class_name RegionalChunkedPersistence
extends RefCounted

const SCHEMA_VERSION := 1
const FORMAT_ID := "regional_caravan_chunks"
const DEFAULT_EVENT_SEGMENT_SIZE := 64
const MAX_EVENT_SEGMENT_SIZE := 1024
const CHUNK_GLOBAL := "global_index"
const CHUNK_LOCATION := "location"
const CHUNK_MOBILE_GROUP := "mobile_group"
const CHUNK_SCHEDULER := "scheduler"
const CHUNK_EVENTS := "event_segment"
const GLOBAL_CHUNK_ID := "global:index"
const SCHEDULER_CHUNK_ID := "scheduler:regional"

var _manifest: Dictionary = {}
var _chunks_by_id: Dictionary = {}
var _ordered_chunk_ids: Array[String] = []


static func capture(
	service: RegionalCaravanService, event_segment_size: int = DEFAULT_EVENT_SEGMENT_SIZE
) -> RegionalChunkedPersistence:
	if (
		service == null
		or not service.is_valid()
		or event_segment_size <= 0
		or event_segment_size > MAX_EVENT_SEGMENT_SIZE
	):
		return null
	var envelope := service.to_dictionary()
	if not _is_primitive_tree(envelope):
		return null
	var chunks := _capture_chunks(service, event_segment_size)
	if chunks.is_empty():
		return null
	chunks.sort_custom(_chunk_precedes)
	var descriptors: Array[Dictionary] = []
	for chunk: Dictionary in chunks:
		descriptors.append(_descriptor_for_chunk(chunk))
	var manifest := {
		"schema_version": SCHEMA_VERSION,
		"format_id": FORMAT_ID,
		"world_id": String(service.get_world_state().get_world_id()),
		"envelope_checksum": service.checksum(),
		"event_segment_size": event_segment_size,
		"chunk_count": chunks.size(),
		"chunks": descriptors,
	}
	var bundle := {
		"schema_version": SCHEMA_VERSION,
		"manifest": manifest,
		"chunks": chunks,
	}
	return from_dictionary(bundle)


static func from_dictionary(bundle: Dictionary) -> RegionalChunkedPersistence:
	if not _is_primitive_tree(bundle):
		return null
	if (
		not _has_exact_fields(bundle, ["schema_version", "manifest", "chunks"])
		or not bundle.get("schema_version") is int
		or int(bundle["schema_version"]) != SCHEMA_VERSION
		or not bundle.get("manifest") is Dictionary
		or not bundle.get("chunks") is Array
	):
		return null
	var manifest: Dictionary = bundle["manifest"]
	var raw_chunks: Array = bundle["chunks"]
	if not _manifest_header_is_valid(manifest, raw_chunks.size()):
		return null
	var descriptors: Array = manifest["chunks"]
	var chunks: Array[Dictionary] = []
	for raw_chunk: Variant in raw_chunks:
		if not raw_chunk is Dictionary:
			return null
		chunks.append(raw_chunk)
	if not _canonical_order_is_valid(descriptors, chunks):
		return null
	var chunks_by_id: Dictionary = {}
	var descriptors_by_id: Dictionary = {}
	for index in range(chunks.size()):
		var chunk: Dictionary = chunks[index]
		var descriptor: Dictionary = descriptors[index]
		if not _chunk_and_descriptor_are_valid(chunk, descriptor):
			return null
		var chunk_id := String(chunk["chunk_id"])
		if chunks_by_id.has(chunk_id) or descriptors_by_id.has(chunk_id):
			return null
		chunks_by_id[chunk_id] = chunk.duplicate(true)
		descriptors_by_id[chunk_id] = descriptor.duplicate(true)
	if not _chunk_topology_is_valid(manifest, chunks, chunks_by_id):
		return null
	var archive := RegionalChunkedPersistence.new()
	archive._manifest = manifest.duplicate(true)
	archive._chunks_by_id = chunks_by_id
	for chunk: Dictionary in chunks:
		archive._ordered_chunk_ids.append(String(chunk["chunk_id"]))
	var restored := archive.restore_service()
	if restored == null or restored.checksum() != String(manifest["envelope_checksum"]):
		return null
	return archive


func get_manifest() -> Dictionary:
	return _manifest.duplicate(true)


func get_chunk_ids() -> Array[String]:
	return _ordered_chunk_ids.duplicate()


func get_chunk(chunk_id: StringName) -> Dictionary:
	var chunk: Dictionary = _chunks_by_id.get(String(chunk_id), {} as Dictionary)
	return chunk.duplicate(true)


func get_chunk_ids_for_type(chunk_type: StringName) -> Array[String]:
	var ids: Array[String] = []
	for chunk_id: String in _ordered_chunk_ids:
		var chunk: Dictionary = _chunks_by_id[chunk_id]
		if String(chunk["chunk_type"]) == String(chunk_type):
			ids.append(chunk_id)
	return ids


func to_dictionary() -> Dictionary:
	var chunks: Array[Dictionary] = []
	for chunk_id: String in _ordered_chunk_ids:
		var chunk: Dictionary = _chunks_by_id[chunk_id]
		chunks.append(chunk.duplicate(true))
	return {
		"schema_version": SCHEMA_VERSION,
		"manifest": _manifest.duplicate(true),
		"chunks": chunks,
	}


func checksum() -> String:
	return JSON.stringify(to_dictionary()).sha256_text()


func restore_service() -> RegionalCaravanService:
	var global_chunk := get_chunk(StringName(GLOBAL_CHUNK_ID))
	var scheduler_chunk := get_chunk(StringName(SCHEDULER_CHUNK_ID))
	if global_chunk.is_empty() or scheduler_chunk.is_empty():
		return null
	var global_payload: Dictionary = global_chunk["payload"]
	var scheduler_payload: Dictionary = scheduler_chunk["payload"]
	var locations: Array[Dictionary] = []
	var settlements: Array[Dictionary] = []
	var mobile_groups: Array[Dictionary] = []
	var persons: Array[Dictionary] = []
	var cohorts: Array[Dictionary] = []
	var event_records: Array[Dictionary] = []
	for chunk_id: String in _ordered_chunk_ids:
		var chunk: Dictionary = _chunks_by_id[chunk_id]
		var payload: Dictionary = chunk["payload"]
		match String(chunk["chunk_type"]):
			CHUNK_LOCATION:
				locations.append(payload["location"].duplicate(true))
				_append_dictionary_records(settlements, payload["settlements"])
				_append_dictionary_records(persons, payload["persons"])
				_append_dictionary_records(cohorts, payload["population_cohorts"])
			CHUNK_MOBILE_GROUP:
				mobile_groups.append(payload["mobile_group"].duplicate(true))
				_append_dictionary_records(persons, payload["persons"])
				_append_dictionary_records(cohorts, payload["population_cohorts"])
			CHUNK_EVENTS:
				_append_dictionary_records(event_records, payload["events"])
	var world_state := {
		"schema_version": int(global_payload["world_state_schema_version"]),
		"world_id": String(global_payload["world_id"]),
		"locations": locations,
		"settlements": settlements,
		"routes": global_payload["routes"].duplicate(true),
		"mobile_groups": mobile_groups,
		"persons": persons,
		"population_cohorts": cohorts,
		"polities": global_payload["polities"].duplicate(true),
		"diplomatic_relations": global_payload["diplomatic_relations"].duplicate(true),
	}
	var envelope := {
		"schema_version": int(global_payload["service_schema_version"]),
		"next_event_id": int(global_payload["next_event_id"]),
		"world_state": world_state,
		"scheduler": scheduler_payload["scheduler"].duplicate(true),
		"event_store":
		{
			"schema_version": int(global_payload["event_store_schema_version"]),
			"events": event_records,
		},
	}
	var service := RegionalCaravanService.from_dictionary(envelope)
	if service == null or service.checksum() != String(_manifest["envelope_checksum"]):
		return null
	return service


func load_active_location_metadata(location_id: StringName) -> Dictionary:
	var location_chunk_id := _location_chunk_id(location_id)
	var location_chunk := get_chunk(StringName(location_chunk_id))
	var global_chunk := get_chunk(StringName(GLOBAL_CHUNK_ID))
	if location_chunk.is_empty() or global_chunk.is_empty():
		return {}
	var loaded_chunk_ids: Array[String] = [GLOBAL_CHUNK_ID, location_chunk_id]
	var unloaded_chunk_ids: Array[String] = []
	var mobile_group_refs: Array[Dictionary] = []
	var descriptors: Array = _manifest["chunks"]
	for descriptor: Dictionary in descriptors:
		var chunk_id := String(descriptor["chunk_id"])
		if chunk_id not in loaded_chunk_ids:
			unloaded_chunk_ids.append(chunk_id)
		if (
			String(descriptor["chunk_type"]) == CHUNK_MOBILE_GROUP
			and String(descriptor["location_id"]) == String(location_id)
		):
			(
				mobile_group_refs
				. append(
					{
						"group_id": String(descriptor["scope_id"]),
						"chunk_id": chunk_id,
					}
				)
			)
	return {
		"schema_version": SCHEMA_VERSION,
		"world_id": String(_manifest["world_id"]),
		"active_location_id": String(location_id),
		"loaded_chunk_ids": loaded_chunk_ids,
		"unloaded_chunk_ids": unloaded_chunk_ids,
		"global_index": (global_chunk["payload"] as Dictionary).duplicate(true),
		"active_location": (location_chunk["payload"] as Dictionary).duplicate(true),
		"mobile_group_refs": mobile_group_refs,
		"envelope_checksum": String(_manifest["envelope_checksum"]),
	}


static func _capture_chunks(
	service: RegionalCaravanService, event_segment_size: int
) -> Array[Dictionary]:
	var chunks: Array[Dictionary] = []
	var state := service.get_world_state()
	var location_ids: Array[String] = []
	for location: LocationStateRecord in state.get_all_locations():
		location_ids.append(String(location.get_location_id()))
	var mobile_group_ids: Array[String] = []
	for group: MobileGroupStateRecord in state.get_all_mobile_groups():
		mobile_group_ids.append(String(group.get_group_id()))
	var global_payload := {
		"service_schema_version": RegionalCaravanService.SCHEMA_VERSION,
		"world_state_schema_version": RegionalWorldState.SCHEMA_VERSION,
		"scheduler_schema_version": RegionalJobScheduler.SCHEMA_VERSION,
		"event_store_schema_version": WorldEventStore.SCHEMA_VERSION,
		"world_id": String(state.get_world_id()),
		"next_event_id": service.get_next_event_id(),
		"location_ids": location_ids,
		"mobile_group_ids": mobile_group_ids,
		"routes": _records_to_dictionaries(state.get_all_routes()),
		"polities": _records_to_dictionaries(state.get_all_polities()),
		"diplomatic_relations": _records_to_dictionaries(state.get_all_diplomatic_relations()),
	}
	chunks.append(_make_chunk(GLOBAL_CHUNK_ID, CHUNK_GLOBAL, state.get_world_id(), global_payload))
	for location: LocationStateRecord in state.get_all_locations():
		var location_id := location.get_location_id()
		var payload := {
			"world_id": String(state.get_world_id()),
			"location_id": String(location_id),
			"location": location.to_dictionary(),
			"settlements": _records_to_dictionaries(state.get_settlements_at_location(location_id)),
			"persons": _records_to_dictionaries(state.get_persons_at_location(location_id)),
			"population_cohorts":
			_records_to_dictionaries(state.get_cohorts_at_location(location_id)),
		}
		chunks.append(
			_make_chunk(_location_chunk_id(location_id), CHUNK_LOCATION, location_id, payload)
		)
	for group: MobileGroupStateRecord in state.get_all_mobile_groups():
		var group_id := group.get_group_id()
		var payload := {
			"world_id": String(state.get_world_id()),
			"group_id": String(group_id),
			"mobile_group": group.to_dictionary(),
			"persons": _records_to_dictionaries(state.get_persons_in_group(group_id)),
			"population_cohorts": _records_to_dictionaries(state.get_cohorts_in_group(group_id)),
		}
		var location_id := group.get_current_location_id() if group.is_at_location() else &""
		var route_id := group.get_route_id() if group.is_on_route() else &""
		chunks.append(
			_make_chunk(
				_mobile_group_chunk_id(group_id),
				CHUNK_MOBILE_GROUP,
				group_id,
				payload,
				location_id,
				route_id
			)
		)
	chunks.append(
		_make_chunk(
			SCHEDULER_CHUNK_ID,
			CHUNK_SCHEDULER,
			&"regional",
			{"scheduler": service.get_scheduler().to_dictionary()}
		)
	)
	var event_data := service.get_event_store().to_dictionary()
	var events: Array = event_data["events"]
	var segment_count := maxi(1, ceili(float(events.size()) / float(event_segment_size)))
	for segment_index in range(segment_count):
		var first := segment_index * event_segment_size
		var last := mini(first + event_segment_size, events.size())
		var segment_events: Array[Dictionary] = []
		for event_index in range(first, last):
			var event_record: Dictionary = events[event_index]
			segment_events.append(event_record.duplicate(true))
		(
			chunks
			. append(
				_make_chunk(
					_event_chunk_id(segment_index),
					CHUNK_EVENTS,
					StringName(str(segment_index)),
					{
						"segment_index": segment_index,
						"events": segment_events,
					}
				)
			)
		)
	return chunks


static func _make_chunk(
	chunk_id: String,
	chunk_type: String,
	scope_id: StringName,
	payload: Dictionary,
	location_id: StringName = &"",
	route_id: StringName = &""
) -> Dictionary:
	return {
		"schema_version": SCHEMA_VERSION,
		"chunk_id": chunk_id,
		"chunk_type": chunk_type,
		"scope_id": String(scope_id),
		"location_id": String(location_id),
		"route_id": String(route_id),
		"payload": payload.duplicate(true),
	}


static func _descriptor_for_chunk(chunk: Dictionary) -> Dictionary:
	var serialized := JSON.stringify(chunk)
	return {
		"chunk_id": String(chunk["chunk_id"]),
		"chunk_type": String(chunk["chunk_type"]),
		"scope_id": String(chunk["scope_id"]),
		"location_id": String(chunk["location_id"]),
		"route_id": String(chunk["route_id"]),
		"record_count": _chunk_record_count(chunk),
		"byte_size": serialized.to_utf8_buffer().size(),
		"checksum": serialized.sha256_text(),
	}


static func _manifest_header_is_valid(manifest: Dictionary, raw_chunk_count: int) -> bool:
	if not _has_exact_fields(
		manifest,
		[
			"schema_version",
			"format_id",
			"world_id",
			"envelope_checksum",
			"event_segment_size",
			"chunk_count",
			"chunks",
		]
	):
		return false
	return (
		manifest["schema_version"] is int
		and int(manifest["schema_version"]) == SCHEMA_VERSION
		and manifest["format_id"] is String
		and String(manifest["format_id"]) == FORMAT_ID
		and manifest["world_id"] is String
		and not String(manifest["world_id"]).is_empty()
		and manifest["envelope_checksum"] is String
		and not String(manifest["envelope_checksum"]).is_empty()
		and manifest["event_segment_size"] is int
		and int(manifest["event_segment_size"]) > 0
		and int(manifest["event_segment_size"]) <= MAX_EVENT_SEGMENT_SIZE
		and manifest["chunk_count"] is int
		and int(manifest["chunk_count"]) == raw_chunk_count
		and manifest["chunks"] is Array
		and (manifest["chunks"] as Array).size() == raw_chunk_count
	)


static func _canonical_order_is_valid(descriptors: Array, chunks: Array[Dictionary]) -> bool:
	var typed_descriptors: Array[Dictionary] = []
	for raw_descriptor: Variant in descriptors:
		if not raw_descriptor is Dictionary:
			return false
		typed_descriptors.append(raw_descriptor)
	var sorted_chunks := chunks.duplicate(true)
	sorted_chunks.sort_custom(_chunk_precedes)
	var sorted_descriptors := typed_descriptors.duplicate(true)
	sorted_descriptors.sort_custom(_descriptor_precedes)
	for index in range(chunks.size()):
		if (
			(
				String(chunks[index].get("chunk_id", ""))
				!= String(sorted_chunks[index].get("chunk_id", ""))
			)
			or (
				String(typed_descriptors[index].get("chunk_id", ""))
				!= String(sorted_descriptors[index].get("chunk_id", ""))
			)
			or (
				String(chunks[index].get("chunk_id", ""))
				!= String(typed_descriptors[index].get("chunk_id", ""))
			)
		):
			return false
	return true


static func _chunk_and_descriptor_are_valid(chunk: Dictionary, descriptor: Dictionary) -> bool:
	var chunk_fields := [
		"schema_version", "chunk_id", "chunk_type", "scope_id", "location_id", "route_id", "payload"
	]
	var descriptor_fields := [
		"chunk_id",
		"chunk_type",
		"scope_id",
		"location_id",
		"route_id",
		"record_count",
		"byte_size",
		"checksum",
	]
	if (
		not _has_exact_fields(chunk, chunk_fields)
		or not _has_exact_fields(descriptor, descriptor_fields)
	):
		return false
	if (
		not chunk["schema_version"] is int
		or int(chunk["schema_version"]) != SCHEMA_VERSION
		or not chunk["chunk_id"] is String
		or String(chunk["chunk_id"]).is_empty()
		or not chunk["chunk_type"] is String
		or not chunk["scope_id"] is String
		or not chunk["location_id"] is String
		or not chunk["route_id"] is String
		or not chunk["payload"] is Dictionary
		or not descriptor["record_count"] is int
		or not descriptor["byte_size"] is int
		or not descriptor["checksum"] is String
	):
		return false
	for field: String in ["chunk_id", "chunk_type", "scope_id", "location_id", "route_id"]:
		if not descriptor[field] is String or String(descriptor[field]) != String(chunk[field]):
			return false
	var serialized := JSON.stringify(chunk)
	var record_count := _chunk_record_count(chunk)
	return (
		record_count >= 0
		and int(descriptor["record_count"]) == record_count
		and int(descriptor["byte_size"]) == serialized.to_utf8_buffer().size()
		and String(descriptor["checksum"]) == serialized.sha256_text()
	)


static func _chunk_topology_is_valid(
	manifest: Dictionary, chunks: Array[Dictionary], chunks_by_id: Dictionary
) -> bool:
	var allowed_types := {
		CHUNK_GLOBAL: true,
		CHUNK_LOCATION: true,
		CHUNK_MOBILE_GROUP: true,
		CHUNK_SCHEDULER: true,
		CHUNK_EVENTS: true,
	}
	for chunk: Dictionary in chunks:
		if not allowed_types.has(String(chunk["chunk_type"])):
			return false
	var global_chunks := _chunks_for_type(chunks, CHUNK_GLOBAL)
	var scheduler_chunks := _chunks_for_type(chunks, CHUNK_SCHEDULER)
	var location_chunks := _chunks_for_type(chunks, CHUNK_LOCATION)
	var group_chunks := _chunks_for_type(chunks, CHUNK_MOBILE_GROUP)
	var event_chunks := _chunks_for_type(chunks, CHUNK_EVENTS)
	if global_chunks.size() != 1 or scheduler_chunks.size() != 1 or event_chunks.is_empty():
		return false
	if (
		String(global_chunks[0]["chunk_id"]) != GLOBAL_CHUNK_ID
		or String(scheduler_chunks[0]["chunk_id"]) != SCHEDULER_CHUNK_ID
		or String(global_chunks[0]["scope_id"]) != String(manifest["world_id"])
		or not String(global_chunks[0]["location_id"]).is_empty()
		or not String(global_chunks[0]["route_id"]).is_empty()
		or String(scheduler_chunks[0]["scope_id"]) != "regional"
		or not String(scheduler_chunks[0]["location_id"]).is_empty()
		or not String(scheduler_chunks[0]["route_id"]).is_empty()
	):
		return false
	var global_payload: Dictionary = global_chunks[0]["payload"]
	if not _global_payload_is_valid(global_payload, manifest):
		return false
	if not _location_chunks_are_valid(location_chunks, global_payload):
		return false
	if not _mobile_group_chunks_are_valid(group_chunks, global_payload):
		return false
	if not _scheduler_chunk_is_valid(scheduler_chunks[0]):
		return false
	if not _event_chunks_are_valid(event_chunks, int(manifest["event_segment_size"])):
		return false
	for location_id: Variant in global_payload["location_ids"]:
		if not chunks_by_id.has(_location_chunk_id(StringName(location_id))):
			return false
	for group_id: Variant in global_payload["mobile_group_ids"]:
		if not chunks_by_id.has(_mobile_group_chunk_id(StringName(group_id))):
			return false
	return true


static func _global_payload_is_valid(payload: Dictionary, manifest: Dictionary) -> bool:
	if not _has_exact_fields(
		payload,
		[
			"service_schema_version",
			"world_state_schema_version",
			"scheduler_schema_version",
			"event_store_schema_version",
			"world_id",
			"next_event_id",
			"location_ids",
			"mobile_group_ids",
			"routes",
			"polities",
			"diplomatic_relations",
		]
	):
		return false
	if (
		not payload["service_schema_version"] is int
		or int(payload["service_schema_version"]) != RegionalCaravanService.SCHEMA_VERSION
		or not payload["world_state_schema_version"] is int
		or int(payload["world_state_schema_version"]) != RegionalWorldState.SCHEMA_VERSION
		or not payload["scheduler_schema_version"] is int
		or int(payload["scheduler_schema_version"]) != RegionalJobScheduler.SCHEMA_VERSION
		or not payload["event_store_schema_version"] is int
		or int(payload["event_store_schema_version"]) != WorldEventStore.SCHEMA_VERSION
		or not payload["world_id"] is String
		or String(payload["world_id"]) != String(manifest["world_id"])
		or not payload["next_event_id"] is int
		or not payload["location_ids"] is Array
		or not payload["mobile_group_ids"] is Array
		or not payload["routes"] is Array
		or not payload["polities"] is Array
		or not payload["diplomatic_relations"] is Array
	):
		return false
	var normalized_locations: Variant = RegionalStateSupport.normalize_id_array(
		payload["location_ids"]
	)
	var normalized_groups: Variant = RegionalStateSupport.normalize_id_array(
		payload["mobile_group_ids"]
	)
	if (
		normalized_locations == null
		or normalized_locations != payload["location_ids"]
		or normalized_groups == null
		or normalized_groups != payload["mobile_group_ids"]
	):
		return false
	return (
		_dictionary_records_are_canonical(
			payload["routes"], "route_id", RouteStateRecord.from_dictionary
		)
		and _dictionary_records_are_canonical(
			payload["polities"], "polity_id", PolityStateRecord.from_dictionary
		)
		and _dictionary_records_are_canonical(
			payload["diplomatic_relations"], "relation_id", DiplomaticRelationRecord.from_dictionary
		)
	)


static func _location_chunks_are_valid(
	chunks: Array[Dictionary], global_payload: Dictionary
) -> bool:
	var ids: Array[String] = []
	for chunk: Dictionary in chunks:
		var payload: Dictionary = chunk["payload"]
		if not _has_exact_fields(
			payload,
			[
				"world_id",
				"location_id",
				"location",
				"settlements",
				"persons",
				"population_cohorts",
			]
		):
			return false
		if (
			not payload["world_id"] is String
			or String(payload["world_id"]) != String(global_payload["world_id"])
			or not payload["location_id"] is String
			or String(payload["location_id"]) != String(chunk["scope_id"])
			or String(chunk["chunk_id"]) != _location_chunk_id(StringName(chunk["scope_id"]))
			or not payload["location"] is Dictionary
			or not payload["settlements"] is Array
			or not payload["persons"] is Array
			or not payload["population_cohorts"] is Array
		):
			return false
		var location := LocationStateRecord.from_dictionary(payload["location"])
		if (
			location == null
			or location.to_dictionary() != payload["location"]
			or location.get_location_id() != StringName(chunk["scope_id"])
			or not String(chunk["location_id"]).is_empty()
			or not String(chunk["route_id"]).is_empty()
		):
			return false
		if not _records_belong_to_location(payload, StringName(chunk["scope_id"])):
			return false
		ids.append(String(chunk["scope_id"]))
	ids.sort()
	return ids == global_payload["location_ids"]


static func _mobile_group_chunks_are_valid(
	chunks: Array[Dictionary], global_payload: Dictionary
) -> bool:
	var ids: Array[String] = []
	for chunk: Dictionary in chunks:
		var payload: Dictionary = chunk["payload"]
		if not _has_exact_fields(
			payload, ["world_id", "group_id", "mobile_group", "persons", "population_cohorts"]
		):
			return false
		if (
			not payload["world_id"] is String
			or String(payload["world_id"]) != String(global_payload["world_id"])
			or not payload["group_id"] is String
			or String(payload["group_id"]) != String(chunk["scope_id"])
			or String(chunk["chunk_id"]) != _mobile_group_chunk_id(StringName(chunk["scope_id"]))
			or not payload["mobile_group"] is Dictionary
			or not payload["persons"] is Array
			or not payload["population_cohorts"] is Array
		):
			return false
		var group := MobileGroupStateRecord.from_dictionary(payload["mobile_group"])
		if (
			group == null
			or group.to_dictionary() != payload["mobile_group"]
			or group.get_group_id() != StringName(chunk["scope_id"])
		):
			return false
		var expected_location := group.get_current_location_id() if group.is_at_location() else &""
		var expected_route := group.get_route_id() if group.is_on_route() else &""
		if (
			String(chunk["location_id"]) != String(expected_location)
			or String(chunk["route_id"]) != String(expected_route)
		):
			return false
		if not _records_belong_to_group(payload, group.get_group_id()):
			return false
		ids.append(String(chunk["scope_id"]))
	ids.sort()
	return ids == global_payload["mobile_group_ids"]


static func _scheduler_chunk_is_valid(chunk: Dictionary) -> bool:
	var payload: Dictionary = chunk["payload"]
	if not _has_exact_fields(payload, ["scheduler"]) or not payload["scheduler"] is Dictionary:
		return false
	var scheduler := RegionalJobScheduler.from_dictionary(payload["scheduler"])
	return scheduler != null and scheduler.to_dictionary() == payload["scheduler"]


static func _event_chunks_are_valid(chunks: Array[Dictionary], segment_size: int) -> bool:
	var all_events: Array[Dictionary] = []
	for index in range(chunks.size()):
		var chunk: Dictionary = chunks[index]
		var payload: Dictionary = chunk["payload"]
		if (
			not _has_exact_fields(payload, ["segment_index", "events"])
			or not payload["segment_index"] is int
			or int(payload["segment_index"]) != index
			or String(chunk["chunk_id"]) != _event_chunk_id(index)
			or String(chunk["scope_id"]) != str(index)
			or not String(chunk["location_id"]).is_empty()
			or not String(chunk["route_id"]).is_empty()
			or not payload["events"] is Array
		):
			return false
		var events: Array = payload["events"]
		if events.size() > segment_size:
			return false
		if index < chunks.size() - 1 and events.size() != segment_size:
			return false
		if chunks.size() > 1 and index == chunks.size() - 1 and events.is_empty():
			return false
		for event: Variant in events:
			if not event is Dictionary:
				return false
			all_events.append(event)
	var store := WorldEventStore.from_dictionary(
		{"schema_version": WorldEventStore.SCHEMA_VERSION, "events": all_events}
	)
	return store != null and store.to_dictionary()["events"] == all_events


static func _chunk_record_count(chunk: Dictionary) -> int:
	if not chunk.get("payload") is Dictionary or not chunk.get("chunk_type") is String:
		return -1
	var payload: Dictionary = chunk["payload"]
	match String(chunk["chunk_type"]):
		CHUNK_GLOBAL:
			if not _payload_has_array_fields(
				payload, ["routes", "polities", "diplomatic_relations"]
			):
				return -1
			return (
				(payload["routes"] as Array).size()
				+ (payload["polities"] as Array).size()
				+ (payload["diplomatic_relations"] as Array).size()
			)
		CHUNK_LOCATION:
			if (
				not payload.get("location") is Dictionary
				or not _payload_has_array_fields(
					payload, ["settlements", "persons", "population_cohorts"]
				)
			):
				return -1
			return (
				1
				+ (payload["settlements"] as Array).size()
				+ (payload["persons"] as Array).size()
				+ (payload["population_cohorts"] as Array).size()
			)
		CHUNK_MOBILE_GROUP:
			if (
				not payload.get("mobile_group") is Dictionary
				or not _payload_has_array_fields(payload, ["persons", "population_cohorts"])
			):
				return -1
			return (
				1
				+ (payload["persons"] as Array).size()
				+ (payload["population_cohorts"] as Array).size()
			)
		CHUNK_SCHEDULER:
			if (
				not payload.get("scheduler") is Dictionary
				or not (payload["scheduler"] as Dictionary).get("jobs") is Array
			):
				return -1
			return ((payload["scheduler"] as Dictionary)["jobs"] as Array).size()
		CHUNK_EVENTS:
			if not payload.get("events") is Array:
				return -1
			return (payload["events"] as Array).size()
	return -1


static func _payload_has_array_fields(payload: Dictionary, fields: Array[String]) -> bool:
	for field: String in fields:
		if not payload.get(field) is Array:
			return false
	return true


static func _records_belong_to_location(payload: Dictionary, location_id: StringName) -> bool:
	if (
		not _dictionary_records_are_canonical(
			payload["settlements"], "settlement_id", SettlementStateRecord.from_dictionary
		)
		or not _dictionary_records_are_canonical(
			payload["persons"], "person_id", PersonStateRecord.from_dictionary
		)
		or not _dictionary_records_are_canonical(
			payload["population_cohorts"], "cohort_id", PopulationCohortRecord.from_dictionary
		)
	):
		return false
	for raw_record: Variant in payload["settlements"]:
		var settlement := SettlementStateRecord.from_dictionary(raw_record)
		if settlement == null or settlement.get_location_id() != location_id:
			return false
	for raw_record: Variant in payload["persons"]:
		var person := PersonStateRecord.from_dictionary(raw_record)
		if (
			person == null
			or not person.is_at_location()
			or person.get_location_address().get_location_id() != location_id
		):
			return false
	for raw_record: Variant in payload["population_cohorts"]:
		var cohort := PopulationCohortRecord.from_dictionary(raw_record)
		if cohort == null or not cohort.is_at_location() or cohort.get_location_id() != location_id:
			return false
	return true


static func _records_belong_to_group(payload: Dictionary, group_id: StringName) -> bool:
	if (
		not _dictionary_records_are_canonical(
			payload["persons"], "person_id", PersonStateRecord.from_dictionary
		)
		or not _dictionary_records_are_canonical(
			payload["population_cohorts"], "cohort_id", PopulationCohortRecord.from_dictionary
		)
	):
		return false
	for raw_record: Variant in payload["persons"]:
		var person := PersonStateRecord.from_dictionary(raw_record)
		if (
			person == null
			or not person.is_in_mobile_group()
			or person.get_mobile_group_id() != group_id
		):
			return false
	for raw_record: Variant in payload["population_cohorts"]:
		var cohort := PopulationCohortRecord.from_dictionary(raw_record)
		if (
			cohort == null
			or not cohort.is_in_mobile_group()
			or cohort.get_mobile_group_id() != group_id
		):
			return false
	return true


static func _dictionary_records_are_canonical(
	records: Array, id_field: String, parser: Callable
) -> bool:
	var previous_id := ""
	for index in range(records.size()):
		var raw_record: Variant = records[index]
		if not raw_record is Dictionary:
			return false
		var record: Dictionary = raw_record
		if not record.get(id_field) is String or String(record[id_field]).is_empty():
			return false
		var parsed_record: Variant = parser.call(record)
		if (
			parsed_record == null
			or not parsed_record.has_method("to_dictionary")
			or parsed_record.call("to_dictionary") != record
		):
			return false
		var record_id := String(record[id_field])
		if index > 0 and previous_id >= record_id:
			return false
		previous_id = record_id
	return true


static func _has_exact_fields(value: Dictionary, fields: Array) -> bool:
	return value.size() == fields.size() and value.has_all(fields)


static func _chunks_for_type(chunks: Array[Dictionary], chunk_type: String) -> Array[Dictionary]:
	var filtered: Array[Dictionary] = []
	for chunk: Dictionary in chunks:
		if String(chunk["chunk_type"]) == chunk_type:
			filtered.append(chunk)
	return filtered


static func _records_to_dictionaries(records: Array) -> Array[Dictionary]:
	var serialized: Array[Dictionary] = []
	for record: Variant in records:
		var record_data: Dictionary = record.call("to_dictionary")
		serialized.append(record_data)
	return serialized


static func _append_dictionary_records(destination: Array[Dictionary], source: Array) -> void:
	for raw_record: Variant in source:
		if raw_record is Dictionary:
			destination.append((raw_record as Dictionary).duplicate(true))


static func _chunk_precedes(first: Dictionary, second: Dictionary) -> bool:
	return _chunk_sort_key(first) < _chunk_sort_key(second)


static func _descriptor_precedes(first: Dictionary, second: Dictionary) -> bool:
	return _chunk_sort_key(first) < _chunk_sort_key(second)


static func _chunk_sort_key(value: Dictionary) -> String:
	var chunk_type := String(value.get("chunk_type", ""))
	var rank := int(
		(
			{
				CHUNK_GLOBAL: 0,
				CHUNK_LOCATION: 1,
				CHUNK_MOBILE_GROUP: 2,
				CHUNK_SCHEDULER: 3,
				CHUNK_EVENTS: 4,
			}
			. get(chunk_type, 99)
		)
	)
	return "%02d:%s" % [rank, String(value.get("chunk_id", ""))]


static func _location_chunk_id(location_id: StringName) -> String:
	return "location:%s" % location_id


static func _mobile_group_chunk_id(group_id: StringName) -> String:
	return "mobile_group:%s" % group_id


static func _event_chunk_id(segment_index: int) -> String:
	return "events:%08d" % segment_index


static func _is_primitive_tree(value: Variant) -> bool:
	match typeof(value):
		TYPE_NIL, TYPE_BOOL, TYPE_INT, TYPE_STRING:
			return true
		TYPE_FLOAT:
			return is_finite(float(value))
		TYPE_ARRAY:
			for item: Variant in value:
				if not _is_primitive_tree(item):
					return false
			return true
		TYPE_DICTIONARY:
			for key: Variant in value:
				if not key is String or not _is_primitive_tree(value[key]):
					return false
			return true
	return false