/***
 * Contains JSON SlickGrid editors.
 * @module Editors
 * @namespace Slick
 */

(function ($) {
  // register namespace
  $.extend(true, window, {
    "Slick": {
      "Editors": {
        "pgText": pgTextEditor,
        "JsonText": JsonTextEditor,
        "CustomNumber": CustomNumberEditor,
        "Checkbox": pgCheckboxEditor,
        // Below editor will read only editors, Just to display data
        "ReadOnlyText": ReadOnlyTextEditor,
        "ReadOnlyCheckbox": ReadOnlyCheckboxEditor,
        "ReadOnlypgText": ReadOnlypgTextEditor,
        "ReadOnlyJsonText": ReadOnlyJsonTextEditor
      }
    }
  });

  // return wrapper element
  function getWrapper() {
    return $("<div class='pg_text_editor' />");
  }

  // return textarea element
  function getTextArea() {
    return $("<textarea class='pg_textarea text-12' hidefocus rows=5'>");
  }

  // Generate and return editor buttons
  function getButtons(editable) {
    var $buttons = $("<div class='pg_buttons' />"),
      label = editable ? 'Cancel': 'OK',
      button_type = editable ? 'btn-danger' : 'btn-primary';

    if (editable) {
      var $save_button = $("<button class='btn btn-primary fa fa-lg fa-save long_text_editor pg-alertify-button'>Save</button>")
          .appendTo($buttons);
    }

    var $cancel_button = $("<button class='btn " + button_type + " fa fa-lg fa-times long_text_editor pg-alertify-button'>"+ label +"</button>")
        .appendTo($buttons);
    return $buttons;
  }

  function is_valid_array(val) {
    val = $.trim(val)
    return !(val != "" && (val.charAt(0) != '{' || val.charAt(val.length - 1) != '}'));
  }
  /*
   * This function handles the [default] and [null] values for cells
   * if row is copied, otherwise returns the editor value.
   * @param {args} editor object
   * @param {item} row cell values
   * @param {state} entered value
   * @param {column_type} type of column
   */
  function setValue(args, item, state, column_type) {
    // declare a 2-d array which tracks the status of each updated cell
    // If a cell is edited for the 1st time and state is null,
    // set cell value to [default] and update its status [row][cell] to 1.
    // If same cell is edited again, and kept blank, set cell value to [null]

    // If a row is copied
    var grid = args.grid;
    if (item.is_row_copied) {
      if (!grid.copied_rows) {
        grid.copied_rows = [[]];
      }

      var active_cell = grid.getActiveCell(),
          row = active_cell['row'],
          cell = active_cell['cell'],
          last_value = item[args.column.pos],
          last_value = (column_type === 'number') ?
                        (_.isEmpty(last_value) || last_value) : last_value;

      item[args.column.field] = state;
      if (last_value && _.isNull(state) &&
          (_.isUndefined(grid.copied_rows[row]) ||
          _.isUndefined(grid.copied_rows[row][cell]))
      ) {
        item[args.column.field] = undefined;
        if (grid.copied_rows[row] == undefined) grid.copied_rows[row] = [];
        grid.copied_rows[row][cell] = 1;
      }
    }
    else {
      item[args.column.field] = state;
    }
  }

  function calculateEditorPosition(position, $wrapper) {
    var $edit_grid = $wrapper.parent().find('#datagrid');
    var _elem_height = $edit_grid.height(),
      is_hidden, _position;
    // We cannot display editor partially visible so we will lift it above select column
    if(position.top > _elem_height) {
      is_hidden = position.bottom - _elem_height;
    }

    if(is_hidden) {
      _position = position.top - is_hidden;
    } else {
      _position = position.top-7;
    }
    position.top = _position;

    var grid_width = $edit_grid.width(),
      popup_width = $wrapper.width() + 32;
    popup_width += position.left;

    if(popup_width > grid_width) {
      position.left -= (popup_width - grid_width);
    }
    return position;
  }

  // Text data type editor
  function pgTextEditor(args) {
    var $input, $wrapper, $buttons;
    var defaultValue;
    var scope = this;

    this.init = function () {
      var $container = $("body");

      $wrapper = getWrapper().appendTo($container);
      $input = getTextArea().appendTo($wrapper);
      $buttons = getButtons(true).appendTo($wrapper);

      $buttons.find("button:first").on("click", this.save);
      $buttons.find("button:last").on("click", this.cancel);
      $input.bind("keydown", this.handleKeyDown);

      scope.position(args.position);
      $input.focus().select();
    };

    this.handleKeyDown = function (e) {
      if (e.which == $.ui.keyCode.ENTER && e.ctrlKey) {
        scope.save();
      } else if (e.which == $.ui.keyCode.ESCAPE) {
        e.preventDefault();
        scope.cancel();
      } else if (e.which == $.ui.keyCode.TAB && e.shiftKey) {
        e.preventDefault();
        args.grid.navigatePrev();
      } else if (e.which == $.ui.keyCode.TAB) {
        e.preventDefault();
        args.grid.navigateNext();
      }
    };

    this.save = function () {
      args.commitChanges();
    };

    this.cancel = function () {
      $input.val(defaultValue);
      args.cancelChanges();
    };

    this.hide = function () {
      $wrapper.hide();
    };

    this.show = function () {
      $wrapper.show();
    };

    this.position = function (position) {
      calculateEditorPosition(position, $wrapper);
      $wrapper
        .css("top", position.top)
        .css("left", position.left)
    }

    this.destroy = function () {
      $wrapper.remove();
    };

    this.focus = function () {
      $input.focus();
    };

    // When text editor opens
    this.loadValue = function (item) {
      var col = args.column;

      if (_.isUndefined(item[args.column.field]) || _.isNull(item[args.column.field])) {
          $input.val(defaultValue = "");
          return;
      }

      if (!args.column.is_array) {
        if (item[args.column.field] === "") {
          $input.val(defaultValue = "''");
        } else if (item[args.column.field] === "''") {
          $input.val(defaultValue = "\\'\\'");
        } else if (item[args.column.field] === '""') {
          $input.val(defaultValue = '\\"\\"');
        } else {
          $input.val(defaultValue = item[args.column.field]);
          $input.select();
        }
      } else {
        var data = [];
        for (var k in item[args.column.field]) {
          if (_.isUndefined(item[args.column.field][k]) || _.isNull(item[args.column.field][k])) {
            data.push('');
          } else if (item[args.column.field][k] === "") {
            data.push("''");
          } else if (item[args.column.field][k] === "''") {
            data.push("\\'\\'");
          } else if (item[args.column.field][k] === '""') {
            data.push('\\"\\"');
          } else {
            data.push(item[args.column.field][k]);
            $input.select();
          }
        }
        defaultValue = data;
        $input.val('{' + data.join() +'}');

      }
    };

    this.serializeValue = function () {
      var value = $input.val();
      // If empty return null
      if (value === "") {
        return null;
      }

      if (!args.column.is_array) {
        if (value === "''" || value === '""') {
          return '';
        } else if (value === "\\'\\'") {
          return "''";
        } else if (value === '\\"\\"') {
          return '""';
        } else {
          return value;
        }
      } else {

        // Remove leading { and trailing }.
        // Also remove leading and trailing whitespaces.
        var value = $.trim(value.slice(1, -1));

        if(value == '') {
          return [];
        }

        var data = [];
        value = value.split(',');
        for (var k in value) {
          if (value[k] == "") {
            data.push(null);  //empty string from editor is null value.
          } else if (value[k] === "''" || value[k] === '""') {
            data.push('');    // double quote from editor is blank string;
          } else if (value[k] === "\\'\\'") {
            data.push("''");
          } else if (value[k] === '\\"\\"') {
            data.push('""');
          } else {
            data.push(value[k]);
          }
        }
        return data;
      }
    };

    this.applyValue = function (item, state) {
      setValue(args, item, state, 'text');
    };

    this.isValueChanged = function () {
      // Use _.isNull(value) for comparison for null instead of
      // defaultValue == null, because it returns true for undefined value.
      if ($input.val() == "" && _.isUndefined(defaultValue)) {
        return false;
      } else {
        return (!($input.val() == "" && _.isNull(defaultValue))) &&
               ($input.val() !== defaultValue);
      }
    };

    this.validate = function () {
      if (args.column.validator) {
        var validationResults = args.column.validator($input.val());
        if (!validationResults.valid) {
          return validationResults;
        }
      }

      if (args.column.is_array && !is_valid_array($input.val())) {
        return {
          valid: false,
          msg: "Array must start with '{' and end with '}'"
        };
      }

      return {
        valid: true,
        msg: null
      };
    };

    this.init();
  }

  // JSON data type editor
  function JsonTextEditor(args) {
    var $input, $wrapper, $buttons;
    var defaultValue;
    var scope = this;

    this.init = function () {
      var $container = $("body");

      $wrapper = getWrapper().appendTo($container);
      $input = getTextArea().appendTo($wrapper);
      $buttons = getButtons(true).appendTo($wrapper);

      $buttons.find("button:first").on("click", this.save);
      $buttons.find("button:last").on("click", this.cancel);
      $input.bind("keydown", this.handleKeyDown);

      scope.position(args.position);
      $input.focus().select();
    };

    this.handleKeyDown = function (e) {
      if (e.which == $.ui.keyCode.ENTER && e.ctrlKey) {
        scope.save();
      } else if (e.which == $.ui.keyCode.ESCAPE) {
        e.preventDefault();
        scope.cancel();
      } else if (e.which == $.ui.keyCode.TAB && e.shiftKey) {
        e.preventDefault();
        args.grid.navigatePrev();
      } else if (e.which == $.ui.keyCode.TAB) {
        e.preventDefault();
        args.grid.navigateNext();
      }
    };

    this.save = function () {
      args.commitChanges();
    };

    this.cancel = function () {
      $input.val(defaultValue);
      args.cancelChanges();
    };

    this.hide = function () {
      $wrapper.hide();
    };

    this.show = function () {
      $wrapper.show();
    };

    this.position = function (position) {
      calculateEditorPosition(position, $wrapper);
      $wrapper
        .css("top", position.top)
        .css("left", position.left)
    }

    this.destroy = function () {
      $wrapper.remove();
    };

    this.focus = function () {
      $input.focus();
    };

    this.loadValue = function (item) {
      var data = defaultValue = item[args.column.field];
      if (data && typeof data === "object" && !Array.isArray(data)) {
        data = JSON.stringify(data);
      } else if (Array.isArray(data)) {
        var temp = [];
        $.each(data, function(i, val) {
          if (typeof val === "object") {
            temp.push(JSON.stringify(val));
          } else {
            temp.push(val)
          }
        });
        data = "[" + temp.join() + "]";
      }
      $input.val(data);
      $input.select();
    };

    this.serializeValue = function () {
      if ($input.val() === "") {
        return null;
      }
      return $input.val();
    };

    this.applyValue = function (item, state) {
      setValue(args, item, state, 'text');
    };

    this.isValueChanged = function () {
      if ($input.val() == "" && _.isUndefined(defaultValue)) {
        return false;
      } else {
        return (!($input.val() == "" && _.isNull(defaultValue))) && ($input.val() != defaultValue);
      }
    };

    this.validate = function () {
      if (args.column.validator) {
        var validationResults = args.column.validator($input.val());
        if (!validationResults.valid) {
          return validationResults;
        }
      }

      return {
        valid: true,
        msg: null
      };
    };

    this.init();
  }

  // Text data type editor
  function ReadOnlypgTextEditor(args) {
    var $input, $wrapper, $buttons;
    var defaultValue;
    var scope = this;

    this.init = function () {
      var $container = $("body");

      $wrapper = getWrapper().appendTo($container);
      $input = getTextArea().appendTo($wrapper);
      $buttons = getButtons(false).appendTo($wrapper);

      $buttons.find("button:first").on("click", this.cancel);
      $input.bind("keydown", this.handleKeyDown);

      scope.position(args.position);
      $input.focus().select();
    };

    this.handleKeyDown = function (e) {
      if (e.which == $.ui.keyCode.ENTER && e.ctrlKey) {
        scope.cancel();
      } else if (e.which == $.ui.keyCode.ESCAPE) {
        e.preventDefault();
        scope.cancel();
      } else if (e.which == $.ui.keyCode.TAB && e.shiftKey) {
        scope.cancel();
        e.preventDefault();
        args.grid.navigatePrev();
      } else if (e.which == $.ui.keyCode.TAB) {
        scope.cancel();
        e.preventDefault();
        args.grid.navigateNext();
      }
    };

    this.cancel = function () {
      $input.val(defaultValue);
      args.cancelChanges();
    };

    this.hide = function () {
      $wrapper.hide();
    };

    this.show = function () {
      $wrapper.show();
    };

    this.position = function (position) {
      calculateEditorPosition(position, $wrapper);
      $wrapper
        .css("top", position.top)
        .css("left", position.left)
    }

    this.destroy = function () {
      $wrapper.remove();
    };

    this.focus = function () {
      $input.focus();
    };

    this.loadValue = function (item) {
      $input.val(defaultValue = item[args.column.field]);
      $input.select();
    };

    this.serializeValue = function () {
      return $input.val();
    };

    this.applyValue = function (item, state) {
      item[args.column.field] = state;
    };

    this.isValueChanged = function () {
      return (!($input.val() == "" && defaultValue == null)) && ($input.val() != defaultValue);
    };

    this.validate = function () {
      if (args.column.validator) {
        var validationResults = args.column.validator($input.val());
        if (!validationResults.valid) {
          return validationResults;
        }
      }

      return {
        valid: true,
        msg: null
      };
    };

    this.init();
  }

  /* Override CheckboxEditor to implement checkbox with three states.
   * 1) checked=true
   * 2) unchecked=false
   * 3) indeterminate=null
   */
  function CheckboxEditor(args) {
    var $select, el;
    var defaultValue, previousState;
    var scope = this;

    this.init = function () {
      $select = $("<input type=checkbox class='editor-checkbox' hideFocus>");
      $select.appendTo(args.container);
      $select.focus();

      // The following code is taken from https://css-tricks.com/indeterminate-checkboxes/
      $select.bind("click", function (e) {
        el = $(this);
        el.prop('indeterminate', false);

        var checkbox_status = el.data('checked');
        // add new row > checkbox clicked
        if (el.data('checked') == undefined) {
          checkbox_status = 1;
        }
        switch(checkbox_status) {
          // State 0 will come when we had indeterminate state
          case 0:
            // We will check now
            el.prop('checked', true);
            el.data('checked', 1);
            break;

          // State 1 will come when we had checked state
          case 1:
            // We will uncheck now
            el.prop('checked', false);
            el.data('checked', 2);
            break;

          // State 2 will come when we had unchecked state
          case 2:
            // We will set to indeterminate state
            el.prop('indeterminate', true);
            el.data('checked', 0);
            break;

          // Default, Set to indeterminate state
          default:
            el.prop('indeterminate', true);
            el.data('checked', 0);
        }
      });
    };

    this.destroy = function () {
      $select.remove();
    };

    this.focus = function () {
      $select.focus();
    };

    this.loadValue = function (item) {
      defaultValue = item[args.column.field];
      previousState = 0;
      if (_.isNull(defaultValue)||_.isUndefined(defaultValue)) {
        $select.prop('indeterminate', true);
        $select.data('checked', 0);
      }
      else {
        defaultValue = !!item[args.column.field];
        if (defaultValue) {
          $select.prop('checked', true);
          $select.data('checked', 1);
          previousState = 1;
        } else {
          $select.prop('checked', false);
          $select.data('checked', 2);
          previousState = 2;
        }
      }
    };

    this.serializeValue = function () {
      if ($select.prop('indeterminate')) {
        return null;
      }
      return $select.prop('checked');
    };

    this.applyValue = function (item, state) {
      item[args.column.field] = state;
    };

    this.isValueChanged = function () {
      var currentState = $select.data('checked');
      return currentState !== previousState;
    };

    this.validate = function () {
      if (args.column.validator) {
        var validationResults = args.column.validator(this.serializeValue());
        if (!validationResults.valid) {
          return validationResults;
        }
      }
      return {
        valid: true,
        msg: null
      };
    };

    this.init();
  }

  // JSON data type editor
  function ReadOnlyJsonTextEditor(args) {
    var $input, $wrapper, $buttons;
    var defaultValue;
    var scope = this;

    this.init = function () {
      var $container = $("body");

      $wrapper = getWrapper().appendTo($container);
      $input = getTextArea().appendTo($wrapper);
      $buttons = getButtons(false).appendTo($wrapper);

      $buttons.find("button:first").on("click", this.cancel);
      $input.bind("keydown", this.handleKeyDown);

      scope.position(args.position);
      $input.focus().select();
    };

    this.handleKeyDown = function (e) {
      if (e.which == $.ui.keyCode.ENTER && e.ctrlKey) {
        scope.cancel();
      } else if (e.which == $.ui.keyCode.ESCAPE) {
        e.preventDefault();
        scope.cancel();
      } else if (e.which == $.ui.keyCode.TAB && e.shiftKey) {
        scope.cancel();
        e.preventDefault();
        args.grid.navigatePrev();
      } else if (e.which == $.ui.keyCode.TAB) {
        scope.cancel();
        e.preventDefault();
        args.grid.navigateNext();
      }
    };

    this.cancel = function () {
      $input.val(defaultValue);
      args.cancelChanges();
    };

    this.hide = function () {
      $wrapper.hide();
    };

    this.show = function () {
      $wrapper.show();
    };

    this.position = function (position) {
      calculateEditorPosition(position, $wrapper);
      $wrapper
        .css("top", position.top)
        .css("left", position.left)
    }

    this.destroy = function () {
      $wrapper.remove();
    };

    this.focus = function () {
      $input.focus();
    };

    this.loadValue = function (item) {
      var data = defaultValue = item[args.column.field];
      if (typeof data === "object" && !Array.isArray(data)) {
        data = JSON.stringify(data);
      } else if (Array.isArray(data)) {
        var temp = [];
        $.each(data, function(i, val) {
          if (typeof val === "object") {
            temp.push(JSON.stringify(val));
          } else {
            temp.push(val)
          }
        });
        data = "[" + temp.join() + "]";
      }
      $input.val(data);
      $input.select();
    };

    this.serializeValue = function () {
      return $input.val();
    };

    this.applyValue = function (item, state) {
      item[args.column.field] = state;
    };

    this.isValueChanged = function () {
      return (!($input.val() == "" && defaultValue == null)) && ($input.val() != defaultValue);
    };

    this.validate = function () {
      if (args.column.validator) {
        var validationResults = args.column.validator($input.val());
        if (!validationResults.valid) {
          return validationResults;
        }
      }

      return {
        valid: true,
        msg: null
      };
    };

    this.init();
  }

  function ReadOnlyTextEditor(args) {
    var $input;
    var defaultValue;
    var scope = this;

    this.init = function () {
      $input = $("<INPUT type=text class='editor-text' readonly/>")
          .appendTo(args.container)
          .bind("keydown.nav", function (e) {
            if (e.keyCode === $.ui.keyCode.LEFT || e.keyCode === $.ui.keyCode.RIGHT) {
              e.stopImmediatePropagation();
            }
          })
          .focus()
          .select();
    };

    this.destroy = function () {
      $input.remove();
    };

    this.focus = function () {
      $input.focus();
    };

    this.getValue = function () {
      return $input.val();
    };

    this.loadValue = function (item) {
      var value = item[args.column.field];

      // Check if value is null or undefined
      if (value === undefined && typeof value === "undefined") {
        value = ""
      }
      defaultValue = value;
      $input.val(defaultValue);
      $input[0].defaultValue = defaultValue;
      $input.select();
    };

    this.serializeValue = function () {
      return $input.val();
    };

    this.applyValue = function (item, state) {
      item[args.column.field] = state;
    };

    this.isValueChanged = function () {
      return (!($input.val() == "" && defaultValue == null)) && ($input.val() != defaultValue);
    };

    this.validate = function () {
      if (args.column.validator) {
        var validationResults = args.column.validator($input.val());
        if (!validationResults.valid) {
          return validationResults;
        }
      }

      return {
        valid: true,
        msg: null
      };
    };

    this.init();
  }

  function ReadOnlyCheckboxEditor(args) {
    var $select, el;
    var defaultValue;
    var scope = this;

    this.init = function () {
      $select = $("<INPUT type=checkbox value='true' class='editor-checkbox' hideFocus disabled>");
      $select.appendTo(args.container);
      $select.focus();
    };

    this.destroy = function () {
      $select.remove();
    };

    this.focus = function () {
      $select.focus();
    };

    this.loadValue = function (item) {
      defaultValue = item[args.column.pos];
      if (_.isNull(defaultValue)|| _.isUndefined(defaultValue)) {
        $select.prop('indeterminate', true);
        $select.data('checked', 2);
      }
      else {
        defaultValue = !!item[args.column.pos];
        if (defaultValue) {
          $select.prop('checked', true);
          $select.data('checked', 0);
        } else {
          $select.prop('checked', false);
          $select.data('checked', 1);
        }
      }
    };

    this.serializeValue = function () {
      if ($select.prop('indeterminate')) {
        return null;
      }
      return $select.prop('checked');
    };

    this.applyValue = function (item, state) {
      item[args.column.pos] = state;
    };

    this.isValueChanged = function () {
      // var select_value = this.serializeValue();
      var select_value = $select.data('checked');
      return (!(select_value === 2 && (defaultValue == null || defaultValue == undefined))) &&
            (select_value !== defaultValue);
    };

    this.validate = function () {
      return {
        valid: true,
        msg: null
      };
    };

    this.init();
  }

  function CustomNumberEditor(args) {
    var $input;
    var defaultValue;
    var scope = this;

    this.init = function () {
      $input = $("<INPUT type=text class='editor-text' />");

      $input.bind("keydown.nav", function (e) {
        if (e.keyCode === $.ui.keyCode.LEFT || e.keyCode === $.ui.keyCode.RIGHT) {
          e.stopImmediatePropagation();
        }
      });

      $input.appendTo(args.container);
      $input.focus().select();
    };

    this.destroy = function () {
      $input.remove();
    };

    this.focus = function () {
      $input.focus();
    };

    this.loadValue = function (item) {
      defaultValue = item[args.column.field];

      if(args.column.is_array && !_.isNull(defaultValue) && !_.isUndefined(defaultValue)) {
        $input.val('{' + defaultValue.join() +'}');
      } else {
        $input.val(defaultValue);
      }

      $input[0].defaultValue = defaultValue;
      $input.select();
    };

    this.serializeValue = function () {
      if ($input.val() === "") {
        return null;
      }

      if(args.column.is_array) {
        // Remove leading { and trailing }.
        // Also remove leading and trailing whitespaces.
        var val = $.trim($input.val().slice(1, -1));

        if(val == '') {
          return [];
        }
        val = val.split(',');
        for (var k in val) {
          if (val[k] == "") {
            val[k] = null;  //empty string from editor is null value.
          }
        }
        return val;
      }

      return $input.val();
    };

    this.applyValue = function (item, state) {
      setValue(args, item, state, 'number');
    };

    this.isValueChanged = function () {
      if ($input.val() == "" && _.isUndefined(defaultValue)) {
        return false;
      } else if ($input.val() == "" && defaultValue == "") {
        return true;
      } else {
        return (!($input.val() == "" && _.isNull(defaultValue ))) &&
        ($input.val() != defaultValue);
      }
    };

    this.validate = function () {
      var value = $input.val();
      if (!args.column.is_array && isNaN(value)) {
        return {
          valid: false,
          msg: "Please enter a valid number"
        };
      }
      if (args.column.validator) {
        var validationResults = args.column.validator(value);
        if (!validationResults.valid) {
          return validationResults;
        }
      }

      if (args.column.is_array) {
        if (!is_valid_array(value)) {
          return {
            valid: false,
            msg: "Array must start with '{' and end with '}'"
          };
        }

        var val = $.trim(value.slice(1, -1)),
            arr;

        if(val == '') {
          arr = [];
        } else {
          var arr = val.split(',');
        }

        for (var k in arr) {
          if (isNaN(arr[k])) {
            return {
              valid: false,
              msg: "Please enter a valid numbers"
            };
          }
        }
      }

      return {
        valid: true,
        msg: null
      };
    };

    this.init();
  }

  // Custom checkbox editor, We need it for runtime as it does not render
  // indeterminate checkbox state
  function pgCheckboxEditor(args) {
    var $select, el;
    var defaultValue, previousState;
    var scope = this;

    this.init = function () {
      $select = $("<div class='multi-checkbox'><span class='check' hideFocus></span></div>");
      $select.appendTo(args.container);
      $select.focus();

      // The following code is taken from https://css-tricks.com/indeterminate-checkboxes/
      $select.bind("click", function (e) {
        el = $(this);
        var states = ["unchecked", "partial", "checked"];
        var curState = el.find(".check").data("state");
        curState++;
        el.find(".check")
          .removeClass("unchecked partial checked")
          .addClass(states[curState % states.length])
          .data("state", curState % states.length);
      });
    };

    this.destroy = function () {
      $select.remove();
    };

    this.focus = function () {
      $select.focus();
    };

    this.loadValue = function (item) {
      defaultValue = item[args.column.field];
      previousState = 1;
      if (_.isNull(defaultValue)||_.isUndefined(defaultValue)) {
        $select.find(".check").data("state", 1).addClass("partial");
      }
      else {
        defaultValue = !!item[args.column.field];
        if (defaultValue) {
          $select.find(".check").data("state", 2).addClass("checked");
          previousState = 2;
        } else {
          $select.find(".check").data("state", 0).addClass("unchecked");
          previousState = 0;
        }
      }
    };

    this.serializeValue = function () {
      if ($select.find(".check").data("state") == 1) {
        return null;
      }
      return $select.find(".check").data("state") == 2 ? true : false;
    };

    this.applyValue = function (item, state) {
      item[args.column.field] = state;
    };

    this.isValueChanged = function () {
      var currentState = $select.find(".check").data("state");
      return currentState !== previousState;
    };

    this.validate = function () {
      if (args.column.validator) {
        var validationResults = args.column.validator(this.serializeValue());
        if (!validationResults.valid) {
          return validationResults;
        }
      }
      return {
        valid: true,
        msg: null
      };
    };

    this.init();
  }

})(jQuery);