ingo@119: package de.intevation.flys.artifacts;
ingo@119: 
ingo@121: import java.util.HashMap;
ingo@119: import java.util.List;
ingo@121: import java.util.Map;
ingo@122: import java.util.Set;
ingo@122: import java.util.Vector;
ingo@121: 
ingo@121: import javax.xml.xpath.XPathConstants;
ingo@119: 
ingo@119: import org.apache.log4j.Logger;
ingo@119: 
ingo@119: import org.w3c.dom.Document;
ingo@121: import org.w3c.dom.Element;
ingo@121: import org.w3c.dom.Node;
ingo@121: import org.w3c.dom.NodeList;
ingo@119: 
ingo@119: import de.intevation.artifacts.ArtifactFactory;
ingo@119: import de.intevation.artifacts.CallContext;
ingo@119: 
ingo@119: import de.intevation.artifacts.common.ArtifactNamespaceContext;
ingo@119: import de.intevation.artifacts.common.utils.XMLUtils;
ingo@119: 
ingo@119: import de.intevation.artifactdatabase.DefaultArtifact;
ingo@121: import de.intevation.artifactdatabase.data.DefaultStateData;
ingo@119: import de.intevation.artifactdatabase.data.StateData;
ingo@119: import de.intevation.artifactdatabase.state.State;
ingo@119: import de.intevation.artifactdatabase.state.StateEngine;
ingo@122: import de.intevation.artifactdatabase.transition.TransitionEngine;
ingo@119: 
ingo@119: import de.intevation.flys.artifacts.context.FLYSContext;
ingo@119: 
ingo@119: 
ingo@119: /**
ingo@119:  * The defaul FLYS artifact.
ingo@119:  *
ingo@119:  * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
ingo@119:  */
ingo@119: public abstract class FLYSArtifact extends DefaultArtifact {
ingo@119: 
ingo@119:     /** The logger that is used in this artifact.*/
ingo@119:     private static Logger logger = Logger.getLogger(FLYSArtifact.class);
ingo@119: 
ingo@119: 
ingo@121:     /** The XPath that points to the input data elements of the FEED document.*/
ingo@121:     public static final String XPATH_FEED_INPUT =
ingo@121:         "/art:action/art:data/art:input";
ingo@119: 
ingo@122:     /** The XPath that points to the name of the target state of ADVANCE.*/
ingo@122:     public static final String XPATH_ADVANCE_TARGET =
ingo@122:         "/art:action/art:target/@art:name";
ingo@122: 
ingo@122:     /** The constant string that shows that an operation was successful.*/
ingo@122:     public static final String OPERATION_SUCCESSFUL = "SUCCESS";
ingo@122: 
ingo@122:     /** The constant string that shows that an operation failed.*/
ingo@122:     public static final String OPERATION_FAILED = "FAILURE";
ingo@122: 
ingo@119: 
ingo@119:     /** The identifier of the current state. */
ingo@119:     protected String currentStateId;
ingo@119: 
ingo@122:     /** The identifiers of previous states on a stack.*/
ingo@122:     protected Vector<String> previousStateIds;
ingo@122: 
ingo@119:     /** The name of the artifact.*/
ingo@119:     protected String name;
ingo@119: 
ingo@121:     /** The data that have been inserted into this artifact.*/
ingo@121:     protected Map<String, StateData> data;
ingo@121: 
ingo@121: 
ingo@121:     /**
ingo@121:      * The default constructor that creates an empty FLYSArtifact.
ingo@121:      */
ingo@121:     public FLYSArtifact() {
ingo@122:         data             = new HashMap<String, StateData>();
ingo@122:         previousStateIds = new Vector<String>();
ingo@121:     }
ingo@121: 
ingo@121: 
ingo@121:     /**
ingo@121:      * Returns the name of the concrete artifact.
ingo@121:      *
ingo@121:      * @return the name of the concrete artifact.
ingo@121:      */
ingo@121:     public abstract String getName();
ingo@121: 
ingo@121: 
ingo@121:     /**
ingo@121:      * Returns the FLYSContext from context object.
ingo@121:      *
ingo@121:      * @param context The CallContext or the FLYSContext.
ingo@121:      *
ingo@121:      * @return the FLYSContext.
ingo@121:      */
ingo@121:     protected FLYSContext getFlysContext(Object context) {
ingo@121:         return context instanceof FLYSContext
ingo@121:             ? (FLYSContext) context
ingo@121:             : (FLYSContext) ((CallContext) context).globalContext();
ingo@121:     }
ingo@121: 
ingo@119: 
ingo@119:     /**
ingo@119:      * Initialize the artifact and insert new data if <code>data</code> contains
ingo@119:      * information necessary for this artifact.
ingo@119:      *
ingo@119:      * @param identifier The UUID.
ingo@119:      * @param factory The factory that is used to create this artifact.
ingo@119:      * @param context The CallContext.
ingo@119:      * @param data Some optional data.
ingo@119:      */
ingo@119:     @Override
ingo@119:     public void setup(
ingo@119:         String          identifier,
ingo@119:         ArtifactFactory factory,
ingo@119:         Object          context,
ingo@119:         Document        data)
ingo@119:     {
ingo@119:         logger.debug("Setup this artifact with the uuid: " + identifier);
ingo@119: 
ingo@119:         super.setup(identifier, factory, context, data);
ingo@119: 
ingo@119:         FLYSContext flysContext = (FLYSContext) context;
ingo@119:         StateEngine engine      = (StateEngine) flysContext.get(
ingo@119:             FLYSContext.STATE_ENGINE_KEY);
ingo@119: 
ingo@121:         String name = getName();
ingo@121: 
ingo@121:         logger.debug("Set initial state for artifact '" + name + "'");
ingo@119:         List<State> states = engine.getStates(name);
ingo@119: 
ingo@119:         setCurrentState(states.get(0));
ingo@119:     }
ingo@119: 
ingo@119: 
ingo@119:     /**
ingo@119:      * Insert new data included in <code>input</code> into the current state.
ingo@119:      *
ingo@119:      * @param target XML document that contains new data.
ingo@119:      * @param context The CallContext.
ingo@119:      *
ingo@119:      * @return a document that contains a SUCCESS or FAILURE message.
ingo@119:      */
ingo@119:     @Override
ingo@119:     public Document feed(Document target, CallContext context) {
ingo@123:         logger.info("FLYSArtifact.feed()");
ingo@123: 
ingo@121:         Document doc = XMLUtils.newDocument();
ingo@119: 
ingo@121:         XMLUtils.ElementCreator creator = new XMLUtils.ElementCreator(
ingo@121:             doc,
ingo@121:             ArtifactNamespaceContext.NAMESPACE_URI,
ingo@121:             ArtifactNamespaceContext.NAMESPACE_PREFIX);
ingo@119: 
ingo@121:         Element result = creator.create("result");
ingo@121:         doc.appendChild(result);
ingo@119: 
ingo@121:         try {
ingo@121:             saveData(target, XPATH_FEED_INPUT);
ingo@123:             return describe(target, context);
ingo@121:         }
ingo@121:         catch (IllegalArgumentException iae) {
ingo@122:             creator.addAttr(result, "type", OPERATION_FAILED, true);
ingo@121: 
ingo@121:             // TODO I18N this message - getMessage() returns a lookup string, no
ingo@121:             // human readable error message
ingo@121:             result.setTextContent(iae.getMessage());
ingo@121:         }
ingo@121: 
ingo@121:         return doc;
ingo@119:     }
ingo@119: 
ingo@119: 
ingo@119:     /**
ingo@122:      * This method handles request for changing the current state of an
ingo@122:      * artifact. It is possible to step forward or backward.
ingo@122:      *
ingo@122:      * @param target The incoming ADVANCE document.
ingo@122:      * @param context The CallContext.
ingo@122:      *
ingo@122:      * @return a document that contains a SUCCESS or FAILURE message.
ingo@122:      */
ingo@122:     public Document advance(Document target, CallContext context) {
ingo@122:         Document doc = XMLUtils.newDocument();
ingo@122: 
ingo@122:         XMLUtils.ElementCreator ec = new XMLUtils.ElementCreator(
ingo@122:             doc,
ingo@122:             ArtifactNamespaceContext.NAMESPACE_URI,
ingo@122:             ArtifactNamespaceContext.NAMESPACE_PREFIX);
ingo@122: 
ingo@122:         Element result = ec.create("result");
ingo@122: 
ingo@122:         String targetState = XMLUtils.xpathString(
ingo@122:             target, XPATH_ADVANCE_TARGET, ArtifactNamespaceContext.INSTANCE);
ingo@122: 
ingo@140:         logger.info("FLYSArtifact.advance() to '" + targetState + "'");
ingo@140: 
ingo@122:         if (isStateReachable(targetState, context)) {
ingo@140:             logger.info("Advance: Step forward");
ingo@122: 
ingo@122:             Vector<String> prev = getPreviousStateIds();
ingo@122:             prev.add(getCurrentStateId());
ingo@122: 
ingo@122:             setCurrentStateId(targetState);
ingo@122: 
ingo@123:             return describe(target, context);
ingo@122:         }
ingo@140:         else if (isPreviousState(targetState, context)) {
ingo@140:             logger.info("Advance: Step back to");
ingo@122: 
ingo@140:             Vector<String> prevs = getPreviousStateIds();
ingo@140:             int targetIdx        = prevs.indexOf(targetState);
ingo@140:             int start            = prevs.size() - 1;
ingo@140: 
ingo@140:             for (int i = start; i >= targetIdx; i--) {
ingo@140:                 String prev = prevs.get(i);
ingo@140:                 logger.debug("Remove state id '" + prev + "'");
ingo@140:                 prevs.remove(prev);
ingo@140:             }
ingo@140: 
ingo@140:             setCurrentStateId(targetState);
ingo@140: 
ingo@140:             return describe(target, context);
ingo@140:         }
ingo@122: 
ingo@122:         logger.warn("Advance: Cannot advance to '" + targetState + "'");
ingo@123:         ec.addAttr(result, "type", OPERATION_FAILED, true);
ingo@122: 
ingo@123:         doc.appendChild(result);
ingo@122: 
ingo@122:         return doc;
ingo@122:     }
ingo@122: 
ingo@122: 
ingo@122:     /**
ingo@119:      * Returns the identifier of the current state.
ingo@119:      *
ingo@119:      * @return the identifier of the current state.
ingo@119:      */
ingo@119:     protected String getCurrentStateId() {
ingo@119:         return currentStateId;
ingo@119:     }
ingo@119: 
ingo@119: 
ingo@119:     /**
ingo@119:      * Sets the identifier of the current state.
ingo@119:      *
ingo@119:      * @param id the identifier of a state.
ingo@119:      */
ingo@119:     protected void setCurrentStateId(String id) {
ingo@119:         currentStateId = id;
ingo@119:     }
ingo@119: 
ingo@119: 
ingo@119:     /**
ingo@119:      * Set the current state of this artifact. <b>NOTE</b>We don't store the
ingo@119:      * State object itself - which is not necessary - but its identifier. So
ingo@119:      * this method will just call the setCurrentStateId() method with the
ingo@119:      * identifier of <i>state</i>.
ingo@119:      *
ingo@119:      * @param state The new current state.
ingo@119:      */
ingo@119:     protected void setCurrentState(State state) {
ingo@119:         setCurrentStateId(state.getID());
ingo@119:     }
ingo@119: 
ingo@119: 
ingo@119:     /**
ingo@119:      * Returns the current state of the artifact.
ingo@119:      *
ingo@119:      * @return the current State of the artifact.
ingo@119:      */
ingo@119:     protected State getCurrentState(Object context) {
ingo@121:         FLYSContext flysContext = getFlysContext(context);
ingo@119:         StateEngine engine      = (StateEngine) flysContext.get(
ingo@119:             FLYSContext.STATE_ENGINE_KEY);
ingo@119: 
ingo@119:         return engine.getState(getCurrentStateId());
ingo@119:     }
ingo@119: 
ingo@119: 
ingo@119:     /**
ingo@122:      * Returns the vector of previous state identifiers.
ingo@122:      *
ingo@122:      * @return the vector of previous state identifiers.
ingo@122:      */
ingo@122:     protected Vector<String> getPreviousStateIds() {
ingo@122:         return previousStateIds;
ingo@122:     }
ingo@122: 
ingo@122: 
ingo@122:     /**
ingo@121:      * Adds a new StateData item to the data pool of this artifact.
ingo@121:      *
ingo@121:      * @param name the name of the data object.
ingo@121:      * @param data the data object itself.
ingo@121:      */
ingo@121:     protected void addData(String name, StateData data) {
ingo@121:         this.data.put(name, data);
ingo@121:     }
ingo@121: 
ingo@121: 
ingo@121:     /**
ingo@122:      * This method returns a specific StateData object that is stored in the
ingo@122:      * data pool of this artifact.
ingo@122:      *
ingo@122:      * @param name The name of the data object.
ingo@122:      *
ingo@122:      * @return the StateData object if existing, otherwise null.
ingo@122:      */
ingo@122:     protected StateData getData(String name) {
ingo@122:         return data.get(name);
ingo@122:     }
ingo@122: 
ingo@122: 
ingo@122:     /**
ingo@121:      * This method stores the data that is contained in the FEED document.
ingo@119:      *
ingo@119:      * @param feed The FEED document.
ingo@119:      * @param xpath The XPath that points to the data nodes.
ingo@119:      */
ingo@121:     public void saveData(Document feed, String xpath)
ingo@121:     throws IllegalArgumentException
ingo@121:     {
ingo@121:         if (feed == null || xpath == null || xpath.length() == 0) {
ingo@121:             throw new IllegalArgumentException("feed.no.input.data");
ingo@121:         }
ingo@119: 
ingo@121:         NodeList nodes = (NodeList) XMLUtils.xpath(
ingo@121:             feed,
ingo@121:             xpath,
ingo@121:             XPathConstants.NODESET,
ingo@121:             ArtifactNamespaceContext.INSTANCE);
ingo@121: 
ingo@121:         if (nodes == null || nodes.getLength() == 0) {
ingo@121:             throw new IllegalArgumentException("feed.no.input.data");
ingo@121:         }
ingo@121: 
ingo@121:         int count = nodes.getLength();
ingo@121:         logger.debug("Try to save " + count + " data items.");
ingo@121: 
ingo@121:         for (int i = 0; i < count; i++) {
ingo@121:             Node node = nodes.item(i);
ingo@121: 
ingo@121:             String name = XMLUtils.xpathString(
ingo@121:                 node, "@art:name", ArtifactNamespaceContext.INSTANCE);
ingo@121:             String value = XMLUtils.xpathString(
ingo@121:                 node, "@art:value", ArtifactNamespaceContext.INSTANCE);
ingo@121: 
ingo@121:             if (name != null && value != null) {
ingo@121:                 logger.debug("Save data item for '" + name + "' : " + value);
ingo@121: 
ingo@121:                 // TODO ADD INPUT VALIDATION!
ingo@121:                 addData(name, new DefaultStateData(name, null, null, value));
ingo@121:             }
ingo@121:         }
ingo@119:     }
ingo@122: 
ingo@122: 
ingo@122:     /**
ingo@122:      * This method fills a state object with the data that have been inserted to
ingo@122:      * this artifact. This is necessary to use the isStateReachable() method,
ingo@122:      * because the Transitions need to know about the inserted data.
ingo@122:      *
ingo@122:      * @param state The state that needs to be filled with data.
ingo@122:      *
ingo@122:      * @return the filled state.
ingo@122:      */
ingo@122:     protected State fillState(State state) {
ingo@122:         Map<String, StateData> stateData = state.getData();
ingo@140: 
ingo@140:         if (stateData == null) {
ingo@140:             return state;
ingo@140:         }
ingo@140: 
ingo@122:         Set<String>                 keys = stateData.keySet();
ingo@122: 
ingo@122:         for (String key: keys) {
ingo@122:             StateData tmp = getData(key);
ingo@122: 
ingo@122:             if (tmp != null) {
ingo@122:                 StateData data = stateData.get(key);
ingo@122:                 data.setValue(tmp.getValue());
ingo@122:             }
ingo@122:         }
ingo@122: 
ingo@122:         return state;
ingo@122:     }
ingo@122: 
ingo@122: 
ingo@122:     /**
ingo@122:      * Determines if the state with the identifier <i>stateId</i> is reachable
ingo@122:      * from the current state. The determination itself takes place in the
ingo@122:      * TransitionEngine.
ingo@122:      *
ingo@122:      * @param stateId The identifier of a state.
ingo@122:      * @param context The context object.
ingo@122:      *
ingo@122:      * @return true, if the state specified by <i>stateId</i> is reacahble,
ingo@122:      * otherwise false.
ingo@122:      */
ingo@122:     protected boolean isStateReachable(String stateId, Object context) {
ingo@122:         logger.debug("Determine if the state '" + stateId + "' is reachable.");
ingo@122: 
ingo@122:         FLYSContext flysContext = getFlysContext(context);
ingo@122: 
ingo@122:         State currentState  = fillState(getCurrentState(context));
ingo@122:         StateEngine sEngine = (StateEngine) flysContext.get(
ingo@122:             FLYSContext.STATE_ENGINE_KEY);
ingo@122: 
ingo@122:         TransitionEngine tEngine = (TransitionEngine) flysContext.get(
ingo@122:             FLYSContext.TRANSITION_ENGINE_KEY);
ingo@122: 
ingo@122:         return tEngine.isStateReachable(stateId, currentState, sEngine);
ingo@122:     }
ingo@140: 
ingo@140: 
ingo@140:     /**
ingo@140:      * Determines if the state with the identifier <i>stateId</i> is a previous
ingo@140:      * state of the current state.
ingo@140:      *
ingo@140:      * @param stateId The target state identifier.
ingo@140:      * @param context The context object.
ingo@140:      */
ingo@140:     protected boolean isPreviousState(String stateId, Object context) {
ingo@140:         logger.debug("Determine if the state '" + stateId + "' is old.");
ingo@140: 
ingo@140:         Vector<String> prevs = getPreviousStateIds();
ingo@140:         if (prevs.contains(stateId)) {
ingo@140:             return true;
ingo@140:         }
ingo@140: 
ingo@140:         return false;
ingo@140:     }
ingo@119: }
ingo@119: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :