/*
 * 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.
 */

#ifndef _LOG4CXX_HELPER_OPTION_CONVERTER_H
#define _LOG4CXX_HELPER_OPTION_CONVERTER_H

#include <log4cxx/logstring.h>
#include <log4cxx/helpers/objectptr.h>

namespace log4cxx
{
class Level;
class File;
typedef helpers::ObjectPtrT<Level> LevelPtr;

namespace spi
{
class LoggerRepository;
typedef helpers::ObjectPtrT<LoggerRepository> LoggerRepositoryPtr;
}

namespace helpers
{
class Properties;

class Object;
typedef ObjectPtrT<Object> ObjectPtr;

class Class;

/** A convenience class to convert property values to specific types.*/
class LOG4CXX_EXPORT OptionConverter
{
		/** OptionConverter is a static class. */
	private:
		OptionConverter() {}

	public:
		static LogString convertSpecialChars(const LogString& s);

		/**
		If <code>value</code> is "true", then <code>true</code> is
		returned. If <code>value</code> is "false", then
		<code>true</code> is returned. Otherwise, <code>default</code> is
		returned.

		<p>Case of value is unimportant.
		*/
		static bool toBoolean(const LogString& value, bool dEfault);
		static int toInt(const LogString& value, int dEfault);
		static long toFileSize(const LogString& value, long dEfault);
		static LevelPtr toLevel(const LogString& value,
			const LevelPtr& defaultValue);

		/**
		Find the value corresponding to <code>key</code> in
		<code>props</code>. Then perform variable substitution on the
		found value.
		*/
		static LogString findAndSubst(const LogString& key, Properties& props);

		/**
		Perform variable substitution in string <code>val</code> from the
		values of keys found in the system propeties.

		<p>The variable substitution delimeters are <b>${</b> and <b>}</b>.

		<p>For example, if the System properties contains "key=value", then
		the call
		<pre>
		String s = OptionConverter.substituteVars("Value of key is ${key}.");
		</pre>

		will set the variable <code>s</code> to "Value of key is value.".

		<p>If no value could be found for the specified key, then the
		<code>props</code> parameter is searched, if the value could not
		be found there, then substitution defaults to the empty string.

		<p>For example, if system propeties contains no value for the key
		"inexistentKey", then the call

		<pre>
		String s = OptionConverter.subsVars("Value of inexistentKey is [${inexistentKey}]");
		</pre>
		will set <code>s</code> to "Value of inexistentKey is []"

		<p>An IllegalArgumentException is thrown if
		<code>val</code> contains a start delimeter "${" which is not
		balanced by a stop delimeter "}". </p>

		@param val The string on which variable substitution is performed.
		@param props The properties from which variable substitution is performed.
		@throws IllegalArgumentException if <code>val</code> is malformed.
		*/
		static LogString substVars(const LogString& val, Properties& props);

		/**
		 *  Gets the specified system property.
		@param key The key to search for.
		@param def The default value to return.
		@return the string value of the system property, or the default
		value if there is no property with that key.
		*/
		static LogString getSystemProperty(const LogString& key, const LogString& def);

		/**
		Instantiate an object given a class name. Check that the
		<code>className</code> is a subclass of
		<code>superClass</code>. If that test fails or the object could
		not be instantiated, then <code>defaultValue</code> is returned.

		@param className The fully qualified class name of the object to instantiate.
		@param superClass The class to which the new object should belong.
		@param defaultValue The object to return in case of non-fulfillment
		*/
		static ObjectPtr instantiateByClassName(const LogString& className,
			const Class& superClass, const ObjectPtr& defaultValue);

		static ObjectPtr instantiateByKey(Properties& props,
			const LogString& key, const Class& superClass,
			const ObjectPtr& defaultValue);

		/**
		Configure log4cxx given a configFileName.

		<p>The configFileName must point to a file which will be
		interpreted by a new instance of a log4cxx configurator.

		<p>All configurations steps are taken on the
		<code>hierarchy</code> passed as a parameter.

		<p>
		@param configFileName The location of the configuration file.
		@param clazz The classname, of the log4cxx configurator which
		will parse the file <code>configFileName</code>. This must be
		a subclass of Configurator, or null. If this value is null then
		a default configurator of PropertyConfigurator is used, unless the
		filename pointed to by <code>configFileName</code> ends in '.xml',
		in which case DOMConfigurator is used.
		@param hierarchy The Hierarchy to act on.
		*/
		static void selectAndConfigure(const File& configFileName,
			const LogString& clazz, spi::LoggerRepositoryPtr& hierarchy);
};
}  // namespace helpers
} // namespace log4cxx

#endif //_LOG4CXX_HELPER_OPTION_CONVERTER_H