;;;; raylib [core] example - window should close
;;;;
;;;; examples/core/core_window_should_close.c. Needed set-exit-key, and one
;;;; enum member to go with it: raylib.fln's `Key` now has `null 0`, read off
;;;; KEY_NULL in raylib.h. The binding is hand-written rather than taken from
;;;; the generated half because the Flan face differs — raylib declares
;;;; `void SetExitKey(int key)` and the generated line therefore takes an i32,
;;;; where this one takes a Key, so `rl/set-exit-key(:key-null)` is checked
;;;; against the enum and `:nul` is a compile error instead of a 0.
;;;;
;;;; The whole example is about what window-should-close means. It is not a
;;;; flag raylib latches: it is "the close button was clicked, or the exit key
;;;; is down", recomputed each frame, and it goes back to false on its own.
;;;; That is what lets this program ask for confirmation and then carry on —
;;;; and it is also why the loop is driven by a `once` of its own rather
;;;; than by the predicate, which is the one structural difference from every
;;;; other example in this directory.
;;;;
;;;; `set-exit-key(:null)` takes ESC away from raylib so the program can read
;;;; it itself. The window's X button still works and is still what
;;;; window-should-close reports.

import rl "vendor:raylib"

const screen-width = 800
const screen-height = 450

once exit-requested: bool
once exiting: bool

fn main() -> ()
  rl/init-window(screen-width, screen-height,
                 "raylib [core] example - window should close")
  defer rl/close-window()
  ;; No key closes the window any more. ESC is an ordinary key from here on.
  rl/set-exit-key(:key-null)
  rl/set-target-fps(60)
  until exiting
    ;; Update. Either way of asking to leave raises the question; only Y and N
    ;; answer it. window-should-close is false again on the next frame, so
    ;; the request has to be remembered in a variable.
    if rl/window-should-close() or rl/is-key-pressed(:key-escape)
      exit-requested = true
    ;; The C's `if (Y) ... else if (N) ...`, which is an `if` with a `when`
    ;; in its else and not a `cond`: a `cond` needs an `:else` arm and there
    ;; is nothing to do when neither key was pressed.
    if exit-requested
      if rl/is-key-pressed(:key-y)
        exiting = true
      elif rl/is-key-pressed(:key-n)
        exit-requested = false
    ;; Draw
    rl/with-drawing:
      rl/clear-background(rl/raywhite)
      if exit-requested
        rl/draw-rectangle(0, 100, screen-width, 200, rl/black)
        rl/draw-text("Are you sure you want to exit program? [Y/N]", 40, 180,
                     30, rl/white)
      else
        rl/draw-text("Try to close the window to get confirmation message!",
                     120, 200, 20, rl/lightgray)