/*
USAGE
?action=create
&name=Form Name
&choices=choice 1,choice 2,choice 3

?action=get
&formId=<formId>
*/

function doGet(request) {
  var result = execute(request.parameters);
  var response = JSON.stringify(result);
  return ContentService.createTextOutput().setContent(response).setMimeType(ContentService.MimeType.JSON);
}

function execute(params) {
  var action = params.action || "view";
  var formId = params.formId || null;
  var name  = params.name || "Default Name";
  var choices = (params.choices || "Default Choice 1,Default Choice 2").split(",");

  if (action != "create") {
    return getResponses(formId);
  }

  var form;
  if (formId == null) {
    form = FormApp.create(name);
  } else {
    form = FormApp.openById(formId);
  }

  clearForm(form);
  initForm(form, name);
  createForm(form, choices);
  return {
    "form_url": form.getPublishedUrl(),
    "form_id": form.getId()
  };
}

function getResponses(formId) {
  if (formId == null) {
    return {};
  }
  var form = FormApp.openById(formId);

  var responses = {};

  var formResponses = form.getResponses();
  for (var i = 0; i < formResponses.length; i++) {
    var formResponse = formResponses[i];
    var itemResponses = formResponse.getItemResponses();

    responses[itemResponses[0].getResponse()] = itemResponses[1].getResponse();
  }

  return responses;
}

function createForm(form, choices) {
  var choiceNum = Math.ceil(choices.length / 3);

  form.addTextItem()
  .setTitle("Discord tag")
  .setValidation(FormApp.createTextValidation()
                 .requireTextMatchesPattern(".{3,16}[\#][0-9]{4,5}")
                 .setHelpText("Invalid Discord Tag")
                 .build())
  .setHelpText("Use your full tag, for example: Jarvis#6352.\nIf you do not, your vote will be counted as invalid.")
  .setRequired(true);

  form.addCheckboxItem()
  .setTitle("Choose users you would like to vote for")
  .setValidation(FormApp.createCheckboxValidation()
                 .requireSelectExactly(choiceNum)
                .setHelpText("Choose " + choiceNum + " applicants")
                .build())
  .setChoiceValues(choices)
  .setRequired(true);
}

function initForm(form, title) {
  form.setTitle(title);
  form.setDescription("Generated at " + new Date());
  form.addEditors(["willsr71@gmail.com", "AltoidGuy2000@gmail.com", "hamockingjay@gmail.com"]);
  form.setAllowResponseEdits(true);
  form.setAcceptingResponses(true);
}

function clearForm(form) {
  form.deleteAllResponses();
  form.getItems().forEach(function(item) {
    form.deleteItem(item);
  });
  form.getEditors().forEach(function(user){
    form.removeEditor(user);
  });
}