extends Node2D

# Space-side: bootstraps the fleet on Main.tscn startup (a fresh 5-ship
# fleet at the origin on first launch, or GameState's surviving ship
# count/position if we just returned from a planet's surface), shows an
# "enter atmosphere" prompt (name + button) when the fleet is standing on
# a landable planet, and - on press - fades out and swaps to a completely
# separate PlanetSurface.tscn scene (not an overlay toggled in place), so
# asteroids/enemies genuinely cannot exist there rather than merely being
# hidden. Fleet size and the world position/zoom to return to are handed
# off via the GameState autoload, since change_scene_to_file() tears down
# this whole scene tree.

@export var fade_duration: float = 0.4
@export var prompt_debounce_time: float = 0.15

@onready var planet_field: Node2D = get_node("../PlanetField")
@onready var asteroid_field: Node2D = get_node("../AsteroidField")
@onready var fleet: Node2D = get_node("../Fleet")
@onready var camera: Camera2D = get_node("../Camera2D")
@onready var planet_name_label: Label = get_node("../UI/PlanetNameLabel")
@onready var enter_button: IconButton = get_node("../UI/EnterAtmosphereButton")
@onready var world_map: Control = get_node("../UI/WorldMap")
@onready var build_controller: Node2D = get_node("../BuildController")
@onready var fade_rect: ColorRect = get_node("../FadeOverlay/FadeRect")

var current_planet: Node2D = null
var transitioning: bool = false
var pending_planet: Node2D = null
var pending_time: float = 0.0


func _ready() -> void:
	enter_button.pressed.connect(_on_enter_pressed)

	if GameState.has_return_position:
		fleet.spawn_ships(GameState.surviving_ship_count, GameState.return_world_position,
			GameState.surviving_vessel_types)
		camera.position = GameState.return_world_position
		camera.zoom = Vector2(GameState.return_camera_zoom, GameState.return_camera_zoom)
		GameState.has_return_position = false
	else:
		# A brand new game. STARTING_SHIP_COUNT rather than a literal: this
		# said 5, which was the old BASE_FLEET_SIZE written out by hand, and
		# it silently became "however many slots exist" once max_fleet_size()
		# clamped it. The opening fleet size is one decision and it lives in
		# GameState.
		fleet.spawn_ships(GameState.STARTING_SHIP_COUNT, Vector2.ZERO)

	# AsteroidField/PlanetField normally only populate nearby chunks once
	# their own check_interval timer elapses (~1s) - fine during normal
	# continuous play (things appear far off-screen, gradually), but
	# right after a fresh scene load it means an empty-looking world for
	# a second before asteroids/the planet visibly pop in. Force an
	# immediate synchronous populate now that the fleet is correctly
	# positioned, so nothing is missing on the very first visible frame.
	# DEFERRED, not called straight through. Everything above runs inside the
	# single frame that builds Main.tscn, and these two populate 25 and 49
	# chunks of world on top of it - 150-odd asteroids plus planets and their
	# visuals. On a phone browser that frame is where the scene appeared to
	# hang forever: nothing can paint until it ends, so a slow frame and a
	# freeze look identical. One frame later is still immediate to the eye,
	# and it lets the scene draw first.
	asteroid_field.update_chunks.call_deferred()
	planet_field.update_chunks.call_deferred()


func _process(delta: float) -> void:
	if transitioning:
		return

	if world_map.visible or build_controller.is_showing_building_prompt():
		# Context actions belong to BuildController. This controller owns the
		# debounced planet selection and label, and suppresses both while a modal
		# screen is open.
		current_planet = null
		pending_planet = null
		planet_name_label.visible = false
		return

	# Debounced: only commit a visible/hidden change once the raw
	# landing-detection result has stayed the same for prompt_debounce_time
	# in a row, instead of reacting to every single frame's reading. Belt
	# and suspenders on top of get_planet_fleet_is_on() already using the
	# fleet's centroid (a single stable number - see Planet.gd) rather
	# than any individual ship's position, so this only has to absorb
	# genuine sub-debounce-window boundary crossings, not constant noise.
	var detected_planet: Node2D = planet_field.get_planet_fleet_is_on()
	if detected_planet != pending_planet:
		pending_planet = detected_planet
		pending_time = 0.0
	else:
		pending_time += delta

	if pending_time < prompt_debounce_time or pending_planet == current_planet:
		return

	current_planet = pending_planet
	if current_planet != null:
		planet_name_label.text = current_planet.planet_name
		planet_name_label.visible = true
	else:
		planet_name_label.visible = false


func _on_enter_pressed() -> void:
	if transitioning or current_planet == null:
		return
	transitioning = true
	planet_name_label.visible = false
	enter_button.visible = false

	GameState.has_return_position = true
	GameState.surviving_ship_count = fleet.ships.size()
	GameState.surviving_vessel_types = fleet.vessel_types()
	# The planet's own position, not fleet.get_centroid() - the fleet only
	# needs to be somewhere within the planet's landing radius (not
	# centered exactly on it) for the prompt to show, so the centroid can
	# be tens of units off from the planet. Returning should always place
	# the fleet back at the planet itself.
	GameState.return_world_position = current_planet.position
	GameState.return_camera_zoom = camera.zoom.x
	GameState.planet_name = current_planet.planet_name
	GameState.planet_id = current_planet.planet_id
	GameState.planet_definition_id = current_planet.definition_id

	var tween: Tween = create_tween()
	tween.tween_property(fade_rect, "color:a", 1.0, fade_duration)
	tween.tween_callback(_enter_surface)


func _enter_surface() -> void:
	get_tree().change_scene_to_file("res://PlanetSurface.tscn")