import type { DungeonId } from "../game/dungeonRegistry";
import type { Frameloop } from "@react-three/fiber";
import type { GameplayFrameRateLimit } from "../game/frameRateSettings";

/**
 * Encounter transitions must never remount the Canvas: R3F intentionally loses
 * the old WebGL context during Canvas disposal. Only explicit graphics recovery
 * is allowed to replace the renderer.
 */
export function rendererCanvasKey(canvasRevision: number): string {
  return `renderer:${Math.max(0, Math.trunc(canvasRevision))}`;
}

/** The Rapier world and all encounter actors are rebuilt for every session. */
export function encounterWorldKey(dungeonId: DungeonId, sessionRevision: number): string {
  return `${dungeonId}:encounter:${Math.max(0, Math.trunc(sessionRevision))}`;
}

/**
 * Readiness belongs to one encounter world. Comparing revisions avoids a
 * child collision-ready effect being overwritten by a later parent reset in
 * the same React effect flush, and prevents stale worlds from unblocking the
 * current session.
 */
export function encounterWorldIsReady(
  readySessionRevision: number | null,
  sessionRevision: number,
): boolean {
  return readySessionRevision !== null
    && readySessionRevision === Math.max(0, Math.trunc(sessionRevision));
}

/**
 * A paused local world only needs a frame when React or R3F invalidates it.
 * Loading, recovery, and shared-online worlds keep the continuous loop so
 * asynchronous scene setup and authoritative remote simulation can progress.
 */
export function sceneFrameLoop(options: {
  readonly worldReady: boolean;
  readonly graphicsRecovering: boolean;
  readonly sharedOnline: boolean;
  readonly paused: boolean;
  readonly mapOpen: boolean;
  readonly companionOpen: boolean;
  readonly documentVisible: boolean;
  readonly frameRateLimit: GameplayFrameRateLimit;
}): Frameloop {
  if (!options.documentVisible && !options.sharedOnline) return "demand";
  const locallyPaused = options.worldReady
    && !options.graphicsRecovering
    && !options.sharedOnline
    && (options.paused || options.mapOpen || options.companionOpen);
  if (locallyPaused) return "demand";
  return options.frameRateLimit === "display" ? "always" : "never";
}