QMK Leader alt

/*  https://www.reddit.com/r/olkb/comments/plqic8/ctrla_macro_sends_a_7_instead/
 *  Code to include a macro key that is normally alt, but sends CTRL+A on tap.
 *  This goes into keymap.c
 *
 *  If you press another key while LDR_ALT is held down, this code assumes you're using ALT like normal
 *  Otherwise, it will tap CTRL+A if you've held LDR_ALT for less than TAPPING_TERM.
 *  This defaults to 200ms, and can be changed by defining it in config.h with   #define TAPPING_TERM 150
 */

#define LEADER LCTL(KC_A)  //CTRL+A, your leader shortcut

enum custom_keycodes {
    LDR_ALT = SAFE_RANGE, //normally alt, Ctrl+A on tap
    //other macros,
};


bool key_pressed = false;    //variable used to check if a key is pressed while LDR_ALT is held
uint16_t LDR_ALT_timer = 0;  //declare a timer variable to track hold time for LDR_ALT

bool process_record_user(uint16_t keycode, keyrecord_t *record) {
    if (record->event.pressed)
        key_pressed = true;  //if any key is pressed, set key_pressed to true

    switch (keycode) {
        case LDR_ALT:
            if (record->event.pressed) {       //when LDR_ALT is pressed
                register_code(KC_RALT);        //  press right alt
                key_pressed = false;           //  set key_pressed to false
                LDR_ALT_timer = timer_read();  //  mark the time LDR_ALT was pressed
            } else {                           //when LDR_ALT is released
                unregister_code(KC_RALT);      //  release right alt
                if (key_pressed) break;  //  if another key was pressed while alt was held, exit and do not tap leader shortcut

                if (timer_elapsed(LDR_ALT_timer) < TAPPING_TERM) {  //if LDR_ALT was held for less than TAPPING_TERM (default 200ms)
                    tap_code16(LEADER);                             //  tap the LEADER shortcut, LCTL(KC_A) CTRL+A
                }
            }
            break;
    }
    return true;
};