var StyleGenerator = require('./style-converter');
var _ = require('underscore');

/**
 * this class manages the changes in layerdef styles and generate the proper cartocss and sql
 */
function StyleManager (layerDefinitionsCollection, map, configModel) {
  this.layerDefinitionsCollection = layerDefinitionsCollection;
  this.map = map;
  this._configModel = configModel;
  this._initBinds();
}

StyleManager.prototype = {
  _initBinds: function () {
    var self = this;

    function _generate (layerDef) {
      return function () {
        self.generate(layerDef);
      };
    }

    function _bind (layerDef) {
      if (layerDef && layerDef.styleModel) {
        layerDef.styleModel.bind('change', _generate(layerDef), this);
        layerDef.bind('change:autoStyle', _generate(layerDef), this);
      }
    }

    function _unbind (layerDef) {
      if (layerDef.styleModel) {
        layerDef.styleModel.unbind('change', _generate(layerDef), this);
        layerDef.unbind('change:autoStyle', _generate(layerDef), this);
      }
    }

    function _bindAll () {
      this.layerDefinitionsCollection.each(_bind, this);
    }

    this.layerDefinitionsCollection.bind('reset', _bindAll, this);
    this.layerDefinitionsCollection.bind('add', _bind, this);
    this.layerDefinitionsCollection.bind('remove', _unbind, this);

    _bindAll.call(this);
  },

  generate: function (layerDef) {
    var isAutoStyleApplied = layerDef.get('autoStyle');
    var stylesChanged = layerDef.styleModel.changed;

    if (isAutoStyleApplied) {
      return;
    }

    if (stylesChanged.type && _.size(stylesChanged) === 1) {
      return;
    }

    var simpleGeometryType = layerDef.getAnalysisDefinitionNodeModel().queryGeometryModel.get('simple_geom') || 'point';
    var generated = StyleGenerator.generateStyle(
      layerDef.styleModel.toJSON(),
      simpleGeometryType,
      {
        zoom: this.map.get('zoom')
      },
      this._configModel
    );

    var properties = {
      cartocss: generated.cartoCSS,
      sql_wrap: generated.sql,
      type: generated.layerType
    };

    if (layerDef.get('previousCartoCSSCustom')) {
      properties = _.extend(properties, {
        cartocss: layerDef.get('previousCartoCSS'),
        cartocss_custom: layerDef.get('previousCartoCSSCustom'),
        previousCartoCSSCustom: false
      });
    }

    layerDef.set(properties);
  }
};

module.exports = StyleManager;