define(
    ['jquery', 'underscore', 'pgadmin', 'backbone', 'backform', 'alertify', 'pgadmin.browser.node'],
function($, _, pgAdmin, Backbone, Backform, Alertify, Node) {

  var pgBrowser = pgAdmin.Browser;

  // Store value in DOM as stringified JSON.
  var StringOrJSONFormatter = function() {};
  _.extend(StringOrJSONFormatter.prototype, {
    fromRaw: function(rawData, model) {
      return JSON.stringify(_.escape(rawData));
    },
    toRaw: function(formattedData, model) {
      if (typeof(formattedData) == 'string') {
        return _.unescape(formattedData);
      }
      return JSON.parse(formattedData);
    }
  });

  /*
   * NodeAjaxOptionsControl
   *   This control will fetch the options required to render the select
   *   control, from the url specific to the pgAdmin.Browser node object.
   *
   *   In order to use this properly, schema require to set the 'url' property,
   *   which exposes the data for this node.
   *
   *   In case the url is not providing the data in proper format, we can
   *   specify the 'transform' function too, which will convert the fetched
   *   data to proper 'label', 'value' format.
   */
  var NodeAjaxOptionsControl = Backform.NodeAjaxOptionsControl =
      Backform.SelectControl.extend({
    defaults: _.extend(Backform.SelectControl.prototype.defaults, {
      url: undefined,
      transform: undefined,
      url_with_id: false,
      first_empty: false,
      empty_value: '-- None --',
      select2: {
        allowClear: true,
        placeholder: 'Select from the list',
        width: 'style'
      }
    }),
    template: _.template([
      '<label class="<%=Backform.controlLabelClassName%>"><%=label%></label>',
      '<div class="<%=Backform.controlsClassName%> <%=extraClasses.join(\' \')%>">',
      '  <select class="pgadmin-node-select form-control" name="<%=name%>" style="width:100%;" value=<%-value%> <%=disabled ? "disabled" : ""%> <%=required ? "required" : ""%> >',
      '    <% if (first_empty) { %>',
      '    <option value="" <%="" === rawValue ? "selected" : "" %>><%- empty_value %></option>',
      '    <% } %>',
      '    <% for (var i=0; i < options.length; i++) { %>',
      '    <% var option = options[i]; %>',
      '    <option <% if (option.image) { %> data-image=<%= option.image %> <% } %> value=<%= formatter.fromRaw(option.value) %> <%=option.value === rawValue ? "selected=\'selected\'" : "" %>><%-option.label%></option>',
      '    <% } %>',
      '  </select>',
      '</div>'].join("\n")),
    formatter: StringOrJSONFormatter,
    initialize: function() {
      /*
       * Initialization from the original control.
       */
      Backform.SelectControl.prototype.initialize.apply(this, arguments);

      /*
       * We're about to fetch the options required for this control.
       */
      var self = this,
          url = self.field.get('url') || self.defaults.url,
          m = self.model.top || self.model;

      // Hmm - we found the url option.
      // That means - we needs to fetch the options from that node.
      if (url) {
        var node = this.field.get('schema_node'),
            node_info = this.field.get('node_info'),
            full_url = node.generate_url.apply(
              node, [
                null, url, this.field.get('node_data'),
                this.field.get('url_with_id') || false, node_info
              ]),
            cache_level = this.field.get('cache_level') || node.type,
            cache_node = this.field.get('cache_node');

        cache_node = (cache_node && pgAdmin.Browser.Nodes['cache_node']) || node;

        /*
         * We needs to check, if we have already cached data for this url.
         * If yes - use that, and do not bother about fetching it again,
         * and use it.
         */
        var data = cache_node.cache(url, node_info, cache_level);

        if (this.field.get('version_compitible') &&
            (_.isUndefined(data) || _.isNull(data))) {
          m.trigger('pgadmin:view:fetching', m, self.field);
          $.ajax({
            async: false,
            url: full_url,
            success: function(res) {
              /*
               * We will cache this data for short period of time for avoiding
               * same calls.
               */
              data = cache_node.cache(url, node_info, cache_level, res.data);
            },
            error: function() {
              m.trigger('pgadmin:view:fetch:error', m, self.field);
            }
          });
          m.trigger('pgadmin:view:fetched', m, self.field);
        }
        // To fetch only options from cache, we do not need time from 'at'
        // attribute but only options.
        //
        // It is feasible that the data may not have been fetched.
        data = (data && data.data) || [];

        /*
         * Transform the data
         */
        transform = this.field.get('transform') || self.defaults.transform;
        if (transform && _.isFunction(transform)) {
          // We will transform the data later, when rendering.
          // It will allow us to generate different data based on the
          // dependencies.
          self.field.set('options', transform.bind(self, data));
        } else {
          self.field.set('options', data);
        }
      }
    },
    render: function() {
      /*
       * Let SelectControl render it, we will do our magic on the
       * select control in it.
       */
      Backform.SelectControl.prototype.render.apply(this, arguments);

      var d = this.field.toJSON(),
          select2_opts = _.defaults({}, d.select2, this.defaults.select2),
          evalF = function(f, d, m) {
            return (_.isFunction(f) ? !!f.apply(d, [m]) : !!f);
          };

      /*
       * If select2 options do not have any disabled property on this field
       * and schema has disabled property then we need to apply it
       */
      if(!_.has(select2_opts, 'disabled') && (d && d.disabled)) {
        _.extend(select2_opts, {
          disabled: evalF(d.disabled, d, this.model)
        });
      }

      /*
       * Add empty option as Select2 requires any empty '<option><option>' for
       * some of its functionality to work and initialize select2 control.
       */
      this.$el.find("select").select2(select2_opts);

      return this;
    }
  });

  var formatNode = function(opt) {
    if (!opt.id) {
      return opt.text;
    }

    var optimage = $(opt.element).data('image');

    if(!optimage){
      return opt.text;
    } else {
      return $(
          '<span><span class="wcTabIcon ' + optimage + '"/>' + opt.text + '</span>'
          );
    }
  };

  var NodeListByIdControl = Backform.NodeListByIdControl = NodeAjaxOptionsControl.extend({
    controlClassName: 'pgadmin-node-select form-control',
    defaults: _.extend({}, NodeAjaxOptionsControl.prototype.defaults, {
      first_empty: true,
      empty_value: '-- None --',
      url: 'nodes',
      filter: undefined,
      transform: function(rows) {
        var self = this,
            node = self.field.get('schema_node'),
            res = [],
            filter = self.field.get('filter') || function() { return true; };

        filter = filter.bind(self);

        _.each(rows, function(r) {
          if (filter(r)) {
            var l = (_.isFunction(node['node_label']) ?
                  (node['node_label']).apply(node, [r, self.model, self]) :
                  r.label),
                image= (_.isFunction(node['node_image']) ?
                  (node['node_image']).apply(
                    node, [r, self.model, self]
                    ) :
                  (node['node_image'] || ('icon-' + node.type)));

            res.push({
              'value': r._id,
              'image': image,
              'label': l
            });
          }
        });

        return res;
      },
      select2: {
        allowClear: true,
        placeholder: 'Select from the list',
        width: 'style',
        templateResult: formatNode,
        templateSelection: formatNode
      }
    })
  });


  var NodeListByNameControl = Backform.NodeListByNameControl = NodeListByIdControl.extend({
    defaults: _.extend({}, NodeListByIdControl.prototype.defaults, {
      transform: function(rows) {
        var self = this,
            node = self.field.get('schema_node'),
            res = [],
            filter = self.field.get('filter') || function() { return true; };

        filter = filter.bind(self);

        _.each(rows, function(r) {
          if (filter(r)) {
            var l = (_.isFunction(node['node_label']) ?
                  (node['node_label']).apply(node, [r, self.model, self]) :
                  r.label),
                image = (_.isFunction(node['node_image']) ?
                  (node['node_image']).apply(
                    node, [r, self.model, self]
                    ) :
                  (node['node_image'] || ('icon-' + node.type)));
            res.push({
              'value': r.label,
              'image': image,
              'label': l
            });
          }
        });

        return res;
      }
    })
  });

  /*
   * Global function to make visible  particular dom element in it's parent
   * with given class.
   */
  $.fn.pgMakeVisible = function( cls ) {
    return this.each(function() {
      if (!this || !$(this.length))
        return;
      var top, p = $(this), hasScrollbar = function(j) {
        if (j && j.length > 0) {
          return j.get(0).scrollHeight > j.height();
        }
        return false;
      };

      while(p) {
        top = p.get(0).offsetTop + p.height();
        p = p.parent();
        if (hasScrollbar(p)) {
          p.scrollTop(top);
        }
        if (p.hasClass(cls)) //'backform-tab'
          return;
      }
    });
  };


  /*
   * NodeAjaxOptionsCell
   *   This cell will fetch the options required to render the select
   *   cell, from the url specific to the pgAdmin.Browser node object.
   *
   *   In order to use this properly, schema require to set the 'url' property,
   *   which exposes the data for this node.
   *
   *   In case the url is not providing the data in proper format, we can
   *   specify the 'transform' function too, which will convert the fetched
   *   data to proper 'label', 'value' format.
   */
  var NodeAjaxOptionsCell = Backgrid.Extension.NodeAjaxOptionsCell = Backgrid.Extension.Select2Cell.extend({
    defaults: _.extend({}, Backgrid.Extension.Select2Cell.prototype.defaults, {
      url: undefined,
      transform: undefined,
      url_with_id: false,
      select2: {
        allowClear: true,
        placeholder: 'Select from the list',
        width: 'style'
      }
    }),
    template: _.template(
      '<option <% if (image) { %> data-image=<%= image %> <% } %> value="<%- value %>" <%= selected ? \'selected="selected"\' : "" %>><%- text %></option>'
    ),
    initialize: function () {
      Backgrid.Extension.Select2Cell.prototype.initialize.apply(this, arguments);

      var col = _.defaults(this.column.toJSON(), this.defaults),
          model = this.model, column = this.column,
          editable = Backgrid.callByNeed(col.editable, column, model),
          optionValues = _.clone(this.optionValues || this.column.get('options'));


      var self = this,
          url = self.column.get('url') || self.defaults.url,
          m = self.model.handler || self.model;

      // Hmm - we found the url option.
      // That means - we needs to fetch the options from that node.
      if (url) {
        var node = this.column.get('schema_node'),
            node_info = this.column.get('node_info'),
            full_url = node.generate_url.apply(
              node, [
                null, url, this.column.get('node_data'),
                this.column.get('url_with_id') || false, node_info
              ]),
            cache_level = this.column.get('cache_level') || node.type,
            cache_node = this.column.get('cache_node');

        cache_node = (cache_node && pgAdmin.Browser.Nodes['cache_node']) || node;

        /*
         * We needs to check, if we have already cached data for this url.
         * If yes - use that, and do not bother about fetching it again,
         * and use it.
         */
        var data = cache_node.cache(url, node_info, cache_level);

        if (this.column.get('version_compitible') &&
            (_.isUndefined(data) || _.isNull(data))) {
          m.trigger('pgadmin:view:fetching', m, self.column);
          $.ajax({
            async: false,
            url: full_url,
            success: function(res) {
              /*
               * We will cache this data for short period of time for avoiding
               * same calls.
               */
              data = cache_node.cache(url, node_info, cache_level, res.data);
            },
            error: function() {
              m.trigger('pgadmin:view:fetch:error', m, self.column);
            }
          });
          m.trigger('pgadmin:view:fetched', m, self.column);
        }
        // To fetch only options from cache, we do not need time from 'at'
        // attribute but only options.
        //
        // It is feasible that the data may not have been fetched.
        data = (data && data.data) || [];

        /*
         * Transform the data
         */
        transform = this.column.get('transform') || self.defaults.transform;
        if (transform && _.isFunction(transform)) {
          // We will transform the data later, when rendering.
          // It will allow us to generate different data based on the
          // dependencies.
          self.column.set('options', transform.bind(self, data));
        } else {
          self.column.set('options', data);
        }
      }
    },
    render: function() {
      /*
       * Let SelectCell render it, we will do our magic on the
       * select control in it.
       */

      var col = _.defaults(this.column.toJSON(), this.defaults),
          model = this.model, column = this.column,
          editable = Backgrid.callByNeed(col.editable, column, model),
          optionValues = _.clone(this.optionValues ||
                _.isFunction(this.column.get('options')) ?
                    this.column.get('options').apply(this) :
                    this.column.get('options')),
          select2_opts = _.defaults({}, col.select2, this.defaults.select2),
          evalF = function(f, col, m) {
            return (_.isFunction(f) ? !!f.apply(col, [m]) : !!f);
          };

      this.$el.empty();

      if (!_.isArray(optionValues)) throw new TypeError("optionValues must be an array");

      /*
       * Add empty option as Select2 requires any empty '<option><option>' for
       * some of its functionality to work.
       */
      optionValues.unshift({'label':null, 'value':null, 'image':null});

      var optionText = null,
          optionValue = null,
          model = this.model,
          selectedValues = model.get(this.column.get("name"));

      delete this.$select;

      this.$select = $("<select>", {tabIndex: -1}).appendTo(this.$el);

      for (var i = 0; i < optionValues.length; i++) {
        var op = optionValues[i];

        optionText  = op['label'];
        optionValue = op['value'];
        optionImage = op['image'];

        this.$select.append(
          this.template({
            text: optionText,
            value: optionValue,
            image: optionImage,
            selected: (selectedValues == optionValue) ||
              (_.indexOf(selectedValues, optionValue) > -1)
          }));
      }
      // Initialize select2 control.
      this.$select.select2(
          _.defaults(
            {'disabled': !editable},
            col.select2,
            this.defaults.select2
            ));

      /*
       * If select2 options do not have any disabled property on this cell
       * and schema has disabled property then we need to apply it
       */
      if(!_.has(select2_opts, 'disabled') && (col && col.disabled)) {
        _.extend(select2_opts, {
          disabled: evalF(col.disabled, col, this.model)
        });
      }

      this.$el.find("select").select2(select2_opts);

      this.delegateEvents();

      return this;
    }
  });

  var NodeListByIdCell =  Backgrid.Extension.NodeListByIdCell = NodeAjaxOptionsCell.extend({
    controlClassName: 'pgadmin-node-select backgrid-cell',
    defaults: _.extend({}, NodeAjaxOptionsCell.prototype.defaults, {
      url: 'nodes',
      filter: undefined,
      transform: function(rows) {
        var self = this,
            node = self.column.get('schema_node'),
            res = [],
            filter = self.column.get('filter') || function() { return true; };

        filter = filter.bind(self);

        _.each(rows, function(r) {
          if (filter(r)) {
            var l = (_.isFunction(node['node_label']) ?
                  (node['node_label']).apply(node, [r, self.model, self]) :
                  r.label),
                image= (_.isFunction(node['node_image']) ?
                  (node['node_image']).apply(
                    node, [r, self.model, self]
                    ) :
                  (node['node_image'] || ('icon-' + node.type)));

            res.push({
              'value': r._id,
              'image': image,
              'label': l
            });
          }
        });

        return res;
      },
      select2: {
        placeholder: 'Select from the list',
        width: 'style',
        templateResult: formatNode,
        templateSelection: formatNode
      }
    })
  });


  var NodeListByNameCell =  Backgrid.Extension.NodeListByNameCell = NodeAjaxOptionsCell.extend({
    controlClassName: 'pgadmin-node-select backgrid-cell',
    defaults: _.extend({}, NodeAjaxOptionsCell.prototype.defaults, {
      url: 'nodes',
      filter: undefined,
      transform: function(rows) {
        var self = this,
            node = self.column.get('schema_node'),
            res = [],
            filter = self.column.get('filter') || function() { return true; };

        filter = filter.bind(self);

        _.each(rows, function(r) {
          if (filter(r)) {
            var l = (_.isFunction(node['node_label']) ?
                  (node['node_label']).apply(node, [r, self.model, self]) :
                  r.label),
                image= (_.isFunction(node['node_image']) ?
                  (node['node_image']).apply(
                    node, [r, self.model, self]
                    ) :
                  (node['node_image'] || ('icon-' + node.type)));

            res.push({
              'value': r.label,
              'image': image,
              'label': l
            });
          }
        });

        return res;
      },
      select2: {
        placeholder: 'Select from the list',
        width: 'style',
        templateResult: formatNode,
        templateSelection: formatNode
      }
    })
  });


  return Backform;
});