extends RefCounted

const AID_HUNGER_THRESHOLD := 80.0
const TRUSTED_HELP_THRESHOLD := 0.6
const FOOD_AID_TRUST_GAIN := 0.15
const SHARED_WORK_FAMILIARITY_GAIN := 0.1

var relationships: Dictionary = {}


func initialize_households(npcs: Array[SimNPC]) -> void:
	relationships.clear()
	for first_index in range(npcs.size()):
		for second_index in range(first_index + 1, npcs.size()):
			var first := npcs[first_index]
			var second := npcs[second_index]
			if first.home_position.distance_to(second.home_position) >= 4.0:
				continue
			_add(RelationshipStateRecord.create(first.id, second.id, 0.5))
			_add(RelationshipStateRecord.create(second.id, first.id, 0.5))


func restore(records: Array[RelationshipStateRecord]) -> void:
	relationships.clear()
	for record in records:
		_add(record)


func get_all_sorted() -> Array[RelationshipStateRecord]:
	var records: Array[RelationshipStateRecord] = []
	for record in relationships.values():
		records.append(record)
	records.sort_custom(_sort_relationships)
	return records


func get_relationship(observer_id: int, subject_id: int) -> RelationshipStateRecord:
	return relationships.get(_key(observer_id, subject_id)) as RelationshipStateRecord


func is_trusted_for_help(observer_id: int, subject_id: int) -> bool:
	var relationship := get_relationship(observer_id, subject_id)
	return (
		relationship != null
		and relationship.get_familiarity() > 0.0
		and relationship.get_trust() >= TRUSTED_HELP_THRESHOLD
	)


func increase_shared_work_familiarity(first_id: int, second_id: int) -> void:
	var first_to_second := _get_or_create(first_id, second_id)
	var second_to_first := _get_or_create(second_id, first_id)
	first_to_second.increase_familiarity(SHARED_WORK_FAMILIARITY_GAIN)
	second_to_first.increase_familiarity(SHARED_WORK_FAMILIARITY_GAIN)


func apply_event(
	event: EconomicEventRecord, npcs: Array[SimNPC], knower_ids: Array[int]
) -> Array[RelationshipStateRecord]:
	var changed: Array[RelationshipStateRecord] = []
	if StringName(event.data["event_type"]) != SimulationIds.EVENT_STORAGE_DEPOSITED:
		return changed
	if StringName(event.data["item_id"]) != SimulationIds.RESOURCE_FOOD:
		return changed
	var contributor_id := int(event.data["actor_id"])
	var event_id := int(event.data["event_id"])
	if contributor_id < 0 or event_id < 0 or float(event.data["amount"]) <= 0.0:
		return changed
	for observer in npcs:
		if observer.id == contributor_id or observer.is_dead:
			continue
		if observer.id not in knower_ids:
			continue
		if observer.hunger < AID_HUNGER_THRESHOLD:
			continue
		var relationship := get_relationship(observer.id, contributor_id)
		if relationship == null or relationship.get_familiarity() <= 0.0:
			continue
		if event_id <= relationship.get_last_trust_cause_event_id():
			continue
		var applied := relationship.increase_trust(FOOD_AID_TRUST_GAIN, event_id)
		if applied <= 0.0:
			continue
		changed.append(relationship)
	return changed


func get_primary_relationship(observer_id: int) -> RelationshipStateRecord:
	var best: RelationshipStateRecord
	for relationship in relationships.values():
		if relationship.get_observer_id() != observer_id:
			continue
		if best == null or _is_stronger(relationship, best):
			best = relationship
	return best


func get_most_familiar_living_subject(observer_id: int, npcs: Array[SimNPC]) -> SimNPC:
	var living_by_id := {}
	for npc in npcs:
		if not npc.is_dead:
			living_by_id[npc.id] = npc
	var best_relationship: RelationshipStateRecord
	for relationship in relationships.values():
		if relationship.get_observer_id() != observer_id:
			continue
		if not living_by_id.has(relationship.get_subject_id()):
			continue
		if (
			best_relationship == null
			or relationship.get_familiarity() > best_relationship.get_familiarity()
			or (
				is_equal_approx(relationship.get_familiarity(), best_relationship.get_familiarity())
				and relationship.get_subject_id() < best_relationship.get_subject_id()
			)
		):
			best_relationship = relationship
	if best_relationship == null:
		return null
	return living_by_id[best_relationship.get_subject_id()] as SimNPC


func get_trusted_starving_subject(observer_id: int, npcs: Array[SimNPC]) -> SimNPC:
	var starving_by_id := {}
	for npc in npcs:
		if not npc.is_dead and npc.is_starving:
			starving_by_id[npc.id] = npc
	var best_relationship: RelationshipStateRecord
	for relationship in relationships.values():
		if relationship.get_observer_id() != observer_id:
			continue
		if relationship.get_trust() < TRUSTED_HELP_THRESHOLD:
			continue
		if not starving_by_id.has(relationship.get_subject_id()):
			continue
		if (
			best_relationship == null
			or relationship.get_trust() > best_relationship.get_trust()
			or (
				is_equal_approx(relationship.get_trust(), best_relationship.get_trust())
				and relationship.get_subject_id() < best_relationship.get_subject_id()
			)
		):
			best_relationship = relationship
	if best_relationship == null:
		return null
	return starving_by_id[best_relationship.get_subject_id()] as SimNPC


func _get_or_create(observer_id: int, subject_id: int) -> RelationshipStateRecord:
	var relationship := get_relationship(observer_id, subject_id)
	if relationship != null:
		return relationship
	relationship = RelationshipStateRecord.create(observer_id, subject_id, 0.0)
	_add(relationship)
	return relationship


func _add(relationship: RelationshipStateRecord) -> void:
	relationships[_key(relationship.get_observer_id(), relationship.get_subject_id())] = relationship


static func _key(observer_id: int, subject_id: int) -> String:
	return "%d:%d" % [observer_id, subject_id]


static func _sort_relationships(
	first: RelationshipStateRecord, second: RelationshipStateRecord
) -> bool:
	if first.get_observer_id() != second.get_observer_id():
		return first.get_observer_id() < second.get_observer_id()
	return first.get_subject_id() < second.get_subject_id()


static func _is_stronger(
	candidate: RelationshipStateRecord, current: RelationshipStateRecord
) -> bool:
	if not is_equal_approx(candidate.get_trust(), current.get_trust()):
		return candidate.get_trust() > current.get_trust()
	if not is_equal_approx(candidate.get_familiarity(), current.get_familiarity()):
		return candidate.get_familiarity() > current.get_familiarity()
	return candidate.get_subject_id() < current.get_subject_id()