PatLillis/acronym

import words from 'more-words'
import capitalize from 'lodash.capitalize'
import lowercase from 'lodash.lowercase'
import defaults from 'lodash.defaults'


// Dictionary of words
// This is indexed by first letter.
// dictionary.a = [ 'apricots', 'always', ...]
const dictionary = {}


// Helper Functions
const isString = (text) => typeof text === 'string'
const isArray = (text) => text instanceof Array
const getWord = (letter) => (isAlpha(letter) ? (dictionary[letter][Math.floor(Math.random() * dictionary[letter].length)]) : letter)
const isAlpha = (letter) => /^[a-zA-Z]+$/g.test(letter)

// Set up the dictionary of words using word-list
function initialize () {
    const alphabet = 'abcdefghijklmnopqrstuvwxyz'

    // Empty array for each letter
    for (let i = 0; i < alphabet.length; i++)
        dictionary[alphabet.charAt(i)] = []

    // Put all the words into the right spot.
    for (let i = 0; i < words.length; i++)
        dictionary[words[i].charAt(0)].push(words[i])
}


// Main function
function acronym (text, options) {
    var actual = defaults(options || {}, {
        capitalize: true,
        separator: ' '
    })

    if (isString(text)) {
        // Return acronym for this word
        return processWord(text, actual)
    } else if (isArray(text)) {
        // Return acronym for each word in the array.
        return text.map((el) => {
            if (isString(el))
                return processWord(el, actual)
            else
                return undefined
        })
    } else {
        // ???
        return undefined
    }
}


function processWord (text, options) {
    // Split word into array of characters
    let arr = text.split('')

    // Transform each character into a whole word
    arr = arr.map((letter) => getWord(letter.toLowerCase()))

    // Correctly capitalize
    if (options.capitalize)
        arr = arr.map((word) => isAlpha(word) ? capitalize(word) : word)
    else
        arr = arr.map((word) => isAlpha(word) ? lowercase(word) : word)

    // Re-join using separator, but only join adjacent words.
    // Otherwise, spit out cahracters verbatim
    let result = ''

    for (let i = 0; i < arr.length; i++) {
        result += arr[i]

        // Add separator?
        if (i !== arr.length - 1 && (isAlpha(arr[i]) || isAlpha(arr[i + 1])))
            result += options.separator
    }

    return result
}


// Exports
initialize()
export default acronym