/*******************************************************************************
 * Copyright (c) 2009, 2011 SAP AG 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:
 *     SAP AG - initial API and implementation
 ******************************************************************************/
package org.eclipse.ocl.examples.eventmanager.util;

import java.util.Arrays;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;



public class StatisticsImpl extends Statistics {
    private Map<String, List<Record>> records = new HashMap<String, List<Record>>();
    private Map<List<Object>, Long> running = new HashMap<List<Object>, Long>();

    @Override
    public void begin(String groupId, Object key) {
        List<Object> groupIdAndKey = Arrays.asList(groupId, key);
        if (running.containsKey(groupIdAndKey)) {
            throw new RuntimeException("beginning an already running measurement: "+groupIdAndKey);
        }
        running.put(groupIdAndKey, System.nanoTime());
    }

    @Override
    public void end(String groupId, Object key) {
        long endTime = System.nanoTime();
        List<Object> groupIdAndKey = Arrays.asList(groupId, key);
        Long startTime = running.get(groupIdAndKey);
        if (startTime == null) {
            throw new RuntimeException("ending a measurement that hasn't been started: "+groupIdAndKey);
        }
        long value = endTime-startTime;
        record(groupId, key, value);
        running.remove(groupIdAndKey);
    }

    @Override
    public void record(String groupId, Object key, long value) {
        List<Record> recordsForGroupId = records.get(groupId);
        if (recordsForGroupId == null) {
            recordsForGroupId = new LinkedList<Record>();
            records.put(groupId, recordsForGroupId);
        }
        recordsForGroupId.add(new Record(key, value));
    }
    
    @Override
    public List<Record> getRecords(String groupId) {
        return records.get(groupId);
    }

    @Override
    public Set<String> getGroupIds() {
        return records.keySet();
    }
    
    @Override
    public void clear() {
        records.clear();
        running.clear();
    }
    
}