/*
 * JBoss, Home of Professional Open Source.
 * See the COPYRIGHT.txt file distributed with this work for information
 * regarding copyright ownership.  Some portions may be licensed
 * to Red Hat, Inc. under one or more contributor license agreements.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301 USA.
 */
package org.teiid.translator.mongodb;

import static org.teiid.language.visitor.SQLStringVisitor.getRecordName;

import java.util.*;

import org.teiid.GeneratedKeys;
import org.teiid.language.Command;
import org.teiid.language.Insert;
import org.teiid.language.Update;
import org.teiid.logging.LogConstants;
import org.teiid.logging.LogManager;
import org.teiid.metadata.*;
import org.teiid.mongodb.MongoDBConnection;
import org.teiid.translator.DataNotAvailableException;
import org.teiid.translator.ExecutionContext;
import org.teiid.translator.TranslatorException;
import org.teiid.translator.UpdateExecution;
import org.teiid.translator.mongodb.MergeDetails.Association;

import com.mongodb.*;

public class MongoDBUpdateExecution extends MongoDBBaseExecution implements UpdateExecution {
	private Command command;
	private MongoDBUpdateVisitor visitor;
	private MongoDBExecutionFactory executionFactory;
	private int[] results = new int[] {0};

	public MongoDBUpdateExecution(MongoDBExecutionFactory executionFactory,
			Command command,
			ExecutionContext executionContext, RuntimeMetadata metadata,
			MongoDBConnection connection) throws TranslatorException {
		super(executionContext, metadata, connection);
		this.command = command;
		this.executionFactory = executionFactory;

		this.visitor = new MongoDBUpdateVisitor(executionFactory, metadata, this.mongoDB);
		this.visitor.visitNode(command);

		if (!this.visitor.exceptions.isEmpty()) {
			throw this.visitor.exceptions.get(0);
		}
	}

	@Override
	public void close() {
	}

	@Override
	public void cancel() throws TranslatorException {
	}

	@Override
	public void execute() throws TranslatorException {
		try {
			executeInternal();
		} catch (MongoException e) {
			throw new TranslatorException(e);
		}
	}

	private void executeInternal() throws TranslatorException {

		DBCollection collection = getCollection(this.visitor.mongoDoc.getTargetTable());
		MongoDocument mongoDoc = this.visitor.mongoDoc;
        AggregationOptions options = this.executionFactory.getOptions(this.executionContext.getBatchSize());		

        List<WriteResult> executionResults = new ArrayList<WriteResult>();

		if (this.command instanceof Insert) {
			// get pull key based documents to embed
			LinkedHashMap<String, DBObject> embeddedDocuments = fetchEmbeddedDocuments();

			// check if this document need to be embedded in any other document
			if (mongoDoc.isMerged()) {
			    DBObject match = getInsertMatch(mongoDoc, this.visitor.columnValues);
				BasicDBObject insert = this.visitor.getInsert(embeddedDocuments);
				
				if (mongoDoc.getMergeKey().getAssociation() == Association.MANY) {
				    removeParentKey(mongoDoc, insert);
				    BasicDBObject insertDoc = new BasicDBObject(mongoDoc.getQualifiedName(true), insert);
				    LogManager.logDetail(LogConstants.CTX_CONNECTOR, "update - {\"$match\": {"+match+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
				    LogManager.logDetail(LogConstants.CTX_CONNECTOR, "update - {\"$push\": {"+insertDoc+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
				    executionResults.add(collection.update(match, new BasicDBObject("$push", insertDoc), false, true, WriteConcern.ACKNOWLEDGED)); //$NON-NLS-1$
				}
				else {
				    insert.remove("_id"); //$NON-NLS-1$
				    BasicDBObject insertDoc = new BasicDBObject(mongoDoc.getQualifiedName(true), insert);
                    LogManager.logDetail(LogConstants.CTX_CONNECTOR, "update - {\"$match\": {"+match+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
                    LogManager.logDetail(LogConstants.CTX_CONNECTOR, "update - {\"$set\": {"+insertDoc+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
                    executionResults.add(collection.update(match, new BasicDBObject("$set", insertDoc), false, true, WriteConcern.ACKNOWLEDGED)); //$NON-NLS-1$
				}
			}
			else {
			    for (String docName:embeddedDocuments.keySet()) {
			        DBObject embeddedDoc = embeddedDocuments.get(docName);
			        embeddedDoc.removeField("_id"); //$NON-NLS-1$
			    }
				// gets its own collection
			    BasicDBObject in = this.visitor.getInsert(embeddedDocuments);
			    LogManager.logDetail(LogConstants.CTX_CONNECTOR, "{\"insert\": {"+in+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
			    executionResults.add(collection.insert(in, WriteConcern.ACKNOWLEDGED));
			}
		}
		else if (this.command instanceof Update) {
			// get pull key based documents to embed
			LinkedHashMap<String, DBObject> embeddedDocuments = fetchEmbeddedDocuments();
			DBObject match = new BasicDBObject();
			if (this.visitor.match != null) {
				match = this.visitor.match;
			}
			if (mongoDoc.isMerged()) {
				// multi items in array update not available, http://jira.mongodb.org/browse/SERVER-1243
				// this work-around for above issue
			    List<String> parentKeyNames = parentKeyNames(mongoDoc);
			    
				DBObject documentMatch = new BasicDBObject("$match", match); //$NON-NLS-1$						
				DBObject projection = new BasicDBObject("$project", buildProjectForUpdate(mongoDoc)); //$NON-NLS-1$
				Cursor output = collection.aggregate(Arrays.asList(documentMatch, projection), options);				
				while(output.hasNext()) {
				    BasicDBObject row = (BasicDBObject)output.next();				    
                    buildUpdate(mongoDoc, collection, row, parentKeyNames, 0, null, executionResults, new UpdateOperationImpl());
				}
			}
			else {
                for (String docName:embeddedDocuments.keySet()) {
                    DBObject embeddedDoc = embeddedDocuments.get(docName);
                    embeddedDoc.removeField("_id"); //$NON-NLS-1$
                }
			    BasicDBObject u = this.visitor.getUpdate(embeddedDocuments);
                LogManager.logDetail(LogConstants.CTX_CONNECTOR, "update - {\"$match\": {"+match+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
                LogManager.logDetail(LogConstants.CTX_CONNECTOR, "update - {\"$set\": {"+u+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
                executionResults.add(collection.update(match, new BasicDBObject("$set", u), false, true, WriteConcern.ACKNOWLEDGED)); //$NON-NLS-1$
			}

			// if the update is for the "embeddable" table, then since it is copied to other tables
			// those references need to be updated. I know this is not atomic operation, but not sure
			// how else to handle it.
			if (mongoDoc.isEmbeddable()) {
				updateReferenceTables(collection, mongoDoc, match, options);
			}
		}
		else {
		    // Delete
			DBObject match = new BasicDBObject();
			if (this.visitor.match != null) {
				match = this.visitor.match;
			}

			if (mongoDoc.isEmbeddable()) {
			    DBObject m = new BasicDBObject("$match", match); //$NON-NLS-1$
				Cursor output = collection.aggregate(Arrays.asList(m), options); 
				while(output.hasNext()) {
					DBObject row = output.next();
					if (row != null) {
						for (MergeDetails ref:mongoDoc.getEmbeddedIntoReferences()) {
							DBCollection parent = getCollection(ref.getParentTable());
							DBObject parentMatch = buildParentMatch(row, ref);
							DBObject refMatch = new BasicDBObject("$match", parentMatch); //$NON-NLS-1$
							Cursor referenceOutput = parent.aggregate(Arrays.asList(refMatch), options); 
							if (referenceOutput.hasNext()) {
								throw new TranslatorException(MongoDBPlugin.Util.gs(MongoDBPlugin.Event.TEIID18010, this.visitor.mongoDoc.getTargetTable().getName(), ref.getParentTable()));
							}
						}
					}
				}
			}

			if (mongoDoc.isMerged()) {
                List<String> parentKeyNames = parentKeyNames(mongoDoc);
                
                DBObject documentMatch = new BasicDBObject("$match", match); //$NON-NLS-1$                      
                DBObject projection = new BasicDBObject("$project", buildProjectForUpdate(mongoDoc)); //$NON-NLS-1$
                Cursor output = collection.aggregate(Arrays.asList(documentMatch, projection), options);                
                while(output.hasNext()) {
                    BasicDBObject row = (BasicDBObject)output.next();                   
                    buildUpdate(mongoDoc, collection, row, parentKeyNames, 0, null, executionResults, new DeleteOperationImpl(match));
                }			    
			}
			else {
                LogManager.logDetail(LogConstants.CTX_CONNECTOR, "remove - {\"$match\": {"+match+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
                executionResults.add(collection.remove(match, WriteConcern.ACKNOWLEDGED));
			}
		}

		if (!executionResults.isEmpty()) {
            if (this.command instanceof Insert) {
                if (this.executionContext.getCommandContext().isReturnAutoGeneratedKeys()) {
                    addAutoGeneretedKeys(executionResults.get(0));
                }
            }
            
            int updated = 0;
            for (WriteResult result:executionResults) {
                updated +=result.getN();
            }
            
			this.results = new int[1];
			this.results[0] = updated;
		}
	}
	
    DBObject getInsertMatch(MongoDocument mongoDocument, Map<String, Object> values) throws TranslatorException {
        List<DBObject> matches = new ArrayList<DBObject>();
        HashMap<String, Object> matchValues = new HashMap<String, Object>();
        MongoDocument mergeDocument = mongoDocument.getMergeDocument();
        MongoDocument targetDocument = mongoDocument.getTargetDocument();
        
        if (mongoDocument.getMergeKey().getAssociation() == Association.ONE) {
            while(mergeDocument.isMerged()) {
                matches.add(QueryBuilder.start(mergeDocument.getDocumentName()).exists(true).get());
                if (mergeDocument.getMergeKey().getAssociation() == Association.ONE) {
                    mergeDocument = mergeDocument.getMergeDocument();
                }
                else {
                    break;
                }
            }
            if (mergeDocument.equals(targetDocument)) {
                matchValues.put("_id", values.get("_id")); //$NON-NLS-1$ //$NON-NLS-2$
            }
            else {
                matchValues.put(mergeDocument+"._id", values.get("_id")); //$NON-NLS-1$ //$NON-NLS-2$
            }
        }
        else {
            // this nested so add exists
            if (!mergeDocument.equals(targetDocument)) {
                matches.add(QueryBuilder.start(mergeDocument.getDocumentName()).exists(true).get());
            }

            // this value can go only one level up
            String columnName = mergeDocument.getColumnName(mongoDocument.getMergeKey().getReferenceColumns().get(0));
            Object value = values.get(mongoDocument.getMergeKey().getColumns().get(0));
            if (value instanceof MergeDetails) {
                value = ((MergeDetails)value).getValue();
            }
            
            if (mergeDocument.equals(targetDocument)) {
                matchValues.put(columnName, value);
            }
            else {
                while(mergeDocument.isMerged()) {
                    if (mergeDocument.getMergeKey().getAssociation() == Association.ONE) {
                        mergeDocument = mergeDocument.getMergeDocument();
                    }
                    else {
                        break;
                    }
                }  
                matchValues.put(columnName, value);
            }
        }

        // build match
        BasicDBObject match = new BasicDBObject();
        for (String key:matchValues.keySet()) {
            match.append(key, matchValues.get(key));
        }
        if (!matches.isEmpty()) {
            matches.add(match);
            QueryBuilder qb = QueryBuilder.start().and(matches.toArray(new BasicDBObject[matches.size()]));
            match = (BasicDBObject)qb.get();
        }
        return match;
    }	
	
	static class RowInfo {
	    String tableName;
	    String mergedTableName;
	    Object PK;
	    int rowNumber;
	    RowInfo parent;
	    boolean istop;
	    
	    static RowInfo build(String name, String mergeName, Object pk, int rowNumber, RowInfo parent) {
	        RowInfo info = new RowInfo();
	        info.tableName = name;
	        info.mergedTableName = mergeName;
	        info.PK = pk;
	        info.rowNumber = rowNumber;
	        if (parent != null) {
	            info.parent = parent;
	            info.istop = false;
	        }
	        else {
	            info.istop = true;    
	        }	        
	        return info;
	    }

        public String getId(MongoDocument parent) {
            StringBuilder sb = new StringBuilder();
            sb.append(parent.getTable().getName());
            if (this.parent != null) {
                getId(sb);    
            }            
            return sb.toString();
        }
        
        private void getId(StringBuilder sb) {
            if (this.parent != null) {                
                if (this.rowNumber != -1) {
                    sb.insert(0, "."); //$NON-NLS-1$
                    sb.insert(0,this.rowNumber);
                }
                this.parent.getId(sb);
            }            
            if (!this.istop) {
                sb.insert(0, "."); //$NON-NLS-1$
                sb.insert(0, this.tableName);
            }            
        }
	}
	
	private interface UpdateOperation {
	    void execute(MongoDocument doc, DBCollection collection, DBObject row, DBObject dataRow,
            RowInfo rowInfo, List<WriteResult> executionResults) throws TranslatorException;
	}
	
    private void buildUpdate(MongoDocument doc, DBCollection collection, BasicDBObject row, List<String> parentKeys, int level,
            RowInfo rowInfo, List<WriteResult> executionResults, UpdateOperation operation) throws TranslatorException {
	    
        String parentKeyName = parentKeys.get(level);
	    boolean top = parentKeyName.equals(doc.getTargetDocument().getQualifiedName(false));
	    Object parentBlock = row.get(top?"_id":parentKeyName); //$NON-NLS-1$

	    // the parent-child must have been one-2-one relationship 
	    if (parentBlock == null) {
	        parentBlock = rowInfo.PK;
	    }
	    String mergeTableName = doc.getTable().getName();
	    if (parentKeys.size() != (level+1)) {
	        mergeTableName = parentKeys.get(level+1);
	    }
	    
	    if (parentBlock instanceof BasicDBList) {
	        // so parent is an array document
	        BasicDBList parentRows = (BasicDBList)parentBlock;
	        //parentRows = (BasicDBList)((BasicDBObject)parentRows.get(0)).get("_id"); //$NON-NLS-1$
	        for (int i = 0; i < parentRows.size(); i++) {
	            RowInfo info = RowInfo.build(parentKeyName,mergeTableName, parentRows.get(i), i, rowInfo);
	            if (parentKeys.size() == (level+1)) {
	                String aliasDocumentName = doc.getQualifiedName(false).replace('.', '_');
	                BasicDBList dataRows = (BasicDBList)row.get(aliasDocumentName);
	                if (dataRows != null && dataRows.size() > i) {
	                    operation.execute(doc, collection, row, (DBObject)dataRows.get(i), info, executionResults);
	                }
	            }
	            else {
	                buildUpdate(doc, collection, row, parentKeys, level+1, info, executionResults, operation);    
	            }
	        }
	    }
	    else {
            // here the _id is same as parent
            RowInfo info = RowInfo.build(parentKeyName, mergeTableName, parentBlock, -1, rowInfo);	        
	        if (parentKeys.size() == (level+1)) {
	            //Leaf, no more down
                String aliasDocumentName = doc.getQualifiedName(false).replace('.', '_');
                DBObject dataRows = (DBObject)row.get(aliasDocumentName);
                if (dataRows != null) {
                    operation.execute(doc, collection, row, dataRows, info, executionResults);
                }
	        }
	        else {
                buildUpdate(doc, collection, row, parentKeys, level+1, info, executionResults, operation);	            
	        }
	    }
	}

    class UpdateOperationImpl implements UpdateOperation { 
        public void execute(MongoDocument doc, DBCollection collection, DBObject row, DBObject dataRow,
                RowInfo rowInfo, List<WriteResult> executionResults) throws TranslatorException {
            if (dataRow instanceof BasicDBList) {
                BasicDBList updatedDoc = new BasicDBList();
                boolean update = visitor.updateMerge((BasicDBList)dataRow, rowInfo, updatedDoc);
                if (update) {
                    BasicDBObject m = new BasicDBObject("_id", row.get("_id"));//$NON-NLS-1$ //$NON-NLS-2$
                    BasicDBObject u = new BasicDBObject(rowInfo.getId(doc), updatedDoc);
                    LogManager.logDetail(LogConstants.CTX_CONNECTOR, "update - {\"$match\": {"+m+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
                    LogManager.logDetail(LogConstants.CTX_CONNECTOR, "update - {\"$set\": {"+u+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
                    WriteResult result = collection.update(m, new BasicDBObject("$set", u), false, true, WriteConcern.ACKNOWLEDGED); //$NON-NLS-1$
                    executionResults.add(result);
                }                   
            }
            else {                  
                BasicDBObject m = new BasicDBObject("_id", row.get("_id"));//$NON-NLS-1$ //$NON-NLS-2$
                boolean update = visitor.updateMerge((BasicDBObject)dataRow, rowInfo);
                if(update) {
                    BasicDBObject u = new BasicDBObject(rowInfo.getId(doc), dataRow);
                    LogManager.logDetail(LogConstants.CTX_CONNECTOR, "update - {\"$match\": {"+m+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
                    LogManager.logDetail(LogConstants.CTX_CONNECTOR, "update - {\"$set\": {"+u+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
                    WriteResult result = collection.update(m, new BasicDBObject("$set", u), false, true, WriteConcern.ACKNOWLEDGED); //$NON-NLS-1$
                    executionResults.add(result);
                }
            }        
        }
    }
    
    class DeleteOperationImpl implements UpdateOperation { 
        private DBObject queryMatch;
        public DeleteOperationImpl(DBObject match) {
            this.queryMatch = match;
        }
        
        public void execute(MongoDocument doc, DBCollection collection, DBObject row, DBObject dataRow,
                RowInfo rowInfo, List<WriteResult> executionResults) throws TranslatorException {
            
            if (dataRow instanceof BasicDBList) {
                BasicDBObject pull = (BasicDBObject)visitor.getPullQuery().get(rowInfo.mergedTableName);
                if(this.queryMatch.keySet().isEmpty()) {
                    queryMatch = QueryBuilder.start(rowInfo.getId(doc)).exists(true).get();                    
                    pull = new BasicDBObject(rowInfo.getId(doc), pull != null ? pull : new BasicDBObject());
                    LogManager.logInfo(LogConstants.CTX_CONNECTOR, "update - {\"$match\": {"+this.queryMatch+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
                    LogManager.logInfo(LogConstants.CTX_CONNECTOR, "update - {\"$pull\": {"+pull+"}}"); //$NON-NLS-1$ //$NON-NLS-2$                    
                    WriteResult result = collection.update(this.queryMatch, new BasicDBObject("$pull", pull), false, true, //$NON-NLS-1$
                            WriteConcern.ACKNOWLEDGED); 
                    executionResults.add(result);
                }
                else {
                    BasicDBList updatedDoc = new BasicDBList();
                    boolean update = visitor.updateDelete((BasicDBList)dataRow, rowInfo, updatedDoc);
                    if (update) {
                        BasicDBObject m = new BasicDBObject("_id", row.get("_id"));//$NON-NLS-1$ //$NON-NLS-2$
                        BasicDBObject u = new BasicDBObject(rowInfo.getId(doc), updatedDoc);
                        LogManager.logDetail(LogConstants.CTX_CONNECTOR, "update - {\"$match\": {"+m+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
                        LogManager.logDetail(LogConstants.CTX_CONNECTOR, "update - {\"$set\": {"+u+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
                        WriteResult result = collection.update(m, new BasicDBObject("$set", u), false, true, WriteConcern.ACKNOWLEDGED); //$NON-NLS-1$
                        executionResults.add(result);
                    }                     
                }
            }
            else {
                if(this.queryMatch.keySet().isEmpty()) {
                    queryMatch = QueryBuilder.start(rowInfo.getId(doc)).exists(true).get();                    
                }                
                BasicDBObject u = new BasicDBObject(rowInfo.getId(doc), ""); //$NON-NLS-1$
                LogManager.logInfo(LogConstants.CTX_CONNECTOR, "update - {\"$match\": {"+this.queryMatch+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
                LogManager.logInfo(LogConstants.CTX_CONNECTOR, "update - {\"$unset\": {"+u+"}}"); //$NON-NLS-1$ //$NON-NLS-2$
                WriteResult result = collection.update(this.queryMatch, new BasicDBObject("$unset", u), false, true, WriteConcern.ACKNOWLEDGED); //$NON-NLS-1$
                executionResults.add(result);                
            }
        }
    }    
	
	private BasicDBObject buildProjectForUpdate(MongoDocument doc) throws TranslatorException {
	    BasicDBObject project = new BasicDBObject();
	    // the preview document for update
	    String aliasDocumentName = doc.getQualifiedName(false).replace('.', '_');
	    project.append(aliasDocumentName, "$"+doc.getQualifiedName(false)); //$NON-NLS-1$
	    
	    while (doc.isMerged()) {
	        doc = doc.getMergeDocument();
	        if (doc.isMerged()) {
	            project.append(doc.getQualifiedName(false), "$"+doc.getQualifiedName(false)+"._id"); //$NON-NLS-1$ //$NON-NLS-2$
	        }
	    }
	    project.append("_id", "$_id"); //$NON-NLS-1$ //$NON-NLS-2$
	    return project;
	}
	
    private List<String> parentKeyNames(MongoDocument doc) throws TranslatorException {
        ArrayList<String> list = new ArrayList<String>();
        while (doc.isMerged()) {
            doc = doc.getMergeDocument();
            list.add(0, doc.getQualifiedName(false));
        }
        return list;
    }

	private void removeParentKey(MongoDocument document, BasicDBObject row) throws TranslatorException {
        Table source = document.getTable();
        Table target = document.getMergeTable();

        for (ForeignKey fk:source.getForeignKeys()) {
            if (fk.getReferenceTableName().equals(target.getName())){
                for (int i = 0; i < fk.getColumns().size(); i++) {
                    if (row != null) {
                        row.remove(fk.getColumns().get(i).getName());
                    }
                }
            }
        }
    }

    private void updateReferenceTables(DBCollection collection, MongoDocument mongoDoc, 
            DBObject match, AggregationOptions options) throws TranslatorException {
        DBObject m = new BasicDBObject("$match", match); //$NON-NLS-1$
        Cursor output = collection.aggregate(Arrays.asList(m), options); 
		while(output.hasNext()) {
			DBObject row = output.next();
			if (row != null) {
				for (MergeDetails ref:mongoDoc.getEmbeddedIntoReferences()) {
					DBCollection parent = getCollection(ref.getParentTable());
					//DBObject parentmatch = new BasicDBObject(ref.getReferenceName()+".$id", row.get("_id")); //$NON-NLS-1$ //$NON-NLS-2$
					DBObject parentmatch = buildParentMatch(row, ref);
					row.removeField("_id"); //$NON-NLS-1$
					parent.update(parentmatch, new BasicDBObject("$set",new BasicDBObject(ref.getName(), row)), //$NON-NLS-1$
							false, true, WriteConcern.ACKNOWLEDGED);

					// see if there are nested references
					Table parentTable = this.metadata.getTable(mongoDoc.getTable().getParent().getName(), ref.getParentTable());
					MongoDocument parentMongoDocument = new MongoDocument(parentTable, this.metadata);
					if (parentMongoDocument.isEmbeddable()) {
						updateReferenceTables(parent, parentMongoDocument, parentmatch,options);
					}
				}
			}
		}
	}

	private DBObject buildParentMatch(DBObject row, MergeDetails ref) {
		DBObject parentmatch = new BasicDBObject();
		Object rowid = row.get("_id"); //$NON-NLS-1$
		if (rowid instanceof BasicDBObject) {
			// composite key..
			for (int i = 0; i < ref.getColumns().size(); i++) {
				parentmatch.put(ref.getColumns().get(i), ((BasicDBObject) rowid).get(ref.getReferenceColumns().get(i)));
			}
		}
		else {
			parentmatch.put(ref.getColumns().get(0), rowid);
		}
		return parentmatch;
	}

	private LinkedHashMap<String, DBObject> fetchEmbeddedDocuments() {
		LinkedHashMap<String, DBObject> additionalDocuments = new LinkedHashMap<String, DBObject>();

		// check if there are any other documents that can be embedded in this
		// document
		MongoDocument mongoDoc = this.visitor.mongoDoc;
		if (mongoDoc.hasEmbeddedDocuments()) {
			for (String docName:mongoDoc.getEmbeddedDocumentNames()) {
				DBObject document = mongoDoc.getEmbeddedDocument(this.mongoDB, docName);
				if (document == null) {
					continue;
				}
				additionalDocuments.put(docName, document);
			}
		}
		return additionalDocuments;
	}

	private DBCollection getCollection(String name) throws TranslatorException {
		return getCollection(this.metadata.getTable(this.visitor.mongoDoc.getTable().getParent().getName(), name));
	}
	private DBCollection getCollection(Table table) {
		DBCollection collection;
		if (!this.mongoDB.collectionExists(table.getName())) {
			collection = this.mongoDB.createCollection(table.getName(), null);

			// since this is the first time creating the tables; create the indexes on the collection
			// index on foreign keys
			for (ForeignKey record:table.getForeignKeys()) {
				createIndex(collection, record, false);
			}

			// index on unique
			for (KeyRecord record:table.getUniqueKeys()) {
				createIndex(collection, record, true);
			}

			// index on index keys
			for (KeyRecord record:table.getIndexes()) {
				createIndex(collection, record, false);
			}
		}
		else {
			collection = this.mongoDB.getCollection(table.getName());
		}
		return collection;
	}

	private void createIndex(DBCollection collection, KeyRecord record, boolean unique) {
		BasicDBObject key = new BasicDBObject();
		for (Column c:record.getColumns()) {
			key.append(getRecordName(c), 1);
		}
		BasicDBObject options = new BasicDBObject();
        options.put( "name" , record.getName()); //$NON-NLS-1$
        if (unique) {
            options.put( "unique" , Boolean.TRUE); //$NON-NLS-1$
        }
		collection.createIndex(key, options);
	}

	@Override
	public int[] getUpdateCounts() throws DataNotAvailableException, TranslatorException {
		return this.results;
	}


	private void addAutoGeneretedKeys(WriteResult result) throws TranslatorException {
		Table table = this.visitor.mongoDoc.getTargetTable();

		int cols = table.getPrimaryKey().getColumns().size();
		Class<?>[] columnDataTypes = new Class<?>[cols];
		String[] columnNames = new String[cols];
		//this is typically expected to be an int/long, but we'll be general here.  we may eventual need the type logic off of the metadata importer
        for (int i = 0; i < cols; i++) {
        	columnDataTypes[i] = table.getPrimaryKey().getColumns().get(i).getJavaType();
        	columnNames[i] = table.getPrimaryKey().getColumns().get(i).getName();
        }
        GeneratedKeys generatedKeys = this.executionContext.getCommandContext().returnGeneratedKeys(columnNames, columnDataTypes);
        List<Object> vals = new ArrayList<Object>(columnDataTypes.length);
        for (int i = 0; i < columnDataTypes.length; i++) {
            Object value = this.executionFactory.retrieveValue(result.getField(columnNames[i]), columnDataTypes[i], this.mongoDB, columnNames[i], columnNames[i]);
            vals.add(value);
        }
        generatedKeys.addKey(vals);
	}
}
