/**
 *  Copyright (C) 2002-2012   The FreeCol Team
 *
 *  This file is part of FreeCol.
 *
 *  FreeCol is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  FreeCol is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with FreeCol.  If not, see <http://www.gnu.org/licenses/>.
 */

package net.sf.freecol.server.ai;

import java.util.logging.Logger;

import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import javax.xml.stream.XMLStreamWriter;

import net.sf.freecol.common.model.GoodsContainer;
import net.sf.freecol.common.model.GoodsType;
import net.sf.freecol.common.model.Location;

import org.w3c.dom.Element;


/**
 * Represents the need for goods within a <code>Colony</code>.
 */
public class GoodsWish extends Wish {

    @SuppressWarnings("unused")
    private static final Logger logger = Logger.getLogger(GoodsWish.class.getName());

    private GoodsType goodsType;
    private int amountRequested;

    /**
     * Creates a new <code>GoodsWish</code>.
     *
     * @param aiMain The main AI-object.
     * @param destination The <code>Location</code> in which the
     *       {@link Wish#getTransportable transportable} assigned to
     *       this <code>GoodsWish</code> will have to reach.
     * @param value The value identifying the importance of
     *       this <code>Wish</code>.
     * @param amountRequested The amount requested.
     * @param goodsType The type of goods needed for releasing this wish
     *       completly.
     */
    public GoodsWish(AIMain aiMain, Location destination, int value, int amountRequested, GoodsType goodsType) {
        super(aiMain, getXMLElementTagName() + ":" + aiMain.getNextID());

        if (destination == null) {
            throw new NullPointerException("destination == null");
        }

        this.destination = destination;
        setValue(value);
        this.goodsType = goodsType;
        this.amountRequested = amountRequested;
    }

    /**
     * Creates a new <code>GoodsWish</code>, using a standard request amount of 100.
     * Possible TODO: Deprecate this in favor of the constructor without std amount?
     *
     * @param aiMain The main AI-object.
     * @param destination The <code>Location</code> in which the
     *       {@link Wish#getTransportable transportable} assigned to
     *       this <code>GoodsWish</code> will have to reach.
     * @param value The value identifying the importance of
     *       this <code>Wish</code>.
     * @param goodsType The type of goods needed for releasing this wish
     *       completly.
     */
    public GoodsWish(AIMain aiMain, Location destination, int value, GoodsType goodsType) {
        this(aiMain,destination,value, GoodsContainer.CARGO_SIZE, goodsType);
    }

    /**
     * Creates a new <code>GoodsWish</code> from the given XML-representation.
     *
     * @param aiMain The main AI-object.
     * @param element The root element for the XML-representation of a <code>GoodsWish</code>.
     */
    public GoodsWish(AIMain aiMain, Element element) {
        super(aiMain, element.getAttribute(ID_ATTRIBUTE));
        readFromXMLElement(element);
    }

    /**
     * Creates a new <code>GoodsWish</code>.
     *
     * @param aiMain The main AI-object.
     * @param id The unique ID of this object.
     */
    public GoodsWish(AIMain aiMain, String id) {
        super(aiMain, id);
    }

    /**
     * Creates a new <code>GoodsWish</code>.
     *
     * @param aiMain The main AI-object.
     * @param in The input stream containing the XML.
     * @throws XMLStreamException if a problem was encountered
     *      during parsing.
     */
    public GoodsWish(AIMain aiMain, XMLStreamReader in) throws XMLStreamException {
        super(aiMain, in.getAttributeValue(null, ID_ATTRIBUTE));
        readFromXML(in);
    }


    /**
     * Describe <code>getGoodsType</code> method here.
     *
     * @return a <code>GoodsType</code> value
     */
    public GoodsType getGoodsType() {
        return goodsType;
    }

    /**
     * Describe <code>getGoodsAmount</code> method here.
     *
     * @return an <code>int</code> value
     */
    public int getGoodsAmount() {
        return amountRequested;
    }


    /**
     * Writes this object to an XML stream.
     *
     * @param out The target stream.
     * @throws XMLStreamException if there are any problems writing
     *      to the stream.
     */
    protected void toXMLImpl(XMLStreamWriter out) throws XMLStreamException {
        out.writeStartElement(getXMLElementTagName());

        out.writeAttribute(ID_ATTRIBUTE, getId());

        out.writeAttribute("destination", destination.getId());
        if (transportable != null) {
            out.writeAttribute("transportable", transportable.getId());
        }
        out.writeAttribute("value", Integer.toString(getValue()));
        out.writeAttribute("goodsType", goodsType.getId());
        out.writeAttribute("amountRequested", Integer.toString(amountRequested));

        out.writeEndElement();
    }

    /**
     * Reads information for this object from an XML stream.
     *
     * @param in The input stream with the XML.
     * @throws XMLStreamException if there are any problems reading
     *      from the stream.
     */
    protected void readFromXMLImpl(XMLStreamReader in)
        throws XMLStreamException {
        setId(in.getAttributeValue(null, ID_ATTRIBUTE));
        destination = (Location) getAIMain().getFreeColGameObject(in.getAttributeValue(null, "destination"));

        final String transportableStr = in.getAttributeValue(null, "transportable");
        if (transportableStr != null) {
            transportable = (Transportable) getAIMain().getAIObject(transportableStr);
            if (transportable == null) {
                transportable = new AIGoods(getAIMain(), transportableStr);
            }
        } else {
            transportable = null;
        }
        setValue(Integer.parseInt(in.getAttributeValue(null, "value")));

        goodsType = getSpecification().getGoodsType(in.getAttributeValue(null, "goodsType"));
        amountRequested = getAttribute(in, "amountRequested",
                                       GoodsContainer.CARGO_SIZE);
        in.nextTag();

        attachToDestination();
    }

    @Override
    public String toString() {
        return "goodsWish: " + getId() + " " + amountRequested
            + " " + goodsType + " (" + getValue() + ")";
    }

    /**
     * Returns the tag name of the root element representing this object.
     *
     * @return "goodsWish"
     */
    public static String getXMLElementTagName() {
        return "goodsWish";
    }
}
