# We are creating a simple script that manages a particle effect.
# In a real UEFN project, you'd attach this to a Device.

using { /Fortnite.com/Devices }
using { /Verse.org/Simulation }

# This is our "Device" — the thing you place in the world.
# Think of it like a Trap or a Prop-Mover.
test_device := class(creative_device):

    # We need a reference to the VFX Spawner device we place in the editor.
    # In UEFN, use a vfx_spawner_device (found in the Creative device library)
    # and assign it here via the Details panel.
    @editable
    Emitter: vfx_spawner_device = vfx_spawner_device{}

    # We need a reference to the Trigger device that detects players.
    # Place a trigger_device on your island and assign it in the Details panel.
    @editable
    Trigger: trigger_device = trigger_device{}

    # This runs once when the game starts.
    OnBegin<override>()<suspends>: void =
        # Connect our trigger to a function.
        # When a player enters the zone, run 'OnPlayerEnter'.
        # TriggeredEvent fires when any agent (player) activates the trigger.
        Trigger.TriggeredEvent.Subscribe(OnPlayerEnter)

    # This is the event handler.
    # 'Agent' is the person who walked into the zone.
    OnPlayerEnter(Agent: ?agent): void =
        # 1. SPAWN THE PARTICLE
        # We tell the VFX Spawner to play its effect.
        # This is like pressing the "Fire" button on a weapon.
        # The emitter's Niagara asset is chosen in the editor Details panel —
        # pick your "SpookySwirl" Niagara System there before pressing Play.
        Emitter.Enable()

        # 2. CONFIGURE THE UPDATE (The Magic Part)
        # In Verse, particle update module values (Drag, Curl Noise strength,
        # etc.) are authored directly inside the Niagara System in the editor.
        # At runtime we choose *which* pre-configured vfx_spawner_device fires.
        #
        # For this tutorial we have two vfx_spawner_device objects placed on
        # the island and wired up in the Details panel:
        #   - HeavySmoke  (Niagara asset: high Drag, no Curl Noise)
        #   - SpookySwirl (Niagara asset: low Drag, high Curl Noise)
        #
        # By calling Emitter.Enable() above we are already using the
        # "SpookySwirl" device, which has these Niagara module values baked in:
        #   Drag:        0.2  (floats easily)
        #   Curl Noise:  500  (swirls violently)

        # 3. WAIT AND CLEAN UP
        # Don't let the particles pile up forever.
        # Wait 5 seconds (their lifetime), then stop the emitter.
        # We spawn a new async coroutine so Sleep is allowed here.
        spawn{ WaitAndDisable() }

    # Waits 5 seconds then disables the emitter.
    # Runs as its own coroutine so Sleep is permitted.
    WaitAndDisable()<suspends>: void =
        Sleep(5.0)

        # Disable the spawner so it stops emitting new particles.
        # Existing particles finish their own lifetime naturally.
        Emitter.Disable()