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/*
 * Copyright 2013 serso aka se.solovyev
 *
 * Licensed 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.
 *
 * ---------------------------------------------------------------------
 * Contact details
 *
 * Email: [email protected]
 * Site:  http://se.solovyev.org
 */

package org.solovyev.common.text;

import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

/**
 * User: serso
 * Date: 9/26/11
 * Time: 11:07 PM
 */
public class NumberParser implements Parser {

	/*
	**********************************************************************
	*
	*                           STATIC
	*
	**********************************************************************
	*/

	static final List> supportedClasses = Arrays.>asList(Integer.class, Float.class, Long.class, Double.class);

	private static final Map, Parser> parsers = new HashMap, Parser>(supportedClasses.size());

	static {
		for (Class supportedClass : supportedClasses) {
			parsers.put(supportedClass, new NumberParser(supportedClass));
		}
	}

	/*
	**********************************************************************
	*
	*                           FIELDS
	*
	**********************************************************************
	*/

	@Nonnull
	private final Class clazz;

	/*
	**********************************************************************
	*
	*                           CONSTRUCTORS
	*
	**********************************************************************
	*/

	private NumberParser(@Nonnull Class clazz) {
		this.clazz = clazz;
	}

	@Nonnull
	public static  Parser of(@Nonnull Class clazz) {
		assert supportedClasses.contains(clazz) : "Class " + clazz + " is not supported by " + NumberParser.class;
		return (Parser) parsers.get(clazz);
	}

	/*
	**********************************************************************
	*
	*                           METHODS
	*
	**********************************************************************
	*/

	@Override
	public N parseValue(@Nullable String value) throws IllegalArgumentException {
		N result;

		if (value != null) {
			if (this.clazz.equals(Integer.class)) {
				result = (N) Integer.valueOf(value);
			} else if (this.clazz.equals(Float.class)) {
				result = (N) Float.valueOf(value);
			} else if (this.clazz.equals(Long.class)) {
				result = (N) Long.valueOf(value);
			} else if (this.clazz.equals(Double.class)) {
				result = (N) Double.valueOf(value);
			} else {
				throw new UnsupportedOperationException(this.clazz + " is not supported!");
			}
		} else {
			result = null;
		}

		return result;
	}
}