program satscore;
uses crt;

const
maxstudents = 9;

var
students : array[1..maxstudents] of string[20];
scores : array[1..2,1..maxstudents] of integer;
x : integer; { misc int }
y : char; { misc char }
sat : text;
fexist : boolean;


procedure input;

begin

writeln;
writeln ('Student number ',x,' :');
write ('Name   : ');
readln (students[x]);
repeat
write ('Verbal : ');
readln (scores[1,x]);
until (scores[1,x] >= 400) and (scores[1,x] <= 800);
repeat
write ('Math   : ');
readln (scores[2,x]);
until (scores[2,x] >= 400) and (scores[2,x] <= 800);

end;


procedure output;

begin

writeln;

if students[x] <> '' then begin

writeln ('Student number ',x,' :');
writeln ('Name   : ',students[x]);
writeln ('Verbal : ',scores[1,x]);
writeln ('Math   : ',scores[2,x]);

end else writeln ('Student number ',x,' : Empty');

if wherey > 20 then begin
writeln;
write('Please press any key');
y := readkey;
clrscr;
end;

end;


procedure slots_full;
var m:integer;

begin

x := 0;
for m := 1 to maxstudents do if students[m] <> '' then x := x + 1;

end;


procedure convert;

begin

case y of
'1' : x := 1;
'2' : x := 2;
'3' : x := 3;
'4' : x := 4;
'5' : x := 5;
'6' : x := 6;
'7' : x := 7;
'8' : x := 8;
'9' : x := 9;
'0' : x := 0;
else y := #1;
end;

end;


procedure FileExists(filename: string);

begin
{$I-}
Assign(sat, filename);
Reset(sat);
Close(sat);
{$I+}
fexist := (IOResult = 0) and (filename <> '');

end;


begin

fexist := false;
for x := 1 to maxstudents do students[x] := '';

repeat

slots_full;

clrscr;
gotoxy (36,2);
textcolor (green); write ('MAIN MENU'); gotoxy (29,4); textcolor (blue);
write ( x,' out of ',maxstudents,' data slots full'); gotoxy (25,5); textcolor (9);
write ('[A]dd a student'); gotoxy (25,6);
write ('[C]hange an existing student''s info'); gotoxy (25,7);
write ('[D]elete an existing student'); gotoxy (25,8);
write ('Delete all [E]xisting students'); gotoxy (25,9);
write ('View [O]ne student'); gotoxy (25,10);
write ('[V]iew all students'); gotoxy (25,11);
write ('[S]ave current data'); gotoxy (25,12);
write ('[L]oad data from a previous session'); gotoxy (25,13);
write ('or [Q]uit?'); gotoxy (29,16);
write ('Please enter a letter : ');  textcolor (7);
repeat
y := upcase(readkey);
until (y = 'A') or (y = 'C') or (y = 'D') or (y = 'E') or (y = 'O') or (y = 'V') or (y = 'S') or (y = 'L') or (y = 'Q');
clrscr;
writeln;
writeln;

case y of

'A' : begin
x := 0;
repeat
x := x + 1;
until (students[x] = '') or (x = maxstudents + 1);
if x <> maxstudents + 1 then begin
input;
end else begin
writeln ('You don''t have any more data slots left');
y := readkey;
end;
end;

'C' : begin
write ('Which student''s information do you want to change?');
repeat
y := readkey;
convert;
until y <> #1;
writeln;
writeln;
if students[x] <> '' then begin
writeln;
writeln ('Old data :');
output;
writeln;
writeln ('New data :');
input;
end else begin
writeln ('You don''t currently have data for that student number. To add a new student,');
writeln ('press ''A'' at the main menu.');
y := readkey;
end;
end;

'D' : begin
write ('Which number data slot do you want to delete?');
repeat
y := readkey;
convert;
until y <> #1;
writeln;
writeln;
if students[x] <> '' then begin
students[x] := '';
writeln ('Data slot ',x,' erased');
end else writeln ('That slot is already empty');
y := readkey;
end;

'E' : begin
writeln ('Are you sure you want to delete all of your data?');
write ('(Y or N)');
repeat
y := upcase(readkey);
until (y = 'Y') or (y = 'N');
if y = 'Y' then begin
for x := 1 to maxstudents do students[x] := '';
writeln;
writeln;
writeln ('Data Erased');
y := readkey;
end;
end;

'O' : begin
write ('What is the number of the student you want to look at?');
repeat
y := readkey;
convert;
until y <> #1;
writeln;
writeln;
output;
if wherey <= 20 then y := readkey;
end;

'V' : begin
clrscr;
for x := 1 to maxstudents do output;
if wherey <= 20 then y := readkey;
end;

'S' : begin
writeln ('Do you want to save the data that you have been working on?');
write ('(Y or N)');
repeat
y := upcase(readkey);
until (y = 'Y') or (y = 'N');
if y = 'Y' then begin
rewrite(sat);
for x := 1 to maxstudents do begin
writeln(sat,students[x]);
writeln(sat,scores[1,x]);
writeln(sat,scores[2,x]);
end;
close(sat);
writeln;
writeln;
writeln ('Data Saved');
fexist := true;
y := readkey;
end;
end;

'L' : begin
fileexists('data.$$$');
if fexist then begin
writeln ('Do you want to load your saved data?');
writeln ('It will overwrite any data you have loaded right now.');
write ('(Y or N)');
repeat
y := upcase(readkey);
until (y = 'Y') or (y = 'N');
if y = 'Y' then begin
reset(sat);
for x := 1 to maxstudents do begin
readln(sat,students[x]);
readln(sat,scores[1,x]);
readln(sat,scores[2,x]);
end;
close(sat);
writeln;
writeln;
writeln ('Data Loaded');
y := readkey;
end;
end else begin
writeln ('You do not have any saved data to load');
y := readkey;
end;
end;

end;

until (y = 'Q');

clrscr;

end.