import java.util.*;
import java.io.*;

// already written  **********************
//     IM( String person ): set up a new im for the person
//     void initialize( String person ): set up the im components for the person
//     ArrayList<String> getFriends(): returns user's im friends
//     ArrayList<String> whoseLoggedOn(): returns user's im online friends
//     String whoami(): returns the name of the person running the im
//     String getXimuLocation(): returns the folder containing the im info
//     void setXimuLocation( String s ): sets the folder containing im info
//     String toString(): returns a text representation of the im
//     void logon(): set status to here
//     void logout(): set status to gone and delete messages

// to be written    **********************
//      boolean isFriend(): return whether person is a friend
//      boolean isLoggedOn( String person ): return whether person is an
//         online friend
//      void initializeFriends(): set up a list of all im friends
//      void updateWhoseOnline(): reset list of online friends
//      void sendMessage( String person, String contents ): if person is a
//         friend; sets the friend's current im message
//      String getMessage( String person ): returns message if person is a 
//         friend; otherwise, returns null

public class IM {

	String ximuFolderLocation;
	String user;
	ArrayList<String> friends;
	ArrayList<String> onlineFriends;

	public static void main( String[] args ) {
		ConsoleIM.main( null );
	}

	// IM(): set ups a new im for the person
	public IM( String person ) {
		this.initialize( person );
	}

	// isFriend(): return whether person is a friend  *****
	public boolean isFriend( String person ) {
		// determine whether person is a friend, if not return false

		return false; // replace with your own code
	}

	// isLoggedOn(): return whether person is an online friend *****
	public boolean isLoggedOn( String person ) {
		// determine whether person is a friend, if not return false

		// determine friend's ximu folder
		
		// try to read status file of friend
		//     no file indicates not logged on
		//     empty file indicates not logged on
		//     file contents do not start with "here" indicates not logged on
		//     file contents start with "here" indicates logged on

		return false; // replace with your own code
	}

	// initializeFriends(): set up a list of all im friends *****
	public void initializeFriends() {
		// first set up an empty list
		this.friends = new ArrayList<String>();

		// now add each person in the friends file to the friend list and
		// send them an empty message ("")

		this.friends.add( "cohoon" ); // replace with your own code
	}

	// updateWhoseOnline(): reset list of online friends *****
	public void updateWhoseOnline() {
		// reset onlist to empty
		this.onlineFriends = new ArrayList<String>();

		// now add each online friend from the friend list to the online list

		this.onlineFriends.add( "cohoon" ); // replace with your own code
	}

	// sendMessage(): sets the current message of the friend to contents *****
	public void sendMessage( String person, String contents ) {
		// determine whether person is a friend, if not return

		// set friend file to contents
	}

	// getMessage(): returns the current message of the friend (if the *****
	// friend is not logged on or has no message for us, returns null
	public String getMessage( String person ) {

		// determine whether person is a friend, if not return null

		// determine friend's logon status
		//     not logged on indicates null return value
		//     logged on but no message indicates null return value
		//     logged on and has message indicates message needs to be read
		//          and returned.

		return "getMessage() not done"; // replace with your own code
	}

	// woe to those who change this code **********************

	// initialize(): sets up the im components
	private void initialize( String person ) {
		this.user = person;
		this.setXimuLocation( person );
		this.initializeFriends();
		this.updateWhoseOnline();
		this.logon();
	}

	public String whoami() {
		return this.user;
	}

	// getFriends(): returns the user's im friends
	public ArrayList<String> getFriends() {
		// hand over friend list
		return this.friends;
	}

	// whoseLoggedOn(): returns the user's online im friends
	public ArrayList<String> whoseLoggedOn() {
		// hand over the logged on list
		return this.onlineFriends;
	}

	// logon(): set status to here
	public void logon() {
		// get the folder for the status file
		String folder = this.getXimuLocation();

		// set up a connection to the status file
		Connection status = new Connection( folder, "status" );

		// get a printer to the file
		PrintStream out = status.getWriter();

		// set contents of status file to "here"
		out.println( "here" );
	}

	// logout(): set contents of status file to "gone" and delete messages
	public void logout() {
		// get the folder for the status file
		String folder = this.getXimuLocation();

		// set up a connection to the status file
		Connection status = new Connection( folder, "status" );

		// get a printer to the file
		PrintStream out = status.getWriter();

		// set contents of status file to "gone"
		out.println( "gone" );

		// get the im friends
		ArrayList<String> list = this.getFriends();
		
		// for each friend, delete the current message
		for ( int i = 0; i < list.size(); ++i ) {
			String friend = list.get( i );
			Connection c  = new Connection( folder, friend );
			c.delete();
		}
	}

	// getXimuLocation(): returns the folder containing the im info
	public String getXimuLocation() {
		return this.ximuFolderLocation;
	}

	// setXimuLocation(): sets the folder containing im info
	public void setXimuLocation( String s ) {
		String os = System.getProperty( "os.name" );
		
		boolean isMac = ( os.indexOf( "Mac" ) == 0 );
		boolean isPC  = ( os.indexOf( "Windows" ) == 0 );

		String location;

		if ( isPC ) {
			location = "J:\\public_html\\ximu\\";
		}
		else if ( isMac ) {
			location = "/Volumes/" + s + "/public_html/ximu/";
		}
		else {
			location = "/home/" + s + "/public_html/ximu/";
		}

		this.ximuFolderLocation = location;
	}

	// toString(): produce a text representation of the instant messenger
	public String toString() {
		String representation = "";

		representation += "IM[ ";
		representation += this.whoami() + ", ";
		representation += this.getXimuLocation() + ", ";
		representation += "friends( " + this.getFriends() + " ), ";
		representation += "online( " + this.whoseLoggedOn() + " ), ";
		representation += " ]";

		return representation;
	}

	// getXimuPage(): returns the name of the web page for the person's ximu
	// account
	public static String getXimuPage( String person ) {
		String base = "http://www.people.virginia.edu/~";

		String page = base + person + "/ximu/";

		return page;
	}
}