program lab9_10;
uses crt;

label main;

type
student = record
    name: string[64];
    result: integer;
    group_number: integer;
    count_students: integer;
end;

var
    file_name: string;
    file_object: file of student;

    select_char: char;

    group_number: integer;
    count_students: integer;
    students: array [1..64] of student;

procedure setwindowstyles;
begin
    clrscr;
    textbackground(7);
    clrscr;
    window(1,1,80,1);
    textbackground(3);
    clrscr;
    textcolor(0);
    clrscr;
end;

procedure writetowindow(x, y: integer; text: string);
begin
    gotoxy(x,y);
    write(text);
end;

procedure enterfilename;
begin
    clrscr;
    window(2,1,79,25);
    textbackground(7);
    textcolor(5);
    clrscr;

    write('Enter file name: ');
    readln(file_name);
end;

procedure writetofile;
var
    i: integer;
begin
    assign(file_object, file_name);
    rewrite(file_object);

    for i := 1 to count_students do
    begin
        students[i].group_number := group_number;
        students[i].count_students := count_students;

        write(file_object, students[i]);
    end;

    close(file_object);
end;

procedure readfromfile;
var
    i: integer;
    tmp: student;
begin
    assign(file_object, file_name);
    reset(file_object);

    i := 1;

    repeat
        read(file_object, tmp);

        students[i].name := tmp.name;
        students[i].result := tmp.result;
        students[i].group_number := tmp.group_number;
        students[i].count_students := tmp.count_students;

        group_number := tmp.group_number;
        count_students := tmp.count_students;

        i := i + 1;
    until EOF(file_object);

    close(file_object);
end;

procedure input;
var
    i: integer;
begin
    clrscr;
    window(2,1,79,25);
    textbackground(7);
    textcolor(5);
    clrscr;

    write('Enter group number: ');
    readln(group_number);

    write('Ender number of students: ');
    readln(count_students);

    for i := 1 to count_students do
    begin
        write('Enter full name: ');
        readln(students[i].name);

        write('Enter time in seconds: ');
        readln(students[i].result);
    end;
end;

procedure output;
var
    i: integer;
    average: real;
begin
    clrscr;
    window(1, 1, 79, 25);
    textbackground(3);
    textcolor(0);
    clrscr;

    gotoxy(20,1);
    write('running results for 100m of group number ', group_number, '.');

    window(3, 3, 78, 23);
    textbackground(7);
    textcolor(0);

    clrscr;
    writetowindow(2, 1, '#');
    writetowindow(5, 1, 'Student full name');
    writetowindow(47, 1, 'Time in sec');

    for i := 1 to count_students do
    begin
        gotoxy(2, 2 + i);
        write(i, '.');

        gotoxy(5, 2 + i);
        write(students[i].name);

        gotoxy(50, 2 + i);
        write(students[i].result);
    end;

    gotoxy(20, 4 + count_students);
    textcolor(0 + 128);

    average := 0;

    for i := 1 to count_students do
    begin
        average := average + students[i].result;
    end;

    if (count_students <> 0) then average := average / count_students;

    writeln('average time of students: ', average:4:2, ' sec.');

    repeat
        window(24, 20, 56, 20);
        textbackground(9);
        clrscr;
        i := random(10) + 1;
        textcolor(i);
        write('  GOOD LUCK IN COMPETITIONS !!!');
        delay(10);
    until keypressed;
end;

begin
    enterfilename;

    main:

    setwindowstyles;

    writetowindow(3, 1, 'i - input');
    writetowindow(34, 1, 'o - output');
    writetowindow(66, 1, 'esc - exit');

    repeat
        select_char := readkey;

        case select_char of
            #105: begin
                input;

                writetofile;

                clrscr;
                goto main;
            end;
            #111: begin
                readfromfile;

                output;

                clrscr;
                goto main;
            end;
        end;
    until select_char = #27;

    clrscr;
end.