'use strict';

const path = require('path');

const declProcessor = require('./lib/decl-processor').declProcessor;

const plugin = (options) => {
    options = options || {};

    return {
        postcssPlugin: 'postcss-url',
        Once(styles, { result }) {
            const promises = [];
            const opts = result.opts;
            const from = opts.from ? path.dirname(opts.from) : '.';
            const to = opts.to ? path.dirname(opts.to) : from;

            styles.walkDecls((decl) =>
                promises.push(declProcessor(from, to, options, result, decl))
            );

            return Promise.all(promises);
        }
    };
};

plugin.postcss = true;

module.exports = plugin;

/**
 * @callback PostcssUrl~UrlProcessor
 * @param {String} from from
 * @param {String} dirname to dirname
 * @param {String} oldUrl url
 * @param {String} to destination
 * @param {Object} options plugin options
 * @param {Object} decl postcss declaration
 * @return {String|undefined} new url or undefined if url is old
 */

/**
 * @typedef {Object} PostcssUrl~HashOptions
 * @property {Function|String} [method=^xxhash32|xxhash64] - hash name or custom function, accepting file content
 * @see https://github.com/pierrec/js-xxhash
 * @property {Number} [shrink=8] - shrink hash string
 */

/**
 * @typedef {Object} Decl - postcss decl
 * @see http://api.postcss.org/Declaration.html
 */

/**
 * @typedef {Object} Result - postcss result
 * @see http://api.postcss.org/Result.html
 */