spaceship/enemies/Enemy.gd

extends Area2D

signal destroyed

const ENEMY_DEFINITIONS = preload("res://enemies/EnemyDefinitions.gd")

@export var enemy_id: String = "chaser"

var definition: Resource
var hp: int

# Mirrors Ship.gd's own max_speed/acceleration: copied from the definition
# once, then mutable, so a test/preview can pin an enemy in place (e.g.
# `enemy.speed = 0.0`) without needing to know about definitions at all.
var speed: float
var acceleration: float
var rotation_speed: float
var max_hp: int


func _ready() -> void:
	add_to_group("enemies")
	definition = ENEMY_DEFINITIONS.get_definition(enemy_id)
	speed = definition.speed
	acceleration = definition.acceleration
	rotation_speed = definition.rotation_speed
	max_hp = definition.max_hp
	hp = max_hp
	for component_scene in definition.component_scenes:
		var component: Node = component_scene.instantiate()
		add_child(component)
		if component.has_method("setup"):
			component.setup()
	queue_redraw()


func get_component(capability: String) -> Node:
	for child in get_children():
		if child.get("capability_id") == capability:
			return child
	return null


func has_capability(capability: String) -> bool:
	return get_component(capability) != null


func _physics_process(delta: float) -> void:
	for child in get_children():
		if child.has_method("tick"):
			child.tick(delta)


# Called by a player vessel this has just collided with. Whether the impact
# destroys it is the definition's call - see EnemyDefinition.dies_on_contact.
# Routed through take_damage so it dies exactly as it dies to gunfire: same
# explosion, same `destroyed` signal, same bookkeeping for whatever is
# listening.
func collide_with_player_vessel() -> void:
	if definition != null and bool(definition.dies_on_contact):
		take_damage(hp)


func take_damage(amount: int) -> void:
	hp -= amount
	if hp <= 0:
		EnemyExplosionVFX.spawn(get_tree().root, position)
		destroyed.emit()
		queue_free()


func _draw() -> void:
	# Drawn through EnemyDefinitions.draw_definition, the same routine the
	# map editor's markers and palette use, so a definition cannot end up
	# looking one way where it is placed and another where it is fought.
	if definition == null:
		NeonDraw.draw_glowing_polygon(self, PackedVector2Array([
			Vector2(0, -16), Vector2(12, 0), Vector2(0, 16), Vector2(-12, 0),
		]), Color(1.0, 0.15, 0.2), 1.0)
		return
	# Constant glow - see Ship.gd. Nothing animates, so no per-frame redraw.
	ENEMY_DEFINITIONS.draw_definition(self, definition, definition.glow_color)