extends CharacterBody3D

## Speed of enemy
@export var speed: float = 2.0
## Target for enemy to follow
@export var target: Node3D

## Whether to use gravity on enemy
@export var gravity_enabled: bool = true

## Use nav mesh or dumb path finding
@export var use_nav_mesh: bool = true

@onready var nav_agent: NavigationAgent3D = $NavigationAgent3D

var gravity : float = ProjectSettings.get_setting("physics/3d/default_gravity")

var original_material: StandardMaterial3D
@onready var red_material = preload("res://models/red_material.tres")

var mesh_ready = false
var found = false

func _ready() -> void:
	if gravity_enabled:
		motion_mode = MotionMode.MOTION_MODE_GROUNDED
		
	NavigationServer3D.connect("map_changed", map_changed)
	original_material = $MeshInstance3D.get_active_material(0)
	
func map_changed(_rid):
	print("Map changed")
	mesh_ready = true
	
func update_target_location(target_location: Vector3):
	nav_agent.target_position = target_location
	
func chase_nav_mesh(delta: float):
	if not mesh_ready:
		return
		
	if target != null:
		update_target_location(target.global_position)
	
	var current_location = global_transform.origin
	var next_location = nav_agent.get_next_path_position()
	var new_velocity = (next_location - current_location).normalized() * speed
	
	#print("Target is ", next_location)
	
	# We only want to navigate on XZ plane
	new_velocity.y = 0
	
	velocity = velocity.move_toward(new_velocity, .25)
	
	if not is_on_floor() and gravity_enabled:
		velocity.y -= gravity * delta
	else:
		velocity.y = 0
	
	move_and_slide()
	
func wander() -> void:
	pass

func _physics_process(delta: float) -> void:
	if Input.is_action_pressed("ui_right"):
		return
		
	if target != null and not found and check_target_visible():
		found = true
		print("Found player")
		
	if not found:
		wander()
	elif found:
		chase_nav_mesh(delta)

func check_target_visible() -> bool:
	var space_state = get_world_3d().direct_space_state
	var starting_pos = global_position
	var ending_pos = target.global_position + Vector3.UP
	var query = PhysicsRayQueryParameters3D.create(starting_pos, ending_pos, 0xFFFFFFFF, [self.get_rid()])
	var result = space_state.intersect_ray(query)
	
	if result and result.collider == target:
		return true

	return false

func on_hit(_hit_position: Vector3) -> void:
	if $HitTimer.is_stopped():
		$MeshInstance3D.set_surface_override_material(0, red_material)
		$HitTimer.start()

func _on_hit_timer_timeout() -> void:
	$MeshInstance3D.set_surface_override_material(0, original_material)
	$HitTimer.stop()
	
	get_parent().remove_child(self)
	queue_free()

func _on_body_entered(body: Node3D) -> void:
	target = body

func _on_body_exited(body: Node3D) -> void:
	if body == target and not found:
		target = null