// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
// See LICENSE.txt for license information.
import { GlobalState } from './store';

export type GetStateFunc = () => GlobalState;
export type GenericAction = {
  type: string;
  data?: any;
  meta?: any;
  error?: any;
  index?: number;
  displayable?: boolean;
  postId?: string;
  sessionId?: string;
  currentUserId?: string;
  timestamp?: number;
  [extraProps: string]: any;
};
export type Thunk = (b: DispatchFunc, a: GetStateFunc) => Promise<ActionResult> | ActionResult;

type BatchAction = {
  type: 'BATCHING_REDUCER.BATCH';
  payload: GenericAction[];
  meta: {
    batch: true;
  };
};
export type Action = GenericAction | Thunk | BatchAction | ActionFunc;

export type ActionResult =
  | {
      data: any;
    }
  | {
      error: any;
    };

export type DispatchFunc = (
  action: Action,
  getState?: GetStateFunc | null
) => Promise<ActionResult>;
export type ActionFunc = (
  dispatch: DispatchFunc,
  getState: GetStateFunc
) => Promise<ActionResult | ActionResult[]> | ActionResult;
export type PlatformType = 'web' | 'ios' | 'android';

export const BATCH = 'BATCHING_REDUCER.BATCH';

export function batchActions(actions: Action[], type = BATCH) {
  return { type, meta: { batch: true }, payload: actions };
}

export type Reducer<S = any, A extends Action = Action> = (state: S | undefined, action: A) => S;

export function enableBatching<S>(reduce: Reducer<S>): Reducer<S> {
  return function batchingReducer(state, action) {
    if (action && 'meta' in action && action.meta.batch) {
      return action.payload.reduce(batchingReducer, state);
    }
    return reduce(state, action);
  };
}