Add enemy foundation: definitions, components, ranged damage (#44)

Enemy.gd now resolves stats/hull/color from EnemyDefinition resources
and composes behaviour from capability components (EnemyPursuitComponent
holds today's chase-the-nearest-ship logic), the same shape Ship.gd
already uses for vessels. Fleet lookups go through a "player_fleet"
group instead of a hardcoded ../Fleet sibling path, so an enemy parented
anywhere (e.g. under a planet surface's SurfaceFeatures) still finds it.

Also closes a real gap: enemies previously had no way to damage the
fleet at range at all (Ship only reacted to physical contact,
Projectile.gd was player-only). Ship.take_damage() is now a proper
entry point - contact damage routes through it unchanged - and
EnemyProjectile lets an enemy component fire at player_ships. Both
ranged enemy archetypes in #45/#46 build on this.

Part of the #40 conquest-mechanic breakdown.

ChaserEnemyDefinition.tres

@@ -0,0 +1,16 @@
+[gd_resource type="Resource" script_class="EnemyDefinition" load_steps=3 format=3]
+
+[ext_resource type="Script" path="res://EnemyDefinition.gd" id="1"]
+[ext_resource type="PackedScene" path="res://EnemyPursuitComponent.tscn" id="2"]
+
+[resource]
+script = ExtResource("1")
+enemy_id = "chaser"
+display_name = "Chaser"
+max_hp = 3
+speed = 140.0
+acceleration = 260.0
+rotation_speed = 6.0
+hull_points = PackedVector2Array(0, -16, 12, 0, 0, 16, -12, 0)
+glow_color = Color(1, 0.15, 0.2, 1)
+component_scenes = Array[PackedScene]([ExtResource("2")])

Enemy.gd

@@ -2,50 +2,53 @@ extends Area2D
 
 signal destroyed
 
-@export var speed: float = 140.0
-@export var acceleration: float = 260.0
-@export var rotation_speed: float = 6.0
-@export var max_hp: int = 3
+const ENEMY_DEFINITIONS = preload("res://EnemyDefinitions.gd")
 
-var velocity: Vector2 = Vector2.ZERO
+@export var enemy_id: String = "chaser"
+
+var definition: Resource
 var hp: int
 
-@onready var fleet: Node2D = get_node("../Fleet")
-
+# 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:
-	hp = max_hp
 	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:
-	var target_pos: Vector2 = _nearest_ship_position()
-	var to_target: Vector2 = target_pos - position
-
-	if to_target.length() > 1.0:
-		var desired_velocity: Vector2 = to_target.normalized() * speed
-		velocity = velocity.move_toward(desired_velocity, acceleration * delta)
-		position += velocity * delta
-
-	if velocity.length() > 5.0:
-		var target_angle: float = velocity.angle() + PI / 2.0
-		rotation = lerp_angle(rotation, target_angle, rotation_speed * delta)
-
-
-func _nearest_ship_position() -> Vector2:
-	if fleet.ships.is_empty():
-		return position
-
-	var nearest: Node2D = fleet.ships[0]
-	var best_dist: float = position.distance_to(nearest.position)
-	for ship in fleet.ships:
-		var d: float = position.distance_to(ship.position)
-		if d < best_dist:
-			best_dist = d
-			nearest = ship
-	return nearest.position
+	for child in get_children():
+		if child.has_method("tick"):
+			child.tick(delta)
 
 
 func take_damage(amount: int) -> void:
@@ -57,8 +60,9 @@ func take_damage(amount: int) -> void:
 
 
 func _draw() -> void:
-	var points: PackedVector2Array = PackedVector2Array([
-		Vector2(0, -16), Vector2(12, 0), Vector2(0, 16), Vector2(-12, 0)
+	var points: PackedVector2Array = definition.hull_points if definition != null else PackedVector2Array([
+		Vector2(0, -16), Vector2(12, 0), Vector2(0, 16), Vector2(-12, 0),
 	])
+	var glow: Color = definition.glow_color if definition != null else Color(1.0, 0.15, 0.2)
 	# Constant glow - see Ship.gd. Nothing animates, so no per-frame redraw.
-	NeonDraw.draw_glowing_polygon(self, points, Color(1.0, 0.15, 0.2), 1.0)
+	NeonDraw.draw_glowing_polygon(self, points, glow, 1.0)

EnemyDefinition.gd

@@ -0,0 +1,19 @@
+class_name EnemyDefinition
+extends Resource
+
+# Data-driven enemy stats and appearance, mirroring VesselDefinition's role
+# for player ships. Enemy.gd instantiates component_scenes exactly like
+# Ship.gd does, so behaviour (pursuit, ranged fire, ...) lives in capability
+# components rather than in a type switch here.
+
+@export var enemy_id: String = "chaser"
+@export var display_name: String = "Chaser"
+@export var max_hp: int = 3
+@export var speed: float = 140.0
+@export var acceleration: float = 260.0
+@export var rotation_speed: float = 6.0
+@export var hull_points: PackedVector2Array = PackedVector2Array([
+	Vector2(0, -16), Vector2(12, 0), Vector2(0, 16), Vector2(-12, 0),
+])
+@export var glow_color: Color = Color(1.0, 0.15, 0.2)
+@export var component_scenes: Array[PackedScene] = []

EnemyDefinition.gd.uid

@@ -0,0 +1 @@
+uid://bkgt6o1m12l0g

EnemyDefinitions.gd

@@ -0,0 +1,19 @@
+class_name EnemyDefinitions
+extends RefCounted
+
+const DEFAULT_ID: String = "chaser"
+const ORDER: PackedStringArray = ["chaser"]
+const DEFINITIONS: Dictionary = {
+	"chaser": preload("res://ChaserEnemyDefinition.tres"),
+}
+
+
+static func get_definition(enemy_id: String) -> Resource:
+	return DEFINITIONS.get(enemy_id, DEFINITIONS[DEFAULT_ID])
+
+
+static func all() -> Array:
+	var result: Array = []
+	for enemy_id in ORDER:
+		result.append(DEFINITIONS[enemy_id])
+	return result

EnemyDefinitions.gd.uid

@@ -0,0 +1 @@
+uid://cfc4w3atpf8yj

EnemyProjectile.gd

@@ -0,0 +1,45 @@
+extends Area2D
+
+# Mirrors Projectile.gd, but travels the other direction: fired by an enemy
+# component (see EnemyRangedWeaponComponent, #45) and damages player_ships.
+# This is the half of ranged combat that never existed before #44 - enemies
+# could previously only hurt the fleet by physical contact.
+
+@export var speed: float = 260.0
+@export var lifetime: float = 3.0
+@export var damage: int = 1
+@export var bolt_length: float = 20.0
+@export var color: Color = Color(1.0, 0.4, 0.35)
+
+var velocity: Vector2 = Vector2.ZERO
+var age: float = 0.0
+
+
+func _ready() -> void:
+	add_to_group("enemy_projectiles")
+	area_entered.connect(_on_area_entered)
+	queue_redraw()
+
+
+func launch(direction: Vector2) -> void:
+	velocity = direction.normalized() * speed
+	rotation = direction.angle() + PI / 2.0
+
+
+func _physics_process(delta: float) -> void:
+	position += velocity * delta
+	age += delta
+	if age >= lifetime:
+		queue_free()
+
+
+func _on_area_entered(area: Area2D) -> void:
+	if area.is_in_group("player_ships"):
+		area.take_damage(damage)
+		queue_free()
+
+
+func _draw() -> void:
+	var tip: Vector2 = Vector2(0, -bolt_length * 0.6)
+	var tail: Vector2 = Vector2(0, bolt_length * 0.4)
+	NeonDraw.draw_glowing_line(self, tail, tip, color, 1.0, 0.5)

EnemyProjectile.gd.uid

@@ -0,0 +1 @@
+uid://b4hja3oj3rdrc

EnemyProjectile.tscn

@@ -0,0 +1,12 @@
+[gd_scene load_steps=3 format=3]
+
+[ext_resource type="Script" path="res://EnemyProjectile.gd" id="1"]
+
+[sub_resource type="CircleShape2D" id="1"]
+radius = 4.0
+
+[node name="EnemyProjectile" type="Area2D"]
+script = ExtResource("1")
+
+[node name="CollisionShape2D" type="CollisionShape2D" parent="."]
+shape = SubResource("1")

EnemyPursuitComponent.gd

@@ -0,0 +1,38 @@
+class_name EnemyPursuitComponent
+extends Node
+
+# Chases the nearest player ship. Moved out of Enemy.gd verbatim so the
+# behaviour is opt-in per definition rather than hardcoded into every enemy.
+
+var capability_id: String = "pursuit"
+var velocity: Vector2 = Vector2.ZERO
+
+
+func tick(delta: float) -> void:
+	var enemy: Node2D = get_parent()
+	var target_pos: Vector2 = _nearest_ship_position(enemy)
+	var to_target: Vector2 = target_pos - enemy.position
+
+	if to_target.length() > 1.0:
+		var desired_velocity: Vector2 = to_target.normalized() * enemy.speed
+		velocity = velocity.move_toward(desired_velocity, enemy.acceleration * delta)
+		enemy.position += velocity * delta
+
+	if velocity.length() > 5.0:
+		var target_angle: float = velocity.angle() + PI / 2.0
+		enemy.rotation = lerp_angle(enemy.rotation, target_angle, enemy.rotation_speed * delta)
+
+
+func _nearest_ship_position(enemy: Node2D) -> Vector2:
+	var fleet: Node2D = get_tree().get_first_node_in_group("player_fleet")
+	if fleet == null or fleet.ships.is_empty():
+		return enemy.position
+
+	var nearest: Node2D = fleet.ships[0]
+	var best_dist: float = enemy.position.distance_to(nearest.position)
+	for ship in fleet.ships:
+		var d: float = enemy.position.distance_to(ship.position)
+		if d < best_dist:
+			best_dist = d
+			nearest = ship
+	return nearest.position

EnemyPursuitComponent.gd.uid

@@ -0,0 +1 @@
+uid://n8wohkrnl42e

EnemyPursuitComponent.tscn

@@ -0,0 +1,6 @@
+[gd_scene load_steps=2 format=3]
+
+[ext_resource type="Script" path="res://EnemyPursuitComponent.gd" id="1"]
+
+[node name="EnemyPursuitComponent" type="Node"]
+script = ExtResource("1")

Fleet.gd

@@ -32,6 +32,10 @@ var steer_direction: Vector2 = Vector2.ZERO
 
 
 func _ready() -> void:
+	# Lets anything resolve "the fleet" without a hardcoded ../Fleet sibling
+	# path - enemies parented under different hosts (e.g. a planet surface's
+	# SurfaceFeatures) need this to find their target.
+	add_to_group("player_fleet")
 	# Researching a vessel upgrade improves the ships already flying, not
 	# just the next one built (#5).
 	GameState.vessel_upgraded.connect(_on_vessel_upgraded)

Ship.gd

@@ -115,17 +115,27 @@ func _physics_process(delta: float) -> void:
 		rotation = lerp_angle(rotation, target_angle, rotation_speed * delta)
 
 
-func _on_area_entered(area: Area2D) -> void:
-	if not (area.is_in_group("enemies") or area.is_in_group("asteroids")):
-		return
+func take_damage(_amount: int) -> bool:
+	# Ships have no hit points - any unabsorbed hit is lethal. A shield
+	# charge absorbs a hit entirely regardless of its amount, matching
+	# VesselShieldComponent's existing all-or-nothing semantics; `_amount`
+	# is accepted (not `int`-clamped away) so callers like EnemyProjectile
+	# have a normal damage parameter to pass even though it isn't graded here.
 	for child in get_children():
 		if child.has_method("absorb_hit") and child.absorb_hit():
-			if area.is_in_group("asteroids") and is_instance_valid(area):
-				area.queue_free()
-			return
+			return true
 	ShipExplosionVFX.spawn(get_tree().root, position)
 	destroyed.emit()
 	queue_free()
+	return false
+
+
+func _on_area_entered(area: Area2D) -> void:
+	if not (area.is_in_group("enemies") or area.is_in_group("asteroids")):
+		return
+	var absorbed: bool = take_damage(1)
+	if absorbed and area.is_in_group("asteroids") and is_instance_valid(area):
+		area.queue_free()
 
 
 func _draw() -> void:

tests/_gas_bomb_aim_preview.gd

@@ -39,5 +39,5 @@ func _ready() -> void:
 	for offset in [Vector2(-65, 0), Vector2(45, -45), Vector2(55, 65)]:
 		var enemy: Node = load("res://Enemy.tscn").instantiate()
 		enemy.position = skill.aim_target + offset
-		enemy.speed = 0.0
 		main.add_child(enemy)
+		enemy.speed = 0.0   # after add_child - _ready() sets it from the definition

tests/test_enemy_composition.gd

@@ -0,0 +1,78 @@
+extends SceneTree
+
+# Headless gameplay test: run with
+#   godot --headless -s res://tests/test_enemy_composition.gd
+# Verifies:
+#   1. an Enemy resolves its stats/hull/color from EnemyDefinitions, not
+#      hardcoded fields
+#   2. an enemy instantiated under a node that is NOT a sibling of Fleet
+#      still finds the fleet and pursues it (the old `../Fleet` path would
+#      break here - this is exactly the planet-surface hazard #44 exists
+#      to close before #45/#46 land)
+
+var main_scene: Node
+var fleet: Node
+var nested_host: Node2D
+var enemy: Node
+var elapsed: float = 0.0
+var stage: int = 0
+
+
+func _initialize() -> void:
+	var chaser_def: Resource = EnemyDefinitions.get_definition("chaser")
+	if chaser_def.enemy_id != "chaser" or chaser_def.max_hp != 3:
+		return _fail("EnemyDefinitions did not resolve the chaser definition")
+
+	main_scene = load("res://Main.tscn").instantiate()
+	root.add_child(main_scene)
+	fleet = main_scene.get_node("Fleet")
+	main_scene.get_node("EnemySpawner").set_process(false)
+
+	# Deliberately NOT a sibling of Fleet - two levels deep under an
+	# unrelated node, the way a planet surface's SurfaceFeatures parents
+	# things.
+	nested_host = Node2D.new()
+	nested_host.name = "NestedHost"
+	main_scene.add_child(nested_host)
+	var inner: Node2D = Node2D.new()
+	inner.name = "Inner"
+	nested_host.add_child(inner)
+
+	enemy = load("res://Enemy.tscn").instantiate()
+	enemy.position = fleet.get_centroid() + Vector2(600, 0)
+	inner.add_child(enemy)
+
+
+func _process(delta: float) -> bool:
+	elapsed += delta
+	match stage:
+		0:
+			if elapsed < 0.1:
+				return false
+			if enemy.definition == null or enemy.definition.enemy_id != "chaser":
+				return _fail("enemy did not resolve its definition on _ready")
+			if enemy.hp != enemy.definition.max_hp:
+				return _fail("enemy hp did not come from the definition")
+			if not enemy.has_capability("pursuit"):
+				return _fail("chaser did not compose a pursuit component")
+			elapsed = 0.0
+			stage = 1
+			return false
+		1:
+			# Give the pursuit component a few physics ticks to close distance.
+			if elapsed < 1.0:
+				return false
+			var distance: float = enemy.position.distance_to(fleet.get_centroid())
+			print("distance_after_1s=%.1f (started at 600)" % distance)
+			if distance >= 550.0:
+				return _fail("enemy under a non-sibling host never approached the fleet")
+			print("TEST_ENEMY_COMPOSITION: PASS")
+			quit(0)
+			return true
+	return false
+
+
+func _fail(message: String) -> bool:
+	print("TEST_ENEMY_COMPOSITION: FAIL (%s)" % message)
+	quit(1)
+	return true

tests/test_enemy_composition.gd.uid

@@ -0,0 +1 @@
+uid://dltu3a0n318lo

tests/test_enemy_projectile_damage.gd

@@ -0,0 +1,91 @@
+extends SceneTree
+
+# Headless gameplay test: run with
+#   godot --headless -s res://tests/test_enemy_projectile_damage.gd
+# Verifies the ranged damage path #44 adds: an EnemyProjectile destroys an
+# unshielded ship on contact, and is absorbed by a shielded ship, removing
+# exactly one charge rather than destroying it.
+
+var game_state: Node
+var scene: Node
+var fleet: Node
+var interceptor: Node
+var shield_ship: Node
+var stage: int = 0
+var elapsed: float = 0.0
+
+
+func _initialize() -> void:
+	game_state = root.get_node("GameState")
+	game_state.buildings.clear()
+	game_state.extractors.clear()
+	game_state.transporters.clear()
+	game_state.stored_vessels.clear()
+	game_state.build_time_scale = 0.02
+	game_state.reset_progression()
+	game_state.rocks = 2000
+	scene = load("res://Main.tscn").instantiate()
+	root.add_child(scene)
+	fleet = scene.get_node("Fleet")
+
+
+func _fire_at(ship: Node) -> void:
+	var projectile: Area2D = load("res://EnemyProjectile.tscn").instantiate()
+	projectile.global_position = ship.global_position
+	projectile.launch(Vector2.ZERO)   # already on top of the target
+	scene.add_child(projectile)
+
+
+func _process(delta: float) -> bool:
+	elapsed += delta
+	match stage:
+		0:
+			scene.get_node("AsteroidField").set_process(false)
+			scene.get_node("EnemySpawner").set_process(false)
+			fleet.spawn_ships(1, Vector2.ZERO)
+			interceptor = fleet.ships[0]
+			fleet.add_ship(GameState.VESSEL_SHIELD)
+			shield_ship = fleet.ships[1]
+			shield_ship.position = Vector2(2000.0, 0.0)
+			elapsed = 0.0
+			stage = 1
+			return false
+		1:
+			if elapsed < 0.2:
+				return false
+			if not shield_ship.has_shield():
+				return _fail("a fresh shield vessel has no shield")
+			_fire_at(interceptor)
+			elapsed = 0.0
+			stage = 2
+			return false
+		2:
+			if elapsed < 0.4:
+				return false
+			if is_instance_valid(interceptor):
+				return _fail("an unshielded ship survived an enemy projectile")
+			print("unshielded interceptor destroyed by an enemy projectile")
+
+			_fire_at(shield_ship)
+			elapsed = 0.0
+			stage = 3
+			return false
+		3:
+			if elapsed < 0.4:
+				return false
+			if not is_instance_valid(shield_ship):
+				return _fail("a shielded ship was destroyed by an enemy projectile")
+			if shield_ship.shield_charges != 0:
+				return _fail("shield charges did not drop to 0 after absorbing one hit (charges=%d)" %
+					shield_ship.shield_charges)
+			print("shielded ship absorbed the hit and lost exactly one charge")
+			print("TEST_ENEMY_PROJECTILE_DAMAGE: PASS")
+			quit(0)
+			return true
+	return false
+
+
+func _fail(message: String) -> bool:
+	print("TEST_ENEMY_PROJECTILE_DAMAGE: FAIL (%s)" % message)
+	quit(1)
+	return true

tests/test_enemy_projectile_damage.gd.uid

@@ -0,0 +1 @@
+uid://cx7f3e82jkumb

tests/test_gas_bomber.gd

@@ -107,16 +107,19 @@ func _process(delta: float) -> bool:
 			if main.get_node("Camera2D").zoom.x >= original_zoom:
 				return _fail_now("long aim did not zoom out")
 
+			# speed is set AFTER add_child(): _ready() copies it from the
+			# enemy's definition, which would otherwise clobber a
+			# pre-add_child override the instant the enemy entered the tree.
 			for offset in [Vector2(-60, 0), Vector2(70, 35)]:
 				var enemy: Node = load("res://Enemy.tscn").instantiate()
 				enemy.position = skill.aim_target + offset
-				enemy.speed = 0.0
 				main.add_child(enemy)
+				enemy.speed = 0.0
 				inside_enemies.append(enemy)
 			outside_enemy = load("res://Enemy.tscn").instantiate()
 			outside_enemy.position = skill.aim_target + Vector2(GasBombController.AOE_RADIUS + 80.0, 0)
-			outside_enemy.speed = 0.0
 			main.add_child(outside_enemy)
+			outside_enemy.speed = 0.0
 
 			var release := InputEventScreenTouch.new()
 			release.index = 7