--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/backend/src/main/java/org/dive4elements/river/importer/parsers/WaterlevelDifferencesParser.java	Mon Jan 20 14:04:20 2014 +0100
@@ -0,0 +1,257 @@
+/* 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.importer.parsers;
+
+import java.io.File;
+import java.io.IOException;
+import java.math.BigDecimal;
+import java.text.NumberFormat;
+import java.text.ParseException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import org.apache.log4j.Logger;
+
+import org.dive4elements.river.importer.ImportTimeInterval;
+import org.dive4elements.river.importer.ImportUnit;
+
+import org.dive4elements.river.importer.ImportWst;
+import org.dive4elements.river.importer.ImportWstQRange;
+import org.dive4elements.river.importer.ImportWstColumn;
+import org.dive4elements.river.importer.ImportWstColumnValue;
+
+
+/**
+ * Parse WaterlevelDifferences CSV file.
+ */
+public class WaterlevelDifferencesParser extends LineParser {
+
+    private static final Logger log =
+        Logger.getLogger(WaterlevelDifferencesParser.class);
+
+    private static final NumberFormat nf =
+        NumberFormat.getInstance(DEFAULT_LOCALE);
+
+    public static final Pattern META_UNIT =
+        Pattern.compile("^Einheit: \\[(.*)\\].*");
+
+    public static final Pattern YEARS_IN_COLUMN =
+        Pattern.compile(".*(\\d{4})-(\\d{4})$");
+
+    public static final double INTERVAL_GAP = 0.00001d;
+
+    /** List of parsed differences as ImportWst s. */
+    private List<ImportWst> differences;
+
+    private ImportWstColumn[] columns;
+
+    /** The currently processed dataset. */
+    private ImportWst current;
+
+
+    public WaterlevelDifferencesParser() {
+        differences = new ArrayList<ImportWst>();
+    }
+
+
+    /** Get the differences as wst parsed so far. */
+    public List<ImportWst> getDifferences() {
+        return differences;
+    }
+
+
+    /**
+     * Parse a csv waterleveldifferenceparser and create a ImportWst object
+     * from it.
+     */
+    @Override
+    public void parse(File file) throws IOException {
+        current = new ImportWst(file.getName());
+        current.setKind(6);
+
+        super.parse(file);
+    }
+
+
+    /** No rewind implemented. */
+    @Override
+    protected void reset() {
+    }
+
+
+    @Override
+    protected void finish() {
+        if (columns != null && current != null) {
+            // TODO figure out if its needed, as the columns
+            //      are registered at their construction time.
+            for (ImportWstColumn col: columns) {
+                // TODO place a current.addColumn(col); here?
+            }
+
+            differences.add(current);
+        }
+
+        // For all differences columns, add a single Q-Range with
+        // -1.
+        // Expand range to minimal length in case it would be 0
+        // TODO: should otherwise be extended to 
+        // (first station of next range - INTERVAL_GAP), 
+        // assuming always ascending stations
+        for (ImportWstColumn column: columns) {
+            List<ImportWstColumnValue> cValues = column.getColumnValues();
+            BigDecimal a = cValues.get(0).getPosition();
+            BigDecimal b = cValues.get(cValues.size() - 1).getPosition();
+            if (a.compareTo(b) == 0) {
+                b = new BigDecimal(b.doubleValue() + INTERVAL_GAP);
+            }
+            column.addColumnQRange(
+                new ImportWstQRange(
+                    a,
+                    b,
+                    new BigDecimal(-1d))
+                );
+        }
+        current = null;
+        columns = null;
+    }
+
+
+    @Override
+    protected void handleLine(int lineNum, String line) {
+        if (line.startsWith(START_META_CHAR)) {
+            handleMetaLine(stripMetaLine(line));
+        }
+        else {
+            handleDataLine(line);
+        }
+    }
+
+
+    private void handleMetaLine(String meta) {
+        if (handleMetaUnit(meta)) {
+            return;
+        }
+        else {
+            handleMetaColumnNames(meta);
+        }
+    }
+
+
+    private boolean handleMetaUnit(String meta) {
+        Matcher m = META_UNIT.matcher(meta);
+
+        if (m.matches()) {
+            String unit = m.group(1);
+            log.debug("Found unit: '" + unit + "'");
+
+            current.setUnit(new ImportUnit(unit));
+
+            return true;
+        }
+
+        return false;
+    }
+
+
+    private boolean handleMetaColumnNames(String meta) {
+        Pattern META_COLUMN_NAMES = Pattern.compile("Fluss-km;(.*)");
+        Matcher m = META_COLUMN_NAMES.matcher(meta);
+
+        if (m.matches()) {
+            String colStr = m.group(1);
+            String[] cols = colStr.split(SEPERATOR_CHAR);
+
+            log.debug("Found " + cols.length + " columns.");
+
+            initColumns(cols);
+
+            return true;
+        }
+
+        return false;
+    }
+
+
+    /** Setup column structures with name, description and time interval. */
+    private void initColumns(String[] cols) {
+        current.setNumberColumns(cols.length);
+        columns = current.getColumns().toArray(new ImportWstColumn[cols.length]);
+
+        for (int i = 0; i < cols.length; i++) {
+            String name = cols[i].replace("\"", "");
+
+            log.debug("Create new column '" + name + "'");
+            ImportWstColumn column = current.getColumn(i);
+            column.setName(name);
+            column.setDescription(name);
+
+            Matcher m = YEARS_IN_COLUMN.matcher(name);
+
+            if (m.matches()) {
+                int startYear = Integer.parseInt(m.group(1));
+                int endYear   = Integer.parseInt(m.group(2));
+                ImportTimeInterval time = new ImportTimeInterval(
+                    getStartDateFromYear(startYear),
+                    getEndDateFromYear(endYear)
+                );
+                column.setTimeInterval(time);
+            } else {
+                log.debug("No time interval in column header found: " + name);
+            }
+        }
+    }
+
+
+    /** Handle one line of data, add one value for all columns.
+     * @param line the line to parse
+     */
+    private void handleDataLine(String line) {
+        // Split by separator, do not exclude trailing empty string.
+        String[] cols = line.split(SEPERATOR_CHAR, -1);
+
+        if (cols == null || cols.length < 2) {
+            log.warn("skip invalid waterlevel-diff line: '" + line + "'");
+            return;
+        }
+
+        try {
+            // The first value in a line like 12,9;4,3;4,5 is the station, later
+            // real values.
+            Double station = nf.parse(cols[0]).doubleValue();
+
+            for (int i = 0; i < columns.length; i++) {
+                int idx = i+1;
+
+                if (idx >= cols.length) {
+                    log.warn("Insufficient column numbers: " + line);
+                    continue;
+                }
+
+                String value = cols[idx];
+
+                if (value != null && !value.equals("")) {
+                    try {
+                        columns[i].addColumnValue(
+                            new BigDecimal(station),
+                            new BigDecimal(nf.parse(value).doubleValue()));
+                    }
+                    catch (ParseException pe) {
+                        log.warn("Could not parse value: '" + value + "'");
+                    }
+                }
+            }
+        }
+        catch (ParseException pe) {
+            log.warn("Could not parse station: '" + line + "'");
+        }
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :