class_name MoveApplier
extends RefCounted
## Writes validated §6 moves to game state. Town-NPC disposition lives in
## GameState.npc_dispositions (NOT CanonLog.party — that is companions only).
## Called by the conversation caller after NpcService.speak, so state writes
## stay explicit (§2). Unknown move names are ignored (they never pass the
## validator, but this stays defensive).

const MAX_DELTA := 15       # one line cannot swing standing wholesale (§7 spirit)
const HOSTILE_FLOOR := -100


static func apply(moves: Array, game_state, canon_log, content_db, npc_id: String) -> void:
	# ONE RULE: a move applies AT MOST ONCE PER REPLY. The tag extractor returns
	# every occurrence and the validator is a membership test, so without this a
	# model repeating a tag N times picks an amount in unary — the AI choosing a
	# number, which is the §2 breach the bounded vocabulary exists to prevent.
	# It is worth the same for real items: three give_item(amulet) tags are one
	# amulet, not three.
	var applied := {}          # "name(id)" -> true
	var dispo_total := 0       # the reply's NET disposition swing, capped at MAX_DELTA
	for move in moves:
		var name: String = move.get("name", "")
		var args: Array = move.get("args", [])
		# MoveValidator.ID_MOVES is the one list of moves that name a thing — those
		# are the ones a (name, id) key can dedupe. Reused, not restated.
		if name in MoveValidator.ID_MOVES and not args.is_empty():
			var key := "%s(%s)" % [name, str(args[0])]
			if applied.has(key):
				continue
			applied[key] = true
		match name:
			"offer_quest":
				var q: String = str(args[0])
				var qd: Dictionary = content_db.quest(q)
				canon_log.add_quest(q, qd.get("name", ""), qd.get("objective", ""))
			"reveal":
				game_state.mark_revealed(str(args[0]))
			"give_item":
				var i: String = str(args[0])
				game_state.grant(i, 1)
				if not Currency.is_currency(i):
					game_state.mark_gift_given(i)  # the one-shot gate is for real items only
			"accept_item":
				game_state.take(str(args[0]), 1)
			"adjust_disposition":
				# MAX_DELTA caps the reply's NET swing, not each tag — clamping per
				# tag let three +15s move standing by 45, which is exactly the
				# "wholesale swing" the constant is here to forbid. Applied inside
				# the loop (not batched at the end) so emission order still holds
				# and a later become_hostile floors what came before it.
				var delta: int = clampi(int(str(args[0])), -MAX_DELTA, MAX_DELTA)
				var capped: int = clampi(dispo_total + delta, -MAX_DELTA, MAX_DELTA)
				var allowed: int = capped - dispo_total
				dispo_total = capped
				var cur: int = int(game_state.npc_dispositions.get(npc_id, 0))
				game_state.set_npc_disposition(npc_id, cur + allowed)
			"become_hostile":
				game_state.set_npc_disposition(npc_id, HOSTILE_FLOOR)
			_:
				pass  # refuse, end_conversation, and anything unknown: no state