extends SceneTree

# Headless test: run with
#   godot --headless -s res://tests/test_planet_map_assignment.gd
# Every planet should draw a map of its own surface type at random, and then
# keep it - leaving a planet and coming back must land on the same layout, or
# the place stops feeling like a place.
#
# Two things could break that, and both are silent:
#   - the candidate list is built by scanning a directory, and the order a
#     filesystem lists files in is not something to seed a choice with. The
#     pick indexes into that list, so an unstable order re-deals every planet
#   - the pool itself changes the moment the map editor saves a new setup,
#     which would re-deal planets mid-session even with a perfect seed
#
# Covers:
#   A. the same planet resolves to the same setup, every time
#   B. the setup it draws is always authored for that planet's own profile
#   C. different planets do not all collapse onto one setup
#   D. an assignment survives a new setup file appearing in the pool
#   E. candidates come back in a deterministic order regardless of scan order

const SCRATCH_ID: String = "test_assignment_scratch"
const SCRATCH_PATH: String = "res://PlanetSetups/%s.tres" % SCRATCH_ID


func _initialize() -> void:
	_remove_scratch()
	PlanetSetups.rescan()

	# --- E. deterministic ordering ------------------------------------------
	var profile_id: String = "rocky"
	var ordered: Array = PlanetSetups.setups_for_profile(profile_id)
	if ordered.size() < 2:
		# Not a failure of the code under test, but this file cannot say
		# anything without a pool to draw from - say so rather than passing
		# vacuously.
		_fail("only %d '%s' setups exist, so nothing here can distinguish a stable draw from a fixed one" \
			% [ordered.size(), profile_id])
		return
	var ids: Array = []
	for setup in ordered:
		ids.append(String(setup.setup_id))
	var sorted_ids: Array = ids.duplicate()
	sorted_ids.sort()
	if ids != sorted_ids:
		_fail("setups_for_profile returned %s, which is not sorted - the draw indexes into this, so the order cannot be left to the filesystem" % str(ids))
		return
	print("'%s' pool is deterministic: %s" % [profile_id, str(ids)])

	# --- A/B/C. stable, correctly typed, and actually varied -----------------
	var first_pass: Dictionary = {}
	var planet_ids: Array = []
	for i in range(40):
		planet_ids.append("planet_%d_%d" % [i * 7, i * 13])
	for planet_id in planet_ids:
		var setup: Resource = PlanetSetups.setup_for_planet(planet_id, profile_id)
		if setup == null:
			_fail("%s drew no setup at all" % planet_id)
			return
		if String(setup.surface_profile_id) != profile_id:
			_fail("%s is a '%s' planet but drew a '%s' map" \
				% [planet_id, profile_id, setup.surface_profile_id])
			return
		first_pass[planet_id] = setup

	for planet_id in planet_ids:
		for repeat in range(3):
			if PlanetSetups.setup_for_planet(planet_id, profile_id) != first_pass[planet_id]:
				_fail("%s drew a different map on a later visit" % planet_id)
				return
	print("40 planets each re-drew the same map on every revisit")

	var distinct: Dictionary = {}
	for planet_id in first_pass:
		distinct[first_pass[planet_id].setup_id] = true
	if distinct.size() < 2:
		_fail("all 40 planets drew the same map (%s), so the draw is not random at all" % str(distinct.keys()))
		return
	print("across 40 planets the draw used %d of the %d available maps" % [distinct.size(), ids.size()])

	# --- D. a new map appearing does not re-deal the planets already visited -
	var scratch: Resource = load("res://PlanetSetup.gd").new()
	scratch.setup_id = SCRATCH_ID
	scratch.display_name = "Assignment Scratch"
	scratch.surface_profile_id = profile_id
	var err: int = ResourceSaver.save(scratch, SCRATCH_PATH)
	if err != OK:
		_fail("could not write the scratch setup (error %d)" % err)
		return
	# Exactly what the map editor does after a save.
	PlanetSetups.rescan()
	var live: Dictionary = {}
	var scratch_in_pool: bool = false
	for setup in PlanetSetups.setups_for_profile(profile_id):
		live[setup] = true
		if String(setup.setup_id) == SCRATCH_ID:
			scratch_in_pool = true
	if not scratch_in_pool:
		_remove_scratch()
		_fail("the scratch setup did not enter the pool, so this case proves nothing")
		return

	var moved: int = 0
	var checked: int = 0
	for planet_id in planet_ids:
		# Skipped if the map this planet drew is no longer in the pool. The
		# suite runs tests in parallel against one project directory, so
		# another test's scratch setup can appear and vanish underneath this
		# one - and a planet losing an assignment because its MAP was deleted
		# is correct behaviour, not the re-deal this case is looking for.
		if not live.has(first_pass[planet_id]):
			continue
		checked += 1
		if PlanetSetups.setup_for_planet(planet_id, profile_id) != first_pass[planet_id]:
			moved += 1
	if checked == 0:
		_remove_scratch()
		_fail("every planet's map disappeared from the pool mid-test, so nothing could be checked")
		return
	_remove_scratch()
	PlanetSetups.rescan()
	if moved > 0:
		_fail("saving one new map re-dealt %d of %d already-visited planets" % [moved, checked])
		return
	print("saving a new map left all %d existing assignments alone" % checked)

	print("TEST_PLANET_MAP_ASSIGNMENT: PASS")
	quit(0)


func _remove_scratch() -> void:
	var path: String = ProjectSettings.globalize_path(SCRATCH_PATH)
	if FileAccess.file_exists(path):
		DirAccess.remove_absolute(path)
	if FileAccess.file_exists(path + ".uid"):
		DirAccess.remove_absolute(path + ".uid")


func _fail(message: String) -> void:
	print("TEST_PLANET_MAP_ASSIGNMENT: FAIL (%s)" % message)
	quit(1)