extends SceneTree

# Headless gameplay test: run with
#   godot --headless -s res://tests/test_planet_atmosphere_transition.gd
# Verifies the full enter/exit atmosphere flow now that it's a genuine
# scene swap (Main.tscn <-> PlanetSurface.tscn) rather than an in-place
# overlay: standing on a planet shows the prompt, pressing it fades out
# and swaps to PlanetSurface.tscn with the SAME surviving ship count,
# where no asteroid ever exists and no space-side EnemySpawner/AsteroidField
# node carries over (structurally absent - PlanetSurface.tscn has no such
# nodes at all), and the fleet is still fully flyable. Landed enemies MAY
# still exist post-#43 (PlanetSetupHost places authored ones to guard
# capture points), which is a different thing from the space-side spawner
# leaking across the swap - see the structural check below. Exiting fades
# back to Main.tscn with the fleet restored at the world position it left
# from.

var main_scene: Node
var fleet: Node
var planet_field: Node
var landing_controller: Node
var asteroid_field_ref: Node
var planet_name_label: Label
var enter_button: IconButton
var elapsed: float = 0.0
var stage: int = 0
var target_chunk: Vector2i
var position_before_leaving: Vector2
var cached_fade_duration: float = 0.4
var returned_ship_count: int = -1
var returned_vessel_types: PackedStringArray = PackedStringArray()
var game_state: Node
var expected_vessel_types: PackedStringArray = PackedStringArray([
	GameState.VESSEL_INTERCEPTOR, GameState.VESSEL_SHIELD,
	GameState.VESSEL_INTERCEPTOR, GameState.VESSEL_SHIELD,
	GameState.VESSEL_INTERCEPTOR,
])


func _initialize() -> void:
	var found: bool = false
	for x in range(-15, 15):
		for y in range(-15, 15):
			var chunk: Vector2i = Vector2i(x, y)
			if WorldGen.has_planet_at_chunk(chunk):
				target_chunk = chunk
				found = true
				break
		if found:
			break

	if not found:
		print("FAIL: could not find any chunk with a planet to test with")
		quit(1)
		return

	game_state = root.get_node("GameState")
	var packed: PackedScene = load("res://world/Main.tscn")
	main_scene = packed.instantiate()
	root.add_child(main_scene)
	# change_scene_to_file() operates on current_scene - the real game
	# gets this set automatically via project.godot's run/main_scene on
	# boot, but a hand-built headless test harness has to do it itself.
	current_scene = main_scene

	fleet = main_scene.get_node("Fleet")
	# A new game now flies STARTING_SHIP_COUNT (1) vessel into BASE_FLEET_SIZE
	# (3) slots. This test needs a crewed fleet, so it asks for one outright
	# rather than inheriting whatever a fresh game happens to open with -
	# which is exactly what changed underneath it.
	root.get_node("GameState").unlocked.append_array(["wing", "squadron", "armada"])
	fleet.spawn_ships(5, Vector2.ZERO)
	planet_field = main_scene.get_node("PlanetField")
	landing_controller = main_scene.get_node("LandingController")
	asteroid_field_ref = main_scene.get_node("AsteroidField")
	planet_name_label = main_scene.get_node("UI/PlanetNameLabel")
	enter_button = main_scene.get_node("UI/BuildActionButton")


func _process(delta: float) -> bool:
	elapsed += delta
	match stage:
		0:
			# target_chunk is guaranteed ASTEROID_FIELD biome (a
			# prerequisite for having a planet), so regular drifting
			# asteroids/enemies could also spawn nearby and interfere with
			# a ship during this focused scenario - isolate it, same as
			# test_enemy_combat.gd does for its own scenario.
			#
			# This has to happen here, not in _initialize(): a node's
			# set_process(false) call made before it has fully finished
			# entering the tree doesn't reliably stick - the engine's own
			# (deferred) tree-entry finalization, which runs strictly
			# after _ready(), can silently reset it back to enabled. Here,
			# at the point _ready() is already confirmed complete
			# (fleet.ships is reliably populated by now), it's safe.
			asteroid_field_ref.set_process(false)
			main_scene.get_node("EnemySpawner").set_process(false)
			# Disabling the spawners stops NEW asteroids, but any already
			# placed keep drifting under their own _process and can still
			# collide with a ship mid-test. Clear the existing ones too.
			for a in get_nodes_in_group("asteroids"):
				a.queue_free()
			# A mixed fleet proves the handoff preserves composition rather
			# than merely reconstructing the same number of interceptors.
			fleet.spawn_ships(expected_vessel_types.size(), fleet.get_centroid(),
				expected_vessel_types)

			# Get the fleet into the target chunk's vicinity first so
			# PlanetField's spawn radius covers it - the planet's own exact
			# position within the chunk is randomized, so this is only
			# enough to trigger spawning, not yet close enough to land on.
			var vicinity_pos: Vector2 = WorldGen.chunk_origin(target_chunk) + Vector2.ONE * WorldGen.CHUNK_SIZE * 0.5
			for ship in fleet.ships:
				ship.position = vicinity_pos
			fleet.move_to(vicinity_pos)
			elapsed = 0.0
			stage = 1
			return false
		1:
			if elapsed < planet_field.check_interval + 0.1:
				return false
			if not planet_field.populated_chunks.has(target_chunk):
				print("TEST_PLANET_ATMOSPHERE_TRANSITION: FAIL (planet never spawned)")
				quit(1)
				return true
			var planet: Node2D = planet_field.populated_chunks[target_chunk][0]
			for ship in fleet.ships:
				ship.position = planet.position
			fleet.move_to(planet.position)
			elapsed = 0.0
			stage = 2
			return false
		2:
			if elapsed < 0.5:
				return false
			var prompt_ok: bool = enter_button.visible and planet_name_label.visible and planet_name_label.text != ""
			print("prompt_ok=%s ship_count=%d name_text=%s" % [prompt_ok, fleet.ships.size(), planet_name_label.text])
			if not prompt_ok:
				print("TEST_PLANET_ATMOSPHERE_TRANSITION: FAIL (prompt never appeared)")
				quit(1)
				return true

			# Let the fleet finish settling onto the planet before recording
			# where it left from. Capturing mid-settle made this test
			# intermittently fail later: the baseline was a still-moving
			# centroid, while the return always places the fleet exactly on
			# the planet, so the two could differ by more than the tolerance.
			for ship in fleet.ships:
				if ship.position.distance_to(ship.move_target) > ship.arrive_radius:
					return false

			position_before_leaving = fleet.get_centroid()
			cached_fade_duration = landing_controller.fade_duration
			_press(enter_button)
			elapsed = 0.0
			stage = 3
			return false
		3:
			# Fade-out + change_scene_to_file + fade-in. landing_controller
			# gets freed once the scene swap completes, so the wait
			# duration must be cached beforehand, not read live each frame.
			if elapsed < cached_fade_duration + 0.3:
				return false
			var on_surface: bool = current_scene != null and current_scene.name == "PlanetSurface"
			print("on_surface=%s current_scene=%s" % [on_surface, current_scene])
			if not on_surface:
				print("TEST_PLANET_ATMOSPHERE_TRANSITION: FAIL (did not swap to PlanetSurface)")
				quit(1)
				return true

			var surface_fleet: Node = current_scene.get_node("Fleet")
			var ship_count_ok: bool = surface_fleet.ships.size() == 5
			var composition_ok: bool = surface_fleet.vessel_types() == expected_vessel_types
			var no_asteroids: bool = get_nodes_in_group("asteroids").is_empty()
			# Landed enemies from an authored PlanetSetup are expected
			# post-#43 (they guard capture points) - what this test actually
			# owes is that the SPACE-SIDE spawner nodes never carry across,
			# checked structurally rather than by assuming zero enemies.
			var no_space_spawners: bool = current_scene.get_node_or_null("EnemySpawner") == null \
				and current_scene.get_node_or_null("AsteroidField") == null
			print("ship_count_ok=%s (count=%d) no_asteroids=%s no_space_spawners=%s" % [
				ship_count_ok, surface_fleet.ships.size(), no_asteroids, no_space_spawners
			])
			if not (ship_count_ok and composition_ok and no_asteroids and no_space_spawners):
				print("TEST_PLANET_ATMOSPHERE_TRANSITION: FAIL (surface scene contents wrong)")
				quit(1)
				return true

			# Clear the landed garrison before flying anywhere. The authored
			# enemies are legitimately there (checked above), but this test is
			# about the TRANSITION - it hands the fleet down, flies it, and
			# hands it back, then asserts every vessel survived the round
			# trip. A chaser destroying one on the way is a correct outcome of
			# a fight this test never meant to pick, and #82 made that outcome
			# more likely by making contact lethal to both. It surfaced when
			# #88 raised every speed by 1.5 and the same 2.5s flight started
			# covering enough ground to reach one.
			for enemy in get_nodes_in_group("enemies"):
				if is_instance_valid(enemy):
					enemy.queue_free()

			# Confirm the fleet is genuinely flyable on the surface.
			var start_pos: Vector2 = surface_fleet.get_centroid()
			surface_fleet.move_to(start_pos + Vector2(400, 0))
			elapsed = 0.0
			stage = 4
			return false
		4:
			if elapsed < 2.5:
				return false
			var surface_fleet: Node = current_scene.get_node("Fleet")
			var moved_ok: bool = surface_fleet.get_centroid().x > 300.0
			print("moved_ok=%s centroid=%s" % [moved_ok, surface_fleet.get_centroid()])
			if not moved_ok:
				print("TEST_PLANET_ATMOSPHERE_TRANSITION: FAIL (fleet could not move on the surface)")
				quit(1)
				return true

			var exit_button: IconButton = current_scene.get_node("UI/ExitButton")
			var surface_controller: Node = current_scene.get_node("SurfaceController")
			cached_fade_duration = surface_controller.fade_duration
			_press(exit_button)
			elapsed = 0.0
			stage = 5
			return false
		5:
			# Poll for the swap rather than waiting a fixed duration, so the
			# ship count can be captured on the very FIRST frame back. The
			# fresh Main.tscn populates asteroids during its own _ready(),
			# and they can destroy a ship within a few frames - waiting out
			# the fade first meant sometimes measuring a fleet that had
			# already lost one to a collision, which says nothing about the
			# transition being tested here.
			var back_in_space: bool = current_scene != null and current_scene.name == "Main"
			if not back_in_space:
				if elapsed > cached_fade_duration + 3.0:
					print("TEST_PLANET_ATMOSPHERE_TRANSITION: FAIL (did not return to Main)")
					quit(1)
					return true
				return false
			if returned_ship_count == -1:
				print("back_in_space=%s current_scene=%s" % [back_in_space, current_scene])

			# Returning builds a BRAND NEW Main.tscn, so the spawners
			# silenced back in stage 0 are live again in this fresh scene.
			# Silence them on the first frame back, and record the ship count
			# right then: asteroids populate immediately on scene load and
			# could destroy a ship during the settle wait below, which is a
			# gameplay collision rather than anything about the transition
			# this test is checking.
			var space_fleet: Node = current_scene.get_node("Fleet")
			if returned_ship_count == -1:
				current_scene.get_node("AsteroidField").set_process(false)
				current_scene.get_node("EnemySpawner").set_process(false)
				for a in get_nodes_in_group("asteroids"):
					a.queue_free()
				returned_ship_count = space_fleet.ships.size()
				returned_vessel_types = space_fleet.vessel_types()

			# Ships respawn in a wedge and then steer into formation, so the
			# centroid only means anything once they have actually stopped.
			# Sampling after a fixed delay made this test intermittently fail
			# by measuring a fleet still on its way in.
			for ship in space_fleet.ships:
				if ship.position.distance_to(ship.move_target) > ship.arrive_radius:
					return false

			# Assert on the HANDOFF, not on how many ships survive the next
			# few frames. Asteroids populate during the fresh scene's own
			# _ready(), so one can spawn overlapping the returning fleet and
			# destroy a ship on the first physics frame - before any test
			# code can run. That is a gameplay collision, not a transition
			# fault, and made this test fail roughly 1 run in 12. What the
			# transition owes us is that the surviving count was carried
			# across correctly and a fleet came back.
			var handoff_ok: bool = game_state.surviving_ship_count == 5
			var ship_count_ok: bool = handoff_ok and returned_ship_count >= 1
			var composition_ok: bool = returned_vessel_types == expected_vessel_types
			var position_ok: bool = space_fleet.get_centroid().distance_to(position_before_leaving) < 50.0
			print("handoff=%d returned_ships=%d ship_count_ok=%s position_ok=%s centroid=%s expected=%s" % [
				game_state.surviving_ship_count, returned_ship_count,
				ship_count_ok, position_ok, space_fleet.get_centroid(), position_before_leaving
			])
			if ship_count_ok and composition_ok and position_ok:
				print("TEST_PLANET_ATMOSPHERE_TRANSITION: PASS")
				quit(0)
			else:
				print("TEST_PLANET_ATMOSPHERE_TRANSITION: FAIL (return state wrong)")
				quit(1)
			return true
	return false


func _press(button: IconButton) -> void:
	var down: InputEventScreenTouch = InputEventScreenTouch.new()
	down.pressed = true
	button._gui_input(down)
	var up: InputEventScreenTouch = InputEventScreenTouch.new()
	up.pressed = false
	button._gui_input(up)