class_name QuestJournalSystem
extends RefCounted

var _entries_by_id: Dictionary = {}
var _entry_id_by_situation: Dictionary = {}
var _next_entry_id := 0


func add_situation(
	situation: SituationStateRecord,
	definition: SituationDefinition,
	alternative_id: StringName,
	current_tick: int
) -> QuestJournalEntryStateRecord:
	if (
		situation == null
		or definition == null
		or not situation.is_active()
		or situation.get_definition_id() != definition.situation_definition_id
		or (not alternative_id.is_empty() and definition.get_alternative(alternative_id) == null)
		or current_tick < situation.get_created_tick()
		or _entry_id_by_situation.has(situation.get_situation_id())
	):
		return null
	if not alternative_id.is_empty() and not situation.select_alternative(alternative_id):
		return null
	var entry := QuestJournalEntryStateRecord.create(
		_next_entry_id,
		situation.get_situation_id(),
		definition.situation_definition_id,
		current_tick,
		alternative_id
	)
	_entries_by_id[_next_entry_id] = entry
	_entry_id_by_situation[situation.get_situation_id()] = _next_entry_id
	_next_entry_id += 1
	return entry


func select_alternative(
	situation: SituationStateRecord, definition: SituationDefinition, alternative_id: StringName
) -> bool:
	if (
		situation == null
		or definition == null
		or alternative_id.is_empty()
		or situation.get_definition_id() != definition.situation_definition_id
		or definition.get_alternative(alternative_id) == null
	):
		return false
	var entry := get_for_situation(situation.get_situation_id())
	if entry == null or not entry.is_active():
		return false
	return situation.select_alternative(alternative_id) and entry.select_alternative(alternative_id)


func synchronize(
	situation: SituationStateRecord, current_tick: int
) -> QuestJournalEntryStateRecord:
	if situation == null:
		return null
	var entry := get_for_situation(situation.get_situation_id())
	if entry == null or not entry.is_active() or situation.is_active():
		return null
	var status := QuestJournalEntryStateRecord.STATUS_ARCHIVED
	if situation.get_status() == SituationStateRecord.STATUS_RESOLVED:
		status = QuestJournalEntryStateRecord.STATUS_COMPLETED
	elif situation.get_status() == SituationStateRecord.STATUS_EXPIRED:
		status = QuestJournalEntryStateRecord.STATUS_FAILED
	return entry if entry.close(status, current_tick) else null


func derive_progress(
	entry: QuestJournalEntryStateRecord,
	situation_system: SituationSystem,
	world_events: WorldEventStore,
	state_facts: Dictionary
) -> SituationProgressSnapshot:
	if entry == null or situation_system == null:
		return SituationProgressSnapshot.new()
	return situation_system.derive_progress(
		situation_system.get_by_id(entry.get_situation_id()),
		world_events,
		state_facts,
		entry.get_selected_alternative_id()
	)


func restore(records: Array[QuestJournalEntryStateRecord], restored_next_id: int) -> bool:
	var by_id: Dictionary = {}
	var by_situation: Dictionary = {}
	var next_id := maxi(restored_next_id, 0)
	for record in records:
		if (
			record == null
			or by_id.has(record.get_entry_id())
			or by_situation.has(record.get_situation_id())
		):
			return false
		by_id[record.get_entry_id()] = record
		by_situation[record.get_situation_id()] = record.get_entry_id()
		next_id = maxi(next_id, record.get_entry_id() + 1)
	_entries_by_id = by_id
	_entry_id_by_situation = by_situation
	_next_entry_id = next_id
	return true


func get_by_id(entry_id: int) -> QuestJournalEntryStateRecord:
	return _entries_by_id.get(entry_id) as QuestJournalEntryStateRecord


func get_for_situation(situation_id: int) -> QuestJournalEntryStateRecord:
	if not _entry_id_by_situation.has(situation_id):
		return null
	return get_by_id(int(_entry_id_by_situation[situation_id]))


func get_all_sorted() -> Array[QuestJournalEntryStateRecord]:
	var records: Array[QuestJournalEntryStateRecord] = []
	for record in _entries_by_id.values():
		records.append(record)
	records.sort_custom(
		func(first: QuestJournalEntryStateRecord, second: QuestJournalEntryStateRecord) -> bool:
			return first.get_entry_id() < second.get_entry_id()
	)
	return records


func get_active_sorted() -> Array[QuestJournalEntryStateRecord]:
	var records: Array[QuestJournalEntryStateRecord] = []
	for record in get_all_sorted():
		if record.is_active():
			records.append(record)
	return records


func get_next_entry_id() -> int:
	return _next_entry_id