/* global marked */
var versionCache = {};
var currentVersion;
onmessage = function (e) {
  if (e.data.version === currentVersion) {
    parse(e);
  } else {
    getVersion(e.data.version).then(function (text) {
      // eslint-disable-next-line no-new-func
      Function(text)();
      currentVersion = e.data.version;

      parse(e);
    });
  }
};

onunhandledrejection = function (e) {
  throw e.reason;
};

function parse(e) {
  switch (e.data.task) {
    case 'defaults':
      var defaults = marked.getDefaults();
      defaults.renderer = null;
      postMessage({
        task: e.data.task,
        defaults: defaults
      });
      break;
    case 'parse':
      var startTime = new Date();
      var lexed = marked.lexer(e.data.markdown, e.data.options);
      var lexedList = [];
      for (var i = 0; i < lexed.length; i++) {
        var lexedLine = [];
        for (var j in lexed[i]) {
          lexedLine.push(j + ':' + jsonString(lexed[i][j]));
        }
        lexedList.push('{' + lexedLine.join(', ') + '}');
      }
      var parsed = marked.parser(lexed, e.data.options);
      var endTime = new Date();
      // setTimeout(function () {
      postMessage({
        task: e.data.task,
        lexed: lexedList.join('\n'),
        parsed: parsed,
        time: endTime - startTime
      });
      // }, 10000);
      break;
  }
}

function jsonString(input) {
  var output = (input + '')
    .replace(/\n/g, '\\n')
    .replace(/\r/g, '\\r')
    .replace(/\t/g, '\\t')
    .replace(/\f/g, '\\f')
    .replace(/[\\"']/g, '\\$&')
    .replace(/\u0000/g, '\\0');
  return '"' + output + '"';
};

function getVersion(ver) {
  if (ver in versionCache) {
    return Promise.resolve(versionCache[ver]);
  }

  return fetch(ver)
    .then(function (res) { return res.text(); })
    .then(function (text) {
      versionCache[ver] = text;
      return text;
    });
}