using { /Fortnite.com/Devices }
using { /Verse.org/Simulation }
using { /UnrealEngine.com/Temporary/Diagnostics }

# PRESS TO PERFORM — drive a skeletal mesh from Verse.
#
# The Animated Mesh device is the creator-friendly door to skeletal animation.
# You can't hand-build an `animation_sequence` in Verse code (those are
# editor-imported assets, and the play_animation_controller that consumes them
# is epic_internal). What you CAN do is pick a skeletal mesh and an animation
# IN THE EDITOR on an Animated Mesh device, then drive its playback from Verse
# with Play / Pause / PlayReverse.
#
# This device turns one Button into a full transport panel for a posed statue,
# a dancing hologram, a swinging gate — any skeletal mesh you drop on the
# Animated Mesh device. First press plays, next pauses, next reverses, and so on.
skel_performer_device := class(creative_device):

    # The skeletal-mesh performer. Choose its mesh + animation in the editor.
    @editable
    Statue : animated_mesh_device = animated_mesh_device{}

    # One button cycles through Play -> Pause -> Reverse.
    @editable
    ControlButton : button_device = button_device{}

    # Which state the next press should APPLY. Starts at "play".
    var Step : int = 0

    OnBegin<override>()<suspends> : void =
        ControlButton.InteractedWithEvent.Subscribe(OnPress)

    # Each press advances the transport: Play, then Pause, then PlayReverse,
    # then back to Play. The Animated Mesh device remembers its own playhead,
    # so Pause freezes mid-animation and Play resumes from there.
    OnPress(Presser : agent) : void =
        case (Step):
            0 =>
                Statue.Play()
                Print("Animated Mesh: Play")
            1 =>
                Statue.Pause()
                Print("Animated Mesh: Pause (frozen on current frame)")
            _ =>
                Statue.PlayReverse()
                Print("Animated Mesh: PlayReverse")
        # Advance, wrapping 0 -> 1 -> 2 -> 0. Verse has no `%` operator; the
        # built-in Mod[] is the failable modulo (it fails only on divide-by-zero,
        # which can't happen here). The if simply re-binds Step to the result.
        if (Next := Mod[Step + 1, 3]):
            set Step = Next