Turret.gd

extends Spatial

export (bool) var use_raycast = false

const TURRET_DAMAGE_BULLET = 20
const TURRET_DAMAGE_RAYCAST = 5

const FLASH_TIME = 0.1
var flash_timer = 0

const FIRE_TIME = 0.3
var fire_timer = 0

var node_turret_head = null
var node_raycast = null
var node_flash_one = null
var node_flash_two = null

var ammo_in_turret = 20
const AMMO_IN_FULL_TURRET = 20
const AMMO_RELOAD_TIME = 2
var ammo_reload_timer = 0

var current_target = null

var is_active = false

const PLAYER_HEIGHT = 3

var smoke_particles

var turret_health = 60
const MAX_TURRET_HEALTH = 60

const DESTROYED_TIME = 20
var destroyed_timer = 0

var bullet_scene = preload("Bullet_Scene.tscn")
var simple_audio_player = preload("res://Simple_Audio_Player.tscn")

func _ready():

    $Vision_Area.connect("body_entered", self, "body_entered_vision")
    $Vision_Area.connect("body_exited", self, "body_exited_vision")

    node_turret_head = $Head
    node_raycast = $Head/Ray_Cast
    node_flash_one = $Head/Flash
    node_flash_two = $Head/Flash_2

    node_raycast.add_exception(self)
    node_raycast.add_exception($Base/Static_Body)
    node_raycast.add_exception($Head/Static_Body)
    node_raycast.add_exception($Vision_Area)

    node_flash_one.visible = false
    node_flash_two.visible = false

    smoke_particles = $Smoke
    smoke_particles.emitting = false

    turret_health = MAX_TURRET_HEALTH


func _physics_process(delta):

    if is_active == true:

        if flash_timer > 0:
            flash_timer -= delta

            if flash_timer <= 0:
                node_flash_one.visible = false
                node_flash_two.visible = false

        if current_target != null:

            node_turret_head.look_at(current_target.global_transform.origin + Vector3(0, PLAYER_HEIGHT, 0), Vector3(0, 1, 0))

            if turret_health > 0:

                if ammo_in_turret > 0:
                    if fire_timer > 0:
                        fire_timer -= delta
                    else:
                        fire_bullet()
                else:
                    if ammo_reload_timer > 0:
                        ammo_reload_timer -= delta
                    else:
                        ammo_in_turret = AMMO_IN_FULL_TURRET

    if turret_health <= 0:
        if destroyed_timer > 0:
            destroyed_timer -= delta
        else:
            turret_health = MAX_TURRET_HEALTH
            smoke_particles.emitting = false


func fire_bullet():

    if use_raycast == true:
        node_raycast.look_at(current_target.global_transform.origin + Vector3(0, PLAYER_HEIGHT, 0), Vector3(0, 1, 0))

        node_raycast.force_raycast_update()

        if node_raycast.is_colliding():
            var body = node_raycast.get_collider()
            if body.has_method("bullet_hit"):
                body.bullet_hit(TURRET_DAMAGE_RAYCAST, node_raycast.get_collision_point())

        ammo_in_turret -= 1

    else:
        var clone = bullet_scene.instance()
        var scene_root = get_tree().root.get_children()[0]
        scene_root.add_child(clone)

        clone.global_transform = $Head/Barrel_End.global_transform
        clone.scale = Vector3(8, 8, 8)
        clone.BULLET_DAMAGE = TURRET_DAMAGE_BULLET
        clone.BULLET_SPEED = 100

        ammo_in_turret -= 1

    create_sound("Pistol_shot", $Head/Barrel_End.global_transform.origin)
    node_flash_one.visible = true
    node_flash_two.visible = true

    flash_timer = FLASH_TIME
    fire_timer = FIRE_TIME

    if ammo_in_turret <= 0:
        ammo_reload_timer = AMMO_RELOAD_TIME


func body_entered_vision(body):
    if current_target == null:
        if body is KinematicBody:
            current_target = body
            is_active = true


func body_exited_vision(body):
    if current_target != null:
        if body == current_target:
            current_target = null
            is_active = false

            flash_timer = 0
            fire_timer = 0
            node_flash_one.visible = false
            node_flash_two.visible = false


func bullet_hit(damage, bullet_hit_pos):
    turret_health -= damage

    if turret_health <= 0:
        smoke_particles.emitting = true
        destroyed_timer = DESTROYED_TIME


func create_sound(sound_name, position=null):
    var audio_clone = simple_audio_player.instance()
    var scene_root = get_tree().root.get_children()[0]
    scene_root.add_child(audio_clone)
    audio_clone.play_sound(sound_name, position)