/**
 * Copyright 2005-2013 Restlet S.A.S.
 * 
 * The contents of this file are subject to the terms of one of the following
 * open source licenses: Apache 2.0 or LGPL 3.0 or LGPL 2.1 or CDDL 1.0 or EPL
 * 1.0 (the "Licenses"). You can select the license that you prefer but you may
 * not use this file except in compliance with one of these Licenses.
 * 
 * You can obtain a copy of the Apache 2.0 license at
 * http://www.opensource.org/licenses/apache-2.0
 * 
 * You can obtain a copy of the LGPL 3.0 license at
 * http://www.opensource.org/licenses/lgpl-3.0
 * 
 * You can obtain a copy of the LGPL 2.1 license at
 * http://www.opensource.org/licenses/lgpl-2.1
 * 
 * You can obtain a copy of the CDDL 1.0 license at
 * http://www.opensource.org/licenses/cddl1
 * 
 * You can obtain a copy of the EPL 1.0 license at
 * http://www.opensource.org/licenses/eclipse-1.0
 * 
 * See the Licenses for the specific language governing permissions and
 * limitations under the Licenses.
 * 
 * Alternatively, you can obtain a royalty free commercial license with less
 * limitations, transferable or non-transferable, directly at
 * http://www.restlet.com/products/restlet-framework
 * 
 * Restlet is a registered trademark of Restlet S.A.S.
 */

package org.restlet.ext.wadl;

import static org.restlet.ext.wadl.WadlRepresentation.APP_NAMESPACE;

import java.util.List;
import java.util.Map;

import org.restlet.data.Reference;
import org.restlet.ext.xml.XmlWriter;
import org.xml.sax.SAXException;
import org.xml.sax.helpers.AttributesImpl;

/**
 * Allows description of links between representations and resources.
 * 
 * @author Jerome Louvel
 */
public class LinkInfo extends DocumentedInfo {
    /**
     * Identifies the relationship of the resource identified by the link to the
     * resource whose representation the link is embedded in.
     */
    private String relationship;

    /**
     * Defines the capabilities of the resource that the link identifies.
     */
    private Reference resourceType;

    /**
     * Identifies the relationship of the resource whose representation the link
     * is embedded in to the resource identified by the link.
     */
    private String reverseRelationship;

    /**
     * Constructor.
     */
    public LinkInfo() {
        super();
    }

    /**
     * Constructor with a single documentation element.
     * 
     * @param documentation
     *            A single documentation element.
     */
    public LinkInfo(DocumentationInfo documentation) {
        super(documentation);
    }

    /**
     * Constructor with a list of documentation elements.
     * 
     * @param documentations
     *            The list of documentation elements.
     */
    public LinkInfo(List<DocumentationInfo> documentations) {
        super(documentations);
    }

    /**
     * Constructor with a single documentation element.
     * 
     * @param documentation
     *            A single documentation element.
     */
    public LinkInfo(String documentation) {
        super(documentation);
    }

    /**
     * Returns the relationship attribute value.
     * 
     * @return The relationship attribute value.
     */
    public String getRelationship() {
        return this.relationship;
    }

    /**
     * Returns the reference to the resource type of the linked resource.
     * 
     * @return The reference to the resource type of the linked resource.
     */
    public Reference getResourceType() {
        return this.resourceType;
    }

    /**
     * Returns the reverse relationship attribute value.
     * 
     * @return The reverse relationship attribute value.
     */
    public String getReverseRelationship() {
        return this.reverseRelationship;
    }

    /**
     * Sets the relationship attribute value.
     * 
     * @param relationship
     *            The relationship attribute value.
     */
    public void setRelationship(String relationship) {
        this.relationship = relationship;
    }

    /**
     * Sets the reference to the resource type of the linked resource.
     * 
     * @param resourceType
     *            The reference to the resource type of the linked resource.
     */
    public void setResourceType(Reference resourceType) {
        this.resourceType = resourceType;
    }

    /**
     * Sets the reverse relationship attribute value.
     * 
     * @param reverseRelationship
     *            The reverse relationship attribute value.
     */
    public void setReverseRelationship(String reverseRelationship) {
        this.reverseRelationship = reverseRelationship;
    }

    @Override
    public void updateNamespaces(Map<String, String> namespaces) {
        namespaces.putAll(resolveNamespaces());
    }

    /**
     * Writes the current object as an XML element using the given SAX writer.
     * 
     * @param writer
     *            The SAX writer.
     * @throws SAXException
     */
    public void writeElement(XmlWriter writer) throws SAXException {
        final AttributesImpl attributes = new AttributesImpl();
        if ((getRelationship() != null) && !getRelationship().equals("")) {
            attributes.addAttribute("", "rel", null, "xs:token",
                    getRelationship());
        }
        if ((getReverseRelationship() != null)
                && !getReverseRelationship().equals("")) {
            attributes.addAttribute("", "rev", null, "xs:token",
                    getReverseRelationship());
        }

        if ((getResourceType() != null)
                && (getResourceType().toString() != null)) {
            attributes.addAttribute("", "resource_type", null, "xs:anyURI",
                    getResourceType().toString());
        }

        if (getDocumentations().isEmpty()) {
            writer.emptyElement(APP_NAMESPACE, "link", null, attributes);
        } else {
            writer.startElement(APP_NAMESPACE, "link", null, attributes);

            for (final DocumentationInfo documentationInfo : getDocumentations()) {
                documentationInfo.writeElement(writer);
            }

            writer.endElement(APP_NAMESPACE, "link");
        }
    }
}