/** 
 * Project    : KANT (LMT)
 * Source Name: User.java
 * Copyright  : Copyright (c) LTI, Carnegie Mellon University
 * Description: Class for user
 * @version     1.0 (created by jko - 10/01/01)
 **/

package lmt;

import java.sql.*;
import java.util.*;

public class User {
  String username;
  String passwd;
  String description;
  String usergroup;
  public SQLConnection con;
  Session session;
	
  /** constructor 
   **/
  public User(SQLConnection con, String username, String passwd) {
    this.username = username;
    this.passwd = passwd;
    this.con = con;
    description = "";
    usergroup = "";
    session = new Session("", con);
  }
	
  public User(SQLConnection con) {
    this (con, "", "");
  }
		
  // setters & getters
  public String getUserName() {
    return username;
  }	
  public void setUserName(String username) {
    if ( username == null )
      username = "";
    this.username = username;
  }	
  public String getPasswd() {
    return passwd;
  }	
  public void setPasswd(String passwd) {
    if ( passwd == null )
      passwd = "";
    this.passwd = passwd;
  }	
  public String getGroup() {
    return usergroup;
  }	
  public void setGroup(String g) {
    if ( g == null )
      g = "";
    this.usergroup = g;
  }	
  public String getDescription() {
    return description;
  }	
  public void setDescription(String d) {
    if ( d == null )
      d = "";
    this.description = d;
  }		

  /** login to the database
   * @return integer representing the result of operation
   **/	
  public boolean login() {
    boolean success = false;
    int ret = 0;
    String session_id = "";
		
    if ( con == null || !con.connect()) {
      Debug.debug("-- login: connnection is null or not connected - " + con);
      return false;
    }
    // start transaction
    con.setAutoCommit(false);	
    con.setTransactionIsolation(Connection.TRANSACTION_SERIALIZABLE);
			
    // check username and password
    String sql = "SELECT * FROM LMT_USER_LISTS";
    sql += " WHERE username = '" + username + "'";
    sql += " AND passwd = '" + passwd + "'";

    SQLConnection.Result r = con.query(sql);
    if (r!=null && r.hasData())
      success = true;
    if (r!=null) r.close();

    // get a new session id
    if ( success ) {
      sql = "SELECT SESSION_ID.NEXTVAL FROM DUAL"; 
      try {		
	r = con.query(sql);
	if (r!= null && r.hasData())		
	  session_id = r.rs.getString(1);			
	else
	  success = false;	
	if ( r!=null) r.close();
      } catch (SQLException E) {
	Debug.debug("login SQLException: " + E.getMessage());
	success = false;
      }	
    }
		
    // create a session
    if ( success ) {
      sql = "INSERT INTO LMT_SESSIONS VALUES ('" + session_id + "','";
      sql += username + "', SYSDATE )";
      //Debug.debug("-- login:" + sql);	
      ret = con.update(sql);	
      if (ret != 1) 
	success = false;
    }

    // close transaction	
    if ( success ) {
      con.commit();	
      session.setSessionID(session_id);
    } else {
      con.rollback();
    }
		
    con.setAutoCommit(true);
    return success;
  }
  /** login to the database
   * @return integer representing the result of operation
   **/	
  public boolean adminLogin() {
	
    if ( con == null || !con.connect()) {
      Debug.debug("-- login: connnection is null or not connected - " + con);
      return false;
    }
			
    // check username and password
    String sql = "SELECT * FROM LMT_USER_LISTS";
    sql += " WHERE username = '" + username + "'";
    sql += " AND passwd = '" + passwd + "'";
    sql += " AND usergroup = 'admin'";
		
    boolean success = false;
    SQLConnection.Result r = con.query(sql);
    if (r!=null) {
      if (r.hasData()) success = true;
      r.close();
    }

    return success;
  }
	
  public void logout() {
    // delete a session
    if ( session != null ) {
      String sql = "DELETE FROM LMT_SESSIONS WHERE session_id = '" + session.getSessionID() + "'";
      //Debug.debug("-- logout:" + sql);	
      int ret = con.update(sql);	
      //Debug.debug("++++ ret: " + ret);
    }
  }
	
  public Session getSession(){
    return session;	
  }
	
  public static Vector fetchUsers(SQLConnection con) {

    String sql = "SELECT username, passwd, usergroup, description FROM LMT_USER_LISTS order by username";
    Debug.debug("-- " + sql);	
		
    Vector userlist = new Vector();

    try {				
      SQLConnection.Result r = con.query(sql);

      while (r!=null && r.hasData()) {
	User user = new User(con);
	user.setUserName(r.rs.getString(1));
	user.setPasswd(r.rs.getString(2));
	user.setGroup(r.rs.getString(3));
	user.setDescription(r.rs.getString(4));
	userlist.addElement(user);
      }
      if (r!=null) r.close();
    } catch (SQLException E) {
      Debug.debug("login SQLException: " + E.getMessage());
    }	
		
    return userlist;
  }
	
  /** insert the data into the table.
   * @return integer representing the result of operation
   **/		
  public int insert() {

    // check where this exists
    if (isExistent())
      return Constants.DUPLICATION;		
		
    String sql = "INSERT INTO LMT_USER_LISTS ";
    sql += "(username, passwd, usergroup, description)  VALUES (";
    sql += "'" + username + "',";
    sql += "'" + passwd + "',";
    sql += "'" + usergroup + "',";
    sql += "'" + description + "')";

    Debug.debug("-- User insertion : " + sql);		
		
    return con.insert(sql);
  }
	
  /** delete the data from the table.
   * @return integer representing the result of operation
   **/	
  public int delete() {
    // check where this exists
    if (!isExistent())
      return Constants.DONOTEXIST;
		
    String sql = "DELETE FROM LMT_USER_LISTS ";
    sql += " WHERE username = '" + username + "'";
		
    Debug.debug("-- User delete : " + sql);		
		
    return con.delete(sql);
  }
	
  /** update the data in the table.
   * @return integer representing the result of operation
   **/	
  public int update() {
    // check where this exists
    if (!isExistent())
      return Constants.DONOTEXIST;
    String sql = "UPDATE LMT_USER_LISTS SET ";
    sql += "passwd = '" + passwd +"', ";
    sql += "usergroup = '" + usergroup +"', ";
    sql += "description = '" + description +"' ";
    sql += "WHERE username = '" + username + "'";
		
    Debug.debug("-- User update : " + sql);		
		
    return con.update(sql);
  }

  /** check whether the information exists or not in the database using username
   * @return boolean representing the result of operation
   **/	
  public boolean isExistent() {
		
    String sql = "SELECT * FROM LMT_USER_LISTS WHERE ";
    sql += " username = '" + username + "'";
		
    Debug.debug("-- isExistent : " + sql);	
    return con.isExistent(sql);
  }
	
}