--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-client/src/main/java/de/intevation/flys/client/server/StepForwardServiceImpl.java	Thu Mar 10 10:53:41 2011 +0000
@@ -0,0 +1,146 @@
+package de.intevation.flys.client.server;
+
+import org.w3c.dom.Document;
+
+import de.intevation.artifacts.common.ArtifactNamespaceContext;
+import de.intevation.artifacts.common.utils.ClientProtocolUtils;
+import de.intevation.artifacts.common.utils.XMLUtils;
+
+import de.intevation.artifacts.httpclient.exceptions.ConnectionException;
+import de.intevation.artifacts.httpclient.http.HttpClient;
+import de.intevation.artifacts.httpclient.http.HttpClientImpl;
+import de.intevation.artifacts.httpclient.http.response.DocumentResponseHandler;
+
+import de.intevation.flys.client.shared.model.Artifact;
+import de.intevation.flys.client.shared.model.ArtifactDescription;
+import de.intevation.flys.client.shared.model.Data;
+import de.intevation.flys.client.shared.model.DataItem;
+import de.intevation.flys.client.client.services.StepForwardService;
+
+
+/**
+ * This interface provides a method that bundles the artifact specific
+ * operations FEED and ADVANCE.
+ *
+ * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
+ */
+public class StepForwardServiceImpl
+extends      AdvanceServiceImpl
+implements   StepForwardService
+{
+    /** XPath that points to the result text of a feed or advance operation.*/
+    public static final String XPATH_RESULT = "/art:result/text()";
+
+    /** A constant that marks errors.*/
+    public static final String OPERATION_FAILURE = "FAILED";
+
+
+    /**
+     * This method wraps the artifact operations FEED and ADVANCE. FEED is
+     * always triggerd, ADVANCE only, if there is at least one reachable state.
+     *
+     * @param serverUrl The url of the artifact server.
+     * @param artifact The artifact that needs to be fed.
+     * @param data An array of Data objects that contain the information that
+     *
+     * @return the modified artifact.
+     */
+    public Artifact go(String serverUrl, Artifact artifact, Data[] data) {
+        Artifact afterFeed = feed(serverUrl, artifact, data);
+
+        if (afterFeed == null) {
+            System.err.println("StepForwardService.feed() - FAILED");
+            // XXX Better handling here!
+            return null;
+        }
+
+        ArtifactDescription desc = afterFeed.getArtifactDescription();
+        String[] reachable       = desc.getReachableStates();
+
+        if (reachable == null || reachable.length == 0) {
+            System.out.println("Did not find any reachable state.");
+            return afterFeed;
+        }
+
+        // We use the first reachable state as default target, maybe we need to
+        // change this later.
+        return advance(serverUrl, afterFeed, reachable[0]);
+    }
+
+
+    /**
+     * This method triggers the FEED operation.
+     *
+     * @param serverUrl The url of the artifact server.
+     * @param artifact The artifact that needs to be fed.
+     * @param data An array of Data objects that contain the information that
+     * are used for the FEED operation.
+     *
+     * @return a new artifact parsed from the description of FEED.
+     */
+    protected Artifact feed(String serverUrl, Artifact artifact, Data[] data) {
+        Document feed = ClientProtocolUtils.newFeedDocument(
+            artifact.getUuid(),
+            artifact.getHash(),
+            createKVP(data));
+
+        HttpClient client = new HttpClientImpl(serverUrl);
+
+        try {
+            Document description = (Document) client.feed(
+                new de.intevation.artifacts.httpclient.objects.Artifact(
+                    artifact.getUuid(),
+                    artifact.getHash()),
+                feed,
+                new DocumentResponseHandler());
+
+            if (description == null) {
+                System.err.println("StepForwardService.feed() - FAILED");
+                return artifact;
+            }
+
+            String result = XMLUtils.xpathString(
+                description,
+                XPATH_RESULT,
+                ArtifactNamespaceContext.INSTANCE);
+
+            if (result == null || !result.equals(OPERATION_FAILURE)) {
+                System.out.println("StepForwardService.feed() - SUCCESS");
+                return (Artifact) new FLYSArtifactCreator().create(description);
+            }
+        }
+        catch (ConnectionException ce) {
+            System.err.println(ce.getLocalizedMessage());
+        }
+
+        System.err.println("StepForwardService.feed() - FAILED");
+
+        return artifact;
+    }
+
+
+    /**
+     * This method creates an array of key/value pairs from an array of Data
+     * objects. The string array is used as parameter for the feed() operation.
+     *
+     * @param data The data that should be transformed into the string array.
+     *
+     * @return a string array that contains key/value pairs.
+     */
+    protected String[][] createKVP(Data[] data) {
+        String[][] kvp = new String[data.length][];
+
+        int i = 0;
+
+        for (Data d: data) {
+            DataItem[] items = d.getItems();
+            String key       = d.getLabel();
+            String value     = items[0].getStringValue();
+
+            kvp[i++] = new String[] { key, value };
+        }
+
+        return kvp;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :