extends CharacterBody3D

signal hit

## How fast the player moves in meters per second.
@export var speed = 14
## Vertical impulse applied to the character upon jumping in meters per second.
@export var jump_impulse = 20
## Vertical impulse applied to the character upon bouncing over a mob in meters per second.
@export var bounce_impulse = 16
## The downward acceleration when in the air, in meters per second.
@export var fall_acceleration = 75


func _physics_process(delta):
	var direction = Vector3.ZERO
	if Input.is_action_pressed("move_right"):
		direction.x += 1
	if Input.is_action_pressed("move_left"):
		direction.x -= 1
	if Input.is_action_pressed("move_back"):
		direction.z += 1
	if Input.is_action_pressed("move_forward"):
		direction.z -= 1

	if direction != Vector3.ZERO:
		# In the lines below, we turn the character when moving and make the animation play faster.
		direction = direction.normalized()
		# Setting the basis property will affect the rotation of the node.
		basis = Basis.looking_at(direction)
		$AnimationPlayer.speed_scale = 4
	else:
		$AnimationPlayer.speed_scale = 1

	velocity.x = direction.x * speed
	velocity.z = direction.z * speed

	# Jumping.
	if is_on_floor() and Input.is_action_just_pressed("jump"):
		velocity.y += jump_impulse

	# We apply gravity every frame so the character always collides with the ground when moving.
	# This is necessary for the is_on_floor() function to work as a body can always detect
	# the floor, walls, etc. when a collision happens the same frame.
	velocity.y -= fall_acceleration * delta
	move_and_slide()

	# Here, we check if we landed on top of a mob and if so, we kill it and bounce.
	# With move_and_slide(), Godot makes the body move sometimes multiple times in a row to
	# smooth out the character's motion. So we have to loop over all collisions that may have
	# happened.
	# If there are no "slides" this frame, the loop below won't run.
	for index in range(get_slide_collision_count()):
		var collision = get_slide_collision(index)
		if collision.get_collider().is_in_group("mob"):
			var mob = collision.get_collider()
			if Vector3.UP.dot(collision.get_normal()) > 0.1:
				mob.squash()
				velocity.y = bounce_impulse
				# Prevent this block from running more than once,
				# which would award the player more than 1 point for squashing a single mob.
				break

	# This makes the character follow a nice arc when jumping
	rotation.x = PI / 6 * velocity.y / jump_impulse


func die():
	emit_signal("hit")
	queue_free()


func _on_MobDetector_body_entered(_body):
	die()