Soothe Bell implementation - StepHappiness

StepHappiness::
; Raise the party's happiness by 1 point every 512 steps.

    ld hl, wHappinessStepCount
    inc [hl]
    ld a, [hl]
    and 1
    ret nz

    ld de, wPartyCount
    ld a, [de]
    and a
    ret z

    ld c, a
    ld hl, wPartyMon1Happiness
.loop
    inc de
    ld a, [de]
    cp EGG
    jr z, .next
    inc [hl] ; increase happiness
    jr nz, .doIncrement
    dec [hl]
    jr .next

.doIncrement
    push hl
    push bc
    ld bc, MON_ITEM - MON_HAPPINESS
    add hl, bc
    pop bc
    ld a, [hl]
    pop hl
    cp SOOTHE_BELL
    jr nz, .next

    inc [hl]
    jr nz, .next
    dec [hl]
.next
    push de
    ld de, PARTYMON_STRUCT_LENGTH
    add hl, de
    pop de
    dec c
    jr nz, .loop
    ret