initiative/apps/web/src/hooks/use-auto-stat-block.ts

import { useEffect, useRef } from "react";
import { useEncounterContext } from "../contexts/encounter-context.js";
import { useSidePanelContext } from "../contexts/side-panel-context.js";

export function useAutoStatBlock(): void {
	const { encounter } = useEncounterContext();
	const { panelView, updateCreature } = useSidePanelContext();

	const activeCreatureId =
		encounter.combatants[encounter.activeIndex]?.creatureId;
	const prevActiveIndexRef = useRef(encounter.activeIndex);

	useEffect(() => {
		const prevIndex = prevActiveIndexRef.current;
		prevActiveIndexRef.current = encounter.activeIndex;

		// Only auto-update when the active turn changes (advance/retreat),
		// not when the panel mode changes (user clicking a different creature).
		if (
			encounter.activeIndex !== prevIndex &&
			activeCreatureId &&
			panelView.mode === "creature"
		) {
			updateCreature(activeCreatureId);
		}
	}, [encounter.activeIndex, activeCreatureId, panelView.mode, updateCreature]);
}