extends Area2D

# #86: faster. The bolt used to crawl far enough behind a moving target that
# leading a shot was guesswork rather than skill.
# #155: was 850, which took 1.1s to cross the gun's own range - long enough
# that a shot read as leaving the ship rather than as hitting something. The
# range below is derived from this (see set_range), so raising it makes shots
# faster without making them fall short.
@export var speed: float = 1400.0
# How long a bolt lives if nothing sets a range. VesselWeaponComponent always
# does - see set_range() - so this only covers a projectile fired by something
# that has no range of its own.
@export var lifetime: float = 1.5
@export var damage: int = 1
@export var bolt_length: float = 20.0

var velocity: Vector2 = Vector2.ZERO
var age: float = 0.0


func _ready() -> void:
	add_to_group("player_projectiles")
	area_entered.connect(_on_area_entered)
	# Draw once. The earlier invisible-bolt bug came from _draw() deriving
	# the bolt's look from `age` - drawing only at age==0 froze it at
	# whatever the age==0 case rendered as. _draw() below is now a fixed
	# shape with no age dependency, so one draw is safe and matches the
	# Ship.gd/Asteroid.gd pattern: position/rotation are transform
	# properties Godot applies at render time without re-tessellating.
	queue_redraw()


# The gun's reach, in world units. Converted to a lifetime here rather than
# stored separately, so the distance a bolt COVERS and the distance the aim
# guide DRAWS are the same number rather than two that have to be kept in
# step. They were not: the guide showed fire_range (320) while a bolt actually
# flew speed * lifetime (750), so shots landed well past the line promising
# where they would stop.
func set_range(world_units: float) -> void:
	if world_units > 0.0 and speed > 0.0:
		lifetime = world_units / speed


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:
	# Asteroids answer take_damage() exactly as enemies do, so both are hit by
	# the same branch rather than by a second special case.
	if area.is_in_group("enemies") or area.is_in_group("asteroids"):
		area.take_damage(damage)
		queue_free()


func _draw() -> void:
	# Fixed-length, constant-brightness bolt. Drawn once and left alone.
	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, 0.85, 0.3), 1.0, 0.5)