extends SceneTree

## M03 closeout gate for cache versions and worker/main-thread render boundaries.

const LOADER_PATH := "res://src/scenes/streaming/streaming_world_loader.gd"
const MANIFEST_PATH := "res://src/tools/render_baseline_manifest.json"
const M2_CACHE_BAKER_PATH := "res://src/tools/bake_m2_cache.gd"
const WORKER_FUNCTIONS: Array[String] = [
	"_load_tile_task",
	"_load_terrain_splat_task",
	"_load_tile_water_task",
	"_group_tile_m2_task",
]
const WORKER_FORBIDDEN_TOKENS: Array[String] = [
	"RenderingServer",
	".add_child(",
	".queue_free(",
	".free(",
	"Node3D.new(",
	"MeshInstance3D.new(",
	"MultiMeshInstance3D.new(",
	"ArrayMesh.new(",
	"build_tile_water_scene(",
	"build_tile_coarse_render_payload(",
]
const MAIN_THREAD_FRAME_STEPS: Array[String] = [
	"_drain_tile_load_results()",
	"_drain_terrain_upgrade_results()",
	"_drain_terrain_control_splat_cache_results()",
	"_drain_terrain_splat_cache_results()",
	"_drain_terrain_splat_results()",
	"_process_water_load_queue()",
	"_drain_water_load_results()",
	"_process_queues()",
	"_drain_m2_group_results()",
	"_drain_m2_animation_loads()",
	"_drain_m2_mesh_loads()",
	"_process_m2_build_jobs()",
	"_process_wmo_build_jobs()",
	"_process_wmo_render_build_jobs()",
	"_process_detail_asset_queue()",
]


func _initialize() -> void:
	var failures: Array[String] = []
	var loader_source := _read_text(LOADER_PATH, failures)
	var process_source := _function_source(loader_source, "_process", failures)
	_verify_frame_entrypoint(process_source, failures)
	_verify_worker_boundaries(loader_source, failures)
	_verify_rendering_server_boundary(loader_source, failures)
	_verify_cache_contract(loader_source, failures)
	_verify_m2_glb_cache_output_contract(failures)

	if not failures.is_empty():
		for failure in failures:
			push_error("RENDERER_CLOSEOUT_CONTRACTS: %s" % failure)
		quit(1)
		return

	print("RENDERER_CLOSEOUT_CONTRACTS PASS workers=%d frame_steps=%d cache_versions=7 nested_glb=1" % [
		WORKER_FUNCTIONS.size(),
		MAIN_THREAD_FRAME_STEPS.size(),
	])
	quit(0)


func _verify_frame_entrypoint(process_source: String, failures: Array[String]) -> void:
	var scheduler_index := process_source.find("_render_budget_scheduler.begin_frame(")
	if scheduler_index < 0:
		failures.append("_process does not begin a render-budget frame")
		return
	for step in MAIN_THREAD_FRAME_STEPS:
		var step_index := process_source.find(step)
		if step_index < 0:
			failures.append("_process is missing main-thread step %s" % step)
		elif step_index < scheduler_index:
			failures.append("%s runs before render-budget frame admission" % step)


func _verify_worker_boundaries(loader_source: String, failures: Array[String]) -> void:
	for function_name in WORKER_FUNCTIONS:
		var function_source := _function_source(loader_source, function_name, failures)
		for forbidden_token in WORKER_FORBIDDEN_TOKENS:
			if function_source.contains(forbidden_token):
				failures.append("worker %s contains main-thread token %s" % [
					function_name,
					forbidden_token,
				])


func _verify_rendering_server_boundary(loader_source: String, failures: Array[String]) -> void:
	var remaining_source := loader_source
	for function_name in ["_create_render_instance", "_free_render_instance"]:
		var function_source := _function_source(loader_source, function_name, failures)
		remaining_source = remaining_source.replace(function_source, "")
	if remaining_source.contains("RenderingServer.instance_create("):
		failures.append("RenderingServer instance creation escaped the owned adapter")
	if remaining_source.contains("RenderingServer.free_rid("):
		failures.append("RenderingServer RID release escaped the owned adapter")


func _verify_cache_contract(loader_source: String, failures: Array[String]) -> void:
	var manifest_source := _read_text(MANIFEST_PATH, failures)
	var parsed_manifest = JSON.parse_string(manifest_source)
	if not (parsed_manifest is Dictionary):
		failures.append("baseline manifest is not a Dictionary")
		return
	var cache_contract: Dictionary = parsed_manifest.get("cache_contract", {})
	var expected_versions := {
		"baked_terrain": 5,
		"streaming_terrain": 2,
		"terrain_splat": 1,
		"terrain_control_splat": 3,
		"wmo_streaming": 2,
		"wmo_builder": 2,
		"m2_material": 2,
	}
	if cache_contract.size() != expected_versions.size():
		failures.append("cache contract key count changed: expected=%d actual=%d" % [
			expected_versions.size(),
			cache_contract.size(),
		])
	for cache_name in expected_versions:
		if not cache_contract.has(cache_name):
			failures.append("cache contract is missing %s" % cache_name)
			continue
		var cache_record: Dictionary = cache_contract[cache_name]
		if int(cache_record.get("version", -1)) != int(expected_versions[cache_name]):
			failures.append("cache version changed for %s" % cache_name)

	var required_loader_declarations := [
		"const REQUIRED_BAKED_TILE_FORMAT_VERSION := 5",
		"const REQUIRED_SPLAT_TILE_FORMAT_VERSION := 1",
		"const REQUIRED_CONTROL_SPLAT_TILE_FORMAT_VERSION := 3",
		"STREAMING_TILE_SCRIPT.FORMAT_VERSION",
		"WMO_STREAMING_SCRIPT.FORMAT_VERSION",
	]
	for declaration in required_loader_declarations:
		if not loader_source.contains(declaration):
			failures.append("loader cache-version boundary is missing %s" % declaration)


func _verify_m2_glb_cache_output_contract(failures: Array[String]) -> void:
	var baker_source := _read_text(M2_CACHE_BAKER_PATH, failures)
	if not baker_source.contains(
			"var converter_output_directory := abs_out_glb.get_base_dir()"):
		failures.append("M2 GLB converter output is not derived from the nested cache path")
	if not baker_source.contains(
			"[abs_converter, abs_m2, converter_output_directory]"):
		failures.append("M2 GLB converter does not receive the nested output directory")


func _function_source(source: String, function_name: String, failures: Array[String]) -> String:
	var signature := "func %s(" % function_name
	var start_index := source.find(signature)
	if start_index < 0:
		failures.append("missing function %s" % function_name)
		return ""
	var next_function_index := source.find("\nfunc ", start_index + signature.length())
	if next_function_index < 0:
		return source.substr(start_index)
	return source.substr(start_index, next_function_index - start_index)


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