class_name StorageRoutingPolicy
extends RefCounted

var catalog: ContentCatalog


func _init(content_catalog: ContentCatalog = null) -> void:
	catalog = content_catalog


func resolve_definition(
	item_id: StringName, available_storage_ids: Array[StringName] = []
) -> StorageDefinition:
	var candidates := get_candidates(item_id, available_storage_ids)
	return candidates[0] if not candidates.is_empty() else null


func resolve_state(
	item_id: StringName, requested_amount: float, states: Array[StorageStateRecord]
) -> StorageStateRecord:
	if not is_finite(requested_amount) or requested_amount <= 0.0:
		return null
	var states_by_id := {}
	var available_ids: Array[StringName] = []
	for state in states:
		if state == null or state.get_available_capacity() < requested_amount:
			continue
		states_by_id[state.get_storage_id()] = state
		available_ids.append(state.get_storage_id())
	var definition := resolve_definition(item_id, available_ids)
	return (
		states_by_id.get(definition.storage_id) as StorageStateRecord
		if definition != null
		else null
	)


func get_candidates(
	item_id: StringName, available_storage_ids: Array[StringName] = []
) -> Array[StorageDefinition]:
	var candidates: Array[StorageDefinition] = []
	if catalog == null or not catalog.is_valid():
		return candidates
	var item := catalog.get_item(item_id)
	if item == null:
		return candidates
	var available := {}
	for storage_id in available_storage_ids:
		available[storage_id] = true
	for definition in catalog.get_storages():
		if not available.is_empty() and not available.has(definition.storage_id):
			continue
		if definition.accepts_item(item):
			candidates.append(definition)
	candidates.sort_custom(_is_preferred_route)
	return candidates


static func _is_preferred_route(first: StorageDefinition, second: StorageDefinition) -> bool:
	if first.routing_priority != second.routing_priority:
		return first.routing_priority > second.routing_priority
	return String(first.storage_id) < String(second.storage_id)