function log(msg) {
  console.log("[Bahn Insight] " + msg);
}

function getMediaURL(path) {
  path = "media/" + path;
  return chrome.runtime.getURL(path) || browser.runtime.getURL(path);
}

/**
  * Return train name in format "PRODUCT TRAIN_NUMER"
  * i.e. "ICE 112", "RE 12734"
  * Sometimes train name is in format "PRODUCT LINE_NUMER (TRAIN_NUMER)"
  * i.e. "STB 12 (62371)"
  * Sometimes 'trains' are not trains or we can't find an unique id for them
  * i.e. busses, ferrys, trams
  * they will also be cleaned up and returned as undefined, because we can't link to them correctly
  */
function bahnParseTrainName(dirty_train_name) {
  var name_list = dirty_train_name.trim().replace(/  +/g, ' ').split(" ");

  // Train name in format "STB 12 (23561)"
  if(name_list.length == 3 && name_list[2].charAt(0) == '(' && name_list[2].charAt(name_list[2].length-1) == ')') {
    return name_list[0] + " " + name_list[2].substring(1, name_list[2].length-1);
  }

  // Exclude linking to specific products
  if(["bus", "fäh", "str"].indexOf(name_list[0].toLowerCase()) !== -1) {
    return undefined;
  }

  return dirty_train_name;
}

function domCreateLink(href) {
  var link = document.createElement("a");
  link.setAttribute("href", href);
  return link;
}

function domCreateImage(src) {
  var image = document.createElement("img");
  image.setAttribute("src", src);
  return image;
}

function domCreateLinebreak() {
  var linebreak = document.createElement("br");
  return linebreak;
}

function domCreateButton(href, image_src) {
  var link = domCreateLink(href);
  link.setAttribute("target", "_blank");
  var image = domCreateImage(image_src);
  image.setAttribute("style", "height: 2em; vertical-align:middle;")
  link.append(image);
  return link;
}

function domCreateButtonMarudor(path) {
  var button = domCreateButton("https://marudor.de" + path, getMediaURL("marudor.svg"));
  return button;
}

var connection_result_observer = new MutationObserver((mutations) => {
  mutations.forEach((mutation) => {
    if (mutation.type === 'childList') {
      var target = mutation.target;
      if (target.tagName === 'TD') {
        var timetable = target.querySelector("td div.detailContainer table.result tbody");

        var trains = timetable.querySelectorAll("tr.first td.products");
        trains.forEach((train) => {
          var train_names = train.querySelectorAll("span a");
          train_names.forEach((train_name) => {
            train_name_text = bahnParseTrainName(train_name.innerText);
            if(typeof train_name_text !== 'undefined') {
              var marudor_button = domCreateButtonMarudor("/details/" + train_name_text);
              train_name.after(marudor_button);

              // Move linebreaks from link inner, after our button
              linebreaks = train_name.querySelectorAll("br");
              if(linebreaks.length != 0) {
                linebreaks.forEach((linebreak) => {
                  train_name.removeChild(linebreak);
                });

                marudor_button.after(domCreateLinebreak());
              }
              
            }
          });
        });

        var stations = timetable.querySelectorAll("tr td.station");
        stations.forEach((station) => {
          var station_name = station.innerText;
          var marudor_button = domCreateButtonMarudor("/" + station_name);
          station.append(marudor_button);
        });

      }
    }
  });
});


var target = document.getElementById('resultsOverview');

if(typeof target !== 'undefined') {
  connection_result_observer.observe(target, {
    subtree: true,
    childList: true
  });
}