--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/org/dive4elements/river/artifacts/states/WDifferencesState.java	Thu Apr 25 12:06:39 2013 +0200
@@ -0,0 +1,191 @@
+package org.dive4elements.river.artifacts.states;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.log4j.Logger;
+
+import org.dive4elements.artifactdatabase.state.Facet;
+import org.dive4elements.artifactdatabase.data.StateData;
+
+import org.dive4elements.artifacts.CallContext;
+import org.dive4elements.artifacts.Artifact;
+import org.dive4elements.river.artifacts.FLYSArtifact;
+import org.dive4elements.river.artifacts.StaticWKmsArtifact;
+import org.dive4elements.river.artifacts.WINFOArtifact;
+import org.dive4elements.river.artifacts.ChartArtifact;
+
+import org.dive4elements.river.artifacts.math.WKmsOperation;
+
+import org.dive4elements.river.artifacts.model.CalculationResult;
+import org.dive4elements.river.artifacts.model.DataFacet;
+import org.dive4elements.river.artifacts.model.DifferenceCurveFacet;
+import org.dive4elements.river.artifacts.model.EmptyFacet;
+
+import org.dive4elements.river.artifacts.model.FacetTypes;
+import org.dive4elements.river.artifacts.model.WKms;
+import org.dive4elements.river.artifacts.model.WQKms;
+
+import org.dive4elements.river.utils.FLYSUtils;
+import org.dive4elements.river.utils.StringUtil;
+
+
+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;
+    }
+
+
+    /**
+     * Access the data (wkms).
+     */
+    protected WKms getWKms(String mingle, CallContext context) {
+        String[] def  = mingle.split(";");
+        String   uuid = def[0];
+        String   name = def[1];
+        int      idx  = Integer.parseInt(def[2]);
+
+        if (name.startsWith("staticwkms")) {
+            StaticWKmsArtifact staticWKms =
+                (StaticWKmsArtifact) FLYSUtils.getArtifact(
+                    uuid,
+                    context);
+            logger.debug("WDifferencesState obtain data from StaticWKms");
+            WKms wkms = staticWKms.getWKms(idx);
+            if (wkms == null)
+                logger.error("No WKms from artifact.");
+            return wkms;
+        }
+
+        WINFOArtifact flys = (WINFOArtifact) FLYSUtils.getArtifact(
+            uuid,
+            context);
+
+        if (flys == null) {
+            logger.warn("One of the artifacts (1) for diff calculation could not be loaded");
+            return null;
+        }
+        else{
+            WQKms[] wqkms = (WQKms[]) flys.getWaterlevelData().
+                                              getData();
+            if (wqkms == null)
+            logger.warn("not  waterlevels in artifact");
+            else if (wqkms.length < idx)
+            logger.warn("not enough waterlevels in artifact");
+            return wqkms[idx];
+        }
+    }
+
+
+    /**
+     * Return CalculationResult with Array of WKms that are difference of
+     * Waterlevels. Add respective facets (DifferencesCurveFacet, DataFacet).
+     */
+    @Override
+    public Object computeAdvance(
+        FLYSArtifact artifact,
+        String       hash,
+        CallContext  context,
+        List<Facet>  facets,
+        Object       old
+    ) {
+        if (artifact instanceof ChartArtifact) {
+            ChartArtifact chart = (ChartArtifact)artifact;
+            facets.add(new EmptyFacet());
+            return null;
+        }
+        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 diffids = winfo.getDataAsString("diffids");
+        logger.debug("WDifferencesState has: " + diffids);
+        String datas[] = diffids.split("#");
+
+        // Validate the Data-Strings.
+        for (String s: datas) {
+            if (!WaterlevelSelectState.isValueValid(s)) {
+                // TODO: escalate.
+            }
+        }
+
+        if (datas.length < 2) {
+            // TODO crash with style
+        }
+
+        List<WKms> wkmss = new ArrayList<WKms>();
+
+        for(int i = 0; i < datas.length; i+=2) {
+            // e.g.:
+            // 42537f1e-3522-42ef-8968-635b03d8e9c6;longitudinal_section.w;1
+            WKms minuendWKms = getWKms(StringUtil.unbracket(datas[i+0]),
+                context);
+            WKms subtrahendWKms = getWKms(StringUtil.unbracket(datas[i+1]),
+                context);
+
+            String facetName = "diff ()";
+
+            if (minuendWKms != null && subtrahendWKms != null) {
+                facetName = StringUtil.wWrap(minuendWKms.getName())
+                    + " - " + StringUtil.wWrap(subtrahendWKms.getName());
+                WKms wkms = WKmsOperation.SUBTRACTION.operate(minuendWKms,
+                     subtrahendWKms);
+                wkms.setName(facetName);
+                wkmss.add(wkms);
+                logger.debug("WKMSSubtraction happened");
+            }
+            if (facets != null) {
+                facets.add(new DifferenceCurveFacet(i/2, W_DIFFERENCES, facetName,
+                    ComputeType.ADVANCE, id, hash));
+            }
+        }
+
+        if (facets != null) {
+            facets.add(new DataFacet(CSV, "CSV data"));
+            facets.add(new DataFacet(PDF, "PDF data"));
+            logger.debug("Adding facets in WDifferencesState.");
+        }
+        else {
+            logger.debug("Not adding facets in WDifferencesState.");
+        }
+
+        // TODO Evaluate whether null is okay as reports.
+        WKms[] diffs = wkmss.toArray(new WKms[wkmss.size()]);
+        CalculationResult result = new CalculationResult(diffs, null);
+        return result;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf-8 :