extends Node2D

# Points every armed vessel's gun wherever the right-hand stick is pushed.
#
# The fleet's guns used to seek their own targets and fire on their own. That
# made combat something that happened TO the player rather than something they
# did, and left the right half of the screen with nothing on it. Aiming is now
# the second stick, and this is the only thing that tells a weapon to fire.
#
# Deliberately a scene node rather than state on the fleet or in GameState:
# it is input plumbing, it belongs to whichever scene is showing the stick,
# and a fleet that moves between scenes should arrive with its guns silent
# until the local stick says otherwise.

# The aim guide: a dotted line from the fleet along the heading being fired,
# out to the guns' own range. Deliberately faint and broken rather than a
# solid beam - it has to answer "where will this go and how far" at a glance
# without competing with the shots themselves for attention.
const GUIDE_DASH: float = 14.0
const GUIDE_GAP: float = 16.0
const GUIDE_WIDTH: float = 2.0
const GUIDE_COLOR: Color = Color(1.0, 0.55, 0.38, 0.28)

# By path rather than by class name, for the load-order reason documented in
# PlanetSetups and elsewhere.
const WEAPON_COMPONENT = preload("res://vessels/VesselWeaponComponent.gd")

@onready var fleet: Node2D = get_node("../Fleet")
# Optional so a scene without a fire stick (a preview, a test harness) still
# runs - the guns simply stay quiet, which is the correct resting state.
@onready var stick: Node = get_node_or_null("../UI/FireStick")

var aim_direction: Vector2 = Vector2.ZERO
# Set by MouseCombatController (#80) when a desktop player holds the left
# button. Kept as a second input rather than a second aimer, so there is still
# exactly one thing in the scene that points a gun.
var external_direction: Vector2 = Vector2.ZERO


func _process(_delta: float) -> void:
	var direction: Vector2 = stick.direction if stick != null else Vector2.ZERO
	if direction == Vector2.ZERO:
		# The stick wins when both are live: a finger on it is a deliberate
		# act, a mouse resting somewhere is not.
		direction = external_direction
	aim(direction)
	# The guide starts at the fleet, which is usually moving, so this redraws
	# while aiming rather than only when the heading changes. Once the stick is
	# released it redraws once more to clear the line, then stops.
	var was_aiming: bool = aim_direction != Vector2.ZERO
	aim_direction = direction
	if direction != Vector2.ZERO or was_aiming:
		queue_redraw()


# Also the entry point for anything driving the guns without a stick - tests
# aim through this rather than reaching into each weapon component, so what
# they exercise is the same path the stick uses.
func aim(direction: Vector2) -> void:
	if fleet == null:
		return
	for ship in fleet.ships:
		if not is_instance_valid(ship):
			continue
		var weapon: Node = ship.get_component("weapon")
		if weapon != null:
			weapon.set_fire_direction(direction)


# How far the guide reaches: the actual range of a gun that is actually
# aboard, so the line never promises reach the fleet does not have.
func guide_range() -> float:
	for ship in fleet.ships:
		if not is_instance_valid(ship):
			continue
		var weapon: Node = ship.get_component("weapon")
		if weapon != null:
			return float(weapon.fire_range)
	return 0.0


func _draw() -> void:
	if aim_direction == Vector2.ZERO or fleet == null or fleet.ships.is_empty():
		return
	var reach: float = guide_range()
	if reach <= 0.0:
		return
	var origin: Vector2 = fleet.get_centroid()
	# Drawn along the heading a shot will ACTUALLY take, assist included, so
	# the line keeps telling the truth about where fire is going (#89).
	var heading: Vector2 = WEAPON_COMPONENT.assisted_heading(get_tree(), origin,
		aim_direction, reach)
	var travelled: float = GUIDE_GAP
	while travelled < reach:
		var dash_end: float = minf(travelled + GUIDE_DASH, reach)
		draw_line(origin + heading * travelled, origin + heading * dash_end,
			GUIDE_COLOR, GUIDE_WIDTH, true)
		travelled = dash_end + GUIDE_GAP


func is_firing() -> bool:
	for ship in fleet.ships:
		if not is_instance_valid(ship):
			continue
		var weapon: Node = ship.get_component("weapon")
		if weapon != null and weapon.is_firing():
			return true
	return false