import org.omg.CORBA.*;
import org.omg.CosNaming.*;
import org.omg.CosNaming.NamingContextPackage.*;
import ssd8exercise5creator.*;
import ssd8exercise5.*;
import java.io.*;
import java.util.*;

/**
 * class <em>TodolistInterfaceImpl</em> represents the implementation 
 * of the remote methods defined in <em>TodolistInterface.idl</em>
 *
 * @author iCarnegie (VP)
 * @version 1.0
 */

public class TodolistInterfaceImpl extends _TodolistInterfaceImplBase {
    
    private String username, password;
    
    /*
     * The to do list is represented as a Vector of
     * object of class ListItem.
     */
    private Vector toDoList;

    /*
     * Keep track of the item ids in this to do list.
     */
    int itemId = 0;

    /**
     * class <em>TodolistInterfaceImpl</em> constructor.
     */
    public TodolistInterfaceImpl( String inUserName, String inPassWord ) {
	username = inUserName;
	password = inPassWord;
	toDoList = new Vector();
    }

    /*
     * parseTime parses a string of the form date-time (12/22/2003-12:45)
     * and returns a <em>java.util.GregorianCalendar</em> object corresponding
     * to the input time string.
     * @param input String input time
     * @return java.util.GregorianCalendar
     */
    private GregorianCalendar parseTime( String inputTime ) {
	
	/*
	 * Tokenize the start_time into date and time
	 * based on the '-' character.
	 */
	StringTokenizer paramTokenizer = new StringTokenizer( inputTime, "-" );
	String tempDate = paramTokenizer.nextToken();

	/*
	 * Tokenize the date based upon the '/' character.
	 */
	StringTokenizer dateTokenizer = new StringTokenizer( tempDate, "/" );
	int mon = Integer.parseInt( dateTokenizer.nextToken() );
	int day = Integer.parseInt( dateTokenizer.nextToken() );
	int year = Integer.parseInt( dateTokenizer.nextToken() );
	String tempTime = paramTokenizer.nextToken();
	dateTokenizer = new StringTokenizer( tempTime, ":" );
	int hour = Integer.parseInt( dateTokenizer.nextToken() );
	int min = Integer.parseInt( dateTokenizer.nextToken() );
	
	/*
	 * Create a new GregorianCalendar based on the parsed out
	 * start time values.  
	 */
	return new GregorianCalendar( year, mon, day, hour, min );
    }
    
    /**
     * Authenticate a user.
     * @param username String name of user
     * @param password String password of user
     * @return boolean true if authenticate succeeds, false otherwise
     */
    private boolean authenticate (String inUserName, String inPassWord ) {
	if ( username.equals(inUserName) && password.equals(inPassWord) ) {
	    return true;
	} else {
	    return false;
	}
    }

    /**
     * Implementation of the add function.
     * @param username String username of user
     * @param password String password of user
     * @param startTime String start time of list item
     * @param endTime String end time of item
     * @param description String description of the item
     * @return boolean indicating success of addition
     */
    public boolean add( String username, String password, String startTime, String endTime, String description ) {	

	/*
	 * Try to authenticate the user.
	 */
	if (!authenticate(username, password)) {
	    return false;
	}

	GregorianCalendar start = parseTime( startTime );
	GregorianCalendar end = parseTime( endTime );
	if (end.before(start)) {
	  return false;
	}

	/*
	 * Create a new ListItem to add to the to do list.
	 */
	ListItem newItem = new ListItem( ++itemId, start, end, description );

	/*
	 * If we have made it to here, then the item must have been acceptable,
	 * so, add it to the Vector of list items and return true.
	 */
	toDoList.add( newItem );
	return true;
    }

    /**
     * Implementation of query function.
     * @param startTime String start time of the interval
     * @param endTime String end time of the interval
     * @param username String username of the person who added the item
     * @param password String password of the person who added the item
     * @return String string representation of each list item.
     */
    public String query( String name, String password, String startTime, String endTime ) {
	
	if (!authenticate( name, password )) {
	    return null;
	}

	StringBuffer matches = new StringBuffer();
	GregorianCalendar start = parseTime( startTime );
	GregorianCalendar end = parseTime( endTime );

	/*
	 * Enumerate through the vector of items and add the item
	 * that match to the return vector.
	 */
	Enumeration items = toDoList.elements();
	
	while( items.hasMoreElements() ) {
	    /*
	     * Get the next element from the enumeration.
	     */
	    ListItem tempItem = (ListItem) items.nextElement();

	    /*
	     * See if tempItem falls in the given time range
	     * and was called by the input name or is to be attended by 
	     * the input name.  If it was, add it to the return vector.
	     */
	    if ( (tempItem.getItemStart().after(start)) && 
		 (tempItem.getItemEnd().before(end))) {
		matches.append(tempItem.toString() + "\n" );
	    }
	}
	return matches.toString();
    }
    
    /**
     * Implementation of delete function.
     * @param username String user name of user
     * @param password String password of user
     * @param itemId int id of item to delete
     * @return boolean indicating success of delete
     */
    public boolean delete( String username, String password, int itemId ) {
	
      int index = -1;
      boolean found = false;
      
      /*
       * Try to authenticate the user.
       */
      if (!authenticate(username, password)) {
	return false;
      }
      
      /*
       * Iterate through an enumeration of 
       * the vector of items and remove the one that
       * with id itemId.
       */
      Enumeration items = toDoList.elements();
      ListItem tempItem = null;
      
      while( items.hasMoreElements() ) {
	/*
	 * Get the next element from the enumeration.
	 */
	tempItem = (ListItem) items.nextElement();

	/*
	 * Increment the index and see if the item we have
	 * just gotten from the enumeration matches the id 
	 * we are searching for.
	 */
	if (tempItem.getId()==itemId) {
	  found = true;
	  break;
	}
      }
      /*
       * If we have found what we are looking for, remove it and return 
       * true;
       */
      if ( found ) {
	toDoList.remove( tempItem );
	return true;
      }
      
	/*
	 * If we have made it to here, then the item was not found, so return false.
	 */
      return false;
    }

    /**
     * Implementation of clear function.
     * @param username String user name of user
     * @param password String password of user
     * @return boolean indicating success of the clear
     */
    public boolean clear( String username, String password ) {
	
	/*
	 * Try to authenticate the user.
	 */
	if (!authenticate(username, password)) {
	    return false;
	}

	/*
	 * Reset the the to do list to a new 
	 * vector.
	 */
	toDoList = new Vector();
	return true;
    }
}