// Released under the MIT/X11 license
// http://www.opensource.org/licenses/mit-license.php
"use strict";

(function createRelationElements() {
  var relation = {};
  var linkLabels = ["First", "Last", "Prev", "Next"];
  var labelToRelation = {
    "First": {
      rel: "start"
    },
    "Last": {
      rel: "last"
    },
    "Prev": {
      rel: "prev"
    },
    "Next": {
      rel: "next"
    }
  };

  function createLinkRel (rel, href) {
    var newLinkElement = document.createElement("link");
    newLinkElement.setAttribute("rel", rel);
    newLinkElement.setAttribute("href", href);
    document.getElementsByTagName("head")[0].
      appendChild(newLinkElement);
  }

  var aNavigElements = document.querySelectorAll("#bugzilla-body .navigation a");
  Array.forEach(aNavigElements, function(elem) {
      var labelText = elem.textContent.trim();
      if (isInList(labelText, linkLabels)) {
        labelToRelation[labelText].href = elem.getAttribute("href");
      };
  });
  console.myDebug("labelToRelation = " + labelToRelation.toSource());

  for (var key in labelToRelation) {
    if (labelToRelation.hasOwnProperty(key)) {
      relation = labelToRelation[key];
      if (relation.href) {
        createLinkRel(relation.rel, relation.href);
      }
    }
  }
})();