extends Node

const PROJECTILE_SCENE := preload("res://scenes/game/weapon_projectile.tscn")
const IMPACT_EFFECT_SCENE := preload("res://scenes/game/impact_effect.tscn")
const WEAPON_AUDIO_SCRIPT := preload("res://scripts/game/weapon_audio.gd")
const RAY_COLLISION_MASK := 13 # World, enemies, and the weapon test target.

@onready var ship: CharacterBody2D = get_parent()
@onready var inventory: ShipInventory = ship.get_node("ShipInventory")

var _shot_timers := [0.0, 0.0]
var _laser_pulse_timers := [0.0, 0.0]
var _laser_lines: Array[Line2D] = []
var _fire_buttons_down := [false, false]
var _fire_just_pressed := [false, false]
var _drag_fire_blocked := false
var missile_cooldown_remaining := 0.0
var missile_cooldown_duration := 5.0
var _missile_just_pressed := false

func _ready() -> void:
	_ensure_input_action(&"ship_fire_primary", MOUSE_BUTTON_LEFT)
	_ensure_input_action(&"ship_fire_secondary", MOUSE_BUTTON_RIGHT)
	_ensure_input_action(&"ship_fire_missile", MOUSE_BUTTON_MIDDLE)
	for slot_index in 2:
		var beam := Line2D.new()
		beam.width = 4.0
		beam.default_color = Color(0.35, 0.9, 1.0, 0.92)
		beam.z_index = 20
		beam.visible = false
		ship.get_parent().call_deferred("add_child", beam)
		_laser_lines.append(beam)

func _ensure_input_action(action_name: StringName, button: MouseButton) -> void:
	if not InputMap.has_action(action_name):
		InputMap.add_action(action_name, 0.5)
	var event := InputEventMouseButton.new()
	event.button_index = button
	if not InputMap.action_has_event(action_name, event):
		InputMap.action_add_event(action_name, event)

func _unhandled_input(event: InputEvent) -> void:
	if not event is InputEventMouseButton:
		return
	if ship.get_viewport().gui_is_dragging() or _drag_fire_blocked:
		return
	var slot_index := -1
	if event.button_index == MOUSE_BUTTON_MIDDLE:
		_missile_just_pressed = event.pressed
		return
	if event.button_index == MOUSE_BUTTON_LEFT:
		slot_index = 0
	elif event.button_index == MOUSE_BUTTON_RIGHT:
		slot_index = 1
	if slot_index < 0:
		return
	_fire_buttons_down[slot_index] = event.pressed
	if event.pressed:
		_fire_just_pressed[slot_index] = true

func _physics_process(delta: float) -> void:
	missile_cooldown_remaining = maxf(0.0, missile_cooldown_remaining - delta)
	if ship.get_viewport().gui_is_dragging():
		_drag_fire_blocked = true
	if _drag_fire_blocked:
		_missile_just_pressed = false
		for index in 2:
			_fire_buttons_down[index] = false
			_fire_just_pressed[index] = false
			_laser_pulse_timers[index] = 0.0
			_laser_lines[index].visible = false
			_shot_timers[index] = maxf(0.0, _shot_timers[index] - delta)
		# Require release after dropping, so the drag gesture cannot become a shot.
		if not ship.get_viewport().gui_is_dragging() and not Input.is_mouse_button_pressed(MOUSE_BUTTON_LEFT) and not Input.is_mouse_button_pressed(MOUSE_BUTTON_RIGHT):
			_drag_fire_blocked = false
		return
	if bool(ship.get("_is_destroyed")) or bool(ship.get("is_docked")):
		_missile_just_pressed = false
		for line in _laser_lines:
			line.visible = false
		return
	var mouse_over_ui := ship.get_viewport().gui_get_hovered_control() != null
	if not mouse_over_ui and (Input.is_action_just_pressed("ship_fire_missile") or _missile_just_pressed):
		try_fire_missile()
	_missile_just_pressed = false
	for slot_index in 2:
		_shot_timers[slot_index] = maxf(0.0, _shot_timers[slot_index] - delta)
		_laser_pulse_timers[slot_index] = maxf(0.0, _laser_pulse_timers[slot_index] - delta)
		var action_name := "ship_fire_primary" if slot_index == 0 else "ship_fire_secondary"
		var is_pressed: bool = not mouse_over_ui and (
			Input.is_action_pressed(action_name) or _fire_buttons_down[slot_index]
		)
		var is_just_pressed: bool = not mouse_over_ui and (
			Input.is_action_just_pressed(action_name) or _fire_just_pressed[slot_index]
		)
		var item: ItemInstance = inventory.weapon_slots[slot_index]
		if not is_pressed or item == null or item.definition == null:
			_laser_lines[slot_index].visible = (
				item != null
				and item.definition != null
				and item.definition.weapon_kind == ItemDefinition.WeaponKind.LASER
				and _laser_pulse_timers[slot_index] > 0.0
			)
			continue

		var definition := item.definition
		if definition.weapon_kind != ItemDefinition.WeaponKind.LASER:
			_laser_pulse_timers[slot_index] = 0.0
			_laser_lines[slot_index].visible = false
		match definition.weapon_kind:
			ItemDefinition.WeaponKind.LASER:
				_laser_lines[slot_index].visible = _laser_pulse_timers[slot_index] > 0.0
				_fire_laser(slot_index, item)
			ItemDefinition.WeaponKind.MISSILE:
				pass # Rockets fire exclusively from slot 3.
			_:
				if _shot_timers[slot_index] <= 0.0 and _consume_shot_resource(item):
					_fire_projectile(item)
					_shot_timers[slot_index] = definition.fire_interval
	for slot_index in 2:
		_fire_just_pressed[slot_index] = false

func try_fire_missile() -> bool:
	if missile_cooldown_remaining > 0.0 or bool(ship.get("_is_destroyed")) or bool(ship.get("is_docked")):
		return false
	var item := inventory.get_item("weapon", ShipInventory.MISSILE_SLOT)
	if item == null or item.definition.weapon_kind != ItemDefinition.WeaponKind.MISSILE:
		return false
	if inventory.missile_ammunition <= 0:
		return false
	missile_cooldown_duration = inventory.get_missile_cooldown(item)
	_fire_projectile(item)
	missile_cooldown_remaining = missile_cooldown_duration
	inventory.consume_missile()
	return true

func _fire_projectile(item: ItemInstance) -> void:
	var definition := item.definition
	var hit: Dictionary = ship.call("roll_weapon_hit", item)
	var muzzle_position := _muzzle_position()
	var direction := _aim_direction_from(muzzle_position)
	var projectile := PROJECTILE_SCENE.instantiate()
	projectile.call(
		"configure",
		muzzle_position,
		direction,
		definition.weapon_kind,
		definition.projectile_speed,
		float(hit["damage"]),
		definition.weapon_range,
		null,
		bool(hit["critical"])
	)
	ship.get_parent().add_child(projectile)
	projectile.set("missile_homing", definition.missile_homing)
	WEAPON_AUDIO_SCRIPT.play(ship.get_parent(), muzzle_position, definition.weapon_kind)

func _fire_laser(slot_index: int, item: ItemInstance) -> void:
	var definition := item.definition
	var line := _laser_lines[slot_index]
	if _shot_timers[slot_index] > 0.0 or float(ship.get("energy")) < item.get_energy_cost():
		return
	var muzzle_position := _muzzle_position()
	var direction := _aim_direction_from(muzzle_position)
	var endpoint := muzzle_position + direction * definition.weapon_range
	var query := PhysicsRayQueryParameters2D.create(
		muzzle_position,
		endpoint,
		RAY_COLLISION_MASK,
		[ship.get_rid()]
	)
	var result := ship.get_world_2d().direct_space_state.intersect_ray(query)
	if not result.is_empty():
		endpoint = result["position"]
	line.clear_points()
	line.add_point(muzzle_position)
	line.add_point(endpoint)
	line.visible = true
	if not _consume_energy(item.get_energy_cost()):
		line.visible = false
		return
	WEAPON_AUDIO_SCRIPT.play(ship.get_parent(), muzzle_position, ItemDefinition.WeaponKind.LASER)
	if not result.is_empty():
		var hit: Dictionary = ship.call("roll_weapon_hit", item)
		_apply_damage(result.get("collider"), float(hit["damage"]), bool(hit["critical"]))
		_spawn_laser_impact(endpoint)
	_laser_pulse_timers[slot_index] = definition.laser_pulse_duration
	_shot_timers[slot_index] = definition.fire_interval

func _aim_direction_from(origin: Vector2) -> Vector2:
	var offset := ship.get_global_mouse_position() - origin
	return offset.normalized() if offset.length_squared() > 0.001 else Vector2.UP.rotated(ship.rotation)

func _muzzle_position() -> Vector2:
	var forward := Vector2.UP.rotated(ship.rotation)
	return ship.global_position + forward * 28.0

func _consume_shot_resource(item: ItemInstance) -> bool:
	if item.definition.weapon_kind == ItemDefinition.WeaponKind.MACHINE_GUN:
		return inventory.consume_ammunition()
	return _consume_energy(item.get_energy_cost())

func _consume_energy(amount: float) -> bool:
	var current_energy := float(ship.get("energy"))
	if current_energy < amount:
		return false
	ship.set("energy", current_energy - amount)
	return true

func _apply_damage(target: Variant, damage: float, critical: bool = false) -> void:
	if target is Node and target.has_method("take_weapon_hit"):
		target.call("take_weapon_hit", damage, critical)
	elif target is Node and target.has_method("take_damage"):
		target.call("take_damage", damage)

func _spawn_laser_impact(at_position: Vector2) -> void:
	var effect := IMPACT_EFFECT_SCENE.instantiate() as Node2D
	effect.global_position = at_position
	ship.get_parent().add_child(effect)
	effect.call("configure", false, Color(0.38, 0.9, 1.0))