--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/flys-artifacts/src/main/java/org/dive4elements/river/artifacts/model/RelativePointFacet.java	Thu Apr 25 12:06:39 2013 +0200
@@ -0,0 +1,193 @@
+package org.dive4elements.river.artifacts.model;
+
+import java.util.List;
+import java.awt.geom.Point2D;
+
+import org.apache.log4j.Logger;
+
+import org.dive4elements.artifacts.Artifact;
+import org.dive4elements.artifacts.CallContext;
+import org.dive4elements.artifacts.DataProvider;
+
+import org.dive4elements.river.artifacts.StaticWKmsArtifact;
+import org.dive4elements.river.artifacts.StaticWQKmsArtifact;
+import org.dive4elements.river.artifacts.math.Linear;
+
+/**
+ * Facet to access a point.
+ */
+public class RelativePointFacet
+extends      BlackboardDataFacet
+implements   FacetTypes {
+
+    /** Own logger. */
+    private static Logger logger = Logger.getLogger(RelativePointFacet.class);
+
+    /** Trivial Constructor. */
+    public RelativePointFacet(String description) {
+        this(RELATIVE_POINT, description);
+    }
+
+
+    public RelativePointFacet(String name, String description) {
+        this.name        = name;
+        this.description = description;
+        this.index       = 0;
+    }
+
+
+    protected Point2D calculateDurationCurvePoint(CallContext context,
+        WKms wKms)
+    {
+        // TODO here and in reference curve calc: Do warn if more than 1
+        // provider found or (way better) handle it.
+        Object wqdays = null;
+        double km     = 0d;
+        List<DataProvider> providers = context.
+            getDataProvider(DurationCurveFacet.BB_DURATIONCURVE);
+        if (providers.size() < 1) {
+            logger.warn("Could not find durationcurve data provider.");
+        }
+        else {
+            wqdays = providers.get(0).provideData(
+                DurationCurveFacet.BB_DURATIONCURVE,
+                null,
+                context);
+        }
+        List<DataProvider> kmproviders = context.
+            getDataProvider(DurationCurveFacet.BB_DURATIONCURVE_KM);
+        if (kmproviders.size() < 1) {
+            logger.warn("Could not find durationcurve.km data provider.");
+        }
+        else {
+            logger.debug("Found durationcurve.km data provider.");
+            String dckm = providers.get(0).provideData(
+                DurationCurveFacet.BB_DURATIONCURVE_KM,
+                null,
+                context).toString();
+            km = Double.valueOf(dckm);
+        }
+
+        if (wqdays != null) {
+            // Which W at this km?
+            double w = StaticWKmsArtifact.getWAtKmLin(wKms, km);
+            if (w == -1) {
+                logger.warn("w is -1, already bad sign!");
+            }
+            // Where is this W passed by in the wq-curve?
+            WQDay wqday = (WQDay) wqdays;
+            // Doing a linear Day Of KM.
+            int idx = 0;
+            boolean wIncreases = wqday.getW(0) < wqday.getW(wqday.size()-1);
+            if (wIncreases) {
+                while (idx < wqday.size() && wqday.getW(idx) < w) {
+                    idx++;
+                }
+            }
+            else {
+                idx = wqday.size() -1;
+                while (idx > 0 && wqday.getW(idx) > w) {
+                    idx--;
+                }
+            }
+
+            double day = 0d;
+            int mod = (wIncreases) ? -1 : +1;
+            if (idx != 0 && idx <= wqday.size()-1) {
+                day = Linear.linear(w, wqday.getW(idx+mod), wqday.getW(idx),
+                    wqday.getDay(idx+mod), wqday.getDay(idx));
+            }
+
+            return new Point2D.Double((double) day, w);
+        }
+        logger.warn("not wqkms / w / day found");
+        // TODO better signal failure.
+        return new Point2D.Double(0d, 0d);
+    }
+
+
+    /**
+     * Calculate a reference curve point, that is, a point made of
+     * the Ws from start and end km param of the reference curve.
+     */
+    public Point2D calculateReferenceCurvePoint(CallContext context,
+        WKms wKms) {
+
+        List<DataProvider> providers = context.
+            getDataProvider(ReferenceCurveFacet.BB_REFERENCECURVE_STARTKM);
+        if (providers.size() < 1) {
+            logger.warn("Could not find reference curve startkm data provider.");
+        }
+
+        Double start = (Double) providers.get(0).
+            provideData(ReferenceCurveFacet.BB_REFERENCECURVE_STARTKM, null, context);
+
+        providers = context.
+            getDataProvider(ReferenceCurveFacet.BB_REFERENCECURVE_ENDKMS);
+        if (providers.size() < 1) {
+            logger.warn("Could not find reference curve endkms data provider.");
+        }
+        double[] ends = (double[]) providers.get(0).
+            provideData(ReferenceCurveFacet.BB_REFERENCECURVE_ENDKMS, null, context);
+
+        logger.debug("Got s " + start + " e " + ends);
+
+        double startW = StaticWKmsArtifact.getWAtKmLin(wKms, start.doubleValue());
+        // TODO handle multiple ends.
+        double endW = StaticWKmsArtifact.getWAtKmLin(wKms, ends[0]);
+        logger.debug("Gotw s " + startW + " e " + endW);
+        return new Point2D.Double(startW, endW);
+    }
+
+
+    /**
+     * Returns the data this facet requires.
+     *
+     * @param artifact the owner artifact.
+     * @param context  the CallContext (ignored).
+     *
+     * @return the data.
+     */
+    @Override
+    public Object getData(Artifact artifact, CallContext context) {
+        WKms wKms = null;
+        if (artifact instanceof StaticWKmsArtifact) {
+            wKms = ((StaticWKmsArtifact) artifact).getWKms(0);
+        }
+        else if (artifact instanceof StaticWQKmsArtifact) {
+            wKms = ((StaticWQKmsArtifact) artifact).getWQKms();
+        }
+        else {
+            logger.error("Cannot handle Artifact to create relative point.");
+            return null;
+        }
+
+        // Find out whether we live in a duration curve context, there we would
+        // provide only a single point.
+
+        if (context.getDataProvider(
+            DurationCurveFacet.BB_DURATIONCURVE_KM).size() > 0) {
+            return calculateDurationCurvePoint(context, wKms);
+        }
+        else if (context.getDataProvider(
+            ReferenceCurveFacet.BB_REFERENCECURVE_STARTKM).size() > 0) {
+            return calculateReferenceCurvePoint(context, wKms);
+        }
+
+        // TODO better signal failure.
+        return new Point2D.Double(0d, 0d);
+    }
+
+
+    /**
+     * Create a deep copy of this Facet.
+     * @return a deep copy.
+     */
+    @Override
+    public RelativePointFacet deepCopy() {
+        RelativePointFacet copy = new RelativePointFacet(description);
+        copy.set(this);
+        return copy;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :