class_name VesselWeaponComponent
extends Node

# The fleet's gun. It does NOT pick its own targets: the player aims it with
# the fire stick, and it shoots along whatever heading that stick reports for
# as long as it is held.
#
# It used to seek the nearest enemy in range and fire on its own, which meant
# combat happened whether or not the player did anything - there was nothing
# to aim, and nothing to decide. Firing is now an action like any other, and
# the right-hand stick is what performs it.
#
# `fire_direction` is set every frame by FireStickController from the stick's
# own reading, and cleared the moment it is released. Zero means "not firing",
# which is the resting state.

var capability_id: String = "weapon"
var fire_range: float
var fire_cooldown: float
var projectile_damage: int
var fire_timer: float = 0.0
var fire_direction: Vector2 = Vector2.ZERO
var projectile_scene: PackedScene = preload("res://Projectile.tscn")


func apply_stats() -> void:
	var ship: Node = get_parent()
	var state: Node = ship.get_tree().root.get_node("GameState")
	fire_range = state.vessel_stat(ship.vessel_type, "fire_range")
	fire_cooldown = state.vessel_stat(ship.vessel_type, "fire_cooldown")
	projectile_damage = int(state.vessel_stat(ship.vessel_type, "damage"))


# Called by FireStickController. A zero vector stops the gun.
func set_fire_direction(direction: Vector2) -> void:
	fire_direction = direction if direction.length() > 0.001 else Vector2.ZERO


func is_firing() -> bool:
	return fire_direction != Vector2.ZERO


func tick(delta: float) -> void:
	# The cooldown runs down whether or not the trigger is held, so tapping
	# the stick in a new direction is not punished by a timer that only
	# started when the stick moved.
	fire_timer -= delta
	if fire_direction == Vector2.ZERO or fire_timer > 0.0:
		return
	var ship: Node2D = get_parent()
	var projectile: Node2D = projectile_scene.instantiate()
	projectile.position = ship.position
	projectile.damage = projectile_damage
	ship.get_tree().root.add_child(projectile)
	# Aimed by DIRECTION, not at a target: launch() takes a displacement, so
	# the gun's own range decides how far the shot is sent.
	projectile.launch(fire_direction.normalized() * fire_range)
	fire_timer = fire_cooldown