/*
 * 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 org.apache.any23.extractor.microdata;

import java.util.Locale;

/**
 * Describes a <b>Microdata item property</b>.
 *
 * @author Michele Mostarda (mostarda@fbk.eu)
 */
public class ItemProp extends Item {

    /**
     * Property name.
     */
    private final String name;

    /**
     * Property value.
     */
    private final ItemPropValue value;

    /**
     * Constructor.
     *
     * @param xpath item location in container document.
     * @param name item property name.
     * @param value item property value.
     */
    public ItemProp(String xpath, String name, ItemPropValue value) {
        this(xpath, name, value, false);
    }

    final boolean reverse;
    ItemProp(String xpath, String name, ItemPropValue value, boolean reverse) {
        super(xpath);

        if(name == null) {
            throw new NullPointerException("name cannot be null.");
        }
        if(name.trim().length() == 0) {
            throw new IllegalArgumentException("invalid property name '" + name + "'");
        }
        if(value == null) {
            throw new NullPointerException("value cannot be null.");
        }
        this.name = name;
        this.value = value;
        this.reverse = reverse;
    }

    /**
     * @return the item property name.
     */
    public String getName() {
        return name;
    }

    /**
     * @return the item property value.
     */
    public ItemPropValue getValue() {
        return value;
    }

    @Override
    public String toJSON() {
        return String.format(Locale.ROOT,
                "{ \"xpath\" : \"%s\", \"name\" : \"%s\", \"value\" : %s }",
                getXpath(),
                name,
                value.toJSON()
        );
    }

    @Override
    public String toString() {
        return toJSON();
    }

    @Override
    public int hashCode() {
        return name.hashCode() * value.hashCode() * 3;
    }

    @Override
    public boolean equals(Object obj) {
        if( obj == null ) {
            return false;
        }
        if(obj == this) {
            return true;
        }
        if(obj instanceof ItemProp) {
            final ItemProp other = (ItemProp) obj;
            return name.equals(other.name) && value.equals( other.value );
        }
        return false;
    }
}
