/**
 * @file
 * Attaches the behaviors for the Field UI module.
 */

(function($) {

Backdrop.behaviors.fieldUIFieldOverview = {
  attach: function (context, settings) {
    $('table#field-overview', context).once('field-overview', function () {
      Backdrop.fieldUIFieldOverview.attachUpdateSelects(this, settings);
    });
  }
};

Backdrop.fieldUIFieldOverview = {
  /**
   * Implements dependent select dropdowns on the 'Manage fields' screen.
   */
  attachUpdateSelects: function(table, settings) {
    var widgetTypes = settings.fieldWidgetTypes;
    var fields = settings.fields;
    var fieldInfo = settings.fieldInfo;
    // Store the default text of widget selects.
    $('.widget-type-select', table).each(function () {
      this.initialValue = this.options[0].text;
    });

    // 'Field type' select updates its 'Widget' select.
    $('.field-type-select', table).each(function () {
      this.targetSelect = $('.widget-type-select', $(this).closest('tr'));

      $(this).bind('change keyup', function () {
        var selectedFieldType = this.options[this.selectedIndex].value;
        var options = (selectedFieldType in widgetTypes ? widgetTypes[selectedFieldType] : []);
        var widgetDefault = null;
        if (typeof selectedFieldType !== 'undefined' && selectedFieldType !== '' && selectedFieldType !== null ) {
          widgetDefault = fieldInfo[selectedFieldType]['defaultWidget'];
        }
        this.targetSelect.fieldUIPopulateOptions(options, null, widgetDefault);
      });

      // Trigger change on initial pageload to get the right widget options
      // when field type comes pre-selected (on failed validation).
      $(this).trigger('change', false);
    });

    // 'Existing field' select updates its 'Widget' select and 'Label' textfield.
    $('.field-select', table).each(function () {
      this.targetSelect = $('.widget-type-select', $(this).closest('tr'));
      this.targetTextfield = $('.label-textfield', $(this).closest('tr'));
      this.targetTextfield
        .data('field_ui_edited', false)
        .bind('keyup', function (e) {
          $(this).data('field_ui_edited', $(this).val() != '');
        });

      $(this).bind('change keyup', function (e, updateText) {
        updateText = (typeof updateText === 'undefined' ? true : updateText);
        var selectedField = this.options[this.selectedIndex].value;
        var selectedFieldType = (selectedField in fields ? fields[selectedField].type : null);
        var selectedFieldWidget = (selectedField in fields ? fields[selectedField].widget : null);
        var options = (selectedFieldType && (selectedFieldType in widgetTypes) ? widgetTypes[selectedFieldType] : []);
        var widgetDefault = null;
        if (typeof selectedFieldType !== 'undefined' && selectedFieldType !== '' && selectedFieldType !== null ) {
          widgetDefault = fieldInfo[selectedFieldType]['defaultWidget'];
        }

        this.targetSelect.fieldUIPopulateOptions(options, selectedFieldWidget, widgetDefault);

        // Only overwrite the "Label" input if it has not been manually
        // changed, or if it is empty.
        if (updateText && !this.targetTextfield.data('field_ui_edited')) {
          this.targetTextfield.val(selectedField in fields ? fields[selectedField].label : '');
        }
      });

      // Trigger change on initial pageload to get the right widget options
      // and label when field type comes pre-selected (on failed validation).
      $(this).trigger('change', false);
    });
  }
};

/**
 * Populates options in a select input.
 */
jQuery.fn.fieldUIPopulateOptions = function (options, selected, widgetDefault) {
  return this.each(function () {
    var disabled = false;
    if (options.length == 0) {
      options = [this.initialValue];
      disabled = true;
    }
    // If possible, keep the same widget selected when changing field type.
    // This is based on textual value, since the internal value might be
    // different (options_buttons vs. node_reference_buttons).
    var previousSelectedText = this.options[this.selectedIndex].text;

    var html = '';
    jQuery.each(options, function (value, text) {
      // Figure out which value should be selected. The 'selected' param
      // takes precedence.
      var is_selected = (
        (typeof selected != 'undefined' && value == selected) ||
        (typeof selected == 'undefined' && text == previousSelectedText) ||
        (typeof selected == 'undefined' && value == widgetDefault)
      );
      html += '<option value="' + value + '"' + (is_selected ? ' selected="selected"' : '') + '>' + text + '</option>';
    });

    $(this).html(html).prop('disabled', disabled);
  });
};

Backdrop.behaviors.fieldUIDisplayOverview = {
  attach: function (context, settings) {
    $('table#field-display-overview', context).once('field-display-overview', function() {
      Backdrop.fieldUIOverview.attach(this, settings.fieldUIRowsData, Backdrop.fieldUIDisplayOverview);
    });
  }
};

Backdrop.fieldUIOverview = {
  /**
   * Attaches the fieldUIOverview behavior.
   */
  attach: function (table, rowsData, rowHandlers) {
    var tableDrag = Backdrop.tableDrag[table.id];

    // Add custom tabledrag callbacks.
    tableDrag.onDrop = this.onDrop;
    tableDrag.row.prototype.onSwap = this.onSwap;

    // Create row handlers.
    $('tr.draggable', table).each(function () {
      // Extract server-side data for the row.
      var row = this;
      if (row.id in rowsData) {
        var data = rowsData[row.id];
        data.tableDrag = tableDrag;

        // Create the row handler, make it accessible from the DOM row element.
        var rowHandler = new rowHandlers[data.rowHandler](row, data);
        $(row).data('fieldUIRowHandler', rowHandler);
      }
    });
  },

  /**
   * Event handler to be attached to form inputs triggering a region change.
   */
  onChange: function () {
    var $trigger = $(this);
    var row = $trigger.closest('tr').get(0);
    var rowHandler = $(row).data('fieldUIRowHandler');

    var refreshRows = {};
    refreshRows[rowHandler.name] = $trigger.get(0);

    // Handle region change.
    var region = rowHandler.getRegion();
    if (region != rowHandler.region) {
      // Remove parenting.
      $('select.field-parent', row).val('');
      // Let the row handler deal with the region change.
      $.extend(refreshRows, rowHandler.regionChange(region));
      // Update the row region.
      rowHandler.region = region;
    }

    // Ajax-update the rows.
    Backdrop.fieldUIOverview.AJAXRefreshRows(refreshRows);
  },

  /**
   * Lets row handlers react when a row is dropped into a new region.
   */
  onDrop: function () {
    var dragObject = this;
    var row = dragObject.rowObject.element;
    var rowHandler = $(row).data('fieldUIRowHandler');
    if (typeof rowHandler !== 'undefined') {
      var regionRow = $(row).prevAll('tr.region-message').get(0);
      var region = regionRow.className.replace(/([^ ]+[ ]+)*region-([^ ]+)-message([ ]+[^ ]+)*/, '$2');

      if (region != rowHandler.region) {
        // Let the row handler deal with the region change.
        refreshRows = rowHandler.regionChange(region);
        // Update the row region.
        rowHandler.region = region;
        // Ajax-update the rows.
        Backdrop.fieldUIOverview.AJAXRefreshRows(refreshRows);
      }
    }
  },

  /**
   * Refreshes placeholder rows in empty regions while a row is being dragged.
   *
   * Copied from block.js.
   *
   * @param table
   *   The table DOM element.
   * @param rowObject
   *   The tableDrag rowObject for the row being dragged.
   */
  onSwap: function (draggedRow) {
    var rowObject = this;
    $('tr.region-message', rowObject.table).each(function () {
      // If the dragged row is in this region, but above the message row, swap
      // it down one space.
      if ($(this).prev('tr').get(0) == rowObject.group[rowObject.group.length - 1]) {
        // Prevent a recursion problem when using the keyboard to move rows up.
        if ((rowObject.method != 'keyboard' || rowObject.direction == 'down')) {
          rowObject.swap('after', this);
        }
      }
      // This region has become empty.
      if ($(this).next('tr').is(':not(.draggable)') || $(this).next('tr').length == 0) {
        $(this).removeClass('region-populated').addClass('region-empty');
      }
      // This region has become populated.
      else if ($(this).is('.region-empty')) {
        $(this).removeClass('region-empty').addClass('region-populated');
      }
    });
  },

  /**
   * Triggers Ajax refresh of selected rows.
   *
   * The 'format type' selects can trigger a series of changes in child rows.
   * The #ajax behavior is therefore not attached directly to the selects, but
   * triggered manually through a hidden #ajax 'Refresh' button.
   *
   * @param rows
   *   A hash object, whose keys are the names of the rows to refresh (they
   *   will receive the 'ajax-new-content' effect on the server side), and
   *   whose values are the DOM element in the row that should get an Ajax
   *   throbber.
   */
  AJAXRefreshRows: function (rows) {
    // Separate keys and values.
    var rowNames = [];
    var ajaxElements = [];
    $.each(rows, function (rowName, ajaxElement) {
      rowNames.push(rowName);
      ajaxElements.push(ajaxElement);
    });

    if (rowNames.length) {
      // Add a throbber next each of the ajaxElements.
      var $throbber = $('<div class="ajax-progress ajax-progress-throbber"><div class="throbber">&nbsp;</div></div>');
      $(ajaxElements)
        .addClass('progress-disabled')
        .after($throbber);

      // Fire the Ajax update.
      $('input[name=refresh_rows]').val(rowNames.join(' '));
      $('input#edit-refresh').mousedown();

      // Disabled elements do not appear in POST ajax data, so we mark the
      // elements disabled only after firing the request.
      $(ajaxElements).prop('disabled', true);
    }
  }
};


/**
 * Row handlers for the 'Manage displays' screen.
 */
Backdrop.fieldUIDisplayOverview = {};

/**
 * Constructor for a 'field' row handler.
 *
 * This handler is used for both fields and 'extra fields' rows.
 *
 * @param row
 *   The row DOM element.
 * @param data
 *   Additional data to be populated in the constructed object.
 */
Backdrop.fieldUIDisplayOverview.field = function (row, data) {
  this.row = row;
  this.name = data.name;
  this.region = data.region;
  this.tableDrag = data.tableDrag;

  // Attach change listener to the 'formatter type' select.
  this.$formatSelect = $('select.field-formatter-type', row);
  this.$formatSelect.change(Backdrop.fieldUIOverview.onChange);

  return this;
};

Backdrop.fieldUIDisplayOverview.field.prototype = {
  /**
   * Returns the region corresponding to the current form values of the row.
   */
  getRegion: function () {
    return (this.$formatSelect.val() == 'hidden') ? 'hidden' : 'visible';
  },

  /**
   * Reacts to a row being changed regions.
   *
   * This function is called when the row is moved to a different region, as a
   * result of either :
   * - a drag-and-drop action (the row's form elements then probably need to be
   *   updated accordingly)
   * - user input in one of the form elements watched by the
   *   Backdrop.fieldUIOverview.onChange change listener.
   *
   * @param region
   *   The name of the new region for the row.
   * @return
   *   A hash object indicating which rows should be Ajax-updated as a result
   *   of the change, in the format expected by
   *   Backdrop.displayOverview.AJAXRefreshRows().
   */
  regionChange: function (region) {

    // When triggered by a row drag, the 'format' select needs to be adjusted
    // to the new region.
    var currentValue = this.$formatSelect.val();
    var value;
    if (region === 'visible') {
      if (currentValue === 'hidden') {
        // Restore the formatter back to the default formatter. Pseudo-fields do
        // not have default formatters, we just return to 'visible' for those.
        value = (typeof this.defaultFormatter !== 'undefined') ? this.defaultFormatter : this.$formatSelect.find('option').val();
      }
    }
    else {
      value = 'hidden';
    }

    if (value != undefined) {
      this.$formatSelect.val(value);
    }

    var refreshRows = {};
    refreshRows[this.name] = this.$formatSelect.get(0);

    return refreshRows;
  }
};

})(jQuery);
