Due:

In this assignment you get to learn a little C++ and practice some of the design skills you've been learning all semester. You will build a small version of a trouble ticket system, like the one in use here in the department which is invoked when you send email to operator asking for system assistance.

Our ticket system has three actors: administrator, operator and submitter. Here's how your program should behave when it's all done:

% ts       // main() is in the executable ts
ts-login> administrator
	display current status of the ticket system: 
	number of tickets currently on the queue
	number of closed tickets
	return to login prompt

ts-login> operator
	if there are no tickets in the ticket queue
		report that fact
	else
		get the next ticket from the queue
		  (high priority before medium before low)
		print the ticket information
		add the ticket to the set of closed tickets
	return to login prompt

ts-login> submit
user name: eb  // user responds to prompt
priority: high // allow high, medium and low
description: whatever // any single line of text
	assign a ticket number
	put a time stamp on the ticket
	add the ticket to the ticket queue
	return to login prompt

ts-login> quit
%

• the current time
• the ticket number
• the user who submitted the ticket
• the priority
• the time at which the ticket was submitted
• the description

Your job is to write C++ code implementing the ticket system. Here are some design tips.

• Help each other out. Ask and answer questions on the forum. If you discover something cool or useful post it even if no one has asked about it.

• Start by making yourself a few CRC cards for the classes you think you will need, their responsibilities and collaborators.

• Remember that this is a very small application. You're writing it to learn C++, not to make your fortune in a startup company. Don't do more than I've asked for. Save your thoughts about improvements you might make for your memo.

• Write a makefile and keep it up to date.

• Write tests before you write code. Automate them using i/o redirection. Make tests targets in your makefile.

• Think of ts (for "ticketsystem") as the view and controller. All i/o goes there. Build a clean model, with just the right number of classes. One is not enough, and six is almost certainly too many. Use header files to share API information between classes.

• Leverage the libraries. Use what C++ provides for string handling and for containers. Don't write C gussied up to look like C++. Don't even think of writing a linked list or using an array. You should be able to find out what you need to know from Lippman (use the index) or using Google.

• Build and test incrementally. End each coding session with an application that works even if it doesn't meet all the requirements. For example, you might start by building a ticketsystem driver that lets the three actors log in, reporting successful logins but doing nothing else.

• Keep your code and your memo up to date. Refactor as needed. Don't wait until the end to "add the comments."

• Consider a preliminary implementation that uses a queue rather than a priority queue to store open tickets. If it's hard to make the timestamps work, ignore them until the end.

• Persistence. It's OK for all the submitted tickets to vanish when you shut the program down.

• Error handling. Don't bother checking for faulty input to any of the prompts.