hash.js

import { toHash } from './to-hash';
import { update } from './update';
import { astish } from './astish';
import { parse } from './parse';

/**
 * In-memory cache.
 */
let cache = {};

/**
 * Stringifies a object structure
 * @param {Object} data
 * @returns {String}
 */
let stringify = (data) => {
    if (typeof data == 'object') {
        let out = '';
        for (let p in data) out += p + stringify(data[p]);
        return out;
    } else {
        return data;
    }
};

/**
 * Generates the needed className
 * @param {String|Object} compiled
 * @param {Object} sheet StyleSheet target
 * @param {Object} global Global flag
 * @param {Boolean} append Append or not
 * @param {Boolean} keyframes Keyframes mode. The input is the keyframes body that needs to be wrapped.
 * @returns {String}
 */
export let hash = (compiled, sheet, global, append, keyframes) => {
    // Get a string representation of the object or the value that is called 'compiled'
    let stringifiedCompiled = stringify(compiled);

    // Retrieve the className from cache or hash it in place
    let className =
        cache[stringifiedCompiled] || (cache[stringifiedCompiled] = toHash(stringifiedCompiled));

    // add or update
    update(
        (cache[className] =
            cache[className] ||
            // If there's no entry for the current className
            // Parse it
            parse(
                // For keyframes
                keyframes
                    ? // Build the _ast_-ish structure if needed
                      {
                          ['@keyframes ' + className]:
                              stringifiedCompiled !== compiled ? compiled : astish(compiled)
                      }
                    : stringifiedCompiled !== compiled
                    ? compiled
                    : astish(compiled),
                global ? '' : '.' + className
            )),
        sheet,
        append
    );

    // return hash
    return className;
};