class_name ArtifactMods
extends RefCounted
## Artifact modification system. Applies trade-off modifiers to ability parameters.
## Artifacts are horizontal progression: they change HOW abilities work, not raw power.

## Represents a single artifact's modifier effect.
class Modifier:
	var target_ability_id: String = ""  # Which ability this modifies ("", or specific id)
	var stat_name: String = ""  # What stat/param to modify (e.g., "damage_mult", "cooldown", "gcd_duration")
	var modification_type: int = 0  # 0 = additive, 1 = multiplicative
	var value: float = 0.0
	var description: String = ""
	
	func _init(target: String, stat: String, mod_type: int, val: float, desc: String = ""):
		target_ability_id = target
		stat_name = stat
		modification_type = mod_type
		value = val
		description = desc


## Represents an equipped artifact.
class EquippedArtifact:
	var id: String = ""
	var name: String = ""
	var slot: int = -1  # 0=Charm, 1=Ring, 2=Talisman, 3=Sigil
	var rarity: int = 0  # 0=Common, 1=Uncommon, 2=Rare, 3=Epic
	var modifiers: Array[Modifier] = []
	
	func _init(id: String, name: String, slot: int, rarity: int):
		self.id = id
		self.name = name
		self.slot = slot
		self.rarity = rarity


## The modifier stack applies all equipped artifacts' modifications to base values.
var _equipped: Array[EquippedArtifact] = []  # Max 4 (one per slot)

## Equips an artifact into its slot. Replaces any existing artifact in that slot.
## Returns true if successfully equipped, false if slot is invalid.
func equip(artifact: EquippedArtifact) -> bool:
	if artifact.slot < 0 or artifact.slot > 3:
		return false
	# Remove existing artifact in this slot
	for i in _equipped.size():
		if _equipped[i].slot == artifact.slot:
			_equipped[i] = artifact
			return true
	_equipped.append(artifact)
	return true

## Unequips an artifact by slot.
func unequip(slot: int) -> void:
	for i in _equipped.size():
		if _equipped[i].slot == slot:
			_equipped.remove_at(i)
			return

## Returns the equipped artifact for a given slot, or null.
func get_artifact_for_slot(slot: int) -> EquippedArtifact:
	for art in _equipped:
		if art.slot == slot:
			return art
	return null


## Applies all relevant modifiers to a base value.
## ability_id: The ability being modified ("" = global modifiers like GCD).
## stat_name: Which stat to modify (e.g., "damage_mult", "cooldown", "gcd_duration").
## base_value: The unmodified value.
## Returns the modified value.
func apply_modifiers(ability_id: String, stat_name: String, base_value: float) -> float:
	var result := base_value
	for art in _equipped:
		for mod in art.modifiers:
			# Match: modifier targets this ability (or is global with "")
			if mod.target_ability_id != "" and mod.target_ability_id != ability_id:
				continue
			if mod.stat_name != stat_name:
				continue
			# Apply modification
			match mod.modification_type:
				0: result += mod.value  # Additive
				1: result *= mod.value  # Multiplicative
	return result


## Returns a summary of all active modifiers (for UI display).
func get_modifier_summary() -> Array[Dictionary]:
	var summary: Array[Dictionary] = []
	for art in _equipped:
		for mod in art.modifiers:
			summary.append({
				"artifact_name": art.name,
				"stat": mod.stat_name,
				"type": "additive" if mod.modification_type == 0 else "multiplicative",
				"value": mod.value,
				"description": mod.description
			})
	return summary


## Clears all equipped artifacts.
func clear_all() -> void:
	_equipped.clear()