001/**
002 *
003 * Copyright 2005-2007 Jive Software.
004 *
005 * Licensed under the Apache License, Version 2.0 (the "License");
006 * you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 *     http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.jivesoftware.smackx.commands;
018
019import java.util.ArrayList;
020import java.util.List;
021import java.util.Set;
022
023import org.jivesoftware.smack.SmackException.NoResponseException;
024import org.jivesoftware.smack.SmackException.NotConnectedException;
025import org.jivesoftware.smack.XMPPException.XMPPErrorException;
026import org.jivesoftware.smack.packet.StanzaError;
027import org.jivesoftware.smack.util.StringUtils;
028import org.jivesoftware.smackx.commands.packet.AdHocCommandData;
029import org.jivesoftware.smackx.commands.packet.AdHocCommandData.Action;
030import org.jivesoftware.smackx.commands.packet.AdHocCommandData.AllowedAction;
031import org.jivesoftware.smackx.commands.packet.AdHocCommandData.Status;
032
033/**
034 * An ad-hoc command is responsible for executing the provided service and
035 * storing the result of the execution. Each new request will create a new
036 * instance of the command, allowing information related to executions to be
037 * stored in it. For example suppose that a command that retrieves the list of
038 * users on a server is implemented. When the command is executed it gets that
039 * list and the result is stored as a form in the command instance, i.e. the
040 * <code>getForm</code> method retrieves a form with all the users.
041 * <p>
042 * Each command has a <code>node</code> that should be unique within a given JID.
043 * </p>
044 * <p>
045 * Commands may have zero or more stages. Each stage is usually used for
046 * gathering information required for the command execution. Users are able to
047 * move forward or backward across the different stages. Commands may not be
048 * cancelled while they are being executed. However, users may request the
049 * "cancel" action when submitting a stage response indicating that the command
050 * execution should be aborted. Thus, releasing any collected information.
051 * Commands that require user interaction (i.e. have more than one stage) will
052 * have to provide the data forms the user must complete in each stage and the
053 * allowed actions the user might perform during each stage (e.g. go to the
054 * previous stage or go to the next stage).
055 * </p>
056 * All the actions may throw an XMPPException if there is a problem executing
057 * them. The <code>XMPPError</code> of that exception may have some specific
058 * information about the problem. The possible extensions are:
059 * <ul>
060 * <li><i>malformed-action</i>. Extension of a <i>bad-request</i> error.</li>
061 * <li><i>bad-action</i>. Extension of a <i>bad-request</i> error.</li>
062 * <li><i>bad-locale</i>. Extension of a <i>bad-request</i> error.</li>
063 * <li><i>bad-payload</i>. Extension of a <i>bad-request</i> error.</li>
064 * <li><i>bad-sessionid</i>. Extension of a <i>bad-request</i> error.</li>
065 * <li><i>session-expired</i>. Extension of a <i>not-allowed</i> error.</li>
066 * </ul>
067 * <p>
068 * See the <code>SpecificErrorCondition</code> class for detailed description
069 * of each one.
070 * </p>
071 * Use the <code>getSpecificErrorConditionFrom</code> to obtain the specific
072 * information from an <code>XMPPError</code>.
073 *
074 * @author Gabriel Guardincerri
075 * @author Florian Schmaus
076 *
077 */
078public abstract class AbstractAdHocCommand {
079    private final List<AdHocCommandData> requests = new ArrayList<>();
080    private final List<AdHocCommandResult> results = new ArrayList<>();
081
082    private final String node;
083
084    private final String name;
085
086    /**
087     * The session ID of this execution.
088     */
089    private String sessionId;
090
091    protected AbstractAdHocCommand(String node, String name) {
092        this.node = StringUtils.requireNotNullNorEmpty(node, "Ad-Hoc command node must be given");
093        this.name = name;
094    }
095
096    protected AbstractAdHocCommand(String node) {
097        this(node, null);
098    }
099
100    void addRequest(AdHocCommandData request) {
101        requests.add(request);
102    }
103
104    void addResult(AdHocCommandResult result) {
105        results.add(result);
106    }
107
108    /**
109     * Returns the specific condition of the <code>error</code> or <code>null</code> if the
110     * error doesn't have any.
111     *
112     * @param error the error the get the specific condition from.
113     * @return the specific condition of this error, or null if it doesn't have
114     *         any.
115     */
116    public static SpecificErrorCondition getSpecificErrorCondition(StanzaError error) {
117        // This method is implemented to provide an easy way of getting a packet
118        // extension of the XMPPError.
119        for (SpecificErrorCondition condition : SpecificErrorCondition.values()) {
120            if (error.getExtension(condition.toString(),
121                    AdHocCommandData.SpecificError.namespace) != null) {
122                return condition;
123            }
124        }
125        return null;
126    }
127
128    /**
129     * Returns the human readable name of the command.
130     *
131     * @return the human readable name of the command
132     */
133    public String getName() {
134        return name;
135    }
136
137    /**
138     * Returns the unique identifier of the command. It is unique for the
139     * <code>OwnerJID</code>.
140     *
141     * @return the unique identifier of the command.
142     */
143    public String getNode() {
144        return node;
145    }
146
147    public String getSessionId() {
148        return sessionId;
149    }
150
151    protected void setSessionId(String sessionId) {
152        assert this.sessionId == null || this.sessionId.equals(sessionId);
153        this.sessionId = StringUtils.requireNotNullNorEmpty(sessionId, "Must provide a session ID");
154    }
155
156    public AdHocCommandData getLastRequest() {
157        if (requests.isEmpty()) return null;
158        return requests.get(requests.size() - 1);
159    }
160
161    public AdHocCommandResult getLastResult() {
162        if (results.isEmpty()) return null;
163        return results.get(results.size() - 1);
164    }
165
166    /**
167     * Returns the notes that the command has at the current stage.
168     *
169     * @return a list of notes.
170     */
171    public List<AdHocCommandNote> getNotes() {
172        AdHocCommandResult result = getLastResult();
173        if (result == null) return null;
174
175        return result.getResponse().getNotes();
176    }
177
178    /**
179     * Cancels the execution of the command. This can be invoked on any stage of
180     * the execution. If there is a problem executing the command it throws an
181     * XMPPException.
182     *
183     * @throws NoResponseException if there was no response from the remote entity.
184     * @throws XMPPErrorException if there is a problem executing the command.
185     * @throws NotConnectedException if the XMPP connection is not connected.
186     * @throws InterruptedException if the calling thread was interrupted.
187     */
188    public abstract void cancel() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException;
189
190    /**
191     * Returns a collection with the allowed actions based on the current stage.
192     * Possible actions are: {@link AllowedAction#prev prev}, {@link AllowedAction#next next} and
193     * {@link AllowedAction#complete complete}. This method will be only invoked for commands that
194     * have one or more stages.
195     *
196     * @return a collection with the allowed actions based on the current stage
197     *      as defined in the SessionData.
198     */
199    public final Set<AllowedAction> getActions() {
200        AdHocCommandResult result = getLastResult();
201        if (result == null) return null;
202
203        return result.getResponse().getActions();
204    }
205
206    /**
207     * Returns the action available for the current stage which is
208     * considered the equivalent to "execute". When the requester sends his
209     * reply, if no action was defined in the command then the action will be
210     * assumed "execute" thus assuming the action returned by this method. This
211     * method will never be invoked for commands that have no stages.
212     *
213     * @return the action available for the current stage which is considered
214     *      the equivalent to "execute".
215     */
216    protected AllowedAction getExecuteAction() {
217        AdHocCommandResult result = getLastResult();
218        if (result == null) return null;
219
220        return result.getResponse().getExecuteAction();
221    }
222
223    /**
224     * Returns the status of the current stage.
225     *
226     * @return the current status.
227     */
228    public Status getStatus() {
229        AdHocCommandResult result = getLastResult();
230        if (result == null) return null;
231
232        return result.getResponse().getStatus();
233    }
234
235    /**
236     * Check if this command has been completed successfully.
237     *
238     * @return <code>true</code> if this command is completed.
239     * @since 4.2
240     */
241    public boolean isCompleted() {
242        return getStatus() == AdHocCommandData.Status.completed;
243    }
244
245    /**
246     * Returns true if the <code>action</code> is available in the current stage.
247     * The {@link Action#cancel cancel} action is always allowed. To define the
248     * available actions use the <code>addActionAvailable</code> method.
249     *
250     * @param action The action to check if it is available.
251     * @return True if the action is available for the current stage.
252     */
253    public final boolean isValidAction(Action action) {
254        if (action == Action.cancel) {
255            return true;
256        }
257
258        final AllowedAction executeAction;
259        if (action == Action.execute) {
260            AdHocCommandResult result = getLastResult();
261            executeAction = result.getResponse().getExecuteAction();
262
263            // This is basically the case that was clarified with
264            // https://github.com/xsf/xeps/commit/fdaee2da8ffd34b5b5151e90ef1df8b396a06531 and
265            // https://github.com/xsf/xeps/pull/591.
266            if (executeAction == null) {
267                return false;
268            }
269        } else {
270            executeAction = action.allowedAction;
271            assert executeAction != null;
272        }
273
274        Set<AllowedAction> actions = getActions();
275        return actions != null && actions.contains(executeAction);
276    }
277}