import { FunctionComponent, ReactNode } from "react";
import { Store } from "@tanstack/react-store";
import { Batcher, BatcherOptions, BatcherState } from "@tanstack/pacer/batcher";

//#region src/batcher/useBatcher.d.ts
interface ReactBatcherOptions<TValue, TSelected = {}> extends BatcherOptions<TValue> {
  /**
   * Optional callback invoked when the component unmounts. Receives the batcher instance.
   * When provided, replaces the default cleanup (cancel); use it to call flush(), reset(), cancel(), add logging, etc.
   */
  onUnmount?: (batcher: ReactBatcher<TValue, TSelected>) => void;
}
interface ReactBatcher<TValue, TSelected = {}> extends Omit<Batcher<TValue>, 'store'> {
  /**
   * A React HOC (Higher Order Component) that allows you to subscribe to the batcher state.
   *
   * This is useful for opting into state re-renders for specific parts of the batcher state
   * deep in your component tree without needing to pass a selector to the hook.
   *
   * @example
   * <batcher.Subscribe selector={(state) => ({ size: state.size, isPending: state.isPending })}>
   *   {({ size, isPending }) => (
   *     <div>Batch: {size} items, {isPending ? 'Pending' : 'Ready'}</div>
   *   )}
   * </batcher.Subscribe>
   */
  Subscribe: <TSelected>(props: {
    selector: (state: BatcherState<TValue>) => TSelected;
    children: ((state: TSelected) => ReactNode) | ReactNode;
  }) => ReturnType<FunctionComponent>;
  /**
   * Reactive state that will be updated and re-rendered when the batcher state changes
   *
   * Use this instead of `batcher.store.state`
   */
  readonly state: Readonly<TSelected>;
  /**
   * @deprecated Use `batcher.state` instead of `batcher.store.state` if you want to read reactive state.
   * The state on the store object is not reactive, as it has not been wrapped in a `useSelector` hook internally.
   * Although, you can make the state reactive by using the `useSelector` in your own usage.
   */
  readonly store: Store<Readonly<BatcherState<TValue>>>;
}
/**
 * A React hook that creates and manages a Batcher instance.
 *
 * This is a lower-level hook that provides direct access to the Batcher's functionality without
 * any built-in state management. This allows you to integrate it with any state management solution
 * you prefer (useState, Redux, Zustand, etc.) by utilizing the onItemsChange callback.
 *
 * The Batcher collects items and processes them in batches based on configurable conditions:
 * - Maximum batch size
 * - Time-based batching (process after X milliseconds)
 * - Custom batch processing logic via getShouldExecute
 *
 * ## State Management and Selector
 *
 * The hook uses TanStack Store for reactive state management. You can subscribe to state changes
 * in two ways:
 *
 * **1. Using `batcher.Subscribe` HOC (Recommended for component tree subscriptions)**
 *
 * Use the `Subscribe` HOC to subscribe to state changes deep in your component tree without
 * needing to pass a selector to the hook. This is ideal when you want to subscribe to state
 * in child components.
 *
 * **2. Using the `selector` parameter (For hook-level subscriptions)**
 *
 * The `selector` parameter allows you to specify which state changes will trigger a re-render
 * at the hook level, optimizing performance by preventing unnecessary re-renders when irrelevant
 * state changes occur.
 *
 * **By default, there will be no reactive state subscriptions** and you must opt-in to state
 * tracking by providing a selector function or using the `Subscribe` HOC. This prevents unnecessary
 * re-renders and gives you full control over when your component updates.
 *
 * Available state properties:
 * - `executionCount`: Number of batch executions that have been completed
 * - `isEmpty`: Whether the batcher has no items to process
 * - `isPending`: Whether the batcher is waiting for the timeout to trigger batch processing
 * - `isRunning`: Whether the batcher is active and will process items automatically
 * - `items`: Array of items currently queued for batch processing
 * - `size`: Number of items currently in the batch queue
 * - `status`: Current processing status ('idle' | 'pending')
 * - `totalItemsProcessed`: Total number of items processed across all batches
 *
 * ## Unmount behavior
 *
 * By default, the hook cancels any pending batch when the component unmounts.
 * Use the `onUnmount` option to customize this. For example, to flush pending work instead:
 *
 * ```tsx
 * const batcher = useBatcher(fn, {
 *   maxSize: 5,
 *   wait: 2000,
 *   onUnmount: (b) => b.flush()
 * });
 * ```
 *
 * @example
 * ```tsx
 * // Default behavior - no reactive state subscriptions
 * const batcher = useBatcher<number>(
 *   (items) => console.log('Processing batch:', items),
 *   { maxSize: 5, wait: 2000 }
 * );
 *
 * // Subscribe to state changes deep in component tree using Subscribe HOC
 * <batcher.Subscribe selector={(state) => ({ size: state.size, isPending: state.isPending })}>
 *   {({ size, isPending }) => (
 *     <div>Batch: {size} items, {isPending ? 'Pending' : 'Ready'}</div>
 *   )}
 * </batcher.Subscribe>
 *
 * // Opt-in to re-render when batch size changes at hook level (optimized for displaying queue size)
 * const batcher = useBatcher<number>(
 *   (items) => console.log('Processing batch:', items),
 *   { maxSize: 5, wait: 2000 },
 *   (state) => ({
 *     size: state.size,
 *     isEmpty: state.isEmpty
 *   })
 * );
 *
 * // Opt-in to re-render when execution metrics change (optimized for stats display)
 * const batcher = useBatcher<number>(
 *   (items) => console.log('Processing batch:', items),
 *   { maxSize: 5, wait: 2000 },
 *   (state) => ({
 *     executionCount: state.executionCount,
 *     totalItemsProcessed: state.totalItemsProcessed
 *   })
 * );
 *
 * // Opt-in to re-render when processing state changes (optimized for loading indicators)
 * const batcher = useBatcher<number>(
 *   (items) => console.log('Processing batch:', items),
 *   { maxSize: 5, wait: 2000 },
 *   (state) => ({
 *     isPending: state.isPending,
 *     isRunning: state.isRunning,
 *     status: state.status
 *   })
 * );
 *
 * // Example with custom state management and batching
 * const [items, setItems] = useState([]);
 *
 * const batcher = useBatcher<number>(
 *   (items) => console.log('Processing batch:', items),
 *   {
 *     maxSize: 5,
 *     wait: 2000,
 *     onItemsChange: (batcher) => setItems(batcher.peekAllItems()),
 *     getShouldExecute: (items) => items.length >= 3
 *   }
 * );
 *
 * // Add items to batch - they'll be processed when conditions are met
 * batcher.addItem(1);
 * batcher.addItem(2);
 * batcher.addItem(3); // Triggers batch processing
 *
 * // Control the batcher
 * batcher.stop();  // Pause batching
 * batcher.start(); // Resume batching
 *
 * // Access the selected state (will be empty object {} unless selector provided)
 * const { size, isPending } = batcher.state;
 * ```
 */
declare function useBatcher<TValue, TSelected = {}>(fn: (items: Array<TValue>) => void, options?: ReactBatcherOptions<TValue, TSelected>, selector?: (state: BatcherState<TValue>) => TSelected): ReactBatcher<TValue, TSelected>;
//#endregion
export { ReactBatcher, ReactBatcherOptions, useBatcher };
//# sourceMappingURL=useBatcher.d.ts.map