extends SceneTree

# Headless gameplay test: run with
#   godot --headless -s res://tests/test_outpost_garrison_patrol.gd
# Forgejo #105 (#97g): "When a vessel is assigned to an outpost, it
# navigates around the outpost by itself, attacking nearby ennemies if any
# are detected."
#
# Covers:
#   A. a crewed outpost puts a real vessel in the world, and that vessel is
#      NOT in the fleet - it must not follow the formation, must not eat a
#      fleet slot, and must not fly off when the player leaves
#   B. left alone it WANDERS its post: it visits genuinely different places,
#      it is actually travelling rather than sliding, and it faces where it
#      is going (#109 - it used to walk a circle in steps shorter than
#      Ship's arrive_radius, so every frame it snapped and zeroed its
#      velocity, and Ship only turns while it is moving)
#   C. an enemy inside its detection range is engaged and shot at
#   D. it will not be walked away: an enemy beyond the leash is ignored, and
#      an engagement never drags it further than the leash from its post
#   E. it goes back to patrolling once the enemy is gone
#   F. losing a garrison vessel frees the berth, so it gets crewed again
#   G. enemies fight back - a garrison vessel is a target like any other
#   H. #186 - with no hostile nearby, the same weapon-target contract lets a
#      garrison shoot asteroids for ore

var game_state: Node
var main: Node
var fleet: Node
var field: Node
var outpost_id: int = 0
var guard: Node2D
var component: Node
var enemy: Node2D
var asteroid: Node2D
var stage: int = 0
var elapsed: float = 0.0
var orbit_min: float = INF
var orbit_max: float = 0.0
var visited: Array = []
var top_speed: float = 0.0
var moving_frames: int = 0
var facing_frames: int = 0
var max_from_post: float = 0.0
var dummy_hp_before: int = 0


func _initialize() -> void:
	# GameState is an autoload: a bare GameState.<instance member> does not
	# compile in a SceneTree script, so the node is fetched by name instead.
	game_state = root.get_node("GameState")
	game_state.buildings.clear()
	game_state.extractors.clear()
	game_state.transporters.clear()
	game_state.stored_vessels.clear()
	game_state.vessel_deliveries.clear()
	game_state.reset_progression()
	game_state.reset_waves()
	game_state.unlocked.append("forward_bases")
	main = load("res://world/Main.tscn").instantiate()
	root.add_child(main)
	current_scene = main
	fleet = main.get_node("Fleet")
	field = main.get_node("GarrisonField")


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


# A pinned target that neither shoots back nor dies. The point of these
# stages is where the GARRISON goes and whether it fires, and a sniper that
# killed the guard mid-check, or a chaser that died to it, would end the
# observation before the thing being measured had happened.
func _dummy(at: Vector2) -> Node2D:
	var dummy: Node2D = load("res://enemies/Enemy.tscn").instantiate()
	dummy.enemy_id = "chaser"
	dummy.position = at
	main.add_child(dummy)
	dummy.speed = 0.0
	dummy.hp = 100000
	return dummy


func _process(delta: float) -> bool:
	elapsed += delta
	match stage:
		0:
			if elapsed < 0.3:
				return false
			main.get_node("EnemySpawner").set_process(false)
			main.get_node("AsteroidField").set_process(false)
			for hazard in get_nodes_in_group("asteroids") + get_nodes_in_group("enemies"):
				if is_instance_valid(hazard):
					hazard.queue_free()
			# The fleet is parked a long way off, so nothing here is the
			# fleet's doing.
			fleet.spawn_ships(1, Vector2(-9000.0, 0.0),
				PackedStringArray([GameState.VESSEL_INTERCEPTOR]))
			fleet.ships[0].move_target = fleet.ships[0].position

			main.get_node("BuildingField").place(GameState.BUILDING_OUTPOST, Vector2.ZERO)
			outpost_id = int(game_state.buildings[-1].id)
			game_state.set_garrison_desired(outpost_id, GameState.VESSEL_INTERCEPTOR, 1)
			game_state.garrison_crew(outpost_id).append(GameState.VESSEL_INTERCEPTOR)
			elapsed = 0.0
			stage = 1
			return false
		1:
			if elapsed < 0.3:
				return false
			# --- A. a real vessel, and not a fleet one -------------------
			var here: Array = field.ships_at(outpost_id)
			if here.size() != 1:
				return _fail("a crewed outpost put %d vessels in the world" % here.size())
			guard = here[0]
			component = guard.get_component("garrison")
			if component == null:
				return _fail("the garrison vessel has no garrison component steering it")
			if guard in fleet.ships:
				return _fail("the garrison vessel joined the fleet")
			if fleet.ships.size() != 1:
				return _fail("stationing a vessel changed the fleet to %d ships" % fleet.ships.size())
			print("outpost crewed with 1 vessel, fleet still %d and untouched" % fleet.ships.size())
			elapsed = 0.0
			stage = 2
			return false
		2:
			# --- B. it wanders its post ---------------------------------
			var from_post: float = guard.global_position.length()
			orbit_min = minf(orbit_min, from_post)
			orbit_max = maxf(orbit_max, from_post)
			visited.append(guard.global_position)
			var speed: float = guard.velocity.length()
			top_speed = maxf(top_speed, speed)
			if speed > 40.0:
				# Facing is only meaningful while actually travelling, which
				# is the whole of what #109 was about. Measured as a FRACTION
				# of the travel rather than as a worst instant: a vessel that
				# has just been given a new heading is legitimately still
				# swinging onto it at its own rotation_speed, and one frame
				# mid-turn says nothing about whether it flies nose-first.
				moving_frames += 1
				var drift: float = absf(angle_difference(guard.rotation,
					guard.velocity.angle() + PI / 2.0))
				if drift <= PI / 4.0:
					facing_frames += 1
			if elapsed < 8.0:
				return false
			if component.is_engaging():
				return _fail("the garrison thinks it is fighting with no enemy on the map")
			if orbit_max > component.leash_range:
				return _fail("patrolling took it %.0fpx from its post, past the %.0fpx leash" \
					% [orbit_max, component.leash_range])
			if top_speed < 60.0:
				return _fail("the picket never got above %.0fpx/s - it is sliding, not flying" \
					% top_speed)
			if moving_frames <= 0:
				return _fail("it never travelled at all")
			var aligned: float = float(facing_frames) / float(moving_frames)
			if aligned < 0.7:
				return _fail("it was pointing where it was going for only %.0f%% of its travel" \
					% (aligned * 100.0))
			# Genuinely different places, not one path walked over and over.
			var spread: float = 0.0
			for a in visited:
				for b in visited:
					spread = maxf(spread, a.distance_to(b))
			if spread < 120.0:
				return _fail("everywhere it went was within %.0fpx - that is not wandering" % spread)
			print("wandered %.0fpx across, %.0f-%.0fpx from its post, up to %.0fpx/s, nose-first %.0f%% of the way" \
				% [spread, orbit_min, orbit_max, top_speed, aligned * 100.0])

			# --- D (first half). an enemy beyond the leash is ignored ----
			enemy = _dummy(Vector2(component.leash_range + component.engage_distance + 900.0, 0.0))
			elapsed = 0.0
			stage = 3
			return false
		3:
			if elapsed < 1.0:
				return false
			if component.is_engaging():
				return _fail("the garrison went after an enemy well beyond its leash")
			print("an enemy %.0fpx out is left alone" % enemy.global_position.length())
			enemy.queue_free()

			# --- C. an enemy in reach is engaged and shot at -------------
			enemy = _dummy(Vector2(300.0, 0.0))
			dummy_hp_before = enemy.hp
			max_from_post = 0.0
			elapsed = 0.0
			stage = 4
			return false
		4:
			if not is_instance_valid(guard):
				return _fail("the garrison vessel was destroyed mid-engagement")
			max_from_post = maxf(max_from_post, guard.global_position.length())
			if elapsed < 2.5:
				return false
			if not component.is_engaging():
				return _fail("an enemy 300px from the outpost was not engaged")
			# Damage taken, not projectiles in flight: a bolt that has already
			# connected has freed itself, so counting live ones at an instant
			# reads zero exactly when the gun is working best.
			if enemy.hp >= dummy_hp_before:
				return _fail("the garrison engaged but the enemy took no damage")
			# --- D (second half). the leash holds during a fight ---------
			if max_from_post > component.leash_range + 60.0:
				return _fail("the fight pulled it %.0fpx from its post, past a %.0fpx leash" \
					% [max_from_post, component.leash_range])
			print("engaged, took %d hp off it, and stayed within %.0fpx of its post" \
				% [dummy_hp_before - enemy.hp, max_from_post])

			# --- G. and it can be fought back ---------------------------
			var targets: Script = load("res://enemies/EnemyTargets.gd")
			var picked: Node2D = targets.nearest_ship(main, enemy.global_position)
			if picked != guard:
				return _fail("an enemy beside the garrison picks %s instead of it - it cannot be fought back" \
					% ("nothing" if picked == null else str(picked.name)))
			print("enemies see the garrison as a target too")

			if is_instance_valid(enemy):
				enemy.queue_free()
			elapsed = 0.0
			stage = 5
			return false
		5:
			# --- E. back to the patrol ----------------------------------
			if elapsed < 1.5:
				return false
			if component.is_engaging():
				return _fail("the garrison is still fighting an enemy that is gone")
			print("stood down and went back to its patrol")

			# --- H. asteroids are valid lower-priority targets -----------
			asteroid = load("res://world/Asteroid.tscn").instantiate()
			asteroid.position = Vector2(300.0, 0.0)
			asteroid.velocity = Vector2.ZERO
			main.add_child(asteroid)
			asteroid.hp = 100000
			dummy_hp_before = asteroid.hp
			elapsed = 0.0
			stage = 6
			return false
		6:
			if elapsed < 2.5:
				return false
			if not component.is_engaging():
				return _fail("an asteroid beside the outpost was not engaged")
			if asteroid.hp >= dummy_hp_before:
				return _fail("the garrison engaged an asteroid but never shot it")
			print("garrison shot a nearby asteroid through the shared target contract")
			asteroid.queue_free()
			elapsed = 0.0
			stage = 7
			return false
		7:
			if elapsed < 0.5:
				return false

			# --- F. a lost vessel frees its berth ------------------------
			if game_state.garrison_crew(outpost_id).size() != 1:
				return _fail("the crew is not 1 before the kill")
			guard.take_damage(1)
			elapsed = 0.0
			stage = 8
			return false
		8:
			if elapsed < 0.3:
				return false
			if not game_state.garrison_crew(outpost_id).is_empty():
				return _fail("a destroyed garrison vessel still holds its berth")
			if game_state.garrison_desired_of(outpost_id, GameState.VESSEL_INTERCEPTOR) != 1:
				return _fail("losing the vessel cancelled the order as well")
			if field.ships_at(outpost_id).size() != 0:
				return _fail("the dead vessel is still stationed")
			print("losing the vessel frees the berth and leaves the order standing")

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