/**
 * Copyright (c) 2008-2010 Andrey Somov
 *
 * 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.
 */
package org.yaml.snakeyaml;

import java.io.InputStream;
import java.io.Reader;
import java.io.StringReader;

import org.yaml.snakeyaml.constructor.Constructor;
import org.yaml.snakeyaml.reader.UnicodeReader;
import org.yaml.snakeyaml.resolver.Resolver;

/**
 * Convenience utility to parse JavaBeans. When the YAML document contains a
 * global tag with the class definition like '!!com.package.MyBean' it is
 * ignored in favour of the runtime class <code>T</code>.
 * 
 * @see http://www.artima.com/weblogs/viewpost.jsp?thread=208860
 */
public class JavaBeanLoader<T> {
    private Loader loader;

    public JavaBeanLoader(TypeDescription typeDescription) {
        Constructor constructor = new Constructor(typeDescription.getType());
        typeDescription.setRoot(true);
        constructor.addTypeDescription(typeDescription);
        loader = new Loader(constructor);
        Resolver resolver = new Resolver();
        loader.setResolver(resolver);
    }

    public JavaBeanLoader(Class<? extends T> clazz) {
        this(new TypeDescription(clazz));
    }

    /**
     * Parse the first YAML document in a stream and produce the corresponding
     * JavaBean.
     * 
     * @param yaml
     *            YAML document
     * @return parsed JavaBean
     */
    @SuppressWarnings("unchecked")
    public T load(String yaml) {
        return (T) loader.load(new StringReader(yaml));
    }

    /**
     * Parse the first YAML document in a stream and produce the corresponding
     * JavaBean.
     * 
     * @param io
     *            data to load from (BOM is respected and removed)
     * @return parsed JavaBean
     */
    @SuppressWarnings("unchecked")
    public T load(InputStream io) {
        return (T) loader.load(new UnicodeReader(io));
    }

    /**
     * Parse the first YAML document in a stream and produce the corresponding
     * Java object.
     * 
     * @param io
     *            data to load from (BOM must not be present)
     * @return parsed JavaBean
     */
    @SuppressWarnings("unchecked")
    public T load(Reader io) {
        return (T) loader.load(io);
    }

}