rung-tools / rung-cli

import dasherize from 'dasherize';

import {

    __,

    contains,

    equals,

    ifElse,

    join,

    map,

    toPairs,

    type,

    unary,

    when

} from 'ramda';

import { transform } from 'babel-core';

/**

 * Generates CSS string from an object

 *

 * @param {Object} obj

 * @return {String}

 */

const compileCSS = toPairs

    & map(([key, value]) => `${dasherize(key)}:${value}`)

    & join(';')

    & JSON.stringify;

/**

 * Generates HTML string for element properties

 *

 * @param {Object} props

 * @return {String}

 */

function compileProps(props) {

    const transformKey = when(equals('className'), ~'class');

    const transformValue = ifElse(type & equals('Object'),

        compileCSS, unary(JSON.stringify));

    const result = props

        | toPairs

        | map(([key, value]) => `${transformKey(key)}=${transformValue(value)}`)

        | join(' ');

    return result.length === 0 ? '' : ` ${result}`;

}

/**

 * Compiles a self-closing tag, dealing with elements that may or not be

 * self-closing

 *

 * @param {String} tag - JSX component name

 * @param {Object} props - Element properties

 */

function compileSelfClosingTag(tag, props) {

    const compiledProps = compileProps(props);

    return contains(tag, ['br', 'hr', 'img'])

        ? `<${tag}${compiledProps} />`

        : `<${tag}${compiledProps}></${tag}>`;

}

/**

 * Generates HTML source code directly from JSX

 *

 * @param {String} tag - JSX component name

 * @param {Object} props - Element properties

 * @param {Array} children - Items to append to inner component

 * @return {String}

 */

export function compileHTML(tag, props, ...children) {

    const filteredTag = tag | when(contains(__, ['style', 'script']), ~'span');

    const render = when(type & equals('Array'), join(''));

    return children.length === 0

        ? compileSelfClosingTag(filteredTag, props)

        : `<${filteredTag}${compileProps(props)}>${children.map(render).join('')}</${filteredTag}>`;

}

/**

 * Precompiles ES6 source to ES5 in order to keep retrocompatibily

 *

 * @author Marcelo Haskell Camargo

 * @param {String} source

 * @return {Promise}

 */

export function compileES6(source) {

    const result = transform(source, {

        comments: false,

        compact: true,

        presets: ['es2015', 'react'],

        plugins: [

            ['transform-react-jsx', { pragma: '__render__' }]

        ]

    });

    return result.code;

}