github.com.js

(function() {
  // Config
  var weeks = 52;
  var beginningOfWeek = 1; // 0:Sun, 1:Mon, 2:Tue, 3:Wed, 4:Thu, 5:Fri, 6:Sat


  // Functions

  function formatDate(date) {
    return [date.getFullYear().toString(), ('0' + (date.getMonth() + 1)).slice(-2), ('0' + date.getDate()).slice(-2)].join("-");
  }

  function getCurrentSearchQuery() {
    return $("#js-issues-search")[0].value.trim().split(" ").map(function(elm){ return elm.split(":") });
  }

  function buildSearchQuery(query) {
    return query.map(function(elm){ return encodeURIComponent(elm.join(":")) }).join("+");
  }

  function addSearchQuery(query, type, dateRange) {
    // Remove existing week query
    for(i = query.length - 1 ; i >= 0 ; i--){
      if(query[i][0] == type) query.splice(i,1);
    }

    // Remove is:open query if closed filter applied
    if (type == "closed") {
      for(i = query.length - 1 ; i >= 0 ; i--){
        if(query[i][1] == "open") query.splice(i,1);
      }
    }

    if (dateRange) query.push([type, dateRange]);
    return query;
  }

  function getLatestBeginningDateOfWeek(dayOfWeek, date) {
    var d = date || new Date();
    d.setDate(d.getDate() - (d.getDay() - dayOfWeek));
    return d;
  }

  function dateToWeek(date) {
    var first = new Date(date.getTime());
    var last = new Date(date.getTime());
    last.setDate(last.getDate() + 6);
    return formatDate(first) + ".." + formatDate(last);
  }

  function buildPath(newQuery) {
    var currentQuery = window.location.search.substr(1).split("&").map(function(e){ return e.split("=") });
    var queryObject = {};

    for(i = 0 ; i < currentQuery.length ; i++) {
      queryObject[currentQuery[i][0]] = currentQuery[i][1]
    }
    queryObject["q"] = buildSearchQuery(newQuery);

    return window.location.pathname + "?" + Object.keys(queryObject).map(function(key){ return [key, queryObject[key]].join("=") }).join("&");
  }

  function buildFilterElementList(dates, type) {
    return "<div class=\"select-menu-list\" role=\"menu\"><div>" + dates.map(function(date){ return buildFilterElement(date, type) }).join("") + "</div></div>";
  }

  function buildFilterElement(date, type) {
    var currentQuery = getCurrentSearchQuery();
    var week = dateToWeek(date)
      var isCurrentQuery = false;

    for (i = 0 ; i < currentQuery.length ; i++) {
      if (currentQuery[i][0] == type && currentQuery[i][1] == week) isCurrentQuery = true;
    }

    if (isCurrentQuery) {
      return "<a href=\"" + buildPath(addSearchQuery(currentQuery, type, null)) + "\" class=\"select-menu-item js-navigation-item js-navigation-open selected \" role=\"menuitem\"><span class=\"select-menu-item-icon octicon octicon-check\"></span><div class=\"select-menu-item-text\">" + week+ "</div></a>";
    } else {
      return "<a href=\"" + buildPath(addSearchQuery(currentQuery, type, week)) + "\" class=\"select-menu-item js-navigation-item js-navigation-open \" role=\"menuitem\"><span class=\"select-menu-item-icon octicon octicon-check\"></span><div class=\"select-menu-item-text\">" + week+ "</div></a>";
    }
  }

  function prependWeekFilter(type) {
    var elementId = ["week", type, "filter"].join("-");
    if ($("#" + elementId).length == 0) {
      $(".table-list-header-toggle.right").prepend("<div id=\"" + elementId + "\" class=\"left select-menu js-menu-container js-select-menu\"><span class=\"btn-link select-menu-button icon-only js-menu-target\" role=\"button\" aria-haspopup=\"true\">" + type.charAt(0).toUpperCase() + type.slice(1) + " at <span class=\"sort-label\"></span></span><div class=\"select-menu-modal-holder js-menu-content js-navigation-container\" aria-hidden=\"true\"><div class=\"select-menu-modal\"><div class=\"select-menu-header\"><span class=\"select-menu-title\">Filter by " + type + " at</span><span class=\"octicon octicon-x js-menu-close\" role=\"button\" aria-label=\"Close\"></span></div>" + buildFilterElementList(beginningDates, type) + "</div></div></div>");
    }
  }

  function prependWeekFilters() {
    if ($(".table-list-header-toggle.right").length > 0) {
      prependWeekFilter("closed");
      prependWeekFilter("created");
    }
  }


  // Main

  var latestBeginningDate = getLatestBeginningDateOfWeek(beginningOfWeek);
  var beginningDates = [];

  for(i = 0 ; i <= weeks ; i ++) {
    var beginningDate = new Date(latestBeginningDate.getTime());
    beginningDate.setDate(latestBeginningDate.getDate() - 7 * i);
    beginningDates.push(beginningDate);
  }

  setInterval(prependWeekFilters, 500); //Fix
})();