declare module 'redux' {
/**
 * An *action* is a plain object that represents an intention to change the
 * state. Actions are the only way to get data into the store. Any data,
 * whether from UI events, network callbacks, or other sources such as
 * WebSockets needs to eventually be dispatched as actions.
 *
 * Actions must have a `type` field that indicates the type of action being
 * performed. Types can be defined as constants and imported from another
 * module. It's better to use strings for `type` than Symbols because strings
 * are serializable.
 *
 * Other than `type`, the structure of an action object is really up to you.
 * If you're interested, check out Flux Standard Action for recommendations on
 * how actions should be constructed.
 *
 * @template T the type of the action's `type` tag.
 */
export interface Action<T = any> {
    type: T;
  }
  
  /* reducers */
  
  /**
   * A *reducer* (also called a *reducing function*) is a function that accepts
   * an accumulation and a value and returns a new accumulation. They are used
   * to reduce a collection of values down to a single value
   *
   * Reducers are not unique to Redux—they are a fundamental concept in
   * functional programming.  Even most non-functional languages, like
   * JavaScript, have a built-in API for reducing. In JavaScript, it's
   * `Array.prototype.reduce()`.
   *
   * In Redux, the accumulated value is the state object, and the values being
   * accumulated are actions. Reducers calculate a new state given the previous
   * state and an action. They must be *pure functions*—functions that return
   * the exact same output for given inputs. They should also be free of
   * side-effects. This is what enables exciting features like hot reloading and
   * time travel.
   *
   * Reducers are the most important concept in Redux.
   *
   * *Do not put API calls into reducers.*
   *
   * @template S The type of state consumed and produced by this reducer.
   * @template A The type of actions the reducer can potentially respond to.
   */
  export type Reducer<S = any, A extends Action = Action> = (state: S | undefined, action: A) => S;
  
  /**
   * Object whose values correspond to different reducer functions.
   *
   * @template A The type of actions the reducers can potentially respond to.
   */
  export type ReducersMapObject<S = any, A extends Action = Action> = {
    [K in keyof S]: Reducer<S[K], A>;
  }
  
  /**
   * Turns an object whose values are different reducer functions, into a single
   * reducer function. It will call every child reducer, and gather their results
   * into a single state object, whose keys correspond to the keys of the passed
   * reducer functions.
   *
   * @template S Combined state object type.
   *
   * @param reducers An object whose values correspond to different reducer
   *   functions that need to be combined into one. One handy way to obtain it
   *   is to use ES6 `import * as reducers` syntax. The reducers may never
   *   return undefined for any action. Instead, they should return their
   *   initial state if the state passed to them was undefined, and the current
   *   state for any unrecognized action.
   *
   * @returns A reducer function that invokes every reducer inside the passed
   *   object, and builds a state object with the same shape.
   */
  export function combineReducers<S, A extends Action = Action>(reducers: ReducersMapObject<S, A>): Reducer<S, A>;
  
  
  /* store */
  
  /**
   * A *dispatching function* (or simply *dispatch function*) is a function that
   * accepts an action or an async action; it then may or may not dispatch one
   * or more actions to the store.
   *
   * We must distinguish between dispatching functions in general and the base
   * `dispatch` function provided by the store instance without any middleware.
   *
   * The base dispatch function *always* synchronously sends an action to the
   * store's reducer, along with the previous state returned by the store, to
   * calculate a new state. It expects actions to be plain objects ready to be
   * consumed by the reducer.
   *
   * Middleware wraps the base dispatch function. It allows the dispatch
   * function to handle async actions in addition to actions. Middleware may
   * transform, delay, ignore, or otherwise interpret actions or async actions
   * before passing them to the next middleware.
   *
   * @template D the type of things (actions or otherwise) which may be dispatched.
   */
  export interface Dispatch<D = Action> {
    <A extends D>(action: A): A;
  }
  
  /**
   * Function to remove listener added by `Store.subscribe()`.
   */
  export interface Unsubscribe {
    (): void;
  }
  
  /**
   * A store is an object that holds the application's state tree.
   * There should only be a single store in a Redux app, as the composition
   * happens on the reducer level.
   *
   * @template S The type of state held by this store.
   * @template A the type of actions which may be dispatched by this store.
   * @template N The type of non-actions which may be dispatched by this store.
   */
  export interface Store<S = any, A extends Action = Action, N = never> {
    /**
     * Dispatches an action. It is the only way to trigger a state change.
     *
     * The `reducer` function, used to create the store, will be called with the
     * current state tree and the given `action`. Its return value will be
     * considered the **next** state of the tree, and the change listeners will
     * be notified.
     *
     * The base implementation only supports plain object actions. If you want
     * to dispatch a Promise, an Observable, a thunk, or something else, you
     * need to wrap your store creating function into the corresponding
     * middleware. For example, see the documentation for the `redux-thunk`
     * package. Even the middleware will eventually dispatch plain object
     * actions using this method.
     *
     * @param action A plain object representing “what changed”. It is a good
     *   idea to keep actions serializable so you can record and replay user
     *   sessions, or use the time travelling `redux-devtools`. An action must
     *   have a `type` property which may not be `undefined`. It is a good idea
     *   to use string constants for action types.
     *
     * @returns For convenience, the same action object you dispatched.
     *
     * Note that, if you use a custom middleware, it may wrap `dispatch()` to
     * return something else (for example, a Promise you can await).
     */
    dispatch: Dispatch<A | N>;
  
    /**
     * Reads the state tree managed by the store.
     *
     * @returns The current state tree of your application.
     */
    getState(): S;
  
    /**
     * Adds a change listener. It will be called any time an action is
     * dispatched, and some part of the state tree may potentially have changed.
     * You may then call `getState()` to read the current state tree inside the
     * callback.
     *
     * You may call `dispatch()` from a change listener, with the following
     * caveats:
     *
     * 1. The subscriptions are snapshotted just before every `dispatch()` call.
     * If you subscribe or unsubscribe while the listeners are being invoked,
     * this will not have any effect on the `dispatch()` that is currently in
     * progress. However, the next `dispatch()` call, whether nested or not,
     * will use a more recent snapshot of the subscription list.
     *
     * 2. The listener should not expect to see all states changes, as the state
     * might have been updated multiple times during a nested `dispatch()` before
     * the listener is called. It is, however, guaranteed that all subscribers
     * registered before the `dispatch()` started will be called with the latest
     * state by the time it exits.
     *
     * @param listener A callback to be invoked on every dispatch.
     * @returns A function to remove this change listener.
     */
    subscribe(listener: GlobalType.VoidFunc): Unsubscribe;
  
    /**
     * Replaces the reducer currently used by the store to calculate the state.
     *
     * You might need this if your app implements code splitting and you want to
     * load some of the reducers dynamically. You might also need this if you
     * implement a hot reloading mechanism for Redux.
     *
     * @param nextReducer The reducer for the store to use instead.
     */
    replaceReducer(nextReducer: Reducer<S, A>): void;
  }
  
  export type DeepPartial<T> = {[K in keyof T]?: DeepPartial<T[K]> };
  
  /**
   * A store creator is a function that creates a Redux store. Like with
   * dispatching function, we must distinguish the base store creator,
   * `createStore(reducer, preloadedState)` exported from the Redux package, from
   * store creators that are returned from the store enhancers.
   *
   * @template S The type of state to be held by the store.
   * @template A The type of actions which may be dispatched.
   * @template D The type of all things which may be dispatched.
   */
  export interface StoreCreator {
    <S, A extends Action, N>(reducer: Reducer<S, A>, enhancer?: StoreEnhancer<N>): Store<S, A, N>;
    <S, A extends Action, N>(reducer: Reducer<S, A>, preloadedState: DeepPartial<S>, enhancer?: StoreEnhancer<N>): Store<S, A, N>;
  }
  
  /**
   * A store enhancer is a higher-order function that composes a store creator
   * to return a new, enhanced store creator. This is similar to middleware in
   * that it allows you to alter the store interface in a composable way.
   *
   * Store enhancers are much the same concept as higher-order components in
   * React, which are also occasionally called “component enhancers”.
   *
   * Because a store is not an instance, but rather a plain-object collection of
   * functions, copies can be easily created and modified without mutating the
   * original store. There is an example in `compose` documentation
   * demonstrating that.
   *
   * Most likely you'll never write a store enhancer, but you may use the one
   * provided by the developer tools. It is what makes time travel possible
   * without the app being aware it is happening. Amusingly, the Redux
   * middleware implementation is itself a store enhancer.
   *
   */
  export type StoreEnhancer<N = never> = (next: StoreEnhancerStoreCreator<N>) => StoreEnhancerStoreCreator<N>;
  export type GenericStoreEnhancer<N = never> = StoreEnhancer<N>;
  export type StoreEnhancerStoreCreator<N = never> = <S = any, A extends Action = Action>(reducer: Reducer<S, A>, preloadedState?: DeepPartial<S>) => Store<S, A, N>;
  
  /**
   * Creates a Redux store that holds the state tree.
   * The only way to change the data in the store is to call `dispatch()` on it.
   *
   * There should only be a single store in your app. To specify how different
   * parts of the state tree respond to actions, you may combine several
   * reducers
   * into a single reducer function by using `combineReducers`.
   *
   * @template S State object type.
   *
   * @param reducer A function that returns the next state tree, given the
   *   current state tree and the action to handle.
   *
   * @param [preloadedState] The initial state. You may optionally specify it to
   *   hydrate the state from the server in universal apps, or to restore a
   *   previously serialized user session. If you use `combineReducers` to
   *   produce the root reducer function, this must be an object with the same
   *   shape as `combineReducers` keys.
   *
   * @param [enhancer] The store enhancer. You may optionally specify it to
   *   enhance the store with third-party capabilities such as middleware, time
   *   travel, persistence, etc. The only store enhancer that ships with Redux
   *   is `applyMiddleware()`.
   *
   * @returns A Redux store that lets you read the state, dispatch actions and
   *   subscribe to changes.
   */
  export const createStore: StoreCreator;
  
  
  /* middleware */
  
  export interface MiddlewareAPI<S = any, D = Action> {
    dispatch: Dispatch<D>;
    getState(): S;
  }
  
  /**
   * A middleware is a higher-order function that composes a dispatch function
   * to return a new dispatch function. It often turns async actions into
   * actions.
   *
   * Middleware is composable using function composition. It is useful for
   * logging actions, performing side effects like routing, or turning an
   * asynchronous API call into a series of synchronous actions.
   */
  export interface Middleware {
    <S = any, D = Action>(api: MiddlewareAPI<S, D>): (next: Dispatch<D>) => Dispatch<D>;
  }
  
  /**
   * Creates a store enhancer that applies middleware to the dispatch method
   * of the Redux store. This is handy for a variety of tasks, such as
   * expressing asynchronous actions in a concise manner, or logging every
   * action payload.
   *
   * See `redux-thunk` package as an example of the Redux middleware.
   *
   * Because middleware is potentially asynchronous, this should be the first
   * store enhancer in the composition chain.
   *
   * Note that each middleware will be given the `dispatch` and `getState`
   * functions as named arguments.
   *
   * @param middlewares The middleware chain to be applied.
   * @returns A store enhancer applying the middleware.
   */
  export function applyMiddleware(...middlewares: Middleware[]): GenericStoreEnhancer;
  
  
  /* action creators */
  
  /**
   * An *action creator* is, quite simply, a function that creates an action. Do
   * not confuse the two terms—again, an action is a payload of information, and
   * an action creator is a factory that creates an action.
   *
   * Calling an action creator only produces an action, but does not dispatch
   * it. You need to call the store's `dispatch` function to actually cause the
   * mutation. Sometimes we say *bound action creators* to mean functions that
   * call an action creator and immediately dispatch its result to a specific
   * store instance.
   *
   * If an action creator needs to read the current state, perform an API call,
   * or cause a side effect, like a routing transition, it should return an
   * async action instead of an action.
   *
   * @template A Returned action type.
   */
  export interface ActionCreator<A> {
    (...args: any[]): A;
  }
  
  /**
   * Object whose values are action creator functions.
   */
  export interface ActionCreatorsMapObject<A = any> {
    [key: string]: ActionCreator<A>;
  }
  
  /**
   * Turns an object whose values are action creators, into an object with the
   * same keys, but with every function wrapped into a `dispatch` call so they
   * may be invoked directly. This is just a convenience method, as you can call
   * `store.dispatch(MyActionCreators.doSomething())` yourself just fine.
   *
   * For convenience, you can also pass a single function as the first argument,
   * and get a function in return.
   *
   * @param actionCreator An object whose values are action creator functions.
   *   One handy way to obtain it is to use ES6 `import * as` syntax. You may
   *   also pass a single function.
   *
   * @param dispatch The `dispatch` function available on your Redux store.
   *
   * @returns The object mimicking the original object, but with every action
   *   creator wrapped into the `dispatch` call. If you passed a function as
   *   `actionCreator`, the return value will also be a single function.
   */
  export function bindActionCreators<A, C extends ActionCreator<A>>(actionCreator: C, dispatch: Dispatch<A>): C;
  
  export function bindActionCreators<
    A extends ActionCreator<any>,
    B extends ActionCreator<any>
    >(actionCreator: A, dispatch: Dispatch<any>): B;
  
  export function bindActionCreators<A, M extends ActionCreatorsMapObject<A>>(actionCreators: M, dispatch: Dispatch<A>): M;
  
  export function bindActionCreators<
    M extends ActionCreatorsMapObject<any>,
    N extends ActionCreatorsMapObject<any>
    >(actionCreators: M, dispatch: Dispatch<any>): N;
  
  
  /* compose */
  
  type Func0<R> = () => R;
  type Func1<T1, R> = (a1: T1) => R;
  type Func2<T1, T2, R> = (a1: T1, a2: T2) => R;
  type Func3<T1, T2, T3, R> = (a1: T1, a2: T2, a3: T3, ...args: any[]) => R;
  
  /**
   * Composes single-argument functions from right to left. The rightmost
   * function can take multiple arguments as it provides the signature for the
   * resulting composite function.
   *
   * @param funcs The functions to compose.
   * @returns R function obtained by composing the argument functions from right
   *   to left. For example, `compose(f, g, h)` is identical to doing
   *   `(...args) => f(g(h(...args)))`.
   */
  export function compose(): <R>(a: R) => R;
  
  export function compose<F extends Function>(f: F): F;
  
  /* two functions */
  export function compose<A, R>(
    f1: (b: A) => R, f2: Func0<A>
  ): Func0<R>;
  export function compose<A, T1, R>(
    f1: (b: A) => R, f2: Func1<T1, A>
  ): Func1<T1, R>;
  export function compose<A, T1, T2, R>(
    f1: (b: A) => R, f2: Func2<T1, T2, A>
  ): Func2<T1, T2, R>;
  export function compose<A, T1, T2, T3, R>(
    f1: (b: A) => R, f2: Func3<T1, T2, T3, A>
  ): Func3<T1, T2, T3, R>;
  
  /* three functions */
  export function compose<A, B, R>(
    f1: (b: B) => R, f2: (a: A) => B, f3: Func0<A>
  ): Func0<R>;
  export function compose<A, B, T1, R>(
    f1: (b: B) => R, f2: (a: A) => B, f3: Func1<T1, A>
  ): Func1<T1, R>;
  export function compose<A, B, T1, T2, R>(
    f1: (b: B) => R, f2: (a: A) => B, f3: Func2<T1, T2, A>
  ): Func2<T1, T2, R>;
  export function compose<A, B, T1, T2, T3, R>(
    f1: (b: B) => R, f2: (a: A) => B, f3: Func3<T1, T2, T3, A>
  ): Func3<T1, T2, T3, R>;
  
  /* four functions */
  export function compose<A, B, C, R>(
    f1: (b: C) => R, f2: (a: B) => C, f3: (a: A) => B, f4: Func0<A>
  ): Func0<R>;
  export function compose<A, B, C, T1, R>(
    f1: (b: C) => R, f2: (a: B) => C, f3: (a: A) => B, f4: Func1<T1, A>
  ): Func1<T1, R>;
  export function compose<A, B, C, T1, T2, R>(
    f1: (b: C) => R, f2: (a: B) => C, f3: (a: A) => B, f4: Func2<T1, T2, A>
  ): Func2<T1, T2, R>;
  export function compose<A, B, C, T1, T2, T3, R>(
    f1: (b: C) => R, f2: (a: B) => C, f3: (a: A) => B, f4: Func3<T1, T2, T3, A>
  ): Func3<T1, T2, T3, R>;
  
  /* rest */
  export function compose<R>(
    f1: (b: any) => R, ...funcs: Function[]
  ): (...args: any[]) => R;
  
  export function compose<R>(...funcs: Function[]): (...args: any[]) => R;
}