$(document).ready(function() {
  const apiRoot = 'https://shrouded-brook-81622.herokuapp.com/v1/';
  const trelloApiRoot = 'https://shrouded-brook-81622.herokuapp.com/v1/trello/';
  const datatableRowTemplate = $('[data-datatable-row-template]').children()[0];
  const $tasksContainer = $('[data-tasks-container]');

  var availableBoards = {};
  var availableTasks = {};

  // init

  getAllTasks();

  function getAllAvailableBoards(callback, callbackArgs) {
    var requestUrl = trelloApiRoot + 'boards';

    $.ajax({
      url: requestUrl,
      method: 'GET',
      contentType: 'application/json',
      success: function(boards) { callback(callbackArgs, boards); }
    });
  }

  function createElement(data) {
    const element = $(datatableRowTemplate).clone();

    element.attr('data-task-id', data.id);
    element.find('[data-task-name-section] [data-task-name-paragraph]').text(data.title);
    element.find('[data-task-name-section] [data-task-name-input]').val(data.title);

    element.find('[data-task-content-section] [data-task-content-paragraph]').text(data.content);
    element.find('[data-task-content-section] [data-task-content-input]').val(data.content);

    return element;
  }

  function prepareBoardOrListSelectOptions(availableChoices) {
    return availableChoices.map(function(choice) {
      return $('<option>')
                .addClass('crud-select__option')
                .val(choice.id)
                .text(choice.name || 'Unknown name');
    });
  }

  function handleDatatableRender(taskData, boards) {
    $tasksContainer.empty();
    boards.forEach(board => {
      availableBoards[board.id] = board;
    });

    taskData.forEach(function(task) {
      var $datatableRowEl = createElement(task);
      var $availableBoardsOptionElements = prepareBoardOrListSelectOptions(boards);

      $datatableRowEl.find('[data-board-name-select]')
        .append($availableBoardsOptionElements);

      $datatableRowEl
        .appendTo($tasksContainer);
    });
  }

  function getAllTasks() {
    const requestUrl = apiRoot + 'tasks';

    $.ajax({
      url: requestUrl,
      method: 'GET',
      contentType: "application/json",
      success: function(tasks) {
        tasks.forEach(task => {
          availableTasks[task.id] = task;
        });

        getAllAvailableBoards(handleDatatableRender, tasks);
      }
    });
  }

  function handleTaskUpdateRequest() {
    var parentEl = $(this).parents('[data-task-id]');
    var taskId = parentEl.attr('data-task-id');
    var taskTitle = parentEl.find('[data-task-name-input]').val();
    var taskContent = parentEl.find('[data-task-content-input]').val();
    var requestUrl = apiRoot + 'tasks';

    $.ajax({
      url: requestUrl,
      method: "PUT",
      processData: false,
      contentType: "application/json; charset=utf-8",
      dataType: 'json',
      data: JSON.stringify({
        id: taskId,
        title: taskTitle,
        content: taskContent
      }),
      success: function(data) {
        parentEl.attr('data-task-id', data.id).toggleClass('datatable__row--editing');
        parentEl.find('[data-task-name-paragraph]').text(taskTitle);
        parentEl.find('[data-task-content-paragraph]').text(taskContent);
      }
    });
  }

  function handleTaskDeleteRequest() {
    var parentEl = $(this).parents('[data-task-id]');
    var taskId = parentEl.attr('data-task-id');
    var requestUrl = apiRoot + 'tasks';

    $.ajax({
      url: requestUrl + '/' + taskId
      ,
      method: 'DELETE',
      success: function() {
        parentEl.slideUp(400, function() { parentEl.remove(); });
      }
    })
  }

  function handleTaskSubmitRequest(event) {
    event.preventDefault();

    var taskTitle = $(this).find('[name="title"]').val();
    var taskContent = $(this).find('[name="content"]').val();

    var requestUrl = apiRoot + 'tasks';

    $.ajax({
      url: requestUrl,
      method: 'POST',
      processData: false,
      contentType: "application/json; charset=utf-8",
      dataType: 'json',
      data: JSON.stringify({
        title: taskTitle,
        content: taskContent
      }),
      success: getAllTasks
    });
  }

  function toggleEditingState() {
    var parentEl = $(this).parents('[data-task-id]');
    parentEl.toggleClass('datatable__row--editing');

    var taskTitle = parentEl.find('[data-task-name-paragraph]').text();
    var taskContent = parentEl.find('[data-task-content-paragraph]').text();

    parentEl.find('[data-task-name-input]').val(taskTitle);
    parentEl.find('[data-task-content-input]').val(taskContent);
  }

  function handleBoardNameSelect(event) {
    var $changedSelectEl = $(event.target);
    var selectedBoardId = $changedSelectEl.val();
    var $listNameSelectEl = $changedSelectEl.siblings('[data-list-name-select]');
    var preparedListOptions = prepareBoardOrListSelectOptions(availableBoards[selectedBoardId].lists);

    $listNameSelectEl.empty().append(preparedListOptions);
  }

  function handleCardCreationRequest(event) {
    var requestUrl = trelloApiRoot + 'cards';
    var $relatedTaskRow = $(event.target).parents('[data-task-id]');
    var relatedTaskId = $relatedTaskRow.attr('data-task-id');
    var relatedTask = availableTasks[relatedTaskId];
    var selectedListId = $relatedTaskRow.find('[data-list-name-select]').val();

    if (!selectedListId) {
      alert('You have to select a board and a list first!');
      return;
    }

    $.ajax({
      url: requestUrl,
      method: 'POST',
      processData: false,
      contentType: "application/json; charset=utf-8",
      dataType: 'json',
      data: JSON.stringify({
        name: relatedTask.title,
        description: relatedTask.content,
        listId: selectedListId
      }),
      success: function(data) {
        console.log('Card created - ' + data.shortUrl);
        alert('Card created - ' + data.shortUrl);
      }
    });
  }

  $('[data-task-add-form]').on('submit', handleTaskSubmitRequest);

  $tasksContainer.on('change','[data-board-name-select]', handleBoardNameSelect);
  $tasksContainer.on('click','[data-trello-card-creation-trigger]', handleCardCreationRequest);
  $tasksContainer.on('click','[data-task-edit-button]', toggleEditingState);
  $tasksContainer.on('click','[data-task-edit-abort-button]', toggleEditingState);
  $tasksContainer.on('click','[data-task-submit-update-button]', handleTaskUpdateRequest);
  $tasksContainer.on('click','[data-task-delete-button]', handleTaskDeleteRequest);
});