import { PerfTrackName } from "../debug/perf-track.js";
import { World } from "koota";
//#region src/ecs/SystemSchedule.d.ts
/**
 * A system function takes only a world — all context comes from world resource traits.
 */
type SystemFn = (world: World) => void;
/**
 * Perf label attached at registration. Mandatory so the whole schedule
 * is tracked — TypeScript guarantees every system carries a track + name.
 */
interface SystemLabel {
  track: PerfTrackName;
  name: string;
}
/**
 * Ordered system runner with frame-level idempotency.
 *
 * Systems are registered via `add()` and executed in registration order
 * by `run()`. Calling `run()` multiple times within the same frame is
 * a no-op after the first — `nextFrame()` advances the frame counter
 * to allow the next execution.
 *
 * Every registration carries a perf label (`{ track, name }`). When
 * devtools is bundled, `run()` emits a `performance.measure` span per
 * system plus an outer `ecs:run` span on the Schedule track. In prod
 * the instrumented branch is dead code (terser folds the devtools build
 * gate) and `run()` is the plain loop.
 *
 * @example
 * ```typescript
 * const schedule = new SystemSchedule()
 * schedule.add(lightSyncSystem, { track: PERF_TRACK.Lighting, name: 'lightSync' })
 * schedule.add(batchAssignSystem, { track: PERF_TRACK.Batch, name: 'batchAssign' })
 *
 * // In render loop:
 * schedule.nextFrame()
 * schedule.run(world)  // executes all systems
 * schedule.run(world)  // no-op (same frame)
 * ```
 */
declare class SystemSchedule {
  private _systems;
  private _frameId;
  private _lastRunFrame;
  /** Register a system at the end. Execution order matches registration order. */
  add(system: SystemFn, label: SystemLabel): this;
  /** Register a system at the beginning. Used to insert phases before existing systems. */
  prepend(system: SystemFn, label: SystemLabel): this;
  /** Unregister a system. */
  remove(system: SystemFn): this;
  /** Execute all registered systems. Idempotent within a frame. */
  run(world: World): void;
  /** Advance the frame counter, allowing the next `run()` to execute. */
  nextFrame(): void;
}
//#endregion
export { SystemFn, SystemLabel, SystemSchedule };
//# sourceMappingURL=SystemSchedule.d.ts.map