class_name KnownEventStateRecord
extends RefCounted

const SCHEMA_VERSION := 4
const LEGACY_SCHEMA_VERSION := 3
const NO_SOURCE_NPC_ID := -1
const NO_SOURCE_ACTOR_ID := -2
const DEFAULT_CONFIDENCE := 1.0
const DEFAULT_SALIENCE := 0.5
const AUTO_HOP_COUNT := -1

const VALID_ACQUISITION_METHODS := [
	SimulationIds.KNOWLEDGE_ACQUISITION_PERFORMED,
	SimulationIds.KNOWLEDGE_ACQUISITION_WITNESSED,
	SimulationIds.KNOWLEDGE_ACQUISITION_COMMUNICATED,
	SimulationIds.KNOWLEDGE_ACQUISITION_LEGACY,
]
const DIRECT_ACQUISITION_METHODS := [
	SimulationIds.KNOWLEDGE_ACQUISITION_PERFORMED,
	SimulationIds.KNOWLEDGE_ACQUISITION_WITNESSED,
]

var data: Dictionary


func _init(record_data: Dictionary = {}) -> void:
	data = record_data.duplicate(true)


static func create(
	knower_id: int,
	event_id: int,
	acquisition_method: StringName = SimulationIds.KNOWLEDGE_ACQUISITION_LEGACY,
	source_npc_id: int = NO_SOURCE_NPC_ID,
	acquired_tick: int = 0,
	source_acquisition_method: StringName = &"",
	hop_count: int = AUTO_HOP_COUNT,
	confidence: float = DEFAULT_CONFIDENCE,
	salience: float = DEFAULT_SALIENCE,
	source_actor_id: int = NO_SOURCE_ACTOR_ID,
	pinned: bool = false
) -> KnownEventStateRecord:
	var is_communicated := acquisition_method == SimulationIds.KNOWLEDGE_ACQUISITION_COMMUNICATED
	var canonical_source_actor_id := source_actor_id
	var canonical_source_npc_id := source_npc_id
	if is_communicated:
		if canonical_source_actor_id == NO_SOURCE_ACTOR_ID:
			canonical_source_actor_id = source_npc_id
		canonical_source_npc_id = (
			canonical_source_actor_id if canonical_source_actor_id >= 0 else NO_SOURCE_NPC_ID
		)
	else:
		canonical_source_actor_id = NO_SOURCE_ACTOR_ID
		canonical_source_npc_id = NO_SOURCE_NPC_ID
	var canonical_hop_count := hop_count
	if canonical_hop_count == AUTO_HOP_COUNT:
		canonical_hop_count = 1 if is_communicated else 0
	return (
		KnownEventStateRecord
		. new(
			{
				"schema_version": SCHEMA_VERSION,
				"knower_id": knower_id,
				"event_id": event_id,
				"acquisition_method": String(acquisition_method),
				"source_npc_id": canonical_source_npc_id,
				"source_actor_id": canonical_source_actor_id,
				"acquired_tick": acquired_tick,
				"source_acquisition_method": String(source_acquisition_method),
				"hop_count": canonical_hop_count,
				"confidence": clampf(confidence, 0.0, 1.0),
				"salience": clampf(salience, 0.0, 1.0),
				"pinned": pinned,
			}
		)
	)


static func from_dictionary(record_data: Dictionary) -> KnownEventStateRecord:
	var version := int(record_data.get("schema_version", -1))
	var normalized := record_data.duplicate(true)
	if version == LEGACY_SCHEMA_VERSION:
		normalized = _migrate_v3(record_data)
	elif version != SCHEMA_VERSION:
		return null
	if not (
		normalized
		. has_all(
			[
				"knower_id",
				"event_id",
				"acquisition_method",
				"source_npc_id",
				"source_actor_id",
				"acquired_tick",
				"source_acquisition_method",
				"hop_count",
				"confidence",
				"salience",
				"pinned",
			]
		)
	):
		return null
	var knower_id := int(normalized["knower_id"])
	var event_id := int(normalized["event_id"])
	var acquisition_method := StringName(normalized["acquisition_method"])
	var source_npc_id := int(normalized["source_npc_id"])
	var source_actor_id := int(normalized["source_actor_id"])
	var acquired_tick := int(normalized["acquired_tick"])
	var source_acquisition_method := StringName(normalized["source_acquisition_method"])
	var hop_count := int(normalized["hop_count"])
	var confidence := float(normalized["confidence"])
	var salience := float(normalized["salience"])
	if not is_valid_actor_id(knower_id) or event_id < 0 or acquired_tick < 0 or hop_count < 0:
		return null
	if not is_finite(confidence) or confidence < 0.0 or confidence > 1.0:
		return null
	if not is_finite(salience) or salience < 0.0 or salience > 1.0:
		return null
	if typeof(normalized["pinned"]) != TYPE_BOOL:
		return null
	if acquisition_method not in VALID_ACQUISITION_METHODS:
		return null
	if acquisition_method == SimulationIds.KNOWLEDGE_ACQUISITION_COMMUNICATED:
		if not is_valid_actor_id(source_actor_id) or source_actor_id == knower_id:
			return null
		if source_actor_id >= 0 and source_npc_id != source_actor_id:
			return null
		if source_actor_id == SimulationIds.PLAYER_ACTOR_ID and source_npc_id != NO_SOURCE_NPC_ID:
			return null
		if source_acquisition_method not in DIRECT_ACQUISITION_METHODS or hop_count != 1:
			return null
	elif (
		source_npc_id != NO_SOURCE_NPC_ID
		or source_actor_id != NO_SOURCE_ACTOR_ID
		or not source_acquisition_method.is_empty()
		or hop_count != 0
	):
		return null
	return KnownEventStateRecord.new(normalized)


func get_knower_id() -> int:
	return int(data["knower_id"])


func get_event_id() -> int:
	return int(data["event_id"])


func get_acquisition_method() -> StringName:
	return StringName(data["acquisition_method"])


func get_source_npc_id() -> int:
	return int(data["source_npc_id"])


func get_source_actor_id() -> int:
	return int(data["source_actor_id"])


func get_acquired_tick() -> int:
	return int(data["acquired_tick"])


func get_source_acquisition_method() -> StringName:
	return StringName(data["source_acquisition_method"])


func get_hop_count() -> int:
	return int(data["hop_count"])


func get_confidence() -> float:
	return float(data["confidence"])


func get_salience() -> float:
	return float(data["salience"])


func is_pinned() -> bool:
	return bool(data["pinned"])


func set_pinned(pinned: bool) -> bool:
	if is_pinned() == pinned:
		return false
	data["pinned"] = pinned
	return true


func set_confidence(confidence: float) -> bool:
	if not is_finite(confidence):
		return false
	var bounded := clampf(confidence, 0.0, 1.0)
	if is_equal_approx(get_confidence(), bounded):
		return false
	data["confidence"] = bounded
	return true


func set_salience(salience: float) -> bool:
	if not is_finite(salience):
		return false
	var bounded := clampf(salience, 0.0, 1.0)
	if is_equal_approx(get_salience(), bounded):
		return false
	data["salience"] = bounded
	return true


func to_dictionary() -> Dictionary:
	return data.duplicate(true)


static func is_valid_actor_id(actor_id: int) -> bool:
	return actor_id >= 0 or actor_id == SimulationIds.PLAYER_ACTOR_ID


static func _migrate_v3(record_data: Dictionary) -> Dictionary:
	var migrated := record_data.duplicate(true)
	var acquisition_method := StringName(migrated.get("acquisition_method", &""))
	var is_communicated := acquisition_method == SimulationIds.KNOWLEDGE_ACQUISITION_COMMUNICATED
	migrated["schema_version"] = SCHEMA_VERSION
	migrated["source_actor_id"] = (
		int(migrated.get("source_npc_id", NO_SOURCE_NPC_ID))
		if is_communicated
		else NO_SOURCE_ACTOR_ID
	)
	migrated["hop_count"] = 1 if is_communicated else 0
	migrated["confidence"] = DEFAULT_CONFIDENCE
	migrated["salience"] = DEFAULT_SALIENCE
	migrated["pinned"] = false
	return migrated