/**
 * Copyright 2011 Bill Brown
 *
 * 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 com.colorfulsoftware.rss;

import java.io.Serializable;
import java.util.LinkedList;
import java.util.List;

/**
 * <p>
 * The &lt;cloud> element.
 * </p>
 * <p>
 * From the <a href="http://cyber.law.harvard.edu/rss/rss.html">RSS 2.0
 * specification</a>...
 * </p>
 * <p>
 * Allows processes to register with a cloud to be notified of updates to the
 * channel, implementing a lightweight publish-subscribe protocol for RSS feeds.
 * More info &lt;a href= &quot;http://cyber.law.harvard.edu/rss/rss.html#
 * ltcloudgtSubelementOfLtchannelgt&quot; &gt;here&lt;/a&gt;
 * </p>
 * 
 * <p>
 * &lt;cloud&gt; sub-element of &lt;channel&gt;
 * </p>
 * 
 * <p>
 * &lt;cloud&gt; is an optional sub-element of &lt;channel&gt;.
 * </p>
 * 
 * <p>
 * It specifies a web service that supports the rssCloud interface which can be
 * implemented in HTTP-POST, XML-RPC or SOAP 1.1.
 * </p>
 * 
 * <p>
 * Its purpose is to allow processes to register with a cloud to be notified of
 * updates to the channel, implementing a lightweight publish-subscribe protocol
 * for RSS feeds.
 * </p>
 * 
 * <p>
 * &lt;cloud domain=&quot;rpc.sys.com&quot; port=&quot;80&quot;
 * path=&quot;/RPC2&quot; registerProcedure=&quot;myCloud.rssPleaseNotify&quot;
 * protocol=&quot;xml-rpc&quot; /&gt;
 * </p>
 * 
 * <p>
 * In this example, to request notification on the channel it appears in, you
 * would send an XML-RPC message to rpc.sys.com on port 80, with a path of
 * /RPC2. The procedure to call is myCloud.rssPleaseNotify.
 * </p>
 * 
 * <p>
 * A full explanation of this element and the rssCloud interface is <a
 * href=&quot
 * ;http://cyber.law.harvard.edu/rss/soapMeetsRss.html#rsscloudInterface&quot;
 * &gt;here&lt;/a&gt;.
 * </p>
 * 
 * 
 * @author Bill Brown
 * 
 */
public class Cloud implements Serializable {

        /**
         * 
         */
        private static final long serialVersionUID = 4431999134564899474L;

        private final List<Attribute> attributes;
        private final Attribute domain;
        private final Attribute port;
        private final Attribute path;
        private final Attribute registerProcedure;
        private final Attribute protocol;

        Cloud(List<Attribute> attributes) throws RSSpectException {
                if (attributes == null) {
                        throw new RSSpectException(
                                        "The cloud element requires attributes:  See \"http://cyber.law.harvard.edu/rss/soapMeetsRss.html#rsscloudInterface\".");
                } else {
                        this.attributes = new LinkedList<Attribute>();
                        for (Attribute attr : attributes) {
                                // check for unsupported attribute.
                                this.attributes.add(new Attribute(attr.getName(), attr
                                                .getValue()));
                        }
                }

                if ((this.domain = getAttribute("domain")) == null) {
                        throw new RSSpectException(
                                        "cloud elements MUST have a domain attribute.");
                }

                if ((this.port = getAttribute("port")) == null) {
                        throw new RSSpectException(
                                        "cloud elements MUST have a port attribute.");
                }

                if ((this.path = getAttribute("path")) == null) {
                        throw new RSSpectException(
                                        "cloud elements MUST have a path attribute.");
                }

                if ((this.registerProcedure = getAttribute("registerProcedure")) == null) {
                        throw new RSSpectException(
                                        "cloud elements MUST have a registerProcedure attribute.");
                }

                if ((this.protocol = getAttribute("protocol")) == null) {
                        throw new RSSpectException(
                                        "cloud elements MUST have a protocol attribute.");
                }
                if (!getAttribute("protocol").getValue().equals("xml-rpc")
                                && !getAttribute("protocol").getValue().equals("soap")) {
                        throw new RSSpectException(
                                        "the cloud's protocol attribute must be 'xml-rpc' or 'soap', case-sensitive.");
                }
        }

        Cloud(Cloud cloud) {
                this.attributes = cloud.getAttributes();
                this.domain = cloud.getDomain();
                this.port = cloud.getPort();
                this.path = cloud.getPath();
                this.registerProcedure = cloud.getRegisterProcedure();
                this.protocol = cloud.getProtocol();
        }

        /**
         * 
         * @return the cloud attribute list.
         */
        public List<Attribute> getAttributes() {

                List<Attribute> attrsCopy = new LinkedList<Attribute>();
                for (Attribute attr : this.attributes) {
                        attrsCopy.add(new Attribute(attr));
                }
                return attrsCopy;
        }

        /**
         * @return the domain attribute.
         */
        public Attribute getDomain() {
                return new Attribute(domain);
        }

        /**
         * @return the port attribute
         */
        public Attribute getPort() {
                return new Attribute(port);
        }

        /**
         * @return the path attribute
         */
        public Attribute getPath() {
                return new Attribute(path);
        }

        /**
         * @return the registerProcedure attribute.
         */
        public Attribute getRegisterProcedure() {
                return new Attribute(registerProcedure);
        }

        /**
         * @return the protocol attribute.
         */
        public Attribute getProtocol() {
                return new Attribute(protocol);
        }

        /**
         * @param attrName
         *            the name of the attribute to get.
         * @return the Attribute object if attrName matches or null if not found.
         */
        public Attribute getAttribute(String attrName) {
                for (Attribute attribute : this.attributes) {
                        if (attribute.getName().equals(attrName)) {
                                return new Attribute(attribute);
                        }
                }
                return null;
        }

        /**
         * Shows the contents of the &lt;cloud> element.
         */
        @Override
        public String toString() {
                StringBuilder sb = new StringBuilder("<cloud");
                for (Attribute attribute : attributes) {
                        sb.append(attribute);
                }
                sb.append(" />");
                return sb.toString();
        }
        
        @Override
        public boolean equals(Object obj) {
                if (obj == this) {
                        return true;
                }
                if (!(obj instanceof Cloud)) {
                        return false;
                }
                return this.toString().equals(obj.toString());
        }
        
        @Override public int hashCode() {
                return toString().hashCode();
        }
}