Notify train accident to Slack using Google Apps Script

slack-train-notify.gs

// GAS Script for train daemon on Slack

// ScriptProperties:
// - trainUrl: JR line information web page URL
// - trainName: Name of JR line
// - slackHookUrl: Slack web hook URL
// - slackChannel: Channel name of Slack

function trainRetrieve() {
  var url = PropertiesService.getScriptProperties().getProperty("trainUrl");
  var res = UrlFetchApp.fetch(url);
  var content = res.getContentText();

  // get train text
  var name = PropertiesService.getScriptProperties().getProperty("trainName");
  var index = content.indexOf(name);
  if (index < 0) {
    return;
  }
  var point = content.substring(index);
  // search second </tr>
  index = point.indexOf("</tr>");
  index = point.indexOf("</tr>", index + 5);
  point = point.substring(0, index);
  index = point.search(/class="cause">/);
  if (index < 0) {
    // no problem
    return;
  }
  var cause = point.substring(index + 14);
  cause = cause.substring(0, cause.indexOf("</"));
  var t = point.substring(point.indexOf("time02") + 8);
  t = t.substring(0, t.indexOf("</"));

  var notify = false;
  if (cause && !(cause == "&nbsp;")) {
    notify = true;
    Logger.log(cause);
  }
  if (notify) {
    sendNotify(cause + " (<" + url + "|" + t + ">)");
  }
}

function sendNotify(text) {
  var channel = PropertiesService.getScriptProperties().getProperty("slackChannel");
  var url = PropertiesService.getScriptProperties().getProperty("slackHookUrl");
  var payload = {"channel": "#" + channel, "username": "train daemon", "text": text};
  var params = {"method": "POST", "payload": JSON.stringify(payload)};
  var res = UrlFetchApp.fetch(url, params);
  Logger.log(text);
  if (res) {
    return true;
  } else {
    return false;
  }
}