string $renderedClass The name of the class which will be

     *        rendered by the renderer.

     * @param string $renderingClass The name of the class which will

     *        perform the rendering.

     */

    public function addRenderer($renderedClass, $renderingClass) {

        // Check the rendering class exists

        if (!class_exists($renderingClass)) {

            trigger_error("log4php: Failed adding renderer. Rendering class [$renderingClass] not found.");

            return;

        }

        // Create the instance

        $renderer = new $renderingClass();

        // Check the class implements the right interface

        if (!($renderer instanceof LoggerRenderer)) {

            trigger_error("log4php: Failed adding renderer. Rendering class [$renderingClass] does not implement the LoggerRenderer interface.");

            return;

        }

        // Convert to lowercase since class names in PHP are not case sensitive

        $renderedClass = strtolower($renderedClass);

        $this->map[$renderedClass] = $renderer;

    }

    /**

     * Sets a custom default renderer class.

     *

     * TODO: there's code duplication here. This method is almost identical to

     * addRenderer(). However, it has custom error messages so let it sit for

     * now.

     *

     * @param string $renderingClass The name of the class which will

     *        perform the rendering.

     */

    public function setDefaultRenderer($renderingClass) {

        // Check the class exists

        if (!class_exists($renderingClass)) {

            trigger_error("log4php: Failed setting default renderer. Rendering class [$renderingClass] not found.");

            return;

        }

        // Create the instance

        $renderer = new $renderingClass();

        // Check the class implements the right interface

        if (!($renderer instanceof LoggerRenderer)) {

            trigger_error("log4php: Failed setting default renderer. Rendering class [$renderingClass] does not implement the LoggerRenderer interface.");

            return;

        }

        $this->defaultRenderer = $renderer;

    }

    /**

     * Returns the default renderer.

     * @var LoggerRenderer

     */

    public function getDefaultRenderer() {

        return $this->defaultRenderer;

    }

    /**

     * Finds the appropriate renderer for the given <var>input</var>, and

     * renders it (i.e. converts it to a string).

     *

     * @param mixed $input Input to render.

     * @return string The rendered contents.

     */

    public function findAndRender($input) {

        if ($input === null) {

            return null;

        }

        // For objects, try to find a renderer in the map

        if (is_object($input)) {

            $renderer = $this->getByClassName(get_class($input));

            if (isset($renderer)) {

                return $renderer->render($input);

            }

        }

        // Fall back to the default renderer

        return $this->defaultRenderer->render($input);

    }

    /**

     * Returns the appropriate renderer for a given object.

     *

     * @param mixed $object

     * @return LoggerRenderer Or null if none found.

     */

    public function getByObject($object) {

        if (!is_object($object)) {

            return null;

        }

        return $this->getByClassName(get_class($object));

    }

    /**

     * Returns the appropriate renderer for a given class name.

     *

     * If no renderer could be found, returns NULL.

     *

     * @param string $class

     * @return LoggerRendererObject Or null if not found.

     */

    public function getByClassName($class) {

        for (; !empty($class); $class = get_parent_class($class)) {

            $class = strtolower($class);

            if (isset($this->map[$class])) {

                return $this->map[$class];

            }

        }

        return null;

    }

    /** Empties the renderer map. */

    public function clear() {

        $this->map = array();

    }

    /** Resets the renderer map to it's default configuration. */

    public function reset() {

        $this->defaultRenderer = new LoggerRendererDefault();

        $this->clear();

        $this->addRenderer('Exception', 'LoggerRendererException');

    }

}