"use strict";

const $ = require("jquery");

function parse() {
    var vars = {},
        hash;
    var q = document.URL.split("?")[1];
    if (q !== undefined) {
        q = q.split("&");
        for (var i = 0; i < q.length; i++) {
            hash = q[i].split("=");
            vars[hash[0]] = hash.slice(1).join("=");
        }
    }
    return vars;
}

function update(key, value) {
    /* https://gist.github.com/excalq/2961415 */
    var baseUrl = [ location.protocol, "//", location.host, location.pathname ].join(""),
        urlQueryString = document.location.search,
        newParam = key + "=" + value,
        params = "?" + newParam;

    // If the "search" string exists, then build params from it
    if (urlQueryString) {
        var keyRegex = new RegExp("([?&])" + key + "[^&]*");

        // If param exists already, update it
        if (urlQueryString.match(keyRegex) !== null) {
            params = urlQueryString.replace(keyRegex, "$1" + newParam);
        } else { // Otherwise, add it to end of query string
            params = urlQueryString + "&" + newParam;
        }
    }
    window.history.replaceState({}, "", baseUrl + params);
}

function remove(key) {
    var baseUrl = [ location.protocol, "//", location.host, location.pathname ].join(""),
        q = parse();
    if (q[key] !== undefined) {
        delete q[key];
        window.history.replaceState({}, "", baseUrl + "?" + $.param(q));
    }
}

exports.parse = parse;
exports.update = update;
exports.remove = remove;