extends SceneTree

var failures: Array[String] = []


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


func _run() -> void:
	await _test_deterministic_continuation()
	await _test_resource_state_round_trip()
	_test_legacy_npc_migration()
	_test_legacy_resource_migration()
	_test_legacy_world_storage_migration()
	_test_previous_world_event_migration()
	_test_previous_world_relationship_migration()
	_test_previous_world_knowledge_migration()
	_test_previous_world_provenance_migration()
	_test_relationship_schema_rejection()
	_test_schema_rejection()

	if failures.is_empty():
		print("[TEST] Simulation state serialization passed")
		quit(0)
		return

	for failure in failures:
		push_error("[TEST] " + failure)
	quit(1)


func _test_deterministic_continuation() -> void:
	var uninterrupted := _create_manager(91234)
	_advance_scenario(uninterrupted, 24)
	uninterrupted.clock.advance(0.5)
	_advance_scenario(uninterrupted, 24)
	var uninterrupted_checksum: String = uninterrupted.get_state_checksum()

	var before_save := _create_manager(91234)
	_advance_scenario(before_save, 24)
	before_save.clock.advance(0.5)
	var saved_json: String = before_save.serialize_state()

	var restored := _create_manager(1)
	_check(
		restored.restore_state_from_json(saved_json),
		"A valid versioned state should restore into a fresh manager"
	)
	_check(restored.tick_count == 24, "Tick count should survive restoration")
	_check(
		is_equal_approx(restored.clock.accumulator, 0.5),
		"Clock remainder should survive restoration"
	)
	_advance_scenario(restored, 24)
	var restored_checksum: String = restored.get_state_checksum()
	if restored_checksum != uninterrupted_checksum:
		print(
			"[TEST] uninterrupted=",
			uninterrupted.serialize_state(),
			"\n[TEST] restored=",
			restored.serialize_state()
		)
	_check(
		restored_checksum == uninterrupted_checksum,
		"Restored simulation should match uninterrupted deterministic continuation"
	)

	uninterrupted.free()
	before_save.free()
	restored.free()


func _test_resource_state_round_trip() -> void:
	var resource: ResourceNode = load("res://world/resource_nodes/ResourceNode.tscn").instantiate()
	resource.node_id = &"SerializationTestBerry"
	resource.initial_amount = 9.0
	resource.yield_per_action = 2.0
	root.add_child(resource)
	await process_frame

	var manager := _create_manager(77)
	_check(
		manager.register_resource_node(resource),
		"Resource presentation should bind to simulation authority"
	)
	var resource_state: ResourceStateRecord = manager.get_resource_state(resource.node_id)
	_check(resource_state.reserve(42), "Resource should accept the test reservation")
	resource_state.extract()
	var saved_json: String = manager.serialize_state()
	resource.free()

	_check(
		is_equal_approx(resource_state.get_amount_remaining(), 7.0),
		"Resource state should survive without its presentation node"
	)
	resource_state.extract(5.0)
	resource_state.release(42)
	resource_state.set_enabled(false)

	_check(
		manager.restore_state_from_json(saved_json),
		"Unloaded resource state should restore with the simulation record"
	)
	resource_state = manager.get_resource_state(&"SerializationTestBerry")
	_check(
		is_equal_approx(resource_state.get_amount_remaining(), 7.0),
		"Resource amount should round-trip"
	)
	_check(resource_state.get_reserved_by() == 42, "Resource reservation should round-trip")
	_check(resource_state.is_enabled(), "Resource enabled state should round-trip")

	var rebound: ResourceNode = load("res://world/resource_nodes/ResourceNode.tscn").instantiate()
	rebound.node_id = &"SerializationTestBerry"
	rebound.initial_amount = 999.0
	root.add_child(rebound)
	await process_frame
	_check(
		rebound.state == resource_state,
		"Reloaded presentation should bind to the existing authoritative record"
	)
	_check(
		is_equal_approx(rebound.get_amount_remaining(), 7.0),
		"Reloaded presentation must not overwrite authoritative amount"
	)

	manager.free()
	rebound.free()


func _test_schema_rejection() -> void:
	var unsupported := JSON.stringify(
		{"schema": SimulationStateRecord.SCHEMA_NAME, "schema_version": 999}
	)
	_check(
		SimulationStateRecord.from_json(unsupported) == null,
		"Unsupported schema versions should be rejected"
	)
	_check(SimulationStateRecord.from_json("[]") == null, "Non-record JSON should be rejected")


func _test_legacy_resource_migration() -> void:
	var migrated := ResourceStateRecord.from_dictionary(
		{
			"schema_version": 1,
			"node_id": "legacy_tree",
			"amount_remaining": 6.0,
			"reserved_by": 12,
			"enabled": true
		}
	)
	_check(migrated != null, "ResourceStateRecord v1 should migrate explicitly")
	if migrated == null:
		return
	_check(
		migrated.data["schema_version"] == ResourceStateRecord.SCHEMA_VERSION,
		"Migrated resource state should use the current nested schema"
	)
	_check(
		is_equal_approx(migrated.get_amount_remaining(), 6.0) and migrated.get_reserved_by() == 12,
		"Resource migration should preserve mutable authority"
	)
	_check(
		(
			is_equal_approx(migrated.get_safety_risk(), 0.0)
			and is_equal_approx(migrated.get_comfort_distance(), 18.0)
		),
		"Resource migration should default discovery metadata"
	)


func _test_legacy_npc_migration() -> void:
	var npc := SimNPC.new(88, "LegacyNPC", SimulationIds.PROFESSION_FARMER, 5.0, 5.0)
	var legacy_data := NPCStateRecord.capture(npc).to_dictionary()
	legacy_data["schema_version"] = NPCStateRecord.LEGACY_SCHEMA_VERSION
	legacy_data.erase("travel_target_position")
	legacy_data.erase("has_travel_target")
	var migrated := NPCStateRecord.from_dictionary(legacy_data)
	_check(migrated != null, "NPCStateRecord v1 should migrate explicitly")
	if migrated == null:
		return
	_check(
		not bool(migrated.data["has_travel_target"]),
		"Legacy NPC migration should not invent an active travel target"
	)


func _test_legacy_world_storage_migration() -> void:
	var manager := _create_manager(55)
	var legacy_data: Dictionary = manager.create_state_record().to_dictionary()
	legacy_data["schema_version"] = SimulationStateRecord.LEGACY_SCHEMA_VERSION
	legacy_data.erase("storages")
	var migrated := SimulationStateRecord.from_dictionary(legacy_data)
	_check(migrated != null, "World schema v1 should migrate authored storage")
	if migrated != null:
		var migrated_storages := {}
		for storage in migrated.storages:
			migrated_storages[storage.get_storage_id()] = storage
		var pantry: StorageStateRecord = migrated_storages.get(SimulationIds.STORAGE_VILLAGE_PANTRY)
		var woodpile: StorageStateRecord = migrated_storages.get(
			SimulationIds.STORAGE_VILLAGE_WOODPILE
		)
		_check(
			(
				pantry != null
				and woodpile != null
				and is_equal_approx(
					pantry.get_amount(SimulationIds.RESOURCE_FOOD), manager.village.food
				)
				and is_equal_approx(
					woodpile.get_amount(SimulationIds.RESOURCE_WOOD), manager.village.wood
				)
			),
			"World migration should preserve legacy village resources in their storage"
		)
	manager.free()


func _test_previous_world_event_migration() -> void:
	var manager := _create_manager(56)
	var previous_data: Dictionary = manager.create_state_record().to_dictionary()
	previous_data["schema_version"] = SimulationStateRecord.EVENT_LEGACY_SCHEMA_VERSION
	previous_data.erase("economic_events")
	previous_data["simulation"].erase("next_event_id")
	var migrated := SimulationStateRecord.from_dictionary(previous_data)
	_check(migrated != null, "World schema v2 should add an empty event stream")
	if migrated != null:
		_check(
			migrated.economic_events.is_empty() and int(migrated.simulation["next_event_id"]) == 0,
			"World v2 migration should initialize deterministic event identity"
		)
	manager.free()


func _test_previous_world_relationship_migration() -> void:
	var manager := _create_manager(57)
	var previous_data: Dictionary = manager.create_state_record().to_dictionary()
	previous_data["schema_version"] = SimulationStateRecord.RELATIONSHIP_LEGACY_SCHEMA_VERSION
	previous_data.erase("relationships")
	previous_data.erase("event_knowledge")
	for npc_data in previous_data["npcs"]:
		npc_data["schema_version"] = NPCStateRecord.RELATIONSHIP_LEGACY_SCHEMA_VERSION
		npc_data["familiarity"] = []
	previous_data["npcs"][0]["familiarity"] = [{"id": 1, "score": 0.75}]
	var migrated := SimulationStateRecord.from_dictionary(previous_data)
	_check(migrated != null, "World schema v3 should migrate NPC familiarity into relationships")
	if migrated != null:
		_check(
			(
				migrated.relationships.size() == 1
				and migrated.relationships[0].get_observer_id() == 0
				and migrated.relationships[0].get_subject_id() == 1
				and is_equal_approx(migrated.relationships[0].get_familiarity(), 0.75)
				and is_equal_approx(
					migrated.relationships[0].get_trust(), RelationshipStateRecord.NEUTRAL_TRUST
				)
			),
			"World v3 migration should preserve familiarity and initialize neutral trust"
		)
		_check(
			not migrated.npcs[0].data.has("familiarity"),
			"World v3 migration should remove obsolete NPC-local familiarity data"
		)
	manager.free()


func _test_previous_world_knowledge_migration() -> void:
	var manager := _create_manager(59)
	var previous_data: Dictionary = manager.create_state_record().to_dictionary()
	previous_data["schema_version"] = SimulationStateRecord.KNOWLEDGE_LEGACY_SCHEMA_VERSION
	previous_data.erase("event_knowledge")
	var deposit_event := EconomicEventRecord.create(
		0,
		SimulationIds.EVENT_STORAGE_DEPOSITED,
		12,
		1,
		SimulationIds.npc_inventory_id(1),
		SimulationIds.STORAGE_VILLAGE_PANTRY,
		SimulationIds.RESOURCE_FOOD,
		2.0
	)
	previous_data["economic_events"] = [deposit_event.to_dictionary()]
	previous_data["simulation"]["next_event_id"] = 1
	previous_data["relationships"] = [
		RelationshipStateRecord.create(0, 1, 0.5, 0.65, 0).to_dictionary()
	]
	var migrated := SimulationStateRecord.from_dictionary(previous_data)
	_check(migrated != null, "World schema v4 should migrate causal facts into NPC knowledge")
	if migrated != null:
		_check(
			(
				migrated.event_knowledge.size() == 1
				and migrated.event_knowledge[0].get_knower_id() == 0
				and migrated.event_knowledge[0].get_event_id() == 0
				and (
					migrated.event_knowledge[0].get_acquisition_method()
					== SimulationIds.KNOWLEDGE_ACQUISITION_LEGACY
				)
			),
			"World v4 migration should preserve the fact implied by a relationship cause"
		)
	manager.free()


func _test_previous_world_provenance_migration() -> void:
	var manager := _create_manager(60)
	var previous_data: Dictionary = manager.create_state_record().to_dictionary()
	previous_data["schema_version"] = SimulationStateRecord.PREVIOUS_SCHEMA_VERSION
	var deposit_event := EconomicEventRecord.create(
		0,
		SimulationIds.EVENT_STORAGE_DEPOSITED,
		12,
		1,
		SimulationIds.npc_inventory_id(1),
		SimulationIds.STORAGE_VILLAGE_PANTRY,
		SimulationIds.RESOURCE_FOOD,
		2.0
	)
	previous_data["economic_events"] = [deposit_event.to_dictionary()]
	previous_data["simulation"]["next_event_id"] = 1
	previous_data["event_knowledge"] = [
		{"schema_version": 1, "knower_id": 0, "event_id": 0},
		{"schema_version": 1, "knower_id": 1, "event_id": 0},
	]
	previous_data["relationships"] = [
		RelationshipStateRecord.create(0, 1, 0.5, 0.65, 0).to_dictionary()
	]
	var migrated := SimulationStateRecord.from_dictionary(previous_data)
	_check(migrated != null, "World schema v5 should add honest acquisition provenance")
	if migrated != null:
		var observer_record: KnownEventStateRecord
		var actor_record: KnownEventStateRecord
		for known_event in migrated.event_knowledge:
			if known_event.get_knower_id() == 0:
				observer_record = known_event
			elif known_event.get_knower_id() == 1:
				actor_record = known_event
		_check(
			(
				actor_record != null
				and (
					actor_record.get_acquisition_method()
					== SimulationIds.KNOWLEDGE_ACQUISITION_PERFORMED
				)
			),
			"World v5 migration can safely identify an actor's own completed fact"
		)
		_check(
			(
				observer_record != null
				and (
					observer_record.get_acquisition_method()
					== SimulationIds.KNOWLEDGE_ACQUISITION_LEGACY
				)
			),
			"World v5 migration must not invent witness or speaker provenance"
		)
	manager.free()


func _test_relationship_schema_rejection() -> void:
	var manager := _create_manager(58)
	var missing_cause_data: Dictionary = manager.create_state_record().to_dictionary()
	missing_cause_data["relationships"] = [
		RelationshipStateRecord.create(0, 1, 0.5, 0.65, 999).to_dictionary()
	]
	_check(
		SimulationStateRecord.from_dictionary(missing_cause_data) == null,
		"Relationship causes must reference an event in the same world record"
	)

	var duplicate_pair_data: Dictionary = manager.create_state_record().to_dictionary()
	var relationship_data := RelationshipStateRecord.create(0, 1, 0.5).to_dictionary()
	duplicate_pair_data["relationships"] = [relationship_data, relationship_data.duplicate(true)]
	_check(
		SimulationStateRecord.from_dictionary(duplicate_pair_data) == null,
		"World state should reject duplicate directed relationship pairs"
	)

	var unknown_knowledge_data: Dictionary = manager.create_state_record().to_dictionary()
	unknown_knowledge_data["event_knowledge"] = [
		KnownEventStateRecord.create(0, 999).to_dictionary()
	]
	_check(
		SimulationStateRecord.from_dictionary(unknown_knowledge_data) == null,
		"Known-event records must reference an event in the same world record"
	)
	var duplicate_knowledge_data: Dictionary = manager.create_state_record().to_dictionary()
	var event := EconomicEventRecord.create(
		0,
		SimulationIds.EVENT_STORAGE_DEPOSITED,
		1,
		0,
		SimulationIds.npc_inventory_id(0),
		SimulationIds.STORAGE_VILLAGE_PANTRY,
		SimulationIds.RESOURCE_FOOD,
		1.0
	)
	duplicate_knowledge_data["economic_events"] = [event.to_dictionary()]
	duplicate_knowledge_data["simulation"]["next_event_id"] = 1
	var known_event_data := KnownEventStateRecord.create(0, 0).to_dictionary()
	duplicate_knowledge_data["event_knowledge"] = [
		known_event_data, known_event_data.duplicate(true)
	]
	_check(
		SimulationStateRecord.from_dictionary(duplicate_knowledge_data) == null,
		"World state should reject duplicate NPC knowledge pairs"
	)

	var wrong_subject_cause_data: Dictionary = manager.create_state_record().to_dictionary()
	var unrelated_deposit := EconomicEventRecord.create(
		0,
		SimulationIds.EVENT_STORAGE_DEPOSITED,
		1,
		2,
		SimulationIds.npc_inventory_id(2),
		SimulationIds.STORAGE_VILLAGE_PANTRY,
		SimulationIds.RESOURCE_FOOD,
		1.0
	)
	wrong_subject_cause_data["economic_events"] = [unrelated_deposit.to_dictionary()]
	wrong_subject_cause_data["simulation"]["next_event_id"] = 1
	wrong_subject_cause_data["event_knowledge"] = [
		KnownEventStateRecord.create(0, 0).to_dictionary()
	]
	wrong_subject_cause_data["relationships"] = [
		RelationshipStateRecord.create(0, 1, 0.5, 0.65, 0).to_dictionary()
	]
	_check(
		SimulationStateRecord.from_dictionary(wrong_subject_cause_data) == null,
		"A trust cause must be a known food deposit performed by the relationship subject"
	)

	var nonpositive_cause_data: Dictionary = manager.create_state_record().to_dictionary()
	var nonpositive_deposit := EconomicEventRecord.create(
		0,
		SimulationIds.EVENT_STORAGE_DEPOSITED,
		1,
		1,
		SimulationIds.npc_inventory_id(1),
		SimulationIds.STORAGE_VILLAGE_PANTRY,
		SimulationIds.RESOURCE_FOOD,
		0.0
	)
	nonpositive_cause_data["economic_events"] = [nonpositive_deposit.to_dictionary()]
	nonpositive_cause_data["simulation"]["next_event_id"] = 1
	nonpositive_cause_data["event_knowledge"] = [KnownEventStateRecord.create(0, 0).to_dictionary()]
	nonpositive_cause_data["relationships"] = [
		RelationshipStateRecord.create(0, 1, 0.5, 0.65, 0).to_dictionary()
	]
	_check(
		SimulationStateRecord.from_dictionary(nonpositive_cause_data) == null,
		"A trust cause must describe a successful positive food deposit"
	)

	var provenance_event := EconomicEventRecord.create(
		0,
		SimulationIds.EVENT_STORAGE_DEPOSITED,
		1,
		0,
		SimulationIds.npc_inventory_id(0),
		SimulationIds.STORAGE_VILLAGE_PANTRY,
		SimulationIds.RESOURCE_FOOD,
		1.0
	)
	var missing_source_data: Dictionary = manager.create_state_record().to_dictionary()
	missing_source_data["economic_events"] = [provenance_event.to_dictionary()]
	missing_source_data["simulation"]["next_event_id"] = 1
	missing_source_data["event_knowledge"] = [
		(
			KnownEventStateRecord
			. create(1, 0, SimulationIds.KNOWLEDGE_ACQUISITION_COMMUNICATED, 2)
			. to_dictionary()
		)
	]
	_check(
		SimulationStateRecord.from_dictionary(missing_source_data) == null,
		"Communicated knowledge must reference a source who knows the same event"
	)

	var wrong_actor_data: Dictionary = manager.create_state_record().to_dictionary()
	wrong_actor_data["economic_events"] = [provenance_event.to_dictionary()]
	wrong_actor_data["simulation"]["next_event_id"] = 1
	wrong_actor_data["event_knowledge"] = [
		(
			KnownEventStateRecord
			. create(1, 0, SimulationIds.KNOWLEDGE_ACQUISITION_PERFORMED)
			. to_dictionary()
		)
	]
	_check(
		SimulationStateRecord.from_dictionary(wrong_actor_data) == null,
		"Performed provenance must belong to the event actor"
	)

	var relayed_source_data: Dictionary = manager.create_state_record().to_dictionary()
	relayed_source_data["economic_events"] = [provenance_event.to_dictionary()]
	relayed_source_data["simulation"]["next_event_id"] = 1
	relayed_source_data["event_knowledge"] = [
		(
			KnownEventStateRecord
			. create(1, 0, SimulationIds.KNOWLEDGE_ACQUISITION_COMMUNICATED, 2)
			. to_dictionary()
		),
		(
			KnownEventStateRecord
			. create(2, 0, SimulationIds.KNOWLEDGE_ACQUISITION_COMMUNICATED, 0)
			. to_dictionary()
		),
		(
			KnownEventStateRecord
			. create(0, 0, SimulationIds.KNOWLEDGE_ACQUISITION_PERFORMED)
			. to_dictionary()
		),
	]
	_check(
		SimulationStateRecord.from_dictionary(relayed_source_data) == null,
		"Communicated facts must not form a second relay hop in this phase"
	)

	var order_independent_data: Dictionary = manager.create_state_record().to_dictionary()
	order_independent_data["economic_events"] = [provenance_event.to_dictionary()]
	order_independent_data["simulation"]["next_event_id"] = 1
	order_independent_data["event_knowledge"] = [
		(
			KnownEventStateRecord
			. create(1, 0, SimulationIds.KNOWLEDGE_ACQUISITION_COMMUNICATED, 2)
			. to_dictionary()
		),
		(
			KnownEventStateRecord
			. create(0, 0, SimulationIds.KNOWLEDGE_ACQUISITION_PERFORMED)
			. to_dictionary()
		),
		(
			KnownEventStateRecord
			. create(2, 0, SimulationIds.KNOWLEDGE_ACQUISITION_WITNESSED)
			. to_dictionary()
		),
	]
	_check(
		SimulationStateRecord.from_dictionary(order_independent_data) != null,
		"Provenance validation should not depend on knowledge array ordering"
	)
	manager.free()


func _create_manager(seed_value: int) -> Node:
	var manager: Node = load("res://simulation/SimulationManager.gd").new()
	manager.simulation_seed = seed_value
	manager.debug_logs = false
	root.add_child(manager)
	manager.set_process(false)
	return manager


func _advance_scenario(manager: Node, steps: int) -> void:
	for step in steps:
		manager.simulate_tick()
		for npc in manager.npcs:
			manager.get_wander_offset(npc.id)
			if npc.task_state == SimNPC.TASK_STATE_TRAVELING:
				manager.notify_npc_arrived(npc.id)


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