extends Node2D

# Space-side building UI. Owns:
#   - the build menu (place a mothership, ship crafter or command centre)
#   - the shared ACTION button, which adapts to whatever the fleet is
#     standing on (craft ships at a crafter, configure formation at a
#     command centre). The enter-atmosphere prompt uses the same slot, and
#     PlanetAtmosphereController suppresses itself while a building prompt
#     is showing so the two can never fight over it.
#   - rebuilding a wiped-out fleet at the mothership
#
# Buildings themselves live in GameState (they must outlive the trip to a
# planet's surface); this only drives the UI and spends resources.

@export var prompt_debounce_time: float = 0.15

@onready var fleet: Node2D = get_node("../Fleet")
@onready var building_field: Node2D = get_node("../BuildingField")
@onready var world_map: Control = get_node("../UI/WorldMap")
@onready var build_button: IconButton = get_node("../UI/BuildButton")
@onready var action_button: IconButton = get_node("../UI/BuildActionButton")
@onready var action_label: Label = get_node("../UI/BuildActionLabel")

@onready var build_menu: Control = get_node("../UI/BuildMenu")
@onready var build_mothership_button: IconButton = get_node("../UI/BuildMenu/MothershipButton")
@onready var build_crafter_button: IconButton = get_node("../UI/BuildMenu/CrafterButton")
@onready var build_command_button: IconButton = get_node("../UI/BuildMenu/CommandButton")
@onready var build_close_button: IconButton = get_node("../UI/BuildMenu/CloseButton")
@onready var build_status: Label = get_node("../UI/BuildMenu/StatusLabel")
@onready var build_extractor_button: IconButton = get_node("../UI/BuildMenu/ExtractorButton")
@onready var planet_field: Node2D = get_node("../PlanetField")
@onready var info_popup: Control = get_node("../UI/BuildMenu/InfoPopup")
@onready var info_title: Label = get_node("../UI/BuildMenu/InfoPopup/Panel/TitleLabel")
@onready var info_message: Label = get_node("../UI/BuildMenu/InfoPopup/Panel/MessageLabel")
@onready var info_cost: NeonNumber = get_node("../UI/BuildMenu/InfoPopup/Panel/CostNumber")
@onready var info_build_button: IconButton = get_node("../UI/BuildMenu/InfoPopup/Panel/BuildButton")
@onready var info_close_button: IconButton = get_node("../UI/BuildMenu/InfoPopup/Panel/CloseButton")

@onready var craft_menu: Control = get_node("../UI/CraftMenu")
@onready var craft_interceptor_button: IconButton = get_node("../UI/CraftMenu/InterceptorButton")
@onready var craft_close_button: IconButton = get_node("../UI/CraftMenu/CloseButton")
@onready var craft_status: Label = get_node("../UI/CraftMenu/StatusLabel")

@onready var formation_menu: Control = get_node("../UI/FormationMenu")
@onready var formation_editor: Control = get_node("../UI/FormationMenu/Editor")
@onready var formation_close_button: IconButton = get_node("../UI/FormationMenu/CloseButton")
@onready var formation_reset_button: IconButton = get_node("../UI/FormationMenu/ResetButton")

# What each option is and does, shown before anything is spent. Picking a
# structure is a real commitment - it costs ore, and a mothership placement
# can destroy the one you already have - so no option builds straight from
# the menu; each one explains itself first and waits for a confirmation.
#
# The bodies are kept short on purpose: at the UI's font size the popup holds
# roughly eight lines, and a placement condition or a price warning is
# appended below them and needs some of those lines.
const BUILDING_INFO: Dictionary = {
	GameState.BUILDING_MOTHERSHIP: {
		"title": "Mothership",
		"body": "Fleet home port. A wiped-out fleet rebuilds here, and extractor haulers deliver ore here.",
	},
	GameState.BUILDING_SHIP_CRAFTER: {
		"title": "Ship Crafter",
		"body": "Fly the fleet onto it, then use the action button to build extra vessels.",
	},
	GameState.BUILDING_COMMAND_CENTER: {
		"title": "Command Center",
		"body": "Fly the fleet onto it to drag your fleet into a new formation. Rebuilt fleets keep it.",
	},
	GameState.BUILDING_EXTRACTOR: {
		"title": "Extractor",
		"body": "Mines a planet and runs a hauler to your mothership. It keeps earning while you are away.",
	},
}

# Which structure the popup is currently offering to build, or "" when it is
# only explaining something that cannot be built right now.
var pending_build_type: String = ""

var current_building: Node2D = null
var pending_building: Node2D = null
var pending_time: float = 0.0


func _ready() -> void:
	build_button.pressed.connect(_on_build_pressed)
	build_close_button.pressed.connect(func(): build_menu.visible = false)
	build_mothership_button.pressed.connect(_on_place_mothership)
	build_crafter_button.pressed.connect(_on_place_crafter)
	build_command_button.pressed.connect(_on_place_command_center)
	build_extractor_button.pressed.connect(_on_place_extractor)
	info_close_button.pressed.connect(_close_info)
	info_build_button.pressed.connect(_confirm_build)

	action_button.pressed.connect(_on_action_pressed)

	craft_interceptor_button.pressed.connect(_on_craft_interceptor)
	craft_close_button.pressed.connect(func(): craft_menu.visible = false)

	formation_close_button.pressed.connect(func(): formation_menu.visible = false)
	formation_reset_button.pressed.connect(_on_reset_formation)
	formation_editor.formation_changed.connect(_on_formation_changed)

	build_menu.visible = false
	info_popup.visible = false
	craft_menu.visible = false
	formation_menu.visible = false
	action_button.visible = false
	action_label.visible = false


# True while a building prompt or panel owns the shared action slot, so the
# enter-atmosphere prompt knows to stay out of the way.
func is_showing_building_prompt() -> bool:
	return current_building != null or build_menu.visible or craft_menu.visible or formation_menu.visible


func _unhandled_input(event: InputEvent) -> void:
	# The formation editor is driven from here rather than via _gui_input,
	# for the same reason as the joystick: its Control must not swallow
	# touches, or dragging a slot would never reach it.
	if not formation_menu.visible:
		return
	if event is InputEventScreenTouch and formation_editor.handle_touch(event):
		get_viewport().set_input_as_handled()
	elif event is InputEventScreenDrag and formation_editor.handle_drag(event):
		get_viewport().set_input_as_handled()


func _process(delta: float) -> void:
	_check_fleet_wipe()

	if build_menu.visible:
		# Keep the greyed state live while the menu is open, so flying onto
		# a planet lights the option up without reopening it.
		build_extractor_button.enabled = _planet_under_fleet() != null

	if world_map.visible or build_menu.visible or craft_menu.visible or formation_menu.visible:
		current_building = null
		pending_building = null
		action_button.visible = false
		action_label.visible = false
		return

	# Debounced exactly like the enter-atmosphere prompt, so the action
	# button can't flicker while the fleet drifts on the interact boundary.
	var detected: Node2D = building_field.get_building_fleet_is_on()
	if detected != null and detected.building_type == GameState.BUILDING_MOTHERSHIP:
		detected = null  # nothing to do at a mothership beyond respawning

	if detected != pending_building:
		pending_building = detected
		pending_time = 0.0
	else:
		pending_time += delta

	if pending_time < prompt_debounce_time or pending_building == current_building:
		return

	current_building = pending_building
	action_button.visible = current_building != null
	action_label.visible = current_building != null
	if current_building != null:
		action_button.icon = IconButton.Icon.SHIP if current_building.building_type == GameState.BUILDING_SHIP_CRAFTER else IconButton.Icon.MAP
		action_label.text = current_building.get_display_name()
		action_button.queue_redraw()


func _check_fleet_wipe() -> void:
	if not fleet.ships.is_empty():
		return
	# Whole fleet destroyed: rebuild a single vessel at the mothership, or
	# at the world origin when none has been built yet.
	var spawn_pos: Variant = GameState.get_mothership_position()
	fleet.spawn_ships(1, spawn_pos if spawn_pos != null else Vector2.ZERO)


func _on_action_pressed() -> void:
	if current_building == null:
		return
	if current_building.building_type == GameState.BUILDING_SHIP_CRAFTER:
		craft_menu.visible = true
		_refresh_craft_status()
	elif current_building.building_type == GameState.BUILDING_COMMAND_CENTER:
		formation_menu.visible = true
		formation_editor.queue_redraw()


func _on_build_pressed() -> void:
	build_menu.visible = true
	info_popup.visible = false
	pending_build_type = ""
	_refresh_build_status()


func _planet_under_fleet() -> Node2D:
	# An extractor mines a specific planet, so one has to be within reach.
	return planet_field.get_planet_fleet_is_on()


func _refresh_build_status() -> void:
	# The extractor option is always listed, but greyed unless the fleet is
	# actually over a planet - showing it only sometimes would leave the
	# player wondering whether the game has it at all.
	build_extractor_button.enabled = _planet_under_fleet() != null

	# Prices are shown under each option now, so this only needs to say
	# whether the fleet is somewhere an extractor could go.
	if _planet_under_fleet() != null:
		build_status.text = "Over %s - an extractor can be built here" % _planet_under_fleet().planet_name
	else:
		build_status.text = ""


func _on_place_mothership() -> void:
	_show_building_info(GameState.BUILDING_MOTHERSHIP)


func _on_place_crafter() -> void:
	_show_building_info(GameState.BUILDING_SHIP_CRAFTER)


func _on_place_command_center() -> void:
	_show_building_info(GameState.BUILDING_COMMAND_CENTER)


func _on_place_extractor() -> void:
	# The option stays pressable while greyed, so this is also how a
	# not-over-a-planet extractor explains itself.
	_show_building_info(GameState.BUILDING_EXTRACTOR)


func cost_of(type: String) -> int:
	match type:
		GameState.BUILDING_MOTHERSHIP:
			return GameState.MOTHERSHIP_COST
		GameState.BUILDING_SHIP_CRAFTER:
			return GameState.SHIP_CRAFTER_COST
		GameState.BUILDING_COMMAND_CENTER:
			return GameState.COMMAND_CENTER_COST
		_:
			return GameState.EXTRACTOR_COST


func _show_building_info(type: String) -> void:
	var info: Dictionary = BUILDING_INFO[type]
	var cost: int = cost_of(type)
	var lines: Array = [info.body]
	var can_build: bool = true

	# Anything that would stop this particular placement is spelled out in
	# the same popup, rather than silently failing after the press.
	if type == GameState.BUILDING_EXTRACTOR:
		var planet: Node2D = _planet_under_fleet()
		if planet == null:
			lines.append("No planet in reach - fly over one.")
			can_build = false
		elif GameState.has_extractor_at(planet.planet_name):
			lines.append("%s already has an extractor." % planet.planet_name)
			can_build = false
		else:
			lines.append("Will mine %s." % planet.planet_name)
	elif type == GameState.BUILDING_MOTHERSHIP and GameState.has_mothership():
		lines.append("WARNING: only one may exist - this destroys your current one.")

	if can_build and not GameState.can_afford(cost):
		lines.append("Not enough rocks - needs %d, you have %d." % [cost, GameState.rocks])
		can_build = false

	info_title.text = info.title
	info_message.text = "\n\n".join(lines)
	info_cost.amount = cost
	info_build_button.visible = can_build
	pending_build_type = type if can_build else ""
	info_popup.visible = true


func _close_info() -> void:
	info_popup.visible = false
	pending_build_type = ""


func _confirm_build() -> void:
	var type: String = pending_build_type
	if type == "":
		return
	pending_build_type = ""
	info_popup.visible = false

	# Everything is re-checked here rather than trusted from when the popup
	# opened: the fleet keeps flying while it is up, so it can drift off the
	# planet an extractor was going to mine.
	if type == GameState.BUILDING_EXTRACTOR:
		var planet: Node2D = _planet_under_fleet()
		if planet == null or GameState.has_extractor_at(planet.planet_name):
			build_status.text = "No planet in reach any more"
			return
		if not GameState.spend(GameState.EXTRACTOR_COST):
			build_status.text = "Not enough rocks (need %d, have %d)" % [GameState.EXTRACTOR_COST, GameState.rocks]
			return
		GameState.add_extractor(planet.planet_name, planet.position)
		build_menu.visible = false
		return

	if type == GameState.BUILDING_MOTHERSHIP and GameState.has_mothership():
		if not GameState.can_afford(GameState.MOTHERSHIP_COST):
			build_status.text = "Not enough rocks (need %d, have %d)" % [
				GameState.MOTHERSHIP_COST, GameState.rocks
			]
			return
		# Only now is the old one destroyed - never before the new one is
		# known to be affordable, or the player would be left with none.
		GameState.remove_buildings_of_type(GameState.BUILDING_MOTHERSHIP)
		building_field.rebuild_all()

	_try_place(type, cost_of(type))


func _try_place(type: String, cost: int) -> void:
	if not GameState.spend(cost):
		build_status.text = "Not enough rocks (need %d, have %d)" % [cost, GameState.rocks]
		return
	building_field.place(type, fleet.get_centroid())
	build_menu.visible = false


func _refresh_craft_status() -> void:
	craft_status.text = "Interceptor  %d rocks      You have %d      Fleet %d/%d" % [
		GameState.SHIP_COST, GameState.rocks, fleet.ships.size(), GameState.formation.size()
	]


func _on_craft_interceptor() -> void:
	if fleet.ships.size() >= GameState.formation.size():
		craft_status.text = "Fleet is full (%d slots)" % GameState.formation.size()
		return
	if not GameState.spend(GameState.SHIP_COST):
		craft_status.text = "Not enough rocks (need %d, have %d)" % [GameState.SHIP_COST, GameState.rocks]
		return
	fleet.add_ship()
	_refresh_craft_status()


func _on_formation_changed() -> void:
	fleet.apply_formation()


func _on_reset_formation() -> void:
	GameState.reset_formation()
	fleet.apply_formation()
	formation_editor.queue_redraw()