(function() {

  var Pos = CodeMirror.Pos;

  function forEach(arr, f) {
    for (var i = 0, e = arr.length; i < e; ++i) f(arr[i]);
  }

  function arrayContains(arr, item) {
    if (!Array.prototype.indexOf) {
      var i = arr.length;
      while (i--) {
        if (arr[i] === item) {
          return true;
        }
      }
      return false;
    }
    return arr.indexOf(item) != -1;
  }

  function scriptHint(editor, keywords, getToken, options) {
    // Find the token at the cursor
    var cur = editor.getCursor(),
        token = getToken(editor, cur),
        tprop = token;
    token.state = CodeMirror.innerMode(editor.getMode(), token.state)
        .state;

    // If it's not a 'word-style' token, ignore the token.
    if (!/^[\w$_]*$/.test(token.string)) {
      token = tprop = {
        start: cur.ch,
        end: cur.ch,
        string: "",
        state: token.state,
        type: token.string == "." ? "property" : null
      };
    }
    // If it is a property, find out what it is a property of.
    while (tprop.type == "property") {
      tprop = getToken(editor, Pos(cur.line, tprop.start));
      if (tprop.string != ".") return;
      tprop = getToken(editor, Pos(cur.line, tprop.start));
      if (tprop.string == ')') {
        var level = 1;
        do {
          tprop = getToken(editor, Pos(cur.line, tprop.start));
          switch (tprop.string) {
          case ')':
            level++;
            break;
          case '(':
            level--;
            break;
          default:
            break;
          }
        } while (level > 0);
        tprop = getToken(editor, Pos(cur.line, tprop.start));
        if (tprop.type.indexOf("variable") === 0) tprop.type = "function";
        else return; // no clue
      }
      if (!context) var context = [];
      context.push(tprop);
    }

    return {
      list: getCompletions(token, context, keywords, options),
      from: Pos(cur.line, token.start),
      to: Pos(cur.line, token.end)
    };
  }

  function columnsHint(editor, options) {
    return scriptHint(editor, [], /* javascriptKeywords */
      function(e, cur) {
        return e.getTokenAt(cur);
      },
    options);
  };


  CodeMirror.registerHelper("hint", "custom-list", columnsHint);

  function getCompletions(token, context, keywords, options) {
    var found = [],
        start = token.string;

    function maybeAdd(str) {
      if (str.indexOf(start) == 0 && start != str && !arrayContains(found, str)) found.push(str);
    }

    function gatherCompletions(obj) {
      for (var name in obj) {
        maybeAdd(obj[name]);
      }
    }

    gatherCompletions(options.list);
    forEach(keywords, maybeAdd);

    return found;
  }
})();