class_name DropTable
extends RefCounted
## Loot drop system. Chance-based artifact drops from boss kills.
## Flat 25% drop rate for all artifacts. No rarity gating.

var _drop_chance: float = 0.25  # 25% base chance per kill

# Each boss has a pool of possible artifact drops.
# Structure: { "boss_id": String, "pool": Array[String] (artifact IDs) }
var _boss_pools: Dictionary = {}


## Registers a boss's drop pool.
func register_boss_pool(boss_id: String, artifact_ids: Array[String]) -> void:
	_boss_pools[boss_id] = artifact_ids


## Sets the global drop chance (for testing or future tuning).
func set_drop_chance(chance: float) -> void:
	_drop_chance = clampf(chance, 0.0, 1.0)


## Rolls for a drop from a specific boss.
## rng: Optional RandomNumberGenerator for testability.
## Returns a result dictionary:
##   { "dropped": bool, "artifact_id": String (empty if no drop) }
func roll_drop(boss_id: String, rng: RandomNumberGenerator = null) -> Dictionary:
	if rng == null:
		rng = RandomNumberGenerator.new()
	
	# Check if this boss has a pool
	if not _boss_pools.has(boss_id):
		return {"dropped": false, "artifact_id": ""}
	
	var pool: Array[String] = _boss_pools[boss_id]
	if pool.is_empty():
		return {"dropped": false, "artifact_id": ""}
	
	# Roll for drop chance
	if rng.randf() >= _drop_chance:
		return {"dropped": false, "artifact_id": ""}
	
	# Drop succeeded — pick random artifact from pool
	var index := rng.randi_range(0, pool.size() - 1)
	return {"dropped": true, "artifact_id": pool[index]}


## Returns the drop pool for a boss (for UI/debugging).
func get_boss_pool(boss_id: String) -> Array[String]:
	if _boss_pools.has(boss_id):
		return _boss_pools[boss_id]
	return []


## Returns the current drop chance.
func get_drop_chance() -> float:
	return _drop_chance