==== STUDENT HUB ====

This code is for an application with three menus:

• the hub ( for timetables + to-dos );
• the timer ( with pomodoro timer );
• the record ( for keeping record of your grades as well as simulate future averages).

This code will be produced in RUST;
This code will first be created for terminal I/O -> then converted to a file output ( database only ) -> then converted to an UI using websockets & HTML / CSS.
This page will hold info on the files of the project, as well as functions, with their expected inputs and outputs, errors and goals.

Structs

to-do list item - struct with vec of structs:to-do, title, to-do counter and dones counter;
to-do items - struct with name, done/not done;

subject item - struct with name, ects, s/t and grade;
year item - struct with name, vec of structs:subjects, average;

program - struct with name of menu it is currently in; 

Functions

TODO

create_todo_list(list_name: String) -> To-do List ;
    - Creates a to-do list with the title 'list_name', progress counter = 0, to-do counter = 0, todos = [].

delete_todo_list(list: To-do List) -> () ;
    - Deletes 'list'; 

add_todo(list: &mut To-do List, todo: String) -> () ; 
    - Creates a to-do item with the name = 'todo', done/not_done = 0 (false) in 'list'.

delete_todo(list: &mut To-do List, todo: String) -> () ;
    - Deletes 'todo' item inside 'list'.

check_todo(list: &mut To-do List, todo: String) -> () ;
    - Checks 'todo' item inside 'list'.

uncheck_todo(list: &mut To-do List, todo: String) -> () ;
    - Unchecks 'todo' item inside 'list'.

show_progress_list(list: &To-do List) -> f32 ;
    - Shows progress (percentage of checked) of 'list'.

print_todo_list(list: To-do List) -> () ; 
    - Prints contents of 'list'.

GRADES

create_year(name: String) -> Year ; 
    - Creates year with the name 'name', todos = [], average = 0.00.

delete_year(year: Year) -> () ; 
    - Deletes 'year';

create_subject(year: Year, subject: String, credits: u8, sim: bool, grade: u8) -> Year ; 
    - Creates subject inside 'year' with name = 'subject', ects = 'credits', s/t = 'sim', grade = 'grade'.

edit_grade(year: &mut Year, subject: String, grade: u8) -> () ;
    - Edits 'grade' from 'subject' in 'year' to the new value. 

edit_sim(year: Year, subject: String, sim: bool) -> Year ; 
    - Edits simulation from 'subject' in 'year' to the new value. 

delete_subject(year: Year, subject: String) -> Year ; 
    - Deletes 'subject' in 'year'.

yearly_average(year: &Year) -> f32 ; 
    - Calculates yearly average from 'year'. 

total_average(years: &[Year]) -> f32 ;
    - Calculates total average of 'years'.

print_year(year: Year) -> () ; 
    - Prints contents of 'year'.

PROGRAM

choose_menu(program: &mut Program, menu: String) -> () ;
    - Chooses what menu it is in ( To-do, Grades ); 

show_menu(program: Program) -> () ; 
    - Displays the name of the menu it is currently in; 

end(program) -> () ;
    - Terminates Program