source: imaps-frontend/node_modules/stylis/src/Middleware.js

import {MS, MOZ, WEBKIT, RULESET, KEYFRAMES, DECLARATION} from './Enum.js'
import {match, charat, substr, strlen, sizeof, replace, combine, filter, assign} from './Utility.js'
import {copy, lift, tokenize} from './Tokenizer.js'
import {serialize} from './Serializer.js'
import {prefix} from './Prefixer.js'

/**
 * @param {function[]} collection
 * @return {function}
 */
export function middleware (collection) {
        var length = sizeof(collection)

        return function (element, index, children, callback) {
                var output = ''

                for (var i = 0; i < length; i++)
                        output += collection[i](element, index, children, callback) || ''

                return output
        }
}

/**
 * @param {function} callback
 * @return {function}
 */
export function rulesheet (callback) {
        return function (element) {
                if (!element.root)
                        if (element = element.return)
                                callback(element)
        }
}

/**
 * @param {object} element
 * @param {number} index
 * @param {object[]} children
 * @param {function} callback
 */
export function prefixer (element, index, children, callback) {
        if (element.length > -1)
                if (!element.return)
                        switch (element.type) {
                                case DECLARATION: element.return = prefix(element.value, element.length, children)
                                        return
                                case KEYFRAMES:
                                        return serialize([copy(element, {value: replace(element.value, '@', '@' + WEBKIT)})], callback)
                                case RULESET:
                                        if (element.length)
                                                return combine(children = element.props, function (value) {
                                                        switch (match(value, callback = /(::plac\w+|:read-\w+)/)) {
                                                                // :read-(only|write)
                                                                case ':read-only': case ':read-write':
                                                                        lift(copy(element, {props: [replace(value, /:(read-\w+)/, ':' + MOZ + '$1')]}))
                                                                        lift(copy(element, {props: [value]}))
                                                                        assign(element, {props: filter(children, callback)})
                                                                        break
                                                                // :placeholder
                                                                case '::placeholder':
                                                                        lift(copy(element, {props: [replace(value, /:(plac\w+)/, ':' + WEBKIT + 'input-$1')]}))
                                                                        lift(copy(element, {props: [replace(value, /:(plac\w+)/, ':' + MOZ + '$1')]}))
                                                                        lift(copy(element, {props: [replace(value, /:(plac\w+)/, MS + 'input-$1')]}))
                                                                        lift(copy(element, {props: [value]}))
                                                                        assign(element, {props: filter(children, callback)})
                                                                        break
                                                        }

                                                        return ''
                                                })
                        }
}

/**
 * @param {object} element
 * @param {number} index
 * @param {object[]} children
 */
export function namespace (element) {
        switch (element.type) {
                case RULESET:
                        element.props = element.props.map(function (value) {
                                return combine(tokenize(value), function (value, index, children) {
                                        switch (charat(value, 0)) {
                                                // \f
                                                case 12:
                                                        return substr(value, 1, strlen(value))
                                                // \0 ( + > ~
                                                case 0: case 40: case 43: case 62: case 126:
                                                        return value
                                                // :
                                                case 58:
                                                        if (children[++index] === 'global')
                                                                children[index] = '', children[++index] = '\f' + substr(children[index], index = 1, -1)
                                                // \s
                                                case 32:
                                                        return index === 1 ? '' : value
                                                default:
                                                        switch (index) {
                                                                case 0: element = value
                                                                        return sizeof(children) > 1 ? '' : value
                                                                case index = sizeof(children) - 1: case 2:
                                                                        return index === 2 ? value + element + element : value + element
                                                                default:
                                                                        return value
                                                        }
                                        }
                                })
                        })
        }
}