actions.js

import { createAction } from 'redux-act'

import { onDatabaseChange } from 'src/pouchdb'
import { filterVisitsByQuery } from 'src/search'
import { ourState } from './selectors'


// == Simple commands to change the state in reducers ==

export const setQuery = createAction('overview/setQuery')
export const setSearchResult = createAction('overview/setSearchResult')
export const showLoadingIndicator = createAction('overview/showLoadingIndicator')
export const hideLoadingIndicator = createAction('overview/hideLoadingIndicator')


// == Actions that trigger other actions ==

// Initialisation
export function init() {
    return function (dispatch, getState) {
        // Perform an initial search to populate the view (empty query = get all docs)
        dispatch(refreshSearch({loadingIndicator:true}))

        // Track database changes, to e.g. trigger search result refresh
        onDatabaseChange(change => dispatch(handlePouchChange({change})))
    }
}

// Search for docs matching the current query, update the results
export function refreshSearch({loadingIndicator=false}) {
    return function (dispatch, getState) {
        const query = ourState(getState()).query
        const oldResult = ourState(getState()).searchResult

        if (loadingIndicator) {
            // Show to the user that search is busy
            dispatch(showLoadingIndicator())
        }

        filterVisitsByQuery({
            query,
            includeContext: true,
        }).then(searchResult => {

            if (loadingIndicator) {
                // Hide our nice loading animation again.
                dispatch(hideLoadingIndicator())
            }

            // First check if the query and result changed in the meantime.
            if (ourState(getState()).query !== query
                && ourState(getState()).searchResult !== oldResult) {
                // The query already changed while we were searching, and the
                // currently displayed result may already be more recent than
                // ours. So we did all that effort for nothing.
                return
            }

            // Set the result to have it displayed to the user.
            dispatch(setSearchResult({searchResult}))
        })
    }
}

// Report a change in the database, to e.g. trigger a search refresh
export const handlePouchChange = createAction('overview/handlePouchChange')