const
	Add = 'a';
	Subtr = 's';
	Mult = 't';
	Divide = 'd';
	Quit = 'x';
        Rndm = 'r';
	Specific = 'p';
	MRec = 'n';
	DRec = 'w';

	numstud = 10;

type
        Ttestrec = record
                name : string;
                number  : integer;
                correct_answers : integer;
                num_questions : integer;
        end;

var
op_choice 	: char;
op1		: integer;
op2		: integer;
op		: string;
answer	: integer;
correct	: integer;
tt_choice : char;
numq : integer;
n    : integer;
numright : integer;
rm_choice : integer;
mm_choice : integer;
studrec : Ttestrec;

procedure proc_exit;
begin
	writeln('Bye bye');
end;


procedure display_mmenu;
begin
	writeln('1 to go to the record menu');
	writeln('2 to take a test');
	writeln('3 to exit');
	readln(mm_choice);
end;
 
procedure display_opmenu;
begin
	writeln('m for main menu');
	writeln('a to add two numbers');
	writeln('s to subtract one number from another');
	writeln('t to multiply two numbers');
	writeln('d to divide one number by another');
	writeln('x to exit');
	write('choice >');
	readln(op_choice);
end;

procedure random_operator;
var
rnd_op : integer;
begin
	randomize;
	rnd_op := random(4);
	case rnd_op of
	1: op_choice :='a';
	2: op_choice :='s';
	3: op_choice :='t';
	4: op_choice :='d';
end;
end;

procedure display_testtype_menu;
begin

	writeln('r for random operators');
	writeln('p for specified operators');
	write('choice >');
	readln(tt_choice);
	case tt_choice of
	Rndm: 
		random_operator;
	Specific:
		display_opmenu;
	end;

end;


{procedures to set the operators and operand - can be replaced later with the
random operator selector}

procedure proc_add;
begin
	op1 := random(50);
	op2 := random(50);
	op 	:= '+';
	correct := op1 + op2;
end;

procedure proc_subtr;
begin
	op1 := random(100);
	op2 := random(op1);
	op	:= '-';
	correct := op1 - op2;
end;

procedure proc_mult;
begin
	op1 := random(12);
	op2 := random(12);
	op 	:= '*';
	correct := op1 * op2
end;

procedure proc_div;
{ divide procedure not yet fixed }
begin
	op1 := random(144);
	op2 := random(12);
	op 	:= '/';
	{correct := op1 / op2};
	correct := 3;
end;

{ask the question and respond according to whether the answer given is correct}

procedure ask_question;
begin
	writeln('Question ',n, ' of ',numq,':');
	writeln(op1,op,op2,' = ');
	readln(answer);
	if answer = correct then
		begin
			numright := numright+1;
			writeln(answer,' is correct.');
		end
	else
		writeln('Incorrect. The correct answer is ', correct);
end;


procedure many_questions;
begin
	numright := 0;
	writeln('How many questions?');
	readln(numq);
	begin
		case op_choice of
        	Add: 
		begin
			for n := 1 to numq do
				begin
				proc_add;
				ask_question;
				end;
		end;
		
       		Subtr:
       		begin
			for n := 1 to numq do
				begin
				proc_subtr;
				ask_question;
				end;
		end;
		Mult:
		begin
			for n := 1 to numq do
				begin
				proc_mult;
				ask_question;
				end;
		end;
       		Divide:
			for n := 1 to numq do
				begin
				proc_div;
				ask_question;
				end;
       		Quit: proc_exit;
        	end;
	end;
end;	

procedure display_score;
begin
	writeln('----------------------------');
	writeln('You got ',numright,' correct out of ',numq,' questions.');
	writeln('Press enter to return to menu');
	readln;
end;

procedure record_menu;
begin
{while rm_choice <> 'x' do}
	writeln('1 to create a new student record');
	writeln('2 to display the record');
	writeln('3 to return');
	write('choice > ');
	readln(rm_choice);
	
	case rm_choice of
	1: 
		begin
		write('Student number: ');
		readln(studrec.number);
		write('Student name: ');
		readln(studrec.name);
		writeln('Record updated. Thank you.');
		end;
	2: 	begin
		writeln('Student number: ',studrec.number);
		writeln('Student name: ',studrec.name);
		writeln('Correct answers: ',studrec.correct_answers);
		writeln('Out of ',studrec.num_questions,' studrec.questions.');
		writeln('Press enter to return to record menu.');
		end;
	end;		
end;

{program starts here}

procedure execute;
begin
        randomize;
        display_mmenu;
        case mm_choice of
        1: begin
		record_menu;
		execute;
	end;
        2: begin
                display_testtype_menu;
                many_questions;
                display_score;
		execute;
        end;
        3: proc_exit;
	end;
end;

begin
	execute;
end;
end.