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

# PLAYER ENTERS -> FIRST PERSON + INPUT — Part 3 of "Scene Graph: Car Primitive".
#
# Getting "into" the car is the moment the experience changes. Two real,
# fully-public mechanisms make it happen:
#
#  1. DETECT ENTRY with a Mutator Zone placed around the car. Its
#     `AgentEntersEvent : listenable(agent)` fires when a player walks in, and
#     `AgentExitsEvent` fires when they leave. (You can also use a vehicle
#     spawner's `AgentEntersVehicleEvent`, but a zone works for our prop "car".)
#
#  2. SWITCH THE VIEW with a Gameplay Camera device. The First-Person flavour,
#     `gameplay_camera_first_person_device`, has a public `AddTo(Agent)` that
#     pushes a first-person camera onto that player, and `RemoveFrom(Agent)` to
#     pop it. So: on enter -> AddTo, on exit -> RemoveFrom.
#
# About input: a creator CANNOT author custom input actions/mappings in Verse
# (those constructors are Epic-internal). What you CAN do is react to input. The
# cleanest public path is an Input Trigger device: configure its key in the
# Details panel, then subscribe to `PressedEvent : listenable(agent)`. Here we
# only honk while the player is in the car — proof the camera switch and the
# input subscription are both live for the right player.
#
# This device uses @editable references (no tags) so you can see exactly which
# zone, camera, and input trigger it drives.

car_first_person_enter_device := class(creative_device):

    # Walk-in zone around the car.
    @editable
    EntryZone : mutator_zone_device = mutator_zone_device{}

    # The first-person camera pushed onto the driver.
    @editable
    DriverCamera : gameplay_camera_first_person_device = gameplay_camera_first_person_device{}

    # An Input Trigger device (configure its key in the Details panel) used as the
    # "horn" while seated.
    @editable
    HornInput : input_trigger_device = input_trigger_device{}

    OnBegin<override>()<suspends> : void =
        EntryZone.AgentEntersEvent.Subscribe(OnEnter)
        EntryZone.AgentExitsEvent.Subscribe(OnExit)
        HornInput.PressedEvent.Subscribe(OnHorn)
        Print("CarFirstPerson: zone, camera, and horn input wired.")

    # Player got in: push first person and register them for the horn input.
    OnEnter(Agent : agent) : void =
        DriverCamera.AddTo(Agent)
        HornInput.Register(Agent)
        Print("CarFirstPerson: driver entered -> first person ON.")

    # Player got out: pop the camera and stop tracking their input.
    OnExit(Agent : agent) : void =
        DriverCamera.RemoveFrom(Agent)
        HornInput.Unregister(Agent)
        Print("CarFirstPerson: driver exited -> first person OFF.")

    # The configured key was pressed by a seated driver.
    OnHorn(Agent : agent) : void =
        Print("CarFirstPerson: HONK!")