/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 org.apache.tuscany.das.rdb.impl;

import java.sql.CallableStatement;
import java.sql.Connection;
import java.sql.DatabaseMetaData;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import org.apache.log4j.Logger;

public class ConnectionImpl {

    private final Logger logger = Logger.getLogger(ConnectionImpl.class);

    private Connection connection;

    private boolean managingTransaction = true;

    private String generatedKeysSupported = null;
    
    public ConnectionImpl(Connection connection) {
        this.connection = connection;

        try {
            if (connection.getAutoCommit()) {
                throw new RuntimeException("AutoCommit must be off");
            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }

    }

    public Connection getJDBCConnection() {
        return connection;
    }

    public String getGeneratedKeysSupported() {
        return this.generatedKeysSupported;
    }
    
    public void setGeneratedKeysSupported(String useGetGeneratedKeys){
        this.generatedKeysSupported = useGetGeneratedKeys;
    }    
    
    public boolean isGeneratedKeysSupported() {
        try{
            if(this.generatedKeysSupported == null){
                DatabaseMetaData dbmsMetadata = this.connection.getMetaData();
                boolean supportsGetGeneratedKeys = dbmsMetadata.supportsGetGeneratedKeys();
                if(supportsGetGeneratedKeys){
                    this.generatedKeysSupported = "true";
                }
                //currently DERBY partially supports this feature and thus returns FALSE,
                //this hardcoding is needed as the partial support is enough for DAS
                //we can remove this later, when DERBY change the behaviour of it's "supportsGetGeneratedKeys"
                else if(dbmsMetadata.getDatabaseProductName().indexOf("Derby") > 0){                    
                    this.generatedKeysSupported = "true";
                }
                else{
                    this.generatedKeysSupported = "false";
                }
            }           
        }catch(Exception e){//can be from supportsGetGeneratedKeys or due to absense of supportsGetGeneratedKeys
            if (this.logger.isDebugEnabled()) {
                this.logger.debug("exception setiing useGetGeneratedKeys false");
            }
            this.generatedKeysSupported = "false";
        }
        
        if (this.logger.isDebugEnabled()) {
            this.logger.debug("returning useGetGeneratedKeys():"+ this.generatedKeysSupported);
        }
        return Boolean.parseBoolean(this.generatedKeysSupported);
    }
    
    public void cleanUp() {
        try {
            if (managingTransaction) {
                if (this.logger.isDebugEnabled()) {
                    this.logger.debug("Committing Transaction");
                }
                connection.commit();
            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }

    public void errorCleanUp() {
        try {
            if (managingTransaction) {
                if (this.logger.isDebugEnabled()) {
                    this.logger.debug("Rolling back Transaction");
                }
                connection.rollback();
            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }
    }

    public PreparedStatement prepareStatement(String queryString, String[] returnKeys) throws SQLException {
        if (this.logger.isDebugEnabled()) {
            this.logger.debug("Preparing Statement: " + queryString);
            this.logger.debug("Boolean value for use gen key: " + this.generatedKeysSupported);
        }

        if (isGeneratedKeysSupported()) {
            return connection.prepareStatement(queryString, Statement.RETURN_GENERATED_KEYS);
        } else if (returnKeys.length > 0) {
            return connection.prepareStatement(queryString, returnKeys);
        }

        return connection.prepareStatement(queryString);
    }
    
    public PreparedStatement preparePagedStatement(String queryString) throws SQLException {
        if (this.logger.isDebugEnabled()) {
            this.logger.debug("Preparing Statement: " + queryString);
        }

        return connection.prepareStatement(queryString, ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
    }

    public void setManageTransactions(boolean manageTransactions) {
        managingTransaction = manageTransactions;

    }

    public CallableStatement prepareCall(String queryString) throws SQLException {
        return connection.prepareCall(queryString);
    }
}