class_name LaserController
extends Node2D

# Same press-drag-release aiming plumbing as GasBombController, adapted for
# an instant beam rather than a lobbed, timed projectile: there is no travel
# time or explosion delay - the beam strikes the instant the shot fires, and
# only a brief flash lingers for feedback. Damage/range/cooldown are read
# straight off the firing ship's own VesselLaserComponent (already resolved
# from vessel_stat/upgrades) rather than hardcoded here, unlike the bomber's
# AOE_RADIUS/DAMAGE/COOLDOWN.
#
# Reused as-is by both Main.tscn and PlanetSurface.tscn (same relative
# ../Fleet, ../Camera2D, ../UI/LaserButton paths as GasBombController), so
# it works identically in space and on a landed surface with no branching.

const BEAM_COLOR := Color(0.3, 0.9, 1.0)
const TARGET_COLOR := Color(0.6, 0.95, 1.0)
const BEAM_HALF_WIDTH := 22.0
const DRAG_DEADZONE := 22.0
const FLASH_DURATION := 0.22
# #61: ammunition from the fleet hold, mirroring #60's gas bomber exactly.
const ENERGY_PER_SHOT: int = 8

@export var minimum_zoom: float = 0.4
@onready var fleet: Node2D = get_node("../Fleet")
@onready var camera: Camera2D = get_node("../Camera2D")
@onready var button: IconButton = get_node("../UI/LaserButton")
@onready var status: Label = get_node("../UI/LaserStatus")

var status_message_until: int = 0

var aiming := false
var aim_touch := -1
var aim_start_screen := Vector2.ZERO
var aim_screen := Vector2.ZERO
var aim_target := Vector2.ZERO
var saved_zoom := 1.0
var restoring_zoom := false
var beams: Array = []
var last_hit_count := 0


func _ready() -> void:
	button.visible = false
	status.text = ""
	queue_redraw()


func _can_afford_shot() -> bool:
	return GameState.fleet_resource(GameState.RESOURCE_ENERGY) >= ENERGY_PER_SHOT


func _say(message: String) -> void:
	status.text = message
	status_message_until = Time.get_ticks_msec() + 3000


func _process(delta: float) -> void:
	var had_visuals := aiming or not beams.is_empty()
	button.visible = fleet.has_capability("laser")
	button.enabled = _next_ready_laser_ship() != null and _can_afford_shot()
	if not button.visible and aiming:
		_cancel_aim()
	if status.text != "" and Time.get_ticks_msec() >= status_message_until:
		status.text = ""

	if restoring_zoom and not aiming:
		var z := move_toward(camera.zoom.x, saved_zoom, maxf(saved_zoom, 0.1) * delta * 5.0)
		camera.zoom = Vector2(z, z)
		if is_equal_approx(z, saved_zoom):
			restoring_zoom = false

	for i in range(beams.size() - 1, -1, -1):
		var beam: Dictionary = beams[i]
		beam.time = maxf(float(beam.time) - delta, 0.0)
		if float(beam.time) <= 0.0:
			beams.remove_at(i)
	if aiming or not beams.is_empty() or had_visuals:
		queue_redraw()


func can_begin_aim() -> bool:
	# Deliberately NOT button.enabled: an unaffordable shot still needs the
	# press to reach here so it can explain itself (#60's identical
	# reasoning on the gas bomber). A wholly unready fleet (no laser ship at
	# all) has nothing more useful to say than "greyed out".
	return button.visible and not button._blocked_by_modal() \
		and not aiming and _next_ready_laser_ship() != null


func handle_touch(event: InputEventScreenTouch) -> bool:
	if event.pressed:
		if not can_begin_aim() or not Rect2(button.global_position, button.size).has_point(event.position):
			return false
		if not _can_afford_shot():
			_say("Need %d energy in the fleet hold to fire (have %d)" \
				% [ENERGY_PER_SHOT, GameState.fleet_resource(GameState.RESOURCE_ENERGY)])
			return true
		aiming = true
		aim_touch = event.index
		aim_start_screen = event.position
		aim_screen = event.position
		saved_zoom = camera.zoom.x
		restoring_zoom = false
		button.pressed_down = true
		button.queue_redraw()
		_update_aim()
		return true
	if event.index != aim_touch:
		return false
	var should_fire := aim_start_screen.distance_to(aim_screen) >= DRAG_DEADZONE
	if should_fire:
		_fire()
	else:
		_cancel_aim()
	return true


func handle_drag(event: InputEventScreenDrag) -> bool:
	if not aiming or event.index != aim_touch:
		return false
	aim_screen = event.position
	_update_aim()
	return true


func _aim_origin() -> Vector2:
	return fleet.get_centroid()


func _aim_max_range() -> float:
	var ship: Node2D = _next_ready_laser_ship()
	if ship == null:
		return 950.0
	var component: Node = ship.get_component("laser")
	return component.beam_range if component != null else 950.0


func _update_aim() -> void:
	# A beam always reaches its full range - only the DIRECTION is aimed,
	# unlike the bomb's drag-controlled distance.
	var drag := aim_screen - aim_start_screen
	var origin: Vector2 = _aim_origin()
	var direction: Vector2 = drag.normalized() if drag.length() > 0.001 else Vector2.UP
	aim_target = origin + direction * _aim_max_range()
	_update_aim_zoom(origin, aim_target)
	queue_redraw()


func _update_aim_zoom(origin: Vector2, target: Vector2) -> void:
	var displacement := target - origin
	var half_screen := get_viewport_rect().size * 0.5 - Vector2(54.0, 54.0)
	var fit_x := saved_zoom if absf(displacement.x) < 1.0 else half_screen.x / (absf(displacement.x) + BEAM_HALF_WIDTH)
	var fit_y := saved_zoom if absf(displacement.y) < 1.0 else half_screen.y / (absf(displacement.y) + BEAM_HALF_WIDTH)
	var desired := clampf(minf(saved_zoom, minf(fit_x, fit_y)), minimum_zoom, saved_zoom)
	camera.zoom = Vector2(desired, desired)


func _finish_aim() -> void:
	aiming = false
	aim_touch = -1
	button.pressed_down = false
	button.queue_redraw()
	restoring_zoom = true


func _cancel_aim() -> void:
	_finish_aim()
	queue_redraw()


func _fire() -> void:
	var shooter: Node2D = _next_ready_laser_ship()
	if shooter == null:
		_cancel_aim()
		return
	if not _can_afford_shot():
		_say("Need %d energy in the fleet hold to fire (have %d)" \
			% [ENERGY_PER_SHOT, GameState.fleet_resource(GameState.RESOURCE_ENERGY)])
		_cancel_aim()
		return
	var component: Node = shooter.get_component("laser")
	if not component.consume_shot():
		_cancel_aim()
		return
	GameState.withdraw_fleet_resource(GameState.RESOURCE_ENERGY, ENERGY_PER_SHOT)
	var direction: Vector2 = (aim_target - _aim_origin())
	direction = direction.normalized() if direction.length() > 0.001 else Vector2.UP
	var beam_to: Vector2 = shooter.global_position + direction * component.beam_range
	_strike(shooter.global_position, beam_to, direction, int(component.damage))
	_finish_aim()
	button.enabled = _next_ready_laser_ship() != null and _can_afford_shot()


func _strike(from: Vector2, to: Vector2, direction: Vector2, damage: int) -> void:
	beams.append({"from": from, "to": to, "time": FLASH_DURATION})
	last_hit_count = 0
	var range_along: float = from.distance_to(to)
	for enemy in get_tree().get_nodes_in_group("enemies"):
		if not is_instance_valid(enemy) or not (enemy is Node2D):
			continue
		var to_enemy: Vector2 = enemy.global_position - from
		var along: float = to_enemy.dot(direction)
		if along < 0.0 or along > range_along:
			continue
		var perpendicular: float = (to_enemy - direction * along).length()
		if perpendicular <= BEAM_HALF_WIDTH:
			enemy.take_damage(damage)
			last_hit_count += 1


func _next_ready_laser_ship() -> Node2D:
	for ship in fleet.ships:
		if not is_instance_valid(ship):
			continue
		var component: Node = ship.get_component("laser")
		if component != null and component.is_ready():
			return ship
	return null


func _draw() -> void:
	if aiming:
		NeonDraw.draw_glowing_line(self, _aim_origin(), aim_target, TARGET_COLOR, 0.7, 0.6)
	for beam in beams:
		var progress: float = 1.0 - float(beam.time) / FLASH_DURATION
		var alpha: float = 1.0 - progress
		NeonDraw.draw_glowing_line(self, beam.from, beam.to, BEAM_COLOR, alpha, 1.2 - progress * 0.6)