extends SceneTree

const Controller := preload("res://world/jajce/GrassInteractionController.gd")

var failures: Array[String] = []


class RestoreSource:
	extends Node
	signal state_restored


func _initialize() -> void:
	call_deferred("_run")


func _run() -> void:
	_check_trail_lifecycle()
	await _check_loaded_binding()
	if failures.is_empty():
		print("Foliage interaction checks passed")
		quit(0)
	else:
		for failure in failures:
			push_error(failure)
		quit(1)


func _check_trail_lifecycle() -> void:
	var field := FoliageTrailMap.new()
	var positions: Dictionary[int, Vector3] = {1: Vector3(0.25, 0, 0.25)}
	field.advance(0.08, Vector3.ZERO, positions)
	positions[1] = Vector3(2.25, 0, 0.25)
	field.advance(0.08, Vector3.ZERO, positions)
	_check(_sample(field, Vector2(1.25, 0.25)).b > 0.9, "Walking should leave a continuous trail")
	_check(
		_sample(field, Vector2(1.25, 0.75)).g > 0 and _sample(field, Vector2(1.25, -0.25)).g < 0,
		"The two sides of a trail should bend away from the travelled line"
	)
	positions[1] = Vector3(18.25, 0, 0.25)
	field.advance(0.08, Vector3.ZERO, positions)
	_check(_sample(field, Vector2(10.25, 0.25)).b == 0, "Teleports must not paint connecting lines")
	_check(
		_sample(field, Vector2(18.25, 0.25)).b > 0.9,
		"Teleported actors still press their destination"
	)
	field.advance(0.08, Vector3(1, 0, 1), {})
	_check(
		_sample(field, Vector2(1.25, 0.25)).b > 0.8,
		"Camera movement must keep trails in world space"
	)
	field.advance(4.0, Vector3.ZERO, {})
	var recovering := _sample(field, Vector2(1.25, 0.25)).b
	_check(recovering > 0.1 and recovering < 0.6, "Abandoned trails should gradually recover")
	field.advance(4.1, Vector3.ZERO, {})
	_check(
		(field.get("_cells") as Dictionary).is_empty(),
		"Recovered trails should release sparse history"
	)
	positions[1] = Vector3(0.25, 6, 0.25)
	field.advance(0.08, Vector3.ZERO, positions)
	var elevated := _sample(field, Vector2(0.25, 0.25))
	_check(
		is_equal_approx(elevated.a / elevated.b, 6.0),
		"Foot height must reach the shader for bridge rejection"
	)
	field.advance(0.08, Vector3(300, 0, 300), {})
	_check((field.get("_cells") as Dictionary).is_empty(), "Off-window trails must be discarded")
	positions[1] = Vector3(2.25, 0, 0.25)
	field.advance(0.08, Vector3.ZERO, positions)
	_check(
		_sample(field, Vector2(1.25, 0.25)).b == 0,
		"Re-entering actors must not connect to stale positions"
	)
	field.clear()
	_check(_sample(field, Vector2(2.25, 0.25)).b == 0, "Reset must clear the uploaded field")
	_check(
		(field.get("_previous_positions") as Dictionary).is_empty(),
		"Reset must discard actor history"
	)


func _check_loaded_binding() -> void:
	var stage := Node3D.new()
	root.add_child(stage)
	var camera := Camera3D.new()
	stage.add_child(camera)
	camera.current = true
	var simulation := RestoreSource.new()
	simulation.name = "SimulationManager"
	stage.add_child(simulation)
	var world := Node3D.new()
	stage.add_child(world)
	var terrain := Node3D.new()
	world.add_child(terrain)
	var patch := (
		load("res://world/jajce/StylizedBerryPatch.tscn").instantiate() as StylizedBerryPatch
	)
	world.add_child(patch)
	patch.scale = Vector3(1.2, 0.8, 1.1)
	patch.rotation.y = 0.6
	var controller := Controller.new()
	controller.grass_material = (
		load("res://world/jajce/materials/cozy_grass_material.tres").duplicate(true)
	)
	terrain.add_child(controller)
	var foreign := Node3D.new()
	root.add_child(foreign)
	foreign.add_to_group("grass_interactors")
	var actors: Array[Node3D] = []
	for index in 12:
		var actor := Node3D.new()
		stage.add_child(actor)
		actor.position.x = 1.0 + index
		actor.add_to_group("grass_interactors")
		actors.append(actor)
	await process_frame
	controller.set_process(false)
	controller.call("_refresh_interactors", 0.08)
	var material := controller.grass_material
	var positions: PackedVector3Array = material.get_shader_parameter("interactor_positions")
	_check(
		int(material.get_shader_parameter("interactor_count")) == 8,
		"Contact work must respect the eight-actor cap"
	)
	_check(
		positions[0] == actors[0].position,
		"A closer actor in another scene container must be rejected"
	)
	_check(
		bool(material.get_shader_parameter("foliage_trails_enabled")),
		"Loaded grass must enable its trail field"
	)
	var leaves := patch.get_node("Leaves") as MultiMeshInstance3D
	var berries := patch.get_node("Berries") as MultiMeshInstance3D
	var leaf_material := leaves.multimesh.mesh.surface_get_material(0) as ShaderMaterial
	var berry_material := berries.multimesh.mesh.surface_get_material(0) as ShaderMaterial
	_check(
		(
			(
				leaf_material.get_shader_parameter("foliage_trail_map")
				== material.get_shader_parameter("foliage_trail_map")
			)
			and (
				berry_material.get_shader_parameter("foliage_trail_map")
				== material.get_shader_parameter("foliage_trail_map")
			)
		),
		"Bush leaves, berries and meadow must use the same world-local footprint field"
	)
	var visible_berries := patch.get_visible_berry_count()
	actors[0].hide()
	controller.primary_interactor_path = controller.get_path_to(actors.back())
	controller.max_interactors = 4
	controller.call("_refresh_interactors", 0.12)
	positions = material.get_shader_parameter("interactor_positions")
	_check(
		(
			int(material.get_shader_parameter("interactor_count")) == 4
			and positions[0].x == 12
			and positions[1].x == 2
		),
		"Balanced must reserve the primary actor slot, cap actors and ignore hidden visuals"
	)
	simulation.state_restored.emit()
	_check(
		not bool(material.get_shader_parameter("foliage_trails_enabled")),
		"Successful restores must clear visual trails immediately"
	)
	controller.set_interaction_enabled(false)
	_check(not controller.is_processing(), "Low quality must stop interaction updates")
	_check(
		not bool(leaf_material.get_shader_parameter("foliage_trails_enabled")),
		"Low quality must release bushes as well as grass"
	)
	_check(
		int(material.get_shader_parameter("interactor_count")) == 0,
		"Low quality must clear direct contacts"
	)
	_check(
		patch.get_visible_berry_count() == visible_berries,
		"Contact bending must not change resource presentation amounts"
	)
	controller.set_interaction_enabled(true)
	controller.call("_refresh_interactors", 0.08)
	_check(
		bool(berry_material.get_shader_parameter("foliage_trails_enabled")),
		"Bush interaction must resume after Low quality"
	)
	var other_field := FoliageTrailMap.new()
	_check(
		other_field.texture != material.get_shader_parameter("foliage_trail_map"),
		"Each world must own a distinct trail texture"
	)
	foreign.free()
	stage.free()
	await process_frame


func _sample(field: FoliageTrailMap, position: Vector2) -> Color:
	var image := field.get("_image") as Image
	var pixel := Vector2i(
		(position - Vector2(field.world_rect.x, field.world_rect.y)) / field.CELL_SIZE
	)
	return image.get_pixelv(pixel)


func _check(condition: bool, message: String) -> void:
	if not condition:
		failures.append(message)