--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/states/WDifferencesState.java	Fri Sep 28 12:14:17 2012 +0200
@@ -0,0 +1,143 @@
+package de.intevation.flys.artifacts.states;
+
+import java.util.List;
+
+import org.apache.log4j.Logger;
+
+import de.intevation.artifacts.CallContext;
+
+import de.intevation.artifactdatabase.state.Facet;
+
+import de.intevation.artifacts.Artifact;
+import de.intevation.flys.artifacts.FLYSArtifact;
+import de.intevation.flys.artifacts.WINFOArtifact;
+
+import de.intevation.flys.artifacts.math.WKmsOperation;
+
+import de.intevation.flys.artifacts.model.FacetTypes;
+import de.intevation.flys.artifacts.model.WKms;
+import de.intevation.flys.artifacts.model.WQKms;
+
+import de.intevation.flys.artifacts.model.DataFacet;
+import de.intevation.artifactdatabase.data.StateData;
+
+import de.intevation.flys.utils.FLYSUtils;
+
+
+public class WDifferencesState
+extends      DefaultState
+implements   FacetTypes
+{
+    /** The logger that is used in this state. */
+    private static Logger logger = Logger.getLogger(WDifferencesState.class);
+
+
+    public WDifferencesState() {
+    }
+
+
+    /** Specify to display nothing (this is kind of a "final" state). */
+    @Override
+    protected String getUIProvider() {
+        return "noinput";
+    }
+
+
+    @Override
+    public boolean validate(Artifact artifact)
+    throws IllegalArgumentException
+    {
+        FLYSArtifact flys = (FLYSArtifact) artifact;
+
+        StateData data = flys.getData("diffids");
+
+        if (data == null) {
+            throw new IllegalArgumentException("diffids is empty");
+        }
+
+        // TODO: Also validate format.
+
+        return true;
+    }
+
+
+
+    @Override
+    public Object computeAdvance(
+        FLYSArtifact artifact,
+        String       hash,
+        CallContext  context,
+        List<Facet>  facets,
+        Object       old
+    ) {
+        WINFOArtifact winfo = (WINFOArtifact)artifact;
+        String id = getID();
+
+        // Load the Artifacts/facets that we want to subtract and display.
+        // Expected format is:
+        // [42537f1e-3522-42ef-8968-635b03d8e9c6;longitudinal_section.w;0]#[1231f2-....]
+        String datas[] = winfo.getDataAsString("diffids").split("#");
+
+        // Validate the Data-Strings.
+        for (String s: datas) {
+            if (!WaterlevelSelectState.isValueValid(winfo.getDataAsString("diffids"))) {
+                // TODO: escalate.
+            }
+        }
+
+        if (datas.length != 2) {
+            // TODO crash with style
+            ;
+        }
+        String uuid1 = WaterlevelSelectState.strip(datas[0]).split(";")[0];
+        String uuid2 = WaterlevelSelectState.strip(datas[1]).split(";")[0];
+
+        WINFOArtifact flys1 = (WINFOArtifact) FLYSUtils.getArtifact(
+            uuid1,
+            context);
+        WINFOArtifact flys2 = (WINFOArtifact) FLYSUtils.getArtifact(
+            uuid2,
+            context);
+
+        if (flys1 == null) {
+            logger.warn("One of the artifacts (1) for diff calculation could not be loaded");
+        }
+        if (flys2 == null) {
+            logger.warn("One of the artifacts (2) for diff calculation could not be loaded");
+        }
+        WKms wkms = null;
+        String facetName = "diff ()";
+
+        if (flys1 != null && flys2 != null) {
+            // TODO also check size.
+            // TODO also need index of wqkms.
+            WQKms[] minuend = (WQKms[]) flys1.getWaterlevelData().getData();
+            WQKms[] subtrahend = (WQKms[]) flys2.getWaterlevelData().getData();
+            wkms = WKmsOperation.SUBTRACTION.operate(minuend[0], subtrahend[0]);
+            facetName = "W ("+minuend[0].getName() + ") - W (" + subtrahend[0].getName()+")";
+            logger.warn("Did a WKMSSubtraction");
+            // Add these datasets also as facets ("absolutes").
+            /*
+            Facet minuendAbsFacet = new WaterlevelFacet(0, LONGITUDINAL_W,
+                "Minuend: W (_todo_)", ComputeType.ADVANCE, id, hash);
+            Facet subtrahendAbsFacet = new WaterlevelFacet(1, LONGITUDINAL_W,
+                "Subtrahend: W (_todo_)", ComputeType.ADVANCE, id, hash);
+            */
+            //facets.add(minuendAbsFacet);
+            //facets.add(subtrahendAbsFacet);
+        }
+
+        if (facets != null) {
+            // TODO: pass computetype and state id.
+            //, ComputeType.ADVANCE, getID(), hash));
+            facets.add(new DataFacet(W_DIFFERENCES, facetName));
+            facets.add(new DataFacet(CSV, "CSV data"));
+        }
+        else {
+            logger.debug("Not adding facets in WDifferencesState.");
+        }
+
+        return wkms;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf-8 :