// @flow

import type React from 'React'
import type { Observable } from 'rxjs'
export type Undux<State: Object> = $ObjMap<State, Lift<State>>

type Lift<State: Object> = <V>(value: V) => Lifted<State, V>

type Lifted<State, T> = {
  key: $Keys<State>,
  previousValue: T,
  value: T,
}

export type Exactly<T> = T

export type Options = {
  isDevMode: boolean,
}

export interface Store<State: Object> {
  get<K: $Keys<State>>(key: K): $ElementType<State, K>;
  set<K: $Keys<State>, V: $ElementType<State, K>>(key: K): (value: V) => void;
  setFrom_EXPERIMENTAL((Store<State>) => void): void;
  on<K: $Keys<State>>(key: K): Observable<$ElementType<State, K>>;
  onAll(): Observable<$Values<Undux<State>>>;
  getState(): $ReadOnly<State>;
}

declare export class StoreSnapshot<State: Object> implements Store<State> {
  get<K: $Keys<State>>(key: K): $ElementType<State, K>;
  set<K: $Keys<State>, V: $ElementType<State, K>>(key: K): (value: V) => void;
  setFrom_EXPERIMENTAL((Store<State>) => void): void;
  on<K: $Keys<State>>(key: K): Observable<$ElementType<State, K>>;
  onAll(): Observable<$Values<Undux<State>>>;
  getState(): $ReadOnly<State>;
}

declare export class StoreDefinition<State: Object> implements Store<State> {
  get<K: $Keys<State>>(key: K): $ElementType<State, K>;
  set<K: $Keys<State>, V: $ElementType<State, K>>(key: K): (value: V) => void;
  setFrom_EXPERIMENTAL((Store<State>) => void): void;
  on<K: $Keys<State>>(key: K): Observable<$ElementType<State, K>>;
  onAll(): Observable<$Values<Undux<State>>>;
  getCurrentSnapshot(): StoreSnapshot<State>;
  getState(): $ReadOnly<State>;
}

declare export function createStore<State: Object>(
  initialState: State,
  options?: Options,
): StoreDefinition<Exactly<State>>

export type Effects<State: Object> = (
  store: StoreDefinition<State>,
) => StoreDefinition<State>

/**
 * @deprecated Use `Effects` instead.
 */
export type Plugin<State: Object> = (
  store: StoreDefinition<State>,
) => StoreDefinition<State>

export type ToStore = <State>(s: State) => Store<State>
type ToStoreDefinition = <State>(s: State) => StoreDefinition<State>
export type EffectsAs<
  States: {
    [alias: string]: any,
  },
> = (
  stores: $ObjMap<States, ToStoreDefinition>,
) => $ObjMap<States, ToStoreDefinition>

declare export function withLogger<State: Object>(
  store: StoreDefinition<State>,
): StoreDefinition<State>

declare export function withReduxDevtools<State: Object>(
  store: StoreDefinition<State>,
): StoreDefinition<State>

declare export function connect<State: Object>(
  store: StoreDefinition<State>,
): <S: Store<State>, Props: { store: S, ... }>(
  Component: React.ComponentType<Props>,
) => Class<React.Component<$Diff<Props, { store: S, ... }>>>

// connectAs

declare export function connectAs<Stores: { [alias: string]: Store<any>, ... }>(
  stores: Stores,
): <Props: Object>(
  Component: React.ComponentType<Props>,
) => Class<React.Component<$Diff<Props, Stores>>>

// createConnectedStore

export type ContainerProps<State: Object> = {|
  children: React.Node,
  effects?: Effects<State>,
  initialState?: State,
|}

export type WithStore<ComponentType: React.ComponentType<Object>> =
  React.ComponentType<$Diff<React.ElementConfig<ComponentType>, { store: any }>>

export type Connect<State: Object> = {|
  Container: React.ComponentType<ContainerProps<State>>,
  useStore: () => Store<State>,
  withStore: <S: Store<State>, Props: { store: S, ... }>(
    Component: React.ComponentType<Props>,
  ) => Class<React.Component<$Diff<Props, { store: S, ... }>>>,
|}

declare export function createConnectedStore<State: Object>(
  initialState: State,
  effects?: Effects<State>,
): Connect<State>

// createConnectedStoreAs

export type ContainerPropsAs<
  States: {
    [alias: string]: any,
  },
> = {|
  children: React.Node,
  effects?: EffectsAs<States>,
  initialStates?: States,
|}

export type ToAny = <State>(s: State) => any

export type WithStores<
  ComponentType: React.ComponentType<Object>,
  States: {
    [alias: string]: any,
  },
> = React.ComponentType<
  $Diff<React.ElementConfig<ComponentType>, $ObjMap<States, ToAny>>,
>

export type ConnectAs<
  States: {
    [alias: string]: any,
  },
> = {|
  Container: React.ComponentType<ContainerPropsAs<States>>,
  useStores: () => $ObjMap<States, ToStore>,
  withStores: <ComponentType: React.ComponentType<Object>>(
    Component: ComponentType,
  ) => React.ComponentType<
    $Diff<React.ElementConfig<ComponentType>, $ObjMap<States, ToAny>>,
  >,
|}

declare export function createConnectedStoreAs<
  States: {
    [alias: string]: any,
  },
>(
  initialStates: States,
  effects?: EffectsAs<States>,
): ConnectAs<Exactly<States>>