class_name Items
extends RefCounted
## Every item in the game, defined in code for the same reasons [Content] is.
##
## [constant ORDER] is load-bearing: an item's position in it is the byte that
## rides the snapshot and every item event. Item ids are strings and a slot is
## sent 20 times a second per player, so the wire carries the index instead.
## Append to the list, never reorder it -- and if you do reorder it, bump
## [constant Protocol.VERSION], because every client would otherwise decode a
## potion as a ration.

const NONE := &""
const HEALTH_POTION := &"health_potion"
const WARDENS_RATION := &"wardens_ration"

## Wire order. Index 0 is reserved for "empty slot" / "no item", so an id's
## wire value is its position here plus one.
const ORDER: Array[StringName] = [
	HEALTH_POTION,
	WARDENS_RATION,
]


static func get_def(id: StringName) -> ItemDef:
	match id:
		HEALTH_POTION: return health_potion()
		WARDENS_RATION: return wardens_ration()
	return null


## Wire value for an id. 0 for an empty slot or an id this build does not know,
## which is the safe direction: an unknown item reads as nothing rather than as
## whatever happens to sit at that index.
static func index_of(id: StringName) -> int:
	var at := ORDER.find(id)
	return at + 1 if at >= 0 else 0


static func by_index(index: int) -> StringName:
	if index <= 0 or index > ORDER.size():
		return NONE
	return ORDER[index - 1]


static func display_name_of(id: StringName) -> String:
	var def := get_def(id)
	return def.display_name if def != null else ""


# --- The items --------------------------------------------------------------

## The only item with an effect. Percentage-based so it stays meaningful across
## the whole level range -- a flat 40 hp would be a full heal at level 1 and
## noise at level 15.
static func health_potion() -> ItemDef:
	var d := ItemDef.new()
	d.id = HEALTH_POTION
	d.display_name = "Health Potion"
	d.effect = ItemDef.Effect.HEAL
	d.effect_value = 40.0
	d.visual = 0
	d.tint = Color(0.95, 0.4, 0.42)
	return d


## Dropped by every boss, one per player who was alive for the kill, and does
## nothing whatsoever when used.
##
## It is not filler. Player-instanced loot is a different code path from shared
## loot -- a separate entity per owner, filtered per peer on the wire -- and the
## cheapest way to keep that path honest is to have something in the game that
## uses it every single boss kill. A trophy nobody has to fight over is exactly
## the right shape for that job.
static func wardens_ration() -> ItemDef:
	var d := ItemDef.new()
	d.id = WARDENS_RATION
	d.display_name = "Warden's Ration"
	d.effect = ItemDef.Effect.NONE
	d.visual = 1
	d.tint = Color(0.95, 0.82, 0.35)
	return d