--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/artifacts/src/main/java/org/dive4elements/river/artifacts/model/river/RiverInfoProvider.java	Thu Sep 27 18:06:26 2018 +0200
@@ -0,0 +1,143 @@
+/** Copyright (C) 2017 by Bundesanstalt für Gewässerkunde
+ * Software engineering by
+ *  Björnsen Beratende Ingenieure GmbH
+ *  Dr. Schumacher Ingenieurbüro für Wasser und Umwelt
+ *
+ * This file is Free Software under the GNU AGPL (>=v3)
+ * and comes with ABSOLUTELY NO WARRANTY! Check out the
+ * documentation coming with Dive4Elements River for details.
+ */
+package org.dive4elements.river.artifacts.model.river;
+
+import java.util.List;
+
+import org.apache.commons.lang.math.DoubleRange;
+import org.dive4elements.artifacts.CallContext;
+import org.dive4elements.river.artifacts.model.LocationProvider;
+import org.dive4elements.river.artifacts.model.WKms;
+import org.dive4elements.river.artifacts.resources.Resources;
+import org.dive4elements.river.artifacts.states.WaterlevelData;
+import org.dive4elements.river.model.Gauge;
+import org.dive4elements.river.model.River;
+import org.dive4elements.river.utils.GaugeIndex;
+
+/**
+ * @author Gernot Belger
+ *
+ */
+public final class RiverInfoProvider {
+
+    private static final String CSV_NOT_IN_GAUGE_RANGE = "export.waterlevel.csv.not.in.gauge.range";
+
+    private final River river;
+    private final GaugeIndex gaugeIndex;
+    private final Gauge refGauge;
+    private final boolean showAllGauges;
+    private final String notinrange;
+
+    public static RiverInfoProvider forRange(final CallContext context, final River river, final DoubleRange calcRange) {
+
+        return forRange(context, river, calcRange, false);
+    }
+
+    public static RiverInfoProvider forRange(final CallContext context, final River river, final DoubleRange calcRange, final boolean firstGaugeIsRefGauge) {
+
+        final List<Gauge> gauges;
+        if (calcRange == null)
+            gauges = river.getGauges();
+        else
+            gauges = river.determineGauges(calcRange.getMinimumDouble(), calcRange.getMaximumDouble());
+
+        final GaugeIndex gaugeIndex = new GaugeIndex(gauges);
+
+        final String notinrange = Resources.getMsg(context.getMeta(), CSV_NOT_IN_GAUGE_RANGE, CSV_NOT_IN_GAUGE_RANGE);
+
+        if (firstGaugeIsRefGauge && !gauges.isEmpty())
+            return new RiverInfoProvider(notinrange, river, false, gaugeIndex, gauges.get(0));
+        return new RiverInfoProvider(notinrange, river, false, gaugeIndex, null);
+    }
+
+    private RiverInfoProvider(final String notinrange, final River river, final boolean showAllGauges, final GaugeIndex gaugeIndex, final Gauge refGauge) {
+        this.notinrange = notinrange;
+        this.river = river;
+        this.showAllGauges = showAllGauges;
+        this.gaugeIndex = gaugeIndex;
+        this.refGauge = refGauge;
+    }
+
+    public RiverInfoProvider forWaterlevel(final WaterlevelData waterlevel) {
+        final WKms wstKms = waterlevel.getWkms();
+        final Gauge waterlevelRefGauge = findReferenceGauge(wstKms);
+        final boolean waterlevelShowAllGauges = waterlevel.isShowAllGauges();
+
+        return new RiverInfoProvider(this.notinrange, this.river, waterlevelShowAllGauges, this.gaugeIndex, waterlevelRefGauge);
+    }
+
+    /**
+     * Re-determines the reference gauge, in the same way as the WaterlevelArtifact would do it
+     */
+    private Gauge findReferenceGauge(final WKms wkms) {
+
+        final double[] wstFromTo = findWstFromTo(wkms);
+        return this.river.determineRefGauge(wstFromTo, true);
+    }
+
+    private static double[] findWstFromTo(final WKms wkms) {
+
+        final double from = wkms.getKm(0);
+        final double to = wkms.getKm(wkms.size() - 1);
+
+        final boolean waterIncreasing = wkms.guessWaterIncreasing();
+        if (waterIncreasing)
+            return new double[] { to, from };
+
+        return new double[] { from, to };
+    }
+
+    public String getLocation(final double km) {
+        return LocationProvider.getLocation(this.river.getName(), km);
+    }
+
+    public String findGauge(final double km) {
+        // REMARK: access the gauge once only during calculation
+        final Gauge gauge = getGauge(km);
+
+        return gauge == null ? this.notinrange : gauge.getName();
+    }
+
+    private String findGauge(final double km, final boolean allGauges) {
+        // REMARK: access the gauge once only during calculation
+        final Gauge gauge = getGauge(km, allGauges);
+
+        return gauge == null ? this.notinrange : gauge.getName();
+    }
+
+    public Gauge getGauge(final double km) {
+
+        // REMARK: using same logic as in WaterlevelExporter here
+
+        return getGauge(km, this.showAllGauges);
+    }
+
+    public Gauge getGauge(final double km, final boolean allGauges) {
+        if (allGauges)
+            return this.gaugeIndex.findGauge(km);
+
+        if ((this.refGauge != null) && this.refGauge.getRange().contains(km))
+            return this.refGauge;
+
+        return null;
+    }
+
+    public String getReferenceGauge() {
+        return this.refGauge == null ? this.notinrange : this.refGauge.getName();
+    }
+
+    public River getRiver() {
+        return this.river;
+    }
+
+    public List<Gauge> getGauges() {
+        return this.gaugeIndex.getGauges();
+    }
+}
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