1 files changed, 106 insertions, 0 deletions
diff --git a/org.eclipse.mylyn.reviews.connector/src/org/eclipse/mylyn/reviews/connector/query/EmfQueryEngine.java b/org.eclipse.mylyn.reviews.connector/src/org/eclipse/mylyn/reviews/connector/query/EmfQueryEngine.java
new file mode 100644
index 00000000..76eccbfa
--- /dev/null
+++ b/org.eclipse.mylyn.reviews.connector/src/org/eclipse/mylyn/reviews/connector/query/EmfQueryEngine.java
@@ -0,0 +1,106 @@
+/*******************************************************************************
+ * Copyright (c) 2012 Tasktop Technologies and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Tasktop Technologies - initial API and implementation
+ *******************************************************************************/
+
+package org.eclipse.mylyn.reviews.connector.query;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.emf.ecore.EStructuralFeature;
+import org.eclipse.mylyn.tasks.core.IRepositoryQuery;
+import org.eclipse.mylyn.tasks.core.TaskRepository;
+import org.eclipse.mylyn.reviews.connector.AbstractEmfConnector;
+
+public abstract class EmfQueryEngine {
+
+	Map<String, QueryOperation> operationForId;
+
+	private final TaskRepository repository;
+
+	private final AbstractEmfConnector connector;
+
+	public static final String QUERY_DELIMITER = "_"; //$NON-NLS-1$
+
+	public static final String QUERY_VALUE = "query.value"; //$NON-NLS-1$
+
+	public static final String QUERY_OPERATION = "query.operation"; //$NON-NLS-1$
+
+	public static final String LIST_ITEM_SEPERATOR = ","; //$NON-NLS-1$
+
+	public EmfQueryEngine(AbstractEmfConnector connector, TaskRepository repository) {
+		this.connector = connector;
+		this.repository = repository;
+		operationForId = new HashMap<String, QueryOperation>();
+		for (QueryOperation op : QueryOperation.ALL_OPERATIONS) {
+			operationForId.put(op.id, op);
+		}
+	}
+
+	public QueryClause[] getClauses(IRepositoryQuery query) throws QueryException {
+		Map<String, QueryClause> queriesById = new HashMap<String, QueryClause>();
+		for (Entry<String, String> entry : query.getAttributes().entrySet()) {
+			String value = entry.getValue();
+			String[] keyParts = entry.getKey().split(QUERY_DELIMITER);
+			if (keyParts.length == 2) {
+				String attributeId = keyParts[0];
+				String queryId = keyParts[1];
+				QueryClause clause = queriesById.get(attributeId);
+				if (clause == null) {
+					clause = new QueryClause();
+					EStructuralFeature feature = connector.getSchema().getFeature(attributeId);
+					clause.setFeature(feature);
+					queriesById.put(attributeId, clause);
+				}
+				if (queryId.equals(QUERY_OPERATION)) {
+					QueryOperation operation = operationForId.get(value);
+					if (operation == null) {
+						throw new QueryException("Unknown operation: " + value); //$NON-NLS-1$
+					}
+					clause.setOperation(operation);
+				} else if (queryId.equals(QUERY_VALUE)) {
+					clause.setValue(value);
+				} else {
+					throw new QueryException("Unknown query identifier: " + queryId); //$NON-NLS-1$
+				}
+			}
+		}
+		return queriesById.values().toArray(new QueryClause[] {});
+	}
+
+	public QueryClause[] getNonEmptyClauses(IRepositoryQuery query) throws QueryException {
+		QueryClause[] clauses = getClauses(query);
+		Collection<QueryClause> results = new ArrayList<QueryClause>();
+		for (QueryClause queryClause : clauses) {
+			if (!queryClause.getValue().equals("")) { //$NON-NLS-1$
+				results.add(queryClause);
+			}
+		}
+		return results.toArray(new QueryClause[] {});
+	}
+
+	public AbstractEmfConnector getConnector() {
+		return connector;
+	}
+
+	public TaskRepository getRepository() {
+		return repository;
+	}
+
+	public abstract List<EObject> performQuery(IRepositoryQuery query, IProgressMonitor monitor) throws QueryException,
+			CoreException;
+}