"use-strict";

const objSerialize = (obj, keys, cb) => {
    let a = Object.create(null)
    for (const key of keys)
        a[key] = obj[key]
    if (cb)
        return cb(a, obj)
    return a
}

const objBulkSet = (obj, target, pairs) => {
    if (typeof obj[target] != "object")
        obj[target] = Object.create(null)
    for (const key in pairs)
        if (pairs[key] != undefined)
            obj[target][key] = pairs[key]
}

const fromConstToPascal = string => {
    let a = ''
    let b = true
    for (const char of string)
        if (char == '_')
            b = true
        else {
            a += b ? char : char.toLowerCase()
            b = false
        }
    return a
}

const notNullElse = (a, fallback) => a != null && a != undefined ? a : fallback

const arrSerializeSort = array => array.filter(Boolean).map((a,i) => a.serialize(i)).sort((a,b) => a.id.localeCompare(b.id))

const SCHEMA_VERSION = 8
const toRadioSongs = songs => ({
    "version": SCHEMA_VERSION,
    songs
})

module.exports = {
    SCHEMA_VERSION,
    objSerialize,
    objBulkSet,
    arrSerializeSort,
    fromConstToPascal,
    notNullElse,
    toRadioSongs
}