function testNewItemPost() {
  var request = {
    parameters: {
      token: "[]",
      user_name: "michelle",
      text: "add: Rural America; Hillbilly Elegy; J.D. Vance; From a former marine and Yale Law School graduate, a powerful account of growing up in a poor Rust Belt town that offers a broader, probing look at the struggles of America’s white working class; https://www.amazon.com/gp/product/0062300547/ref=pd_bxgy_14_2?ie=UTF8&pd_rd_i=0062300547&pd_rd_r=MG2AV2PZZVEXNYZ1Y84V&pd_rd_w=xCKNl&pd_rd_wg=55Iya&psc=1&refRID=MG2AV2PZZVEXNYZ1Y84V;"
    }
  };
  doPost(request);
}

function testListTopics() {
  var request = {
    parameters: {
      token: "[]",
      user_name: "michelle",
      text: "List topics"
    }
  };
  doPost(request);
}

function doPost(request) {
  Logger.log("request" + request.parameters.text);
  
  var params = request.parameters;

  // Make sure that the request came from our slack integration.
  if (params.token == "[]") {
    
    // Get the spreadsheet
    var sheets = SpreadsheetApp.openById('[]');

    // Check command name. If it starts with add, then add to sheet, if it's list topics, then respond with list of topics.
    var text = String(params.text);
    if (text.match(/^add:/i)) {
      addNewItemToSheet(sheets, params);
    } else if (text.match(/^list topics/i)) {
      listSheetNames(sheets, params.channel_name)
    }
    
  // If the token does not match then do nothing
  } else {
    return;
  }
}
  
function addNewItemToSheet(sheets, params) {
  // PROCESS TEXT FROM MESSAGE
  var textRaw = String(params.text).replace(/^\s*add\s*:*\s*/gi,'');
  var text = textRaw.split(/\s*;\s*/g);

  // FALL BACK TO DEFAULT TEXT IF NO UPDATE PROVIDED
  var sheetName   = text[0] || "";
  var title       = text[1] || "";
  var author      = text[2] || "";
  var description = text[3] || "";
  var link        = (text[4] || "").replace("<", "");
    
  var sheet = sheets.getSheetByName(sheetName)
  var nR = getNextRow(sheet) + 1;

  // RECORD USER NAME IN SPREADSHEET
  sheet.getRange('E:E').getCell(nR,1).setValue(params.user_name);

  // RECORD UPDATE INFORMATION INTO SPREADSHEET
  sheet.getRange('A:A').getCell(nR,1).setValue(title);
  sheet.getRange('B:B').getCell(nR,1).setValue(author);
  sheet.getRange('C:C').getCell(nR,1).setValue(description);
  sheet.getRange('D:D').getCell(nR,1).setValue('=HYPERLINK("' + link + '", "Link")');

  var channel = "reading-list";

  postResponse(channel,params.user_name, sheetName, title, author, description, link);    
}

function listSheetNames(sheets, channelName) {
  var sheetNames = sheets.getSheets().map(function(sheet) { return sheet.getName() });
  postTopicNamesResponse(channelName, sheetNames.slice(1));
}

function getNextRow(sheet) {
  var timestamps = sheet.getRange("A:A").getValues();
  for (i in timestamps) {
    if(timestamps[i][0] == "") {
      return Number(i);
      break;
    }
  }
}