--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/artifacts/src/main/java/org/dive4elements/river/artifacts/services/AbstractDynamicMainValuesService.java	Wed Aug 15 13:59:09 2018 +0200
@@ -0,0 +1,96 @@
+/* Copyright (C) 2011, 2012, 2013 by Bundesanstalt für Gewässerkunde
+ * Software engineering by Intevation GmbH
+ *
+ * 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.services;
+
+import java.util.Date;
+import java.util.List;
+
+import org.dive4elements.artifacts.CallMeta;
+import org.dive4elements.artifacts.GlobalContext;
+import org.dive4elements.artifacts.common.ArtifactNamespaceContext;
+import org.dive4elements.artifacts.common.utils.XMLUtils;
+import org.dive4elements.river.model.Gauge;
+import org.dive4elements.river.model.MainValue;
+import org.dive4elements.river.model.River;
+import org.w3c.dom.Document;
+
+/**
+ * This service returns the main values of a river's gauge based on the start
+ * and end point of the river.
+ *
+ * @author <a href="mailto:ingo.weinzierl@intevation.de">Ingo Weinzierl</a>
+ */
+abstract public class AbstractDynamicMainValuesService extends AbstractMainValuesService {
+
+    private static final long serialVersionUID = 1L;
+
+    @Override
+    public Document doProcess(final Document data, final GlobalContext context, final CallMeta callMeta) {
+        try {
+
+            final River river = getRequestedRiver(data, "/art:mainvalues/art:river/text()");
+            final Gauge gauge = getRequestedGauge(data, river);
+            final Date startTime = getRequestedStartDate(data, "/art:mainvalues/art:startDate/text()");
+            final Date endTime = getRequestedEndDate(data, "/art:mainvalues/art:endDate/text()");
+
+            final List<MainValue> mainValues = getMainValues(river, gauge, startTime, endTime);
+
+            return buildDocument(river, gauge, mainValues, context);
+        }
+        catch (final MainValuesServiceException e) {
+            // e.printStackTrace();
+            return error(e.getMessage());
+        }
+        catch (final Exception e) {
+            e.printStackTrace();
+            return error(e.getMessage());
+        }
+    }
+
+    public static final Date getRequestedStartDate(final Document data, final String XPATH_END_YEAR) throws MainValuesServiceException {
+
+        final String startStr = XMLUtils.xpathString(data, XPATH_END_YEAR, ArtifactNamespaceContext.INSTANCE);
+
+        if (startStr == null)
+            throw new MainValuesServiceException("no start date");
+
+        try {
+            return new Date(Long.parseLong(startStr));
+            // FIXME: timezone? probably must match timezone of database
+        }
+        catch (final NumberFormatException e) {
+            e.printStackTrace();
+            throw new MainValuesServiceException("invalid start date");
+        }
+    }
+
+    public static final Date getRequestedEndDate(final Document data, final String XPATH_END_DATE) throws MainValuesServiceException {
+
+        final String endStr = XMLUtils.xpathString(data, XPATH_END_DATE, ArtifactNamespaceContext.INSTANCE);
+
+        if (endStr == null)
+            throw new MainValuesServiceException("no end date");
+
+        try {
+            return new Date(Long.parseLong(endStr));
+            // FIXME: timezone? probably must match timezone of database
+        }
+        catch (final NumberFormatException e) {
+            e.printStackTrace();
+            throw new MainValuesServiceException("invalid end date");
+        }
+    }
+
+    /**
+     * Computes a gauge's main values for a period of time based on its daily discharges stored in the database
+     */
+    protected abstract List<MainValue> getMainValues(final River river, final Gauge gauge, final Date startTime, final Date endTime)
+            throws MainValuesServiceException;
+
+}
\ No newline at end of file