extends SceneTree

# Headless gameplay test: run with
#   godot --headless -s res://tests/test_distorder_energy.gd
# Forgejo #62: sustaining a boost above the fleet's default speed drains
# energy from the fleet hold, continuously, proportional to how far above
# 1.0x the multiplier is.
#
# Most of this is pure GameState math (GameState._advance_distorder_drain,
# called directly the same way other tests call _advance_lab_research/
# _advance_production) - no Main.tscn/Fleet needed for it, which is itself
# proof the drain is scene-independent (it lives in the autoload's own
# _process(), unlike a component's tick() which only runs while its ship's
# scene is loaded) and so "continues correctly across a landing and
# return" without a scene-swap simulation to re-prove that.
#
# Covers:
#   A. sustained boost drains energy at the configured rate; half boost
#      drains proportionally less than full boost
#   B. a small multiplier still drains a nonzero amount over time - no
#      fractional rounding loss
#   D. at exactly 1.0x, energy is never consumed
#   C. hitting zero energy forces the multiplier back to 1.0, and the
#      SpeedFader visibly follows it down with the reason shown

var game_state: Node
var main: Node
var fleet: Node
var fader: Node
var stage: int = 0
var elapsed: float = 0.0


func _initialize() -> void:
	game_state = root.get_node("GameState")
	game_state.reset_progression()
	game_state.fleet_speed_multiplier = 1.0
	game_state.deposit_fleet_resource(GameState.RESOURCE_ENERGY, 1000)


func _process(delta: float) -> bool:
	elapsed += delta
	match stage:
		0:
			# --- D. nothing drains at exactly 1.0x ----------------------------
			var before: int = game_state.fleet_resource(GameState.RESOURCE_ENERGY)
			for i in range(60):
				game_state._advance_distorder_drain(1.0)
			if game_state.fleet_resource(GameState.RESOURCE_ENERGY) != before:
				return _fail_now("energy drained at 1.0x: %d -> %d" \
					% [before, game_state.fleet_resource(GameState.RESOURCE_ENERGY)])
			print("no drain at 1.0x, even over 60 simulated seconds")

			# --- A. full boost drains at the configured rate ------------------
			game_state.fleet_speed_multiplier = GameState.MAX_FLEET_SPEED_MULTIPLIER
			var full_before: int = game_state.fleet_resource(GameState.RESOURCE_ENERGY)
			for i in range(10):
				game_state._advance_distorder_drain(1.0)
			var full_drained: int = full_before - game_state.fleet_resource(GameState.RESOURCE_ENERGY)
			if full_drained != 20:
				return _fail_now("full boost drained %d over 10s, expected 20 (ENERGY_DRAIN_PER_SECOND=2.0)" \
					% full_drained)
			print("full boost drained %d over 10s, matches ENERGY_DRAIN_PER_SECOND" % full_drained)

			# --- A continued: half boost drains proportionally less -----------
			game_state.fleet_speed_multiplier = 2.0
			var half_before: int = game_state.fleet_resource(GameState.RESOURCE_ENERGY)
			for i in range(10):
				game_state._advance_distorder_drain(1.0)
			var half_drained: int = half_before - game_state.fleet_resource(GameState.RESOURCE_ENERGY)
			if half_drained <= 0 or half_drained >= full_drained:
				return _fail_now("half boost drained %d over 10s, expected between 0 and full's %d" \
					% [half_drained, full_drained])
			print("half boost drained %d over 10s - less than full's %d, still nonzero" \
				% [half_drained, full_drained])

			# --- B. a small multiplier still drains a nonzero amount ----------
			game_state.fleet_speed_multiplier = 1.05
			var small_before: int = game_state.fleet_resource(GameState.RESOURCE_ENERGY)
			for i in range(600):
				game_state._advance_distorder_drain(0.1)
			var small_drained: int = small_before - game_state.fleet_resource(GameState.RESOURCE_ENERGY)
			if small_drained <= 0:
				return _fail_now("a small (1.05x) sustained boost drained nothing over 60s - fractional rounding loss")
			print("small boost (1.05x) still drained %d over 60s (no rounding loss)" % small_drained)

			# --- C. running out resets the multiplier and raises the notice ---
			game_state.withdraw_fleet_resource(GameState.RESOURCE_ENERGY,
				game_state.fleet_resource(GameState.RESOURCE_ENERGY))
			game_state.deposit_fleet_resource(GameState.RESOURCE_ENERGY, 5)
			game_state.fleet_speed_multiplier = GameState.MAX_FLEET_SPEED_MULTIPLIER
			game_state.boost_depleted_notice = false
			for i in range(10):
				game_state._advance_distorder_drain(1.0)
			if game_state.fleet_resource(GameState.RESOURCE_ENERGY) != 0:
				return _fail_now("fleet energy did not reach exactly 0, got %d" \
					% game_state.fleet_resource(GameState.RESOURCE_ENERGY))
			if not is_equal_approx(game_state.fleet_speed_multiplier, 1.0):
				return _fail_now("multiplier was not forced back to 1.0 after running out: %f" \
					% game_state.fleet_speed_multiplier)
			if not game_state.boost_depleted_notice:
				return _fail_now("no depleted notice was raised when energy ran out")
			print("running out of energy dropped the multiplier to 1.0 and raised the notice")

			stage = 1
			elapsed = 0.0
			return false
		1:
			# --- C continued: the SpeedFader visibly follows it down ----------
			if elapsed < 0.2:
				return false
			main = load("res://world/Main.tscn").instantiate()
			root.add_child(main)
			fleet = main.get_node("Fleet")
			fader = main.get_node("UI/SpeedFader")
			fleet.spawn_ships(1, Vector2.ZERO, PackedStringArray([GameState.VESSEL_DISTORDER]))
			fader._process(0.0)
			if not fader.visible:
				return _fail_now("fader hidden with a distorder ship in the fleet")

			game_state.deposit_fleet_resource(GameState.RESOURCE_ENERGY, 4)
			game_state.set_fleet_speed_multiplier(GameState.MAX_FLEET_SPEED_MULTIPLIER)
			fader._process(0.0)
			if fader.knob_t < 0.9:
				return _fail_now("fader knob did not reflect the boosted multiplier before draining: %f" \
					% fader.knob_t)

			for i in range(10):
				game_state._advance_distorder_drain(1.0)
			if not is_equal_approx(game_state.fleet_speed_multiplier, 1.0):
				return _fail_now("multiplier was not forced back to 1.0 after running out (with a live fleet)")
			fader._process(0.0)
			if fader.knob_t > 0.05:
				return _fail_now("fader knob did not snap down after the boost was depleted: %f" % fader.knob_t)
			if fader.label.text != "Out of energy!":
				return _fail_now("fader did not show the depleted reason, text was '%s'" % fader.label.text)
			if game_state.boost_depleted_notice:
				return _fail_now("boost_depleted_notice was not consumed by the fader")
			print("fader visibly snapped its knob down and explained the depletion")

			print("TEST_DISTORDER_ENERGY: PASS")
			quit(0)
			return true
	return false


func _fail_now(message: String) -> bool:
	print("TEST_DISTORDER_ENERGY: FAIL (%s)" % message)
	quit(1)
	return true