do not return anything if the field/value does not exist

The computation of proposals is done by searching for values in a
combined index. If one of the values didn't exist, then the algorithm
returned all values. Fixed by checking that we query only existing
field/values from the combined index.

data-store/src/main/java/org/lucares/pdb/datastore/internal/QueryCompletionIndex.java

@@ -5,6 +5,7 @@ import java.nio.file.Path;
 import java.util.List;
 import java.util.SortedSet;
 import java.util.TreeSet;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 import org.lucares.collections.LongList;
 import org.lucares.pdb.api.DateTimeRange;
@@ -250,6 +251,8 @@ public class QueryCompletionIndex implements AutoCloseable {
 	public SortedSet<String> find(final DateTimeRange dateRange, final String property, final String value,
 			final String field) {
 		final Tag tag = new Tag(property, value);
+		Preconditions.checkGreaterOrEqual(tag.getKey(), 0, "The property '{0}' is unkown", property);
+		Preconditions.checkGreaterOrEqual(tag.getValue(), 0, "The value '{0}' is unkown", value);
 		return find(dateRange, tag, field);
 	}
 
@@ -310,4 +313,15 @@ public class QueryCompletionIndex implements AutoCloseable {
 		});
 		return result;
 	}
+
+	public boolean hasField(final DateTimeRange dateRange, final String field) {
+		final AtomicBoolean found = new AtomicBoolean(false);
+		final PartitionIdSource partitionIdSource = new DatePartitioner(dateRange);
+		fieldIndex.visitValues(partitionIdSource, "", (k, v) -> {
+			if (k.equals(field)) {
+				found.set(true);
+			}
+		});
+		return found.get();
+	}
 }

data-store/src/main/java/org/lucares/pdb/datastore/lang/FindValuesForQueryCompletion.java

@@ -42,10 +42,22 @@ public class FindValuesForQueryCompletion extends ExpressionVisitor<SortedSet<St
 		@Override
 		public SortedSet<String> visit(final Property property) {
 			final long start = System.nanoTime();
+			final TreeSet<String> result = new TreeSet<>();
+
 			final String fieldA = property.getProperty();
 			final String valueA = property.getValue().getValue();
 
-			final SortedSet<String> result = index.find(dateTimeRange, fieldA, valueA, field);
+			final boolean hasField = index.hasField(dateTimeRange, fieldA);
+			if (hasField) {
+				final SortedSet<String> allValuesForField = index.findAllValuesForField(dateTimeRange, fieldA);
+				final SortedSet<String> valuesA = GloblikePattern.filterValues(allValuesForField, valueA, TreeSet::new);
+
+				for (final String v : valuesA) {
+					final SortedSet<String> tmp = index.find(dateTimeRange, fieldA, v, field);
+					result.addAll(tmp);
+				}
+			}
+
 			METRIC_AND_CARET_LOGGER.debug("{}: {}ms", property, (System.nanoTime() - start) / 1_000_000.0);
 			return result;
 		}

data-store/src/main/java/org/lucares/pdb/datastore/lang/GloblikePattern.java

@@ -12,6 +12,10 @@ public class GloblikePattern {
 
 	private static final Logger LOGGER = LoggerFactory.getLogger(GloblikePattern.class);
 
+	enum FilterMode {
+		KEEP_EQUAL
+	}
+
 	static Pattern globlikeToRegex(final String globPattern) {
 		// a character that cannot be in the globPattern
 		final String dotPlaceholder = "\ue003"; // fourth character in the private use area
@@ -43,7 +47,7 @@ public class GloblikePattern {
 
 		for (final String value : availableValues) {
 			final Matcher matcher = pattern.matcher(value);
-			if (matcher.find() && !value.equals(valuePattern)) {
+			if (matcher.find()) {
 				result.add(value);
 			}
 		}

data-store/src/main/java/org/lucares/pdb/datastore/lang/NewProposerParser.java

@@ -170,8 +170,7 @@ public class NewProposerParser implements QueryConstants {
 			final SortedSet<String> candidateValuesCutAtDots = cutAtDots(candidateValues, queryWithCaretMarker);
 
 			// translate the candidate values to proposals
-			final List<Proposal> proposals = generateProposals(queryWithCaretMarker, expression,
-					candidateValuesCutAtDots);
+			final List<Proposal> proposals = generateProposals(queryWithCaretMarker, candidateValuesCutAtDots);
 
 			return proposals;
 		} catch (final SyntaxException e) {
@@ -186,7 +185,7 @@ public class NewProposerParser implements QueryConstants {
 		return grouper.group(candidateValues, queryWithCaretMarker);
 	}
 
-	private List<Proposal> generateProposals(final String queryWithCaretMarker, final Expression expression,
+	private List<Proposal> generateProposals(final String queryWithCaretMarker,
 			final SortedSet<String> candidateValues) {
 		final List<Proposal> proposals = new ArrayList<>();