/**
    * Copyright 2004-2012 The Kuali Foundation
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    *
   * 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.kuali.db;
  
  import java.sql.Connection;
  import java.sql.Driver;
  import java.sql.SQLException;
  import java.util.Properties;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  public class ConnectionHandler {
  	private static final Log log = LogFactory.getLog(ConnectionHandler.class);
  
  	public static final String DRIVER_INFO_PROPERTIES_USER = "user";
  	public static final String DRIVER_INFO_PROPERTIES_PASSWORD = "password";
  
  	String url;
  	boolean autocommit = true;
  	boolean skipOnConnectionError = false;
  	boolean connectionError = false;
  	boolean enableAnonymousPassword = false;;
  	boolean enableAnonymousUsername = false;;
  	Credentials credentials;
  	Properties driverProperties;
  	String driver;
  	boolean showPassword = false;
  
  	protected void showConnectionInfo(Properties properties) {
  		log.info("------------------------------------------------------------------------");
  		log.info("JDBC Connection Information");
  		log.info("------------------------------------------------------------------------");
  		log.info("URL: " + getUrl());
  		String username = properties.getProperty(DRIVER_INFO_PROPERTIES_USER);
  		String password = properties.getProperty(DRIVER_INFO_PROPERTIES_PASSWORD);
  		if (StringUtils.isEmpty(username)) {
  			log.info("Username: <no username was supplied>");
  		} else {
  			log.info("Username: " + username);
  		}
  		if (isShowPassword()) {
  			log.info("Password: " + password);
  		} else {
  			if (StringUtils.isEmpty(password)) {
  				log.info("Password: <no password was supplied>");
  			} else {
  				log.info("Password: " + StringUtils.repeat("*", password.length()));
  			}
  		}
  		log.info("Driver: " + getDriver());
  		log.info("------------------------------------------------------------------------");
  	}
  
  	protected Driver getDriverInstance() throws SQLException {
  		try {
  			Class<?> dc = Class.forName(getDriver());
  			return (Driver) dc.newInstance();
  		} catch (ClassNotFoundException e) {
  			throw new SQLException("Driver class not found: " + getDriver(), e);
  		} catch (Exception e) {
  			throw new SQLException("Failure loading driver: " + getDriver(), e);
  		}
  	}
  
  	protected Properties getInfo() throws SQLException {
  		Properties info = new Properties();
  		if (!enableAnonymousUsername) {
  			info.put(DRIVER_INFO_PROPERTIES_USER, credentials.getUsername());
  		}
  		if (!enableAnonymousPassword) {
  			info.put(DRIVER_INFO_PROPERTIES_PASSWORD, credentials.getPassword());
  		}
  		if (driverProperties != null) {
  			info.putAll(getDriverProperties());
  		}
  		return info;
  	}
  
  	protected void validateConfiguration() throws SQLException {
  		String username = credentials.getUsername();
  		String password = credentials.getPassword();
  		if (!enableAnonymousUsername && StringUtils.isBlank(username)) {
  			throw new SQLException("\n\nNo username was supplied.\nYou can supply a username in the plugin configuration or provide it as a system property.\n\nFor example:\n-Dusername=myuser\n\n.");
  		}
 		if (!enableAnonymousPassword && StringUtils.isBlank(password)) {
 			throw new SQLException("\n\nNo password was supplied.\nYou can supply a password in the plugin configuration or provide it as a system property.\n\nFor example:\n-Dpassword=mypassword\n\n.");
 		}
 		// Convert null to the empty string if needed
 		if (StringUtils.isBlank(username)) {
 			credentials.setUsername("");
 		}
 		if (StringUtils.isBlank(password)) {
 			credentials.setPassword("");
 		}
 	}
 
 	public Connection getConnection() throws SQLException {
 		validateConfiguration();
 		Properties info = getInfo();
 		Connection conn = null;
 		try {
 			Driver driverInstance = getDriverInstance();
 			showConnectionInfo(info);
 			conn = driverInstance.connect(getUrl(), info);
 
 			if (conn == null) {
 				// Driver doesn't understand the URL
 				throw new SQLException("No suitable Driver for " + getUrl());
 			}
 
 			conn.setAutoCommit(autocommit);
 		} catch (SQLException e) {
 			if (skipOnConnectionError) {
 				// Error getting the connection but they have asked us not to throw an exception
 				// Set our flag and return
 				connectionError = true;
 				return null;
 			} else {
 				// Otherwise, throw an exception
 				throw new SQLException("Connection error: " + e.getMessage().toString(), e);
 			}
 		}
 		return conn;
 	}
 
 	public String getUrl() {
 		return url;
 	}
 
 	public void setUrl(String url) {
 		this.url = url;
 	}
 
 	public boolean isAutocommit() {
 		return autocommit;
 	}
 
 	public void setAutocommit(boolean autocommit) {
 		this.autocommit = autocommit;
 	}
 
 	public boolean isSkipOnConnectionError() {
 		return skipOnConnectionError;
 	}
 
 	public void setSkipOnConnectionError(boolean skipOnConnectionError) {
 		this.skipOnConnectionError = skipOnConnectionError;
 	}
 
 	public boolean isConnectionError() {
 		return connectionError;
 	}
 
 	public void setConnectionError(boolean connectionError) {
 		this.connectionError = connectionError;
 	}
 
 	public boolean isEnableAnonymousPassword() {
 		return enableAnonymousPassword;
 	}
 
 	public void setEnableAnonymousPassword(boolean enableAnonymousPassword) {
 		this.enableAnonymousPassword = enableAnonymousPassword;
 	}
 
 	public Credentials getCredentials() {
 		return credentials;
 	}
 
 	public void setCredentials(Credentials credentials) {
 		this.credentials = credentials;
 	}
 
 	public Properties getDriverProperties() {
 		return driverProperties;
 	}
 
 	public void setDriverProperties(Properties driverProperties) {
 		this.driverProperties = driverProperties;
 	}
 
 	public String getDriver() {
 		return driver;
 	}
 
 	public void setDriver(String driver) {
 		this.driver = driver;
 	}
 
 	public boolean isShowPassword() {
 		return showPassword;
 	}
 
 	public void setShowPassword(boolean showPassword) {
 		this.showPassword = showPassword;
 	}
 
 	public boolean isEnableAnonymousUsername() {
 		return enableAnonymousUsername;
 	}
 
 	public void setEnableAnonymousUsername(boolean enableAnonymousUsername) {
 		this.enableAnonymousUsername = enableAnonymousUsername;
 	}
 
 }