/**
 * 1.) Context. For lifting our state up to any tree below the Provider.
 */
const ActivityContext = createContext()

/**
 * 2.) Provider. For sharing our state across many render trees.
 */
export const ActivityProvider = ({ children }) => {
    const [activity, setActivity] = useState([])

    /**
     * @function abort
     * @returns {undefined}
     */
    const abort = useCallback(() => abort(getRecentActivity), [])

    /**
     * @function loadActivity
     * @async
     * @returns {undefined}
     */
    const load = useCallback(async () => {
        try {
            const result = await getRecentActivity()

            if (!result || !result.ok || !result.body) {
                throw new Error('Unable to fetch recent activity.')
            }

            setActivity(result.body.items)
        } catch (err) {
            log.error(err)
        }
    }, [])

    return (
        <ActivityContext.Provider value={{ abort, activity, load }}>
            {children}
        </ActivityContext.Provider>
    )
}

/**
 * 3.) Custom Hook. For consuming the shared state in any component within the Provider.
 */
export const useActivity = () => {
    const context = useContext(ActivityContext)

    if (context === undefined) {
        throw new Error(`useActivity must be used within a ActivityProvider.`)
    }

    return context
}

/**
 * 4a.) Use the Provider.
 *
 * <ActivityProvider>
 *     <YourComponent />
 *     <MaybeSomeOtherThing />
 * </ActivityProvider>
 *
 * 4b.) Use the Hook.
 *
 * const YourComponent = (props) => {
 *     const { abort, activity, load } = useActivity()
 *
 *     useEffect(() => {
 *         load()
 *         return abort
 *     }, [])
 *
 *     return <ActivityItems items={activity} />
 * }
 *
 */