import "fpkit: system/first_person_player.modifier.api" for API, Modifier, APIGet, APISet, Wire, Fields, State, Op
import "luxe: io" for IO
import "luxe: assets" for Strings
import "luxe: world" for Entity, World, Transform
import "luxe.project/asset" for Asset
import "luxe: math" for Math
import "luxe: system/physics/physics3D.modifier" for Phyiscs3D
import "luxe: system/physics/character3D.modifier" for Character3D

#block = data
class Data {
	var camera: Link

	var acceleration: Num = 0.6
	var decelleration: Num = 0.6
	var ground_check_dist: Num = 0.15

	var jump_impulse: Num = 2.25
	var jump_force: Num = 1.0
	var jump_force_falloff: Num = 0.3

	#hidden
	var is_grounded: Bool = false

	#hidden
	var target_input: Float3 = [0, 0, 0]
}

#api
#display = "First-Person Player"
#desc = "**A new modifier**. You should update this description" 
#icon = "luxe: image/modifier/modifier.svg"
class FirstPersonPlayer is API {
	//add public facing API here
}

#system
#phase(on, tick)
class System is Modifier {

	//required atm
	construct new(world: World) { super(world) }

	init(world: World) {
		_world = world
		Log.print("init `%(This)` in world `%(world)`")
		Physics3D.create_in(world)
	}

	#hidden
	attach(entity: Entity, data: Data) {
		Log.print("attached to `%(Strings.get(Entity.get_name(entity)))` `%(entity)` - `%(This)`")

		if (data.camera == null) {
			data.camera = Entity.get_named(world, "app.camera")
		}
	}

	#hidden
	tick(delta: Num) {
		var fore = Input.event_active("up", "game") ? -1 : 0
		var back = Input.event_active("down", "game") ? 1 : 0
		var left = Input.event_active("left", "game") ? -1 : 0
		var right = Input.event_active("right", "game") ? 1 : 0

		each {|entity: Entity, data: Data|
			if (data.camera == null) return
			if (!Character3D.has(entity)) return

			target_input = Transform.local_vector_to_world(data.camera, right + left, 0, fore + back)
			target_input.y = 0
			Math.normalize(target_input)
			target_input.y = Input.event_began("jump", "game") && data.is_grounded ? data.jump_impulse : 0

			Character3D.set.input(entity, input)
		}
	}

	check_if_grounded(player: Entity, data: Data): Bool {
		var half_height: Num = Character3D.get.height(player) * 0.5
		var padding: Num = Character3D.get.character_padding(player)
		var dist = half_height + padding + data.ground_check_dist

		var result = Physics3D.cast_ray_closest(_world, Transform.get_pos_world(player), [0,-1,0], dist)

		return result != null
	}
}