using { /Verse.org/SceneGraph }
using { /Verse.org/SceneGraph/KeyframedMovement }
using { /Verse.org/Simulation }
using { /Verse.org/SpatialMath }
using { /UnrealEngine.com/Temporary/Diagnostics }

# Bolt this onto an entity with a Keyframed Movement component to make it
# PATROL: walk out to a far point, then back, forever — like a guard pacing
# a hallway or a security drone sweeping a vault.
patrol_component := class<final_super>(component):

    # How far the patrol walks before turning back, in units.
    @editable
    var PatrolDistance<public>:float = 600.0

    # Seconds for ONE leg (out OR back).
    @editable
    var LegSeconds<public>:float = 3.0

    OnBeginSimulation<override>():void =
        (super:)OnBeginSimulation()

        if (Mover := Entity.GetComponent[keyframed_movement_component]):
            # The single outbound leg: glide PatrolDistance to the left,
            # easing in and out so each turn feels like a real pause-and-go.
            Outbound := keyframed_movement_delta:
                Duration := LegSeconds
                Easing := ease_in_out_cubic_bezier_easing_function{}
                Transform := transform:
                    Translation := vector3:
                        Left := PatrolDistance
                        Forward := 0.0
                        Up := 0.0

            # Ping-pong: play the leg forward, then reverse it, forever.
            Mover.SetKeyframes(array{Outbound}, pingpong_keyframed_movement_playback_mode{})
            Mover.Play()

            # Listen for the turn-around so we could react (sound, score, etc.).
            Mover.KeyframeReachedEvent.Subscribe(OnReachedWaypoint)

    # Fires each time a keyframe is hit. Keyframe is the index reached;
    # IsReversed is true when we're on the way back.
    OnReachedWaypoint(Reached:tuple(int, logic)):void =
        # A real game might play a footstep here or flip a patrol flag.
        Print("Patrol reached a waypoint")