class_name ServiceRequest
extends RefCounted

## Immutable-at-enqueue quotation for one facility visit.
##
## FacilityService owns the lifecycle.  Price and policy values are copied when
## this object is configured so later facility policy changes cannot alter an
## already queued request.

var request_id: StringName = &""
var guest_ids: Array[StringName] = []
var facility_id: StringName = &""
var service_type: StringName = &"default"
var created_at := 0
var quoted_price := 0
var policy_snapshot: Dictionary = {}
var policy_revision := 0
var reserved_inventory_ids: Array[StringName] = []
var preference_match := 0
var expected_quality := 0
var expected_wait := 0
var priority := 0
var enqueued_at := -1
var service_minutes := 1


func configure(
	p_request_id: StringName,
	p_facility_id: StringName,
	p_guest_ids: Array[StringName],
	p_service_type: StringName,
	p_created_at: int,
	options: Dictionary = {}
) -> ServiceRequest:
	request_id = p_request_id
	facility_id = p_facility_id
	guest_ids.assign(p_guest_ids)
	service_type = p_service_type
	created_at = maxi(p_created_at, 0)
	quoted_price = maxi(int(_value(options, &"quoted_price", 0)), 0)
	policy_snapshot = _dictionary_copy(_value(options, &"policy_snapshot", {}))
	policy_revision = maxi(int(_value(options, &"policy_revision", 0)), 0)
	reserved_inventory_ids = _string_name_array(
		_value(options, &"reserved_inventory_ids", [])
	)
	preference_match = int(_value(options, &"preference_match", 0))
	expected_quality = int(_value(options, &"expected_quality", 0))
	expected_wait = maxi(int(_value(options, &"expected_wait", 0)), 0)
	priority = int(_value(options, &"priority", 0))
	enqueued_at = int(_value(options, &"enqueued_at", -1))
	service_minutes = maxi(int(_value(options, &"service_minutes", 1)), 1)
	return self


func is_valid() -> bool:
	if request_id.is_empty() or facility_id.is_empty() or service_type.is_empty():
		return false
	if guest_ids.is_empty() or service_minutes <= 0 or quoted_price < 0:
		return false
	var seen: Dictionary = {}
	for guest_id: StringName in guest_ids:
		if guest_id.is_empty() or seen.has(guest_id):
			return false
		seen[guest_id] = true
	return true


func create_snapshot() -> Dictionary:
	return {
		&"request_id": String(request_id),
		&"guest_ids": _names_to_strings(guest_ids),
		&"facility_id": String(facility_id),
		&"service_type": String(service_type),
		&"created_at": created_at,
		&"quoted_price": quoted_price,
		&"policy_snapshot": policy_snapshot.duplicate(true),
		&"policy_revision": policy_revision,
		&"reserved_inventory_ids": _names_to_strings(reserved_inventory_ids),
		&"preference_match": preference_match,
		&"expected_quality": expected_quality,
		&"expected_wait": expected_wait,
		&"priority": priority,
		&"enqueued_at": enqueued_at,
		&"service_minutes": service_minutes,
	}


static func from_snapshot(snapshot: Dictionary) -> ServiceRequest:
	if not snapshot.get(&"guest_ids", null) is Array:
		return null
	if not snapshot.get(&"policy_snapshot", null) is Dictionary:
		return null
	if not snapshot.get(&"reserved_inventory_ids", null) is Array:
		return null
	var request := ServiceRequest.new().configure(
		StringName(snapshot.get(&"request_id", "")),
		StringName(snapshot.get(&"facility_id", "")),
		_string_name_array(snapshot.get(&"guest_ids", [])),
		StringName(snapshot.get(&"service_type", "default")),
		int(snapshot.get(&"created_at", 0)),
		{
			&"quoted_price": snapshot.get(&"quoted_price", 0),
			&"policy_snapshot": snapshot.get(&"policy_snapshot", {}),
			&"policy_revision": snapshot.get(&"policy_revision", 0),
			&"reserved_inventory_ids": snapshot.get(&"reserved_inventory_ids", []),
			&"preference_match": snapshot.get(&"preference_match", 0),
			&"expected_quality": snapshot.get(&"expected_quality", 0),
			&"expected_wait": snapshot.get(&"expected_wait", 0),
			&"priority": snapshot.get(&"priority", 0),
			&"enqueued_at": snapshot.get(&"enqueued_at", -1),
			&"service_minutes": snapshot.get(&"service_minutes", 1),
		}
	)
	return request if request.is_valid() else null


static func _value(source: Dictionary, key: StringName, fallback: Variant) -> Variant:
	return source.get(key, source.get(String(key), fallback))


static func _dictionary_copy(source: Variant) -> Dictionary:
	return source.duplicate(true) if source is Dictionary else {}


static func _string_name_array(source: Variant) -> Array[StringName]:
	var values: Array[StringName] = []
	if not source is Array:
		return values
	for value: Variant in source:
		values.append(StringName(value))
	return values


static func _names_to_strings(source: Array[StringName]) -> Array[String]:
	var values: Array[String] = []
	for value: StringName in source:
		values.append(String(value))
	return values