class_name WorldEventRecord
extends RefCounted

const SCHEMA_VERSION := 1
const ENTITY_TYPE_NPC := &"npc"
const ENTITY_TYPE_WORLD := &"world_entity"
const ROLE_ACTOR := &"actor"
const ROLE_SOURCE := &"source"
const ROLE_DESTINATION := &"destination"
const ECONOMIC_CORE_FIELDS := [
	"schema_version",
	"event_id",
	"event_type",
	"tick",
	"actor_id",
	"source_id",
	"destination_id",
	"world_position",
]

var _event_id := -1
var _event_type: StringName
var _tick := -1
var _participants: Dictionary = {}
var _location: SpatialAddress
var _payload: Dictionary = {}


static func create(
	event_id: int,
	event_type: StringName,
	tick: int,
	participants: Dictionary = {},
	location: SpatialAddress = null,
	payload: Dictionary = {}
) -> WorldEventRecord:
	var normalized_participants: Variant = _normalize_participants(participants)
	if normalized_participants == null:
		return null
	var payload_status := [true]
	var normalized_payload: Variant = _normalize_serializable_value(payload, payload_status)
	if not payload_status[0] or not normalized_payload is Dictionary:
		return null
	var event := WorldEventRecord.new()
	event._event_id = event_id
	event._event_type = event_type
	event._tick = tick
	event._participants = normalized_participants
	event._location = location.duplicate_address() if location != null else null
	event._payload = normalized_payload
	return event if event.is_valid() else null


static func from_dictionary(record_data: Dictionary) -> WorldEventRecord:
	if int(record_data.get("schema_version", -1)) != SCHEMA_VERSION:
		return null
	if not record_data.has_all(
		["event_id", "event_type", "tick", "participants", "location", "payload"]
	):
		return null
	var saved_participants = record_data["participants"]
	if not saved_participants is Array:
		return null
	var participants: Dictionary = {}
	for participant_data in saved_participants:
		if not participant_data is Dictionary or not participant_data.has_all(["role", "entity"]):
			return null
		var role := StringName(participant_data["role"])
		if (
			role.is_empty()
			or participants.has(role)
			or not participant_data["entity"] is Dictionary
		):
			return null
		var entity_ref := WorldEntityRef.from_dictionary(participant_data["entity"])
		if entity_ref == null:
			return null
		participants[role] = entity_ref
	var location: SpatialAddress
	var saved_location = record_data["location"]
	if saved_location != null:
		if not saved_location is Dictionary:
			return null
		location = SpatialAddress.from_dictionary(saved_location)
		if location == null:
			return null
	if not record_data["payload"] is Dictionary:
		return null
	return create(
		int(record_data["event_id"]),
		StringName(record_data["event_type"]),
		int(record_data["tick"]),
		participants,
		location,
		record_data["payload"]
	)


static func from_economic_event(
	economic_event: EconomicEventRecord, world_id: StringName = &"", location_id: StringName = &""
) -> WorldEventRecord:
	if economic_event == null:
		return null
	var economic_data := economic_event.to_dictionary()
	var participants: Dictionary = {
		ROLE_ACTOR:
		WorldEntityRef.create(ENTITY_TYPE_NPC, StringName(str(int(economic_data["actor_id"]))))
	}
	var source_id := StringName(economic_data["source_id"])
	if not source_id.is_empty():
		participants[ROLE_SOURCE] = WorldEntityRef.create(ENTITY_TYPE_WORLD, source_id)
	var destination_id := StringName(economic_data["destination_id"])
	if not destination_id.is_empty():
		participants[ROLE_DESTINATION] = WorldEntityRef.create(ENTITY_TYPE_WORLD, destination_id)
	var payload: Dictionary = {}
	for field in economic_data:
		var field_name := String(field)
		if field_name in ECONOMIC_CORE_FIELDS:
			continue
		payload[field_name] = economic_data[field]
	var location := SpatialAddress.create(
		world_id, location_id, economic_event.get_world_position()
	)
	return create(
		int(economic_data["event_id"]),
		StringName(economic_data["event_type"]),
		int(economic_data["tick"]),
		participants,
		location,
		payload
	)


func is_valid() -> bool:
	if _event_id < 0 or _tick < 0 or _event_type.is_empty():
		return false
	if _location != null and not _location.is_valid():
		return false
	for role in _participants:
		if StringName(role).is_empty():
			return false
		var entity_ref := _participants[role] as WorldEntityRef
		if entity_ref == null or not entity_ref.is_valid():
			return false
	return true


func get_event_id() -> int:
	return _event_id


func get_event_type() -> StringName:
	return _event_type


func get_tick() -> int:
	return _tick


func has_location() -> bool:
	return _location != null


func get_location() -> SpatialAddress:
	return _location.duplicate_address() if _location != null else null


func get_payload() -> Dictionary:
	return _payload.duplicate(true)


func get_participant(role: StringName) -> WorldEntityRef:
	var entity_ref := _participants.get(role) as WorldEntityRef
	return entity_ref.duplicate_ref() if entity_ref != null else null


func get_participant_roles() -> Array[StringName]:
	var roles: Array[StringName] = []
	for role in _participants:
		roles.append(StringName(role))
	roles.sort_custom(
		func(left: StringName, right: StringName) -> bool: return String(left) < String(right)
	)
	return roles


func get_participant_refs() -> Array[WorldEntityRef]:
	var refs: Array[WorldEntityRef] = []
	for role in get_participant_roles():
		var entity_ref := _participants[role] as WorldEntityRef
		refs.append(entity_ref.duplicate_ref())
	return refs


func get_participant_index_keys() -> Array[String]:
	var keys: Array[String] = []
	var seen: Dictionary = {}
	for role in get_participant_roles():
		var entity_ref := _participants[role] as WorldEntityRef
		var key := entity_ref.index_key()
		if seen.has(key):
			continue
		seen[key] = true
		keys.append(key)
	keys.sort()
	return keys


func to_economic_event() -> EconomicEventRecord:
	var actor := _participants.get(ROLE_ACTOR) as WorldEntityRef
	if actor == null:
		return null
	var actor_text := String(actor.get_entity_id())
	if not actor_text.is_valid_int():
		return null
	var source := _participants.get(ROLE_SOURCE) as WorldEntityRef
	var destination := _participants.get(ROLE_DESTINATION) as WorldEntityRef
	var economic_data := _payload.duplicate(true)
	economic_data["schema_version"] = EconomicEventRecord.SCHEMA_VERSION
	economic_data["event_id"] = _event_id
	economic_data["event_type"] = String(_event_type)
	economic_data["tick"] = _tick
	economic_data["actor_id"] = actor_text.to_int()
	economic_data["source_id"] = String(source.get_entity_id()) if source != null else ""
	economic_data["destination_id"] = (
		String(destination.get_entity_id()) if destination != null else ""
	)
	economic_data["item_id"] = String(economic_data.get("item_id", ""))
	economic_data["amount"] = float(economic_data.get("amount", 0.0))
	economic_data["action_id"] = String(economic_data.get("action_id", ""))
	economic_data["required_amount"] = float(economic_data.get("required_amount", 0.0))
	var position := _location.get_position() if _location != null else Vector3.ZERO
	economic_data["world_position"] = [position.x, position.y, position.z]
	return EconomicEventRecord.from_dictionary(economic_data)


func to_dictionary() -> Dictionary:
	var serialized_participants: Array[Dictionary] = []
	for role in get_participant_roles():
		var entity_ref := _participants[role] as WorldEntityRef
		(
			serialized_participants
			. append(
				{
					"role": String(role),
					"entity": entity_ref.to_dictionary(),
				}
			)
		)
	return {
		"schema_version": SCHEMA_VERSION,
		"event_id": _event_id,
		"event_type": String(_event_type),
		"tick": _tick,
		"participants": serialized_participants,
		"location": _location.to_dictionary() if _location != null else null,
		"payload": _payload.duplicate(true),
	}


static func _normalize_participants(participants: Dictionary) -> Variant:
	var normalized: Dictionary = {}
	var role_names: Dictionary = {}
	for raw_role in participants:
		if not raw_role is String and not raw_role is StringName:
			return null
		var role := StringName(raw_role)
		var role_text := String(role)
		if role.is_empty() or role_names.has(role_text):
			return null
		var entity_ref := participants[raw_role] as WorldEntityRef
		if entity_ref == null or not entity_ref.is_valid():
			return null
		role_names[role_text] = true
		normalized[role] = entity_ref.duplicate_ref()
	return normalized


static func _normalize_serializable_value(value: Variant, status: Array) -> Variant:
	match typeof(value):
		TYPE_NIL, TYPE_BOOL, TYPE_INT, TYPE_STRING:
			return value
		TYPE_FLOAT:
			if not is_finite(float(value)):
				status[0] = false
			return value
		TYPE_STRING_NAME:
			return String(value)
		TYPE_ARRAY:
			var normalized_array: Array = []
			for element in value:
				normalized_array.append(_normalize_serializable_value(element, status))
			return normalized_array
		TYPE_DICTIONARY:
			return _normalize_serializable_dictionary(value, status)
		_:
			status[0] = false
			return null


static func _normalize_serializable_dictionary(value: Dictionary, status: Array) -> Dictionary:
	var source_keys: Dictionary = {}
	for raw_key in value:
		if not raw_key is String and not raw_key is StringName:
			status[0] = false
			return {}
		var key_text := String(raw_key)
		if source_keys.has(key_text):
			status[0] = false
			return {}
		source_keys[key_text] = raw_key
	var sorted_keys: Array = source_keys.keys()
	sorted_keys.sort()
	var normalized: Dictionary = {}
	for key_text in sorted_keys:
		var raw_key = source_keys[key_text]
		normalized[key_text] = _normalize_serializable_value(value[raw_key], status)
	return normalized