YMCA actions, reducers, selectors

ymca.js

type Dispatch = (action: Action | ThunkAction) => any;
type GetState = () => Object;
type ThunkAction = (dispatch: Dispatch, getState: GetState) => any;
type Image = {
    publicId: string,
    tags: Array<string>
    // ...
};

// actions
type Action = 
    { type: 'LOAD_TOTAL_COUNT' }
  | { type: 'LOAD_TOTAL_COUNT_SUCCESS', payload: { count: number } }
  | { type: 'LOAD_TOTAL_COUNT_ERROR', payload: { err: Error } }
  | { type: 'LOAD_IMAGES' }
  | { type: 'LOAD_IMAGES_SUCCESS', payload: { images: Array<Image> } }
  | { type: 'LOAD_IMAGES_ERROR', payload: { err: Error } }
  | { type: 'UPLOAD_IMAGE', payload: { file: File } }
  | { type: 'UPLOAD_IMAGE_PROGRESS', payload: { progress: number } }
  | { type: 'UPLOAD_IMAGE_SUCCESS', payload: { image: Image } }
  | { type: 'UPLOAD_IMAGE_ERROR', payload: { err: Error } }
  | { type: 'LOAD_TAGS' }
  | { type: 'LOAD_TAGS_SUCCESS', payload: { tags: Array<string> } }
  | { type: 'LOAD_TAGS_ERROR', payload: { err: Error } }
  | { type: 'LOAD_IMAGE' }
  | { type: 'LOAD_IMAGE_SUCCESS', payload: { image: Image } }
  | { type: 'LOAD_IMAGE_ERROR', payload: { err: Error } }

// action creators
function loadTotalCount(): ThunkAction {}
function loadTotalCountSuccess(count: number): Action {}
function loadTotalCountError(err: Error): Action {}
function loadImages(itemsPerPage: number, terms: ?string, nextCursor: ?string): ThunkAction {}
function loadImagesSuccess(images: Array<Image>): Action {}
function loadImagesError(err: Error): Action {}
function uploadImage(file: File): ThunkAction {}
function uploadImageProgress(progress: number): Action {}
function uploadImageSuccess(image: Image): Action {}
function uploadImageError(err: Error): Action {}
function loadTags(prefix: string): ThunkAction {}
function loadTagsSuccess(tags: Array<string>): Action {}
function loadTagsError(err: Error): Action {}
function loadImage(id: string, options: Object): ThunkAction {}
function loadImageSuccess(image: Image): Action {}
function loadImageError(err: Error): Action {}

type Filter = 'All' | 'Recent';

// reducer
type State = {
    images: Array<Image>,
    totalCount: number,
    suggestions: Array<string>,
    searchTerm: string,
    imageToChoose: ?Image,
    activeFilter: Filter,
    isLoading: boolean
};

const initialState = {
    images: [],
    totalCount: 0,
    suggestions: [],
    searchTerm: '',
    imageToChoose: null,
    activeFilter: 'All',
    isLoading: false
};

function (state: State = initialState, action: Action): State {

}

// selectors
function getAllImages(state: State): Array<Image> {
    return state.images;
}

function getRecentImages(state: State): Array<Image> {
    // implement logic
}

function getFilteredImages(state: State): Array<Image> {
    if (state.activeFilter === 'Recent') {
        return getRecentImages(state);
    }
    return getAllImages(state);
}