class_name RouteSubslotPathAdapter
extends RefCounted

## Atomic projection boundary between SpatialSubslotService ROUTE slots and
## PathService. The adapter owns projection metadata and idempotency evidence;
## both domain services remain authoritative for their own state.

const CommandResultType = preload("res://scripts/core/command_result.gd")
const SpatialSubslotServiceType = preload("res://scripts/world/spatial_subslot_service.gd")
const PathServiceType = preload("res://scripts/world/path_service.gd")

const SNAPSHOT_SCHEMA_VERSION := 1
const MAX_REQUEST_ID_LENGTH := 128
const MAX_PROCESSED_REQUESTS := 4_096
const MAX_HISTORY_CELL_REFERENCES := 262_144
const MAX_BASE_WALKABLE_CELLS := 65_536
const MAX_PROJECTED_CELLS := 131_072
const MAX_CELLS_PER_ROUTE_REQUEST := 256
const MAX_COORDINATE_ABS := 100_000
const MAX_SAFE_INTEGER := 9_007_199_254_740_991
const MAX_SNAPSHOT_DEPTH := 9
const MAX_CONTAINER_ITEMS := 131_072

const OPERATION_PLACE: StringName = &"PLACE"
const OPERATION_REPLACE: StringName = &"REPLACE"
const OPERATION_REMOVE: StringName = &"REMOVE"
const OPERATION_SYNCHRONIZE: StringName = &"SYNCHRONIZE"
const OPERATIONS: Array[StringName] = [
	OPERATION_PLACE,
	OPERATION_REPLACE,
	OPERATION_REMOVE,
	OPERATION_SYNCHRONIZE,
]

const QUARANTINE_CONFIGURE_ROLLBACK: StringName = &"CONFIGURE_ROLLBACK_UNCERTAIN"
const QUARANTINE_TRANSACTION_ROLLBACK: StringName = &"TRANSACTION_ROLLBACK_UNCERTAIN"
const QUARANTINE_REASONS: Array[StringName] = [
	QUARANTINE_CONFIGURE_ROLLBACK,
	QUARANTINE_TRANSACTION_ROLLBACK,
]

var source_revision := 0
var projection_revision := 0
var last_error := ""

var _source: SpatialSubslotService
var _path: PathService
var _configured := false
var _base_walkable_cells: Dictionary = {}
var _projected_route_cells: Array[Vector3i] = []
var _projected_walkable_cells: Array[Vector3i] = []
var _processed_requests: Dictionary = {}
var _quarantined := false
var _quarantine_reason: StringName = &""
var _transaction_active := false
# One private successful parse input; live graph/source checks still run each time.
var _validated_owned_snapshot: Dictionary = {}


## Binds the two authoritative services once and establishes projection 1.
## Existing primary World occupancy is intentionally not consulted: ROUTE is
## an independent subslot and is merged with the supplied base walkable cells.
func configure(
	source_value: Variant,
	path_value: Variant,
	base_walkable_cells: Variant
) -> bool:
	if _transaction_active:
		return _fail("Route projection configuration cannot reenter an active transaction.")
	if _configured:
		return _fail("Route projection adapter is already configured.")
	if not source_value is SpatialSubslotService or not path_value is PathService:
		return _fail("Route projection requires SpatialSubslotService and PathService instances.")
	var normalized_base := _normalize_cells(
		base_walkable_cells,
		true,
		MAX_BASE_WALKABLE_CELLS,
		"Base walkable cells"
	)
	if not bool(normalized_base[&"ok"]):
		return _fail(String(normalized_base[&"message"]))
	var source_service: SpatialSubslotService = source_value
	var path_service: PathService = path_value
	var source_audit: Dictionary = source_service.validate_invariants()
	if not bool(source_audit.get(&"ok", false)):
		return _fail("Spatial subslot source invariants are invalid.")
	var route_cells := source_service.get_route_cells()
	var projected := _union_cells(normalized_base[&"cells"], route_cells)
	if projected.size() > MAX_PROJECTED_CELLS:
		return _fail("Projected walkable-cell capacity is exceeded.")

	var owned_before := _capture_owned_state()
	_transaction_active = true
	var guard_state := _capture_owned_state()
	var source_snapshot := source_service.create_snapshot()
	var path_capture := _capture_path_state(path_service)
	if not bool(path_capture[&"ok"]):
		_restore_owned_state(owned_before)
		return _fail(String(path_capture[&"message"]))
	var apply_ok := path_service.rebuild_graph(projected.duplicate())
	var callback_tampered := not _owned_state_matches(guard_state)
	var source_tampered := source_service.create_snapshot() != source_snapshot
	var path_matches := _path_cells_match(path_service, projected)
	if not apply_ok or callback_tampered or source_tampered or not path_matches:
		var rollback_ok := _restore_dependencies_exact(
			source_service,
			path_service,
			source_snapshot,
			path_capture
		)
		_restore_owned_state(owned_before)
		if not rollback_ok:
			_bind_quarantined_configuration(
				source_service,
				path_service,
				normalized_base[&"cells"],
				route_cells,
				projected,
				QUARANTINE_CONFIGURE_ROLLBACK
			)
			return _fail("Route projection configuration failed and rollback is uncertain.")
		return _fail(
			"Route projection callback tampered with the adapter and was rolled back."
			if callback_tampered or source_tampered
			else "Path graph rejected the initial route projection; state was rolled back."
		)

	_source = source_service
	_path = path_service
	_configured = true
	_base_walkable_cells = _cell_set(normalized_base[&"cells"])
	_projected_route_cells = route_cells.duplicate()
	_projected_walkable_cells = projected.duplicate()
	source_revision = source_service.get_revision_for_category(source_service.CATEGORY_ROUTE)
	projection_revision = 1
	_processed_requests.clear()
	_quarantined = false
	_quarantine_reason = &""
	_transaction_active = false
	last_error = ""
	return true


func place_route(
	request_id: Variant,
	entity_id: Variant,
	cells: Variant
) -> CommandResult:
	return _execute_route_request(OPERATION_PLACE, request_id, entity_id, cells)


func replace_route(
	request_id: Variant,
	entity_id: Variant,
	cells: Variant
) -> CommandResult:
	return _execute_route_request(OPERATION_REPLACE, request_id, entity_id, cells)


func remove_route(request_id: Variant, entity_id: Variant) -> CommandResult:
	return _execute_route_request(OPERATION_REMOVE, request_id, entity_id, [])


## Reconciles direct, out-of-adapter ROUTE changes or Path topology drift. A
## supplied base set atomically replaces the prior World walkability projection.
func synchronize_projection(
	request_id: Variant,
	base_walkable_cells: Variant = null
) -> CommandResult:
	var requested_base: Variant = (
		get_base_walkable_cells() if base_walkable_cells == null else base_walkable_cells
	)
	return _execute_route_request(OPERATION_SYNCHRONIZE, request_id, &"", requested_base)


func is_configured() -> bool:
	return _configured


## Identity-only binding check for higher-level atomic coordinators.  The
## authoritative service references themselves remain encapsulated.
func is_bound_to(source_value: Variant, path_value: Variant) -> bool:
	return _configured and _source == source_value and _path == path_value


func is_quarantined() -> bool:
	return _quarantined


func get_quarantine_reason() -> StringName:
	return _quarantine_reason


func get_base_walkable_cells(sort_result := true) -> Array[Vector3i]:
	return _sorted_cells(_base_walkable_cells.keys(), sort_result)


func get_projected_route_cells() -> Array[Vector3i]:
	return _projected_route_cells.duplicate()


func get_projected_walkable_cells() -> Array[Vector3i]:
	return _projected_walkable_cells.duplicate()


func get_processed_request_ids() -> Array[StringName]:
	return _sorted_names(_processed_requests)


func get_projection_status() -> Dictionary:
	return _projection_status_internal().duplicate(true)


func is_projection_stale() -> bool:
	return bool(_projection_status_internal()[&"stale"])


func create_snapshot() -> Dictionary:
	if not _configured:
		return {}
	var request_rows: Array[Dictionary] = []
	for request_id: StringName in _sorted_names(_processed_requests):
		var record: Dictionary = _processed_requests[request_id]
		var details: Dictionary = record[&"details"]
		request_rows.append({
			&"request_id": String(request_id),
			&"operation": String(record[&"operation"]),
			&"entity_id": String(record[&"entity_id"]),
			&"input_source_revision": int(record[&"input_source_revision"]),
			&"input_cells": (record[&"input_cells"] as Array).duplicate(),
			&"fingerprint": String(record[&"fingerprint"]),
			&"details": {
				&"request_id": String(details[&"request_id"]),
				&"operation": String(details[&"operation"]),
				&"entity_id": String(details[&"entity_id"]),
				&"cells": (details[&"cells"] as Array).duplicate(),
				&"changed": bool(details[&"changed"]),
				&"source_revision": int(details[&"source_revision"]),
				&"projection_revision": int(details[&"projection_revision"]),
			},
		})
	return {
		&"schema_version": SNAPSHOT_SCHEMA_VERSION,
		&"source_revision": source_revision,
		&"projection_revision": projection_revision,
		&"base_walkable_cells": get_base_walkable_cells(),
		&"projected_route_cells": get_projected_route_cells(),
		&"projected_walkable_cells": get_projected_walkable_cells(),
		&"processed_requests": request_rows,
		&"quarantined": _quarantined,
		&"quarantine_reason": String(_quarantine_reason),
	}


## Restores adapter-owned state only. Non-quarantined snapshots must crosslink
## exactly with the already-restored SpatialSubslotService and PathService.
func restore_snapshot(snapshot: Dictionary) -> bool:
	if _transaction_active:
		return _fail("Route projection snapshot cannot restore during a transaction.")
	if not _configured:
		return _fail("Route projection adapter must be configured before restore.")
	var parsed := _parse_snapshot(snapshot)
	if not bool(parsed[&"ok"]):
		return _fail(String(parsed[&"message"]))
	var owned_before := _capture_owned_state()
	_transaction_active = true
	var guard_state := _capture_owned_state()
	if not bool(parsed[&"quarantined"]):
		var live_matches := _live_projection_matches(
			int(parsed[&"source_revision"]),
			parsed[&"projected_route_cells"],
			parsed[&"projected_walkable_cells"]
		)
		if not live_matches or not _owned_state_matches(guard_state):
			_restore_owned_state(owned_before)
			return _fail("Route projection snapshot does not match the live source and Path graph.")
	_source_revision_from_parsed(parsed)
	_transaction_active = false
	last_error = ""
	return true


func validate_invariants() -> Dictionary:
	var errors: Array[String] = []
	if not _configured or _source == null or _path == null:
		errors.append("Route projection adapter is not configured.")
		return {&"ok": false, &"errors": errors}
	var owned_snapshot := create_snapshot()
	if owned_snapshot != _validated_owned_snapshot:
		var parsed := _parse_snapshot(owned_snapshot)
		if not bool(parsed[&"ok"]):
			errors.append(String(parsed[&"message"]))
		else:
			_validated_owned_snapshot = owned_snapshot
	if not _quarantine_state_is_valid(_quarantined, _quarantine_reason):
		errors.append("Route projection quarantine state is inconsistent.")
	if not _quarantined:
		var status := _projection_status_internal()
		if bool(status[&"stale"]):
			errors.append("Route projection crosslinks are stale.")
	return {&"ok": errors.is_empty(), &"errors": errors}


func _execute_route_request(
	operation: StringName,
	request_id_value: Variant,
	entity_id_value: Variant,
	cells_value: Variant
) -> CommandResult:
	if _transaction_active:
		return _failure(
			CommandResultType.Code.TRANSACTION_CLOSED,
			"Route projection transaction is already active."
		)
	if not _configured:
		return _failure(CommandResultType.Code.TRANSACTION_CLOSED, "Route projection adapter is not configured.")
	if not _stable_id_is_valid(request_id_value):
		return _failure(CommandResultType.Code.INVALID_PAYLOAD, "Route projection request ID is invalid.")
	if not OPERATIONS.has(operation):
		return _failure(CommandResultType.Code.INVALID_COMMAND, "Route projection operation is invalid.")
	var request_id := StringName(request_id_value)
	var entity_id: StringName = &""
	var input_cells: Array[Vector3i] = []
	var input_source_revision := -1
	if operation == OPERATION_SYNCHRONIZE:
		input_source_revision = _source.get_revision_for_category(_source.CATEGORY_ROUTE)
		var normalized_base := _normalize_cells(
			cells_value,
			true,
			MAX_BASE_WALKABLE_CELLS,
			"Synchronization base walkable cells"
		)
		if not bool(normalized_base[&"ok"]):
			return _failure(CommandResultType.Code.INVALID_PAYLOAD, String(normalized_base[&"message"]))
		input_cells = normalized_base[&"cells"]
	else:
		if not _stable_id_is_valid(entity_id_value):
			return _failure(CommandResultType.Code.INVALID_PAYLOAD, "Route entity ID is invalid.")
		entity_id = StringName(entity_id_value)
		if operation in [OPERATION_PLACE, OPERATION_REPLACE]:
			var normalized := _normalize_cells(
				cells_value,
				false,
				MAX_CELLS_PER_ROUTE_REQUEST,
				"Route request cells"
			)
			if not bool(normalized[&"ok"]):
				return _failure(CommandResultType.Code.INVALID_PAYLOAD, String(normalized[&"message"]))
			input_cells = normalized[&"cells"]
	var fingerprint := _request_fingerprint(
		operation,
		entity_id,
		input_source_revision,
		input_cells
	)
	if _processed_requests.has(request_id):
		var previous: Dictionary = _processed_requests[request_id]
		if String(previous[&"fingerprint"]) != fingerprint:
			return _failure(
				CommandResultType.Code.DUPLICATE_IDEMPOTENCY_KEY,
				"Route projection request ID conflicts with earlier input."
			)
		var replay := _success((previous[&"details"] as Dictionary).duplicate(true))
		replay.is_replay = true
		return replay
	if _quarantined:
		return _failure(
			CommandResultType.Code.TRANSACTION_CLOSED,
			"Route projection adapter is quarantined until an exact snapshot is restored.",
			{&"quarantine_reason": _quarantine_reason}
		)
	if _processed_requests.size() >= MAX_PROCESSED_REQUESTS:
		return _failure(CommandResultType.Code.VALIDATION_FAILED, "Route request history capacity is exhausted.")
	if _history_cell_reference_count(_processed_requests) > MAX_HISTORY_CELL_REFERENCES - input_cells.size():
		return _failure(CommandResultType.Code.VALIDATION_FAILED, "Route request history cell budget is exhausted.")

	var owned_before := _capture_owned_state()
	_transaction_active = true
	var guard_state := _capture_owned_state()
	var status_before := _projection_status_internal()
	if operation != OPERATION_SYNCHRONIZE and bool(status_before[&"stale"]):
		_restore_owned_state(owned_before)
		return _failure(
			CommandResultType.Code.TRANSACTION_CLOSED,
			"Route projection is stale and must be synchronized before mutation.",
			status_before
		)
	var source_audit: Dictionary = _source.validate_invariants()
	if not bool(source_audit.get(&"ok", false)):
		_restore_owned_state(owned_before)
		return _failure(CommandResultType.Code.VALIDATION_FAILED, "Spatial route source invariants are invalid.")
	if operation in [OPERATION_REPLACE, OPERATION_REMOVE]:
		if not _source.has_entity(entity_id):
			_restore_owned_state(owned_before)
			return _failure(CommandResultType.Code.NOT_FOUND, "Route entity was not found.")
		if _source.get_entity_category(entity_id) != _source.CATEGORY_ROUTE:
			_restore_owned_state(owned_before)
			return _failure(CommandResultType.Code.VALIDATION_FAILED, "Adapter may mutate only ROUTE entities.")

	var source_service := _source
	var path_service := _path
	var source_snapshot := source_service.create_snapshot()
	var path_capture := _capture_path_state(path_service)
	if not bool(path_capture[&"ok"]) or not _owned_state_matches(guard_state):
		var capture_rollback_ok := false
		if bool(path_capture[&"ok"]):
			capture_rollback_ok = _restore_dependencies_exact(
				source_service, path_service, source_snapshot, path_capture
			)
		else:
			capture_rollback_ok = source_service.create_snapshot() == source_snapshot
		_restore_owned_state(owned_before)
		if not capture_rollback_ok:
			_quarantine(QUARANTINE_TRANSACTION_ROLLBACK)
			return _failure(
				CommandResultType.Code.TRANSACTION_CLOSED,
				"Route capture was tampered with and rollback is uncertain.",
				{&"rollback_ok": false, &"quarantined": true}
			)
		return _failure(
			CommandResultType.Code.TRANSACTION_APPLY_FAILED,
			"Route transaction capture failed without changing authoritative state.",
			{&"rollback_ok": true, &"quarantined": false}
		)

	var result_cells: Array[Vector3i] = []
	var source_result: CommandResult
	match operation:
		OPERATION_PLACE:
			result_cells = input_cells.duplicate()
			source_result = source_service.place(entity_id, source_service.CATEGORY_ROUTE, input_cells)
		OPERATION_REPLACE:
			result_cells = input_cells.duplicate()
			source_result = source_service.replace_entity_cells(entity_id, input_cells)
		OPERATION_REMOVE:
			result_cells = source_service.get_entity_cells(entity_id)
			source_result = source_service.remove(entity_id)
		OPERATION_SYNCHRONIZE:
			source_result = CommandResultType.succeeded()
		_:
			source_result = CommandResultType.failed(CommandResultType.Code.INVALID_COMMAND, 0, "Unknown route operation.")

	var callback_tampered := not _owned_state_matches(guard_state)
	if not source_result.is_success() or callback_tampered:
		return _rollback_transaction_failure(
			owned_before,
			source_service,
			path_service,
			source_snapshot,
			path_capture,
			"Spatial route apply failed." if not source_result.is_success() else "Spatial callback tampered with the route adapter."
		)

	var next_route_cells := source_service.get_route_cells()
	var next_base_cells := (
		input_cells.duplicate() if operation == OPERATION_SYNCHRONIZE else get_base_walkable_cells()
	)
	var next_walkable_cells := _union_cells(next_base_cells, next_route_cells)
	if next_walkable_cells.size() > MAX_PROJECTED_CELLS:
		return _rollback_transaction_failure(
			owned_before,
			source_service,
			path_service,
			source_snapshot,
			path_capture,
			"Projected walkable-cell capacity is exceeded."
		)
	var path_apply_ok := path_service.rebuild_graph(next_walkable_cells.duplicate())
	callback_tampered = not _owned_state_matches(guard_state)
	var next_source_revision := source_service.get_revision_for_category(source_service.CATEGORY_ROUTE)
	var post_source_audit: Dictionary = source_service.validate_invariants()
	var postcondition_ok := (
		path_apply_ok
		and not callback_tampered
		and bool(post_source_audit.get(&"ok", false))
		and source_service.get_route_cells() == next_route_cells
		and _path_cells_match(path_service, next_walkable_cells)
	)
	if not postcondition_ok:
		return _rollback_transaction_failure(
			owned_before,
			source_service,
			path_service,
			source_snapshot,
			path_capture,
			"Path projection failed or violated its postcondition."
		)

	var changed := (
		bool(status_before[&"stale"]) or next_base_cells != get_base_walkable_cells()
		if operation == OPERATION_SYNCHRONIZE
		else bool(source_result.details.get(&"changed", true))
	)
	if changed:
		projection_revision += 1
	source_revision = next_source_revision
	_base_walkable_cells = _cell_set(next_base_cells)
	_projected_route_cells = next_route_cells.duplicate()
	_projected_walkable_cells = next_walkable_cells.duplicate()
	var details := {
		&"request_id": request_id,
		&"operation": operation,
		&"entity_id": entity_id,
		&"cells": result_cells.duplicate(),
		&"changed": changed,
		&"source_revision": source_revision,
		&"projection_revision": projection_revision,
	}
	_processed_requests[request_id] = {
		&"operation": operation,
		&"entity_id": entity_id,
		&"input_source_revision": input_source_revision,
		&"input_cells": input_cells.duplicate(),
		&"fingerprint": fingerprint,
		&"details": details.duplicate(true),
	}
	_transaction_active = false
	last_error = ""
	return _success(details)


func _rollback_transaction_failure(
	owned_before: Dictionary,
	source_service: SpatialSubslotService,
	path_service: PathService,
	source_snapshot: Dictionary,
	path_capture: Dictionary,
	message: String
) -> CommandResult:
	var rollback_ok := _restore_dependencies_exact(
		source_service,
		path_service,
		source_snapshot,
		path_capture
	)
	_restore_owned_state(owned_before)
	if not rollback_ok:
		_quarantine(QUARANTINE_TRANSACTION_ROLLBACK)
		return _failure(
			CommandResultType.Code.TRANSACTION_CLOSED,
			"%s Rollback is uncertain; adapter was quarantined." % message,
			{&"rollback_ok": false, &"quarantined": true, &"quarantine_reason": _quarantine_reason}
		)
	return _failure(
		CommandResultType.Code.TRANSACTION_APPLY_FAILED,
		"%s Both services were rolled back exactly." % message,
		{&"rollback_ok": true, &"quarantined": false}
	)


func _projection_status_internal() -> Dictionary:
	if not _configured or _source == null or _path == null:
		return {
			&"configured": false,
			&"stale": true,
			&"quarantined": _quarantined,
			&"quarantine_reason": _quarantine_reason,
			&"source_revision": -1,
			&"projected_source_revision": source_revision,
			&"projection_revision": projection_revision,
			&"source_changed": true,
			&"path_changed": true,
		}
	var current_source_revision := _source.get_revision_for_category(_source.CATEGORY_ROUTE)
	var current_route_cells := _source.get_route_cells()
	var path_capture := _capture_path_state(_path, false)
	var source_changed: bool = (
		current_source_revision != source_revision
		or current_route_cells != _projected_route_cells
	)
	var path_changed: bool = (
		not bool(path_capture[&"ok"])
		or path_capture[&"cells"] != _projected_walkable_cells
	)
	var projection_crosslink_ok: bool = (
		_union_cells(get_base_walkable_cells(false), _projected_route_cells)
		== _projected_walkable_cells
	)
	return {
		&"configured": true,
		&"stale": _quarantined or source_changed or path_changed or not projection_crosslink_ok,
		&"quarantined": _quarantined,
		&"quarantine_reason": _quarantine_reason,
		&"source_revision": current_source_revision,
		&"projected_source_revision": source_revision,
		&"projection_revision": projection_revision,
		&"source_changed": source_changed,
		&"path_changed": path_changed,
	}


func _live_projection_matches(
	expected_source_revision: int,
	expected_route_cells: Array[Vector3i],
	expected_walkable_cells: Array[Vector3i]
) -> bool:
	var audit: Dictionary = _source.validate_invariants()
	return (
		bool(audit.get(&"ok", false))
		and _source.get_revision_for_category(_source.CATEGORY_ROUTE) == expected_source_revision
		and _source.get_route_cells() == expected_route_cells
		and _path_cells_match(_path, expected_walkable_cells)
	)


func _source_revision_from_parsed(parsed: Dictionary) -> void:
	source_revision = int(parsed[&"source_revision"])
	projection_revision = int(parsed[&"projection_revision"])
	_base_walkable_cells = _cell_set(parsed[&"base_walkable_cells"])
	_projected_route_cells = (parsed[&"projected_route_cells"] as Array).duplicate()
	_projected_walkable_cells = (parsed[&"projected_walkable_cells"] as Array).duplicate()
	_processed_requests = (parsed[&"processed_requests"] as Dictionary).duplicate(true)
	_quarantined = bool(parsed[&"quarantined"])
	_quarantine_reason = parsed[&"quarantine_reason"]


func _capture_owned_state() -> Dictionary:
	return {
		&"source": _source,
		&"path": _path,
		&"configured": _configured,
		&"base_walkable_cells": _base_walkable_cells.duplicate(true),
		&"projected_route_cells": _projected_route_cells.duplicate(),
		&"projected_walkable_cells": _projected_walkable_cells.duplicate(),
		&"source_revision": source_revision,
		&"projection_revision": projection_revision,
		&"processed_requests": _processed_requests.duplicate(true),
		&"quarantined": _quarantined,
		&"quarantine_reason": _quarantine_reason,
		&"transaction_active": _transaction_active,
	}


func _owned_state_matches(capture: Dictionary) -> bool:
	return (
		_source == capture[&"source"]
		and _path == capture[&"path"]
		and _configured == bool(capture[&"configured"])
		and _base_walkable_cells == capture[&"base_walkable_cells"]
		and _projected_route_cells == capture[&"projected_route_cells"]
		and _projected_walkable_cells == capture[&"projected_walkable_cells"]
		and source_revision == int(capture[&"source_revision"])
		and projection_revision == int(capture[&"projection_revision"])
		and _processed_requests == capture[&"processed_requests"]
		and _quarantined == bool(capture[&"quarantined"])
		and _quarantine_reason == capture[&"quarantine_reason"]
		and _transaction_active == bool(capture[&"transaction_active"])
	)


func _restore_owned_state(capture: Dictionary) -> void:
	_source = capture[&"source"]
	_path = capture[&"path"]
	_configured = bool(capture[&"configured"])
	_base_walkable_cells = (capture[&"base_walkable_cells"] as Dictionary).duplicate(true)
	_projected_route_cells.assign(capture[&"projected_route_cells"])
	_projected_walkable_cells.assign(capture[&"projected_walkable_cells"])
	source_revision = int(capture[&"source_revision"])
	projection_revision = int(capture[&"projection_revision"])
	_processed_requests = (capture[&"processed_requests"] as Dictionary).duplicate(true)
	_quarantined = bool(capture[&"quarantined"])
	_quarantine_reason = capture[&"quarantine_reason"]
	_transaction_active = bool(capture[&"transaction_active"])


func _bind_quarantined_configuration(
	source_service: SpatialSubslotService,
	path_service: PathService,
	base_cells: Array[Vector3i],
	route_cells: Array[Vector3i],
	projected_cells: Array[Vector3i],
	reason: StringName
) -> void:
	_source = source_service
	_path = path_service
	_configured = true
	_base_walkable_cells = _cell_set(base_cells)
	_projected_route_cells = route_cells.duplicate()
	_projected_walkable_cells = projected_cells.duplicate()
	source_revision = source_service.get_revision_for_category(source_service.CATEGORY_ROUTE)
	projection_revision = 1
	_processed_requests.clear()
	_transaction_active = false
	_quarantine(reason)


func _quarantine(reason: StringName) -> void:
	_quarantined = true
	_quarantine_reason = reason
	_transaction_active = false


static func _capture_path_state(path_service: PathService, capture_snapshot := true) -> Dictionary:
	var snapshot := path_service.create_snapshot()
	var parsed_cells := _path_cells_from_snapshot(snapshot)
	if not bool(parsed_cells[&"ok"]):
		return {&"ok": false, &"message": parsed_cells[&"message"]}
	for cell: Vector3i in parsed_cells[&"cells"]:
		if not path_service.has_cell(cell):
			return {
				&"ok": false,
				&"message": "Path snapshot topology has not been materialized into the live graph.",
			}
	var result := {&"ok": true}
	if capture_snapshot:
		result[&"snapshot"] = snapshot.duplicate(true)
	result[&"cells"] = (parsed_cells[&"cells"] as Array).duplicate()
	return result


static func _path_cells_from_snapshot(snapshot: Dictionary) -> Dictionary:
	var raw_rows: Variant = snapshot.get(&"cell_traffic", null)
	if not raw_rows is Array or raw_rows.size() > MAX_PROJECTED_CELLS:
		return {&"ok": false, &"message": "Path snapshot does not expose a bounded cell topology."}
	var cells: Array[Vector3i] = []
	var seen: Dictionary = {}
	for raw_row: Variant in raw_rows:
		if not raw_row is Dictionary:
			return {&"ok": false, &"message": "Path snapshot cell topology is malformed."}
		var raw_cell: Variant = raw_row.get(&"cell", raw_row.get("cell", null))
		if not _cell_is_valid(raw_cell) or seen.has(raw_cell):
			return {&"ok": false, &"message": "Path snapshot contains an invalid or duplicate cell."}
		seen[raw_cell] = true
		cells.append(raw_cell)
	cells.sort_custom(_cell_less)
	return {&"ok": true, &"cells": cells}


static func _path_cells_match(path_service: PathService, expected: Array[Vector3i]) -> bool:
	var capture := _capture_path_state(path_service)
	if not bool(capture[&"ok"]) or capture[&"cells"] != expected:
		return false
	for cell: Vector3i in expected:
		if not path_service.has_cell(cell):
			return false
	return true


static func _restore_dependencies_exact(
	source_service: SpatialSubslotService,
	path_service: PathService,
	source_snapshot: Dictionary,
	path_capture: Dictionary
) -> bool:
	for _attempt: int in range(2):
		source_service.restore_snapshot(source_snapshot.duplicate(true))
		_restore_path_once(path_service, path_capture)
		if (
			source_service.create_snapshot() == source_snapshot
			and _path_state_matches_capture(path_service, path_capture)
		):
			return true
	return false


static func _restore_path_once(path_service: PathService, capture: Dictionary) -> void:
	var cells: Array = capture[&"cells"]
	var snapshot: Dictionary = capture[&"snapshot"]
	# The second rebuild materializes PathService's pending graph revision when
	# the authoritative graph is empty. Calls are intentionally best-effort;
	# exact equality below is the authoritative rollback verdict.
	path_service.rebuild_graph(cells.duplicate())
	path_service.restore_snapshot(snapshot.duplicate(true))
	path_service.rebuild_graph(cells.duplicate())


static func _path_state_matches_capture(path_service: PathService, capture: Dictionary) -> bool:
	return (
		path_service.create_snapshot() == capture[&"snapshot"]
		and _path_cells_match(path_service, capture[&"cells"])
	)


static func _parse_snapshot(snapshot: Dictionary) -> Dictionary:
	if not _variant_depth_is_valid(snapshot, 0):
		return {&"ok": false, &"message": "Route projection snapshot depth or capacity is exceeded."}
	if not _keys_match(snapshot, [
		&"base_walkable_cells",
		&"processed_requests",
		&"projected_route_cells",
		&"projected_walkable_cells",
		&"projection_revision",
		&"quarantine_reason",
		&"quarantined",
		&"schema_version",
		&"source_revision",
	]):
		return {&"ok": false, &"message": "Route projection snapshot root fields are not canonical."}
	if typeof(snapshot.get(&"schema_version", null)) != TYPE_INT \
			or int(snapshot[&"schema_version"]) != SNAPSHOT_SCHEMA_VERSION:
		return {&"ok": false, &"message": "Unsupported RouteSubslotPathAdapter snapshot version."}
	if typeof(snapshot.get(&"source_revision", null)) != TYPE_INT \
			or typeof(snapshot.get(&"projection_revision", null)) != TYPE_INT:
		return {&"ok": false, &"message": "Route projection revisions must be integers."}
	var next_source_revision := int(snapshot[&"source_revision"])
	var next_projection_revision := int(snapshot[&"projection_revision"])
	if next_source_revision < 0 or next_source_revision > MAX_SAFE_INTEGER \
			or next_projection_revision < 1 or next_projection_revision > MAX_SAFE_INTEGER:
		return {&"ok": false, &"message": "Route projection revisions are outside supported bounds."}
	if typeof(snapshot.get(&"quarantined", null)) != TYPE_BOOL \
			or typeof(snapshot.get(&"quarantine_reason", null)) not in [TYPE_STRING, TYPE_STRING_NAME]:
		return {&"ok": false, &"message": "Route projection quarantine state has invalid types."}
	var next_quarantined := bool(snapshot[&"quarantined"])
	var next_quarantine_reason := StringName(snapshot[&"quarantine_reason"])
	if not _quarantine_state_is_valid(next_quarantined, next_quarantine_reason):
		return {&"ok": false, &"message": "Route projection quarantine state is inconsistent."}

	var base_result := _normalize_cells(
		snapshot.get(&"base_walkable_cells", null),
		true,
		MAX_BASE_WALKABLE_CELLS,
		"Snapshot base walkable cells"
	)
	var route_result := _normalize_cells(
		snapshot.get(&"projected_route_cells", null),
		true,
		SpatialSubslotServiceType.MAX_TOTAL_SLOTS,
		"Snapshot projected route cells"
	)
	var projected_result := _normalize_cells(
		snapshot.get(&"projected_walkable_cells", null),
		true,
		MAX_PROJECTED_CELLS,
		"Snapshot projected walkable cells"
	)
	for result: Dictionary in [base_result, route_result, projected_result]:
		if not bool(result[&"ok"]):
			return result
	if snapshot[&"base_walkable_cells"] != base_result[&"cells"] \
			or snapshot[&"projected_route_cells"] != route_result[&"cells"] \
			or snapshot[&"projected_walkable_cells"] != projected_result[&"cells"]:
		return {&"ok": false, &"message": "Route projection snapshot cells are not canonically ordered."}
	if _union_cells(base_result[&"cells"], route_result[&"cells"]) != projected_result[&"cells"]:
		return {&"ok": false, &"message": "Route projection snapshot union crosslink is invalid."}

	var raw_requests: Variant = snapshot.get(&"processed_requests", null)
	if not raw_requests is Array or raw_requests.size() > MAX_PROCESSED_REQUESTS:
		return {&"ok": false, &"message": "Route projection request history is malformed or too large."}
	var next_requests: Dictionary = {}
	var previous_request_id := ""
	var history_cell_references := 0
	var latest_recorded_projection_revision := 1
	for raw_record: Variant in raw_requests:
		var record_result := _parse_request_record(
			raw_record,
			next_source_revision,
			next_projection_revision,
			previous_request_id
		)
		if not bool(record_result[&"ok"]):
			return record_result
		var request_id: StringName = record_result[&"request_id"]
		var parsed_record: Dictionary = record_result[&"record"]
		history_cell_references += (parsed_record[&"input_cells"] as Array).size()
		if history_cell_references > MAX_HISTORY_CELL_REFERENCES:
			return {&"ok": false, &"message": "Route projection request history cell budget is exceeded."}
		latest_recorded_projection_revision = max(
			latest_recorded_projection_revision,
			int((parsed_record[&"details"] as Dictionary)[&"projection_revision"])
		)
		next_requests[request_id] = parsed_record
		previous_request_id = String(request_id)
	if latest_recorded_projection_revision != next_projection_revision:
		return {&"ok": false, &"message": "Route projection revision lacks matching request history."}
	return {
		&"ok": true,
		&"source_revision": next_source_revision,
		&"projection_revision": next_projection_revision,
		&"base_walkable_cells": base_result[&"cells"],
		&"projected_route_cells": route_result[&"cells"],
		&"projected_walkable_cells": projected_result[&"cells"],
		&"processed_requests": next_requests,
		&"quarantined": next_quarantined,
		&"quarantine_reason": next_quarantine_reason,
	}


static func _parse_request_record(
	raw_record: Variant,
	current_source_revision: int,
	current_projection_revision: int,
	previous_request_id: String
) -> Dictionary:
	if not raw_record is Dictionary or not _keys_match(raw_record, [
		&"details", &"entity_id", &"fingerprint", &"input_cells",
		&"input_source_revision", &"operation", &"request_id",
	]):
		return {&"ok": false, &"message": "Route projection request record fields are invalid."}
	for field: StringName in [&"request_id", &"operation", &"entity_id", &"fingerprint"]:
		if typeof(raw_record.get(field, null)) not in [TYPE_STRING, TYPE_STRING_NAME]:
			return {&"ok": false, &"message": "Route projection request record string fields are invalid."}
	if typeof(raw_record.get(&"input_source_revision", null)) != TYPE_INT:
		return {&"ok": false, &"message": "Route projection request source revision is invalid."}
	var request_id := StringName(raw_record[&"request_id"])
	var request_text := String(request_id)
	var operation := StringName(raw_record[&"operation"])
	var entity_id := StringName(raw_record[&"entity_id"])
	var input_source_revision := int(raw_record[&"input_source_revision"])
	if not _stable_id_is_valid(request_id) \
			or (not previous_request_id.is_empty() and request_text <= previous_request_id) \
			or not OPERATIONS.has(operation):
		return {&"ok": false, &"message": "Route projection request identity/order is invalid."}
	if operation == OPERATION_SYNCHRONIZE:
		if not entity_id.is_empty() \
				or input_source_revision < 0 \
				or input_source_revision > current_source_revision:
			return {&"ok": false, &"message": "Synchronization request input is inconsistent."}
	else:
		if not _stable_id_is_valid(entity_id) or input_source_revision != -1:
			return {&"ok": false, &"message": "Route mutation request input is inconsistent."}
	var allow_empty := operation in [OPERATION_REMOVE, OPERATION_SYNCHRONIZE]
	var maximum_cells := (
		MAX_BASE_WALKABLE_CELLS
		if operation == OPERATION_SYNCHRONIZE
		else MAX_CELLS_PER_ROUTE_REQUEST
	)
	var cells_result := _normalize_cells(
		raw_record.get(&"input_cells", null),
		allow_empty,
		maximum_cells,
		"Route projection request input cells"
	)
	if not bool(cells_result[&"ok"]):
		return cells_result
	var input_cells: Array[Vector3i] = cells_result[&"cells"]
	if raw_record[&"input_cells"] != input_cells \
			or (operation == OPERATION_REMOVE and not input_cells.is_empty()):
		return {&"ok": false, &"message": "Route projection request cells are not canonical."}
	var expected_fingerprint := _request_fingerprint(
		operation,
		entity_id,
		input_source_revision,
		input_cells
	)
	if String(raw_record[&"fingerprint"]) != expected_fingerprint:
		return {&"ok": false, &"message": "Route projection request fingerprint is invalid."}
	var details_result := _parse_request_details(
		raw_record.get(&"details", null),
		request_id,
		operation,
		entity_id,
		input_cells,
		current_source_revision,
		current_projection_revision
	)
	if not bool(details_result[&"ok"]):
		return details_result
	return {
		&"ok": true,
		&"request_id": request_id,
		&"record": {
			&"operation": operation,
			&"entity_id": entity_id,
			&"input_source_revision": input_source_revision,
			&"input_cells": input_cells,
			&"fingerprint": expected_fingerprint,
			&"details": details_result[&"details"],
		},
	}


static func _parse_request_details(
	raw_details: Variant,
	request_id: StringName,
	operation: StringName,
	entity_id: StringName,
	input_cells: Array[Vector3i],
	current_source_revision: int,
	current_projection_revision: int
) -> Dictionary:
	if not raw_details is Dictionary or not _keys_match(raw_details, [
		&"cells", &"changed", &"entity_id", &"operation", &"projection_revision",
		&"request_id", &"source_revision",
	]):
		return {&"ok": false, &"message": "Route projection request result fields are invalid."}
	if typeof(raw_details.get(&"request_id", null)) not in [TYPE_STRING, TYPE_STRING_NAME] \
			or typeof(raw_details.get(&"operation", null)) not in [TYPE_STRING, TYPE_STRING_NAME] \
			or typeof(raw_details.get(&"entity_id", null)) not in [TYPE_STRING, TYPE_STRING_NAME] \
			or typeof(raw_details.get(&"changed", null)) != TYPE_BOOL \
			or typeof(raw_details.get(&"source_revision", null)) != TYPE_INT \
			or typeof(raw_details.get(&"projection_revision", null)) != TYPE_INT:
		return {&"ok": false, &"message": "Route projection request result types are invalid."}
	var detail_source_revision := int(raw_details[&"source_revision"])
	var detail_projection_revision := int(raw_details[&"projection_revision"])
	if StringName(raw_details[&"request_id"]) != request_id \
			or StringName(raw_details[&"operation"]) != operation \
			or StringName(raw_details[&"entity_id"]) != entity_id \
			or detail_source_revision < 0 \
			or detail_source_revision > current_source_revision \
			or detail_projection_revision < 1 \
			or detail_projection_revision > current_projection_revision:
		return {&"ok": false, &"message": "Route projection request result crosslink is invalid."}
	var cells_result := _normalize_cells(
		raw_details.get(&"cells", null),
		operation == OPERATION_SYNCHRONIZE,
		MAX_CELLS_PER_ROUTE_REQUEST,
		"Route projection request result cells"
	)
	if not bool(cells_result[&"ok"]) or raw_details[&"cells"] != cells_result[&"cells"]:
		return {&"ok": false, &"message": "Route projection request result cells are invalid."}
	var result_cells: Array[Vector3i] = cells_result[&"cells"]
	if operation in [OPERATION_PLACE, OPERATION_REPLACE] and result_cells != input_cells:
		return {&"ok": false, &"message": "Route projection request input/result cells diverge."}
	if operation == OPERATION_SYNCHRONIZE and not result_cells.is_empty():
		return {&"ok": false, &"message": "Synchronization result cells must be empty."}
	var changed := bool(raw_details[&"changed"])
	if operation in [OPERATION_PLACE, OPERATION_REMOVE] and not changed:
		return {&"ok": false, &"message": "Place/remove result must record a changed projection."}
	if changed and detail_projection_revision < 2:
		return {&"ok": false, &"message": "Changed projection result has an invalid revision."}
	return {
		&"ok": true,
		&"details": {
			&"request_id": request_id,
			&"operation": operation,
			&"entity_id": entity_id,
			&"cells": result_cells,
			&"changed": changed,
			&"source_revision": detail_source_revision,
			&"projection_revision": detail_projection_revision,
		},
	}


static func _normalize_cells(
	value: Variant,
	allow_empty: bool,
	maximum: int,
	label: String
) -> Dictionary:
	if not value is Array or value.size() > maximum or (not allow_empty and value.is_empty()):
		return {&"ok": false, &"message": "%s have an invalid collection shape or capacity." % label}
	var seen: Dictionary = {}
	var cells: Array[Vector3i] = []
	for raw_cell: Variant in value:
		if not _cell_is_valid(raw_cell) or seen.has(raw_cell):
			return {&"ok": false, &"message": "%s contain an invalid or duplicate cell." % label}
		seen[raw_cell] = true
		cells.append(raw_cell)
	cells.sort_custom(_cell_less)
	return {&"ok": true, &"cells": cells}


static func _cell_is_valid(value: Variant) -> bool:
	if not value is Vector3i:
		return false
	var cell: Vector3i = value
	return (
		cell.z in [SpatialSubslotServiceType.LAYER_FRONT, SpatialSubslotServiceType.LAYER_BACK]
		and cell.x >= -MAX_COORDINATE_ABS
		and cell.x <= MAX_COORDINATE_ABS
		and cell.y >= -MAX_COORDINATE_ABS
		and cell.y <= MAX_COORDINATE_ABS
	)


static func _cell_set(cells: Array) -> Dictionary:
	var result: Dictionary = {}
	for raw_cell: Variant in cells:
		result[raw_cell] = true
	return result


static func _union_cells(first: Array, second: Array) -> Array[Vector3i]:
	var union: Dictionary = {}
	for raw_cell: Variant in first:
		if raw_cell is Vector3i:
			union[raw_cell] = true
	for raw_cell: Variant in second:
		if raw_cell is Vector3i:
			union[raw_cell] = true
	return _sorted_cells(union.keys())


static func _sorted_cells(source: Variant, sort_result := true) -> Array[Vector3i]:
	var result: Array[Vector3i] = []
	if not source is Array:
		return result
	for raw_cell: Variant in source:
		if raw_cell is Vector3i:
			result.append(raw_cell)
	if sort_result:
		result.sort_custom(_cell_less)
	return result


static func _cell_less(left: Vector3i, right: Vector3i) -> bool:
	if left.y != right.y:
		return left.y < right.y
	if left.x != right.x:
		return left.x < right.x
	return left.z < right.z


static func _sorted_names(source: Dictionary) -> Array[StringName]:
	var result: Array[StringName] = []
	for raw_name: Variant in source:
		result.append(StringName(raw_name))
	result.sort_custom(_name_less)
	return result


static func _history_cell_reference_count(source: Dictionary) -> int:
	var total := 0
	for record_value: Variant in source.values():
		if record_value is Dictionary:
			var cells: Variant = record_value.get(&"input_cells", [])
			if cells is Array:
				total += cells.size()
	return total


static func _name_less(left: StringName, right: StringName) -> bool:
	return String(left) < String(right)


static func _stable_id_is_valid(value: Variant) -> bool:
	if typeof(value) not in [TYPE_STRING, TYPE_STRING_NAME]:
		return false
	var text := String(value)
	if text.is_empty() or text.length() > MAX_REQUEST_ID_LENGTH:
		return false
	for index: int in range(text.length()):
		var code := text.unicode_at(index)
		var allowed := (
			code >= 48 and code <= 57
			or code >= 65 and code <= 90
			or code >= 97 and code <= 122
			or code in [45, 46, 58, 64, 95]
		)
		if not allowed:
			return false
	return true


static func _request_fingerprint(
	operation: StringName,
	entity_id: StringName,
	input_source_revision: int,
	cells: Array[Vector3i]
) -> String:
	var entity_text := String(entity_id)
	var canonical := "%s|%d:%s|source=%d|cells=%d|" % [
		String(operation), entity_text.length(), entity_text, input_source_revision, cells.size(),
	]
	for cell: Vector3i in cells:
		canonical += "%d,%d,%d;" % [cell.x, cell.y, cell.z]
	return canonical.sha256_text()


static func _keys_match(source: Dictionary, expected: Array) -> bool:
	if source.size() != expected.size():
		return false
	var seen: Dictionary = {}
	for raw_key: Variant in source:
		if typeof(raw_key) not in [TYPE_STRING, TYPE_STRING_NAME]:
			return false
		var key := StringName(raw_key)
		if seen.has(key) or not expected.has(key):
			return false
		seen[key] = true
	return seen.size() == expected.size()


static func _quarantine_state_is_valid(value: bool, reason: StringName) -> bool:
	return (value and QUARANTINE_REASONS.has(reason)) or (not value and reason.is_empty())


static func _variant_depth_is_valid(value: Variant, depth: int) -> bool:
	if depth > MAX_SNAPSHOT_DEPTH:
		return false
	if value is Array:
		if value.size() > MAX_CONTAINER_ITEMS:
			return false
		for child: Variant in value:
			if not _variant_depth_is_valid(child, depth + 1):
				return false
	elif value is Dictionary:
		if value.size() > MAX_CONTAINER_ITEMS:
			return false
		for key: Variant in value:
			if not _variant_depth_is_valid(key, depth + 1) \
					or not _variant_depth_is_valid(value[key], depth + 1):
				return false
	elif typeof(value) in [TYPE_OBJECT, TYPE_CALLABLE, TYPE_SIGNAL, TYPE_RID]:
		return false
	return true


func _success(details: Dictionary = {}) -> CommandResult:
	last_error = ""
	return CommandResultType.succeeded(0, details)


func _failure(code: CommandResult.Code, message: String, details: Dictionary = {}) -> CommandResult:
	last_error = message
	return CommandResultType.failed(code, 0, message, details)


func _fail(message: String) -> bool:
	last_error = message
	return false