/*
 * Copyright 2011 Cloud.com, Inc.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.cloud.bridge.service.core.ec2;

import java.text.ParseException;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import com.cloud.bridge.service.UserContext;
import com.cloud.bridge.service.exception.EC2ServiceException;
import com.cloud.bridge.util.DateHelper;

public class EC2SnapshotFilterSet {

	protected List<EC2Filter> filterSet = new ArrayList<EC2Filter>();    
	
	private Map<String,String> filterTypes = new HashMap<String,String>();

	public EC2SnapshotFilterSet() 
	{
		// -> use these values to check that the proper filter is passed to this type of filter set
		filterTypes.put( "owner-alias", "string"  );
		filterTypes.put( "owner-id",    "string"  );
		filterTypes.put( "snapshot-id", "string"  );
		filterTypes.put( "start-time",  "xsd:dateTime" );
		filterTypes.put( "status",      "string"  );
		filterTypes.put( "volume-id",   "string"  ); 
		filterTypes.put( "volume-size", "string"  );
	}
	
	
	public void addFilter( EC2Filter param ) 
	{	
		String filterName = param.getName();
		String value = (String) filterTypes.get( filterName );
		
		if (null == value)
			throw new EC2ServiceException( "Unsupported filter [" + filterName + "] - 1", 501 );
		
		if (null != value && value.equalsIgnoreCase( "null" ))
			throw new EC2ServiceException( "Unsupported filter [" + filterName + "] - 2", 501 );

		// ToDo we could add checks to make sure the type of a filters value is correct (e.g., an integer)
		filterSet.add( param );
	}
	
	
	public EC2Filter[] getFilterSet() {
		return filterSet.toArray(new EC2Filter[0]);
	}
	
	
	/**
	 * For a filter to match a snapshot just one of its values has to match the volume.
	 * For a snapshot to be included in the instance response it must pass all the defined filters.
	 * 
	 * @param sampleList - list of snapshots to test against the defined filters
	 * @return EC2DescribeSnapshotsResponse
	 * @throws ParseException 
	 */
	public EC2DescribeSnapshotsResponse evaluate( EC2DescribeSnapshotsResponse sampleList ) throws ParseException 
	{
		EC2DescribeSnapshotsResponse resultList = new EC2DescribeSnapshotsResponse();
    	boolean matched;
    	
    	EC2Snapshot[] snapshotSet = sampleList.getSnapshotSet();
    	EC2Filter[]   filterSet   = getFilterSet();
    	for (EC2Snapshot snap : snapshotSet) {
    		matched = true;
    		for (EC2Filter filter : filterSet) {
    			if (!filterMatched( snap, filter )) {
    				matched = false;
    				break;
    			}
    		}
    		
    		if (matched) resultList.addSnapshot( snap );
    	}

		return resultList;
	}
	
	
	private boolean filterMatched( EC2Snapshot snap, EC2Filter filter ) throws ParseException
	{
		String filterName = filter.getName();
		String[] valueSet = filter.getValueSet();
		
	    if ( filterName.equalsIgnoreCase( "owner-alias" )) 
	    {
	    	 return containsString( UserContext.current().getAccessKey(), valueSet );	
	    }
	    else if (filterName.equalsIgnoreCase( "owner-id" )) 
	    {	
	    	 String owner = new String( snap.getDomainId() + ":" + snap.getAccountName()); 
	    	 return containsString( owner, valueSet );	
	    }
	    else if (filterName.equalsIgnoreCase( "snapshot-id" )) 
	    {	
	    	 return containsString( snap.getId().toString(), valueSet );	
	    }
	    else if (filterName.equalsIgnoreCase( "start-time" )) 
	    {	
	    	 return containsTime( snap.getCreated(), valueSet );	
	    }
	    else if (filterName.equalsIgnoreCase( "status" ))
	    {
	         return containsString( "completed", valueSet );	
	    }
	    else if (filterName.equalsIgnoreCase( "volume-id" )) 
	    {
	    	 return containsString( snap.getVolumeId().toString(), valueSet );		
	    }
	    else if (filterName.equalsIgnoreCase( "volume-size" )) 
	    {
	    	 return containsLong( snap.getVolumeSize(), valueSet );		
	    }
	    else return false;
	}
	
	
	private boolean containsString( String lookingFor, String[] set )
	{
		if (null == lookingFor) return false;
		
		for (String s : set) {
	    	//System.out.println( "contsinsString: " + lookingFor + " " + set[i] );
	    	if (lookingFor.matches( s )) return true;
	    }
	    return false;
	}

	
	private boolean containsLong( long lookingFor, String[] set )
	{
		for (String s : set) {
	    	//System.out.println( "contsinsInteger: " + lookingFor + " " + set[i] );
        	int temp = Integer.parseInt( s );
        	if (lookingFor == temp) return true;
        }
		return false;
	}

	
	private boolean containsTime( Calendar lookingFor, String[] set ) throws ParseException
	{
		for (String s : set) {
	    	//System.out.println( "contsinsCalendar: " + lookingFor + " " + set[i] );
        	Calendar toMatch = Calendar.getInstance();
        	toMatch.setTime( DateHelper.parseISO8601DateString( s ));
        	if (0 == lookingFor.compareTo( toMatch )) return true;
        }
		return false;
	}
}