/*
 * DbBaseConnect.java
 */
package uw.ischool.info340.labs;

import javax.naming.*;
import javax.sql.*;
import java.sql.*;

public class DbBaseConnect
{
  /* CHECK that this connection string is right 
   *    a) dhendry == is the name of the database 
   *    b) 5432 is the port number -- it is optional
   *    c) linux.ischool.washington.edu -- is the name of the host 
   */
  private static String cDB_URL_STRING		= 
        "jdbc:postgresql://linux.ischool.washington.edu:5432/dhendry";
  
  /*
   * NOTE: Check that the user ID and password are correct 
   */
  private static String cUserID			= "dhendry";
  private static String cUserPassword		= "bluemonster";
  
  /* This is the name of the JDBC driver for using postgresql */
  private static String cDRIVER_STRING  	= "org.postgresql.Driver";

  /* Holds the connection to database -- created by init() */
  /* By default, transactions are auto-committed */
  /* NOTE: Subclasses will need to use this BUT not clients */ 
  protected Connection conn = null;

  /* 
   * Used to hold error messages 
   */
  protected String debugString; 
  
  /* 
   * Returns of a string containing basic information about the connection 
   */ 
  private String _getConnInfo()
  {
	String  t	 = "["; 
		t       += "Driver:" 	+ cDRIVER_STRING 	+ ";";
		t 	+= "DB URL: " 	+ cDB_URL_STRING 	+ ";";
		t 	+= "UserID: " 	+ cUserID 		+ ";";
		t 	+= "Password: " + cUserPassword		+ ";";
		t       +=  "]<p>" + debugString;
	return t;
  }

  /**
   * Returns information about the connection 
   */
  public String getConnectInfo() 
  {
	  if (conn != null) 
		  return "Connection up! " + _getConnInfo();
	  else
		  return "Connection DOWN " + _getConnInfo();
  }
  
  /**
   * Return true if the connection has been initialized
   */
  public boolean isConnected() {
      return (conn == null) ? false : true; 
  }

/*
 *  Subclasses MUST call this to initialize the connection 
 */
  public void init() {
    
   // Already initialized 
    if (conn != null) {
        return; 
    }
    
    try {
      /* This statement implicitly loads the driver */
      Class.forName(cDRIVER_STRING);

      /* Now, attempt to create a connection */
      conn = DriverManager.getConnection(cDB_URL_STRING,cUserID,cUserPassword);

      if (conn == null) 
	throw new Exception("Could not connect to " + getConnectInfo());
    }
    catch(Exception e) {
      debugString = e.toString();
      e.printStackTrace();
    }
  }
}