extends SceneTree

## Asset-free contract, dependency and timing regression for WMO placements.

const RESOLVER_SCRIPT := preload("res://src/render/wmo/wmo_placement_resolver.gd")
const RESOLVER_PATH := "res://src/render/wmo/wmo_placement_resolver.gd"
const LOADER_PATH := "res://src/scenes/streaming/streaming_world_loader.gd"


func _initialize() -> void:
	var failures: Array[String] = []
	_verify_path_normalization(failures)
	_verify_positive_unique_id(failures)
	_verify_synthetic_unique_keys(failures)
	_verify_default_transform(failures)
	_verify_position_rotation_and_scale(failures)
	_verify_unclamped_scale(failures)
	_verify_node_property_equivalence(failures)
	_verify_source_boundaries(failures)
	_verify_fresh_stateless_results(failures)
	var elapsed_milliseconds := _verify_bounded_timing(failures)
	if not failures.is_empty():
		for failure in failures:
			push_error("WMO_PLACEMENT_RESOLVER: %s" % failure)
		quit(1)
		return
	print(
		"WMO_PLACEMENT_RESOLVER PASS cases=9 iterations=20000 elapsed_ms=%.3f"
		% elapsed_milliseconds
	)
	quit(0)


func _verify_path_normalization(failures: Array[String]) -> void:
	var resolver := RESOLVER_SCRIPT.new()
	_expect_equal_string(
		resolver.normalize_relative_path("World\\WMO\\Stormwind\\Keep.WMO"),
		"world/wmo/stormwind/keep.wmo",
		"slash and case normalization",
		failures
	)
	_expect_equal_string(resolver.normalize_relative_path(""), "", "empty path", failures)


func _verify_positive_unique_id(failures: Array[String]) -> void:
	var resolver := RESOLVER_SCRIPT.new()
	_expect_equal_string(
		resolver.resolve_unique_key({"unique_id": 11785}, "31:49", 6),
		"uid:11785",
		"positive unique ID",
		failures
	)


func _verify_synthetic_unique_keys(failures: Array[String]) -> void:
	var resolver := RESOLVER_SCRIPT.new()
	for placement in [{}, {"unique_id": 0}, {"unique_id": -4}]:
		_expect_equal_string(
			resolver.resolve_unique_key(placement, "31:49", 6),
			"tile:31:49:6",
			"synthetic unique key",
			failures
		)


func _verify_default_transform(failures: Array[String]) -> void:
	var resolver := RESOLVER_SCRIPT.new()
	var transform: Transform3D = resolver.resolve_world_transform({})
	_expect_basis_near(transform.basis, Basis.IDENTITY, "default basis", failures)
	_expect_vector_near(transform.origin, Vector3.ZERO, "default origin", failures)


func _verify_position_rotation_and_scale(failures: Array[String]) -> void:
	var resolver := RESOLVER_SCRIPT.new()
	var position := Vector3(10.0, 20.0, 30.0)
	var rotation := Vector3(0.2, -0.4, 0.6)
	var transform: Transform3D = resolver.resolve_world_transform({
		"pos": position,
		"rot": rotation,
		"scale": 2.5,
	})
	_expect_basis_near(
		transform.basis,
		Basis.from_euler(rotation).scaled(Vector3.ONE * 2.5),
		"rotated scaled basis",
		failures
	)
	_expect_vector_near(transform.origin, position, "world origin", failures)


func _verify_unclamped_scale(failures: Array[String]) -> void:
	var resolver := RESOLVER_SCRIPT.new()
	var zero_transform: Transform3D = resolver.resolve_world_transform({"scale": 0.0})
	_expect_basis_near(
		zero_transform.basis,
		Basis.IDENTITY.scaled(Vector3.ZERO),
		"zero scale",
		failures
	)
	var negative_transform: Transform3D = resolver.resolve_world_transform({"scale": -2.0})
	_expect_basis_near(
		negative_transform.basis,
		Basis.IDENTITY.scaled(Vector3.ONE * -2.0),
		"negative scale",
		failures
	)


func _verify_node_property_equivalence(failures: Array[String]) -> void:
	var resolver := RESOLVER_SCRIPT.new()
	for scale_value in [2.5, 0.0, -2.0]:
		var placement := {
			"pos": Vector3(10.0, 20.0, 30.0),
			"rot": Vector3(0.2, -0.4, 0.6),
			"scale": scale_value,
		}
		var historical_node := Node3D.new()
		historical_node.position = placement["pos"]
		historical_node.rotation = placement["rot"]
		historical_node.scale = Vector3.ONE * scale_value
		var historical_transform := historical_node.transform
		historical_node.free()
		var resolved_transform: Transform3D = resolver.resolve_world_transform(placement)
		_expect_basis_near(
			resolved_transform.basis,
			historical_transform.basis,
			"Node3D property equivalence scale %s" % scale_value,
			failures
		)
		_expect_vector_near(
			resolved_transform.origin,
			historical_transform.origin,
			"Node3D origin equivalence scale %s" % scale_value,
			failures
		)


func _verify_source_boundaries(failures: Array[String]) -> void:
	var loader_source := _read_text(LOADER_PATH, failures)
	var resolver_source := _read_text(RESOLVER_PATH, failures)
	_expect_true(
		loader_source.contains("WMO_PLACEMENT_RESOLVER_SCRIPT.new()"),
		"loader composes resolver",
		failures
	)
	_expect_equal_int(
		loader_source.count("_wmo_placement_resolver.normalize_relative_path("),
		3,
		"three normalization adapters",
		failures
	)
	_expect_equal_int(
		loader_source.count("_wmo_placement_resolver.resolve_unique_key("),
		1,
		"one identity adapter",
		failures
	)
	_expect_equal_int(
		loader_source.count("_wmo_placement_resolver.resolve_world_transform("),
		3,
		"three transform adapters",
		failures
	)
	_expect_true(
		not loader_source.contains("func _normalize_wmo_rel_path("),
		"loader omits normalization formula",
		failures
	)
	_expect_true(
		not loader_source.contains("func _wmo_unique_key("),
		"loader omits identity formula",
		failures
	)
	for forbidden_dependency in [
		"Node",
		"ResourceLoader",
		"RenderingServer",
		"WorkerThreadPool",
		"Mutex",
		"FileAccess",
	]:
		_expect_true(
			not resolver_source.contains(forbidden_dependency),
			"resolver omits %s" % forbidden_dependency,
			failures
		)


func _verify_fresh_stateless_results(failures: Array[String]) -> void:
	var resolver := RESOLVER_SCRIPT.new()
	var placement := {"pos": Vector3(1.0, 2.0, 3.0), "scale": 4.0}
	var first: Transform3D = resolver.resolve_world_transform(placement)
	first.origin = Vector3.ZERO
	var second: Transform3D = resolver.resolve_world_transform(placement)
	_expect_vector_near(second.origin, Vector3(1.0, 2.0, 3.0), "stateless result", failures)


func _verify_bounded_timing(failures: Array[String]) -> float:
	var resolver := RESOLVER_SCRIPT.new()
	var placement := {
		"unique_id": 11785,
		"pos": Vector3(10.0, 20.0, 30.0),
		"rot": Vector3(0.1, 0.2, 0.3),
		"scale": 1.5,
	}
	var started_microseconds := Time.get_ticks_usec()
	for iteration in range(20000):
		resolver.normalize_relative_path("World\\WMO\\Stormwind\\Keep.WMO")
		resolver.resolve_unique_key(placement, "31:49", iteration)
		resolver.resolve_world_transform(placement)
	var elapsed_milliseconds := float(Time.get_ticks_usec() - started_microseconds) / 1000.0
	_expect_true(elapsed_milliseconds < 1000.0, "20000 placement triples bounded", failures)
	return elapsed_milliseconds


func _read_text(path: String, failures: Array[String]) -> String:
	var file := FileAccess.open(path, FileAccess.READ)
	if file == null:
		failures.append("cannot open %s" % path)
		return ""
	return file.get_as_text()


func _expect_basis_near(
		actual_basis: Basis,
		expected_basis: Basis,
		label: String,
		failures: Array[String]
) -> void:
	if not actual_basis.is_equal_approx(expected_basis):
		failures.append("%s basis mismatch" % label)


func _expect_vector_near(
		actual_value: Vector3,
		expected_value: Vector3,
		label: String,
		failures: Array[String]
) -> void:
	if not actual_value.is_equal_approx(expected_value):
		failures.append("%s expected %s, got %s" % [label, expected_value, actual_value])


func _expect_equal_string(
		actual_value: String,
		expected_value: String,
		label: String,
		failures: Array[String]
) -> void:
	if actual_value != expected_value:
		failures.append("%s expected %s, got %s" % [label, expected_value, actual_value])


func _expect_equal_int(
		actual_value: int,
		expected_value: int,
		label: String,
		failures: Array[String]
) -> void:
	if actual_value != expected_value:
		failures.append("%s expected %d, got %d" % [label, expected_value, actual_value])


func _expect_true(actual_value: bool, label: String, failures: Array[String]) -> void:
	if not actual_value:
		failures.append("%s expected true" % label)