import {
  assign
} from 'min-dash';

import inherits from 'inherits';

import BpmnElementFactory from 'lib/features/modeling/ElementFactory';

import {
  DEFAULT_LABEL_SIZE
} from 'lib/util/LabelUtil';


export default function CustomElementFactory(injector) {
  injector.invoke(BpmnElementFactory, this);

  var self = this;

  this.create = function(elementType, attrs) {
    var type = attrs.type,
        businessObject,
        size;

    if (elementType === 'label') {
      return self.baseCreate(elementType, assign({ type: 'label' }, DEFAULT_LABEL_SIZE, attrs));
    }

    if (/^custom:/.test(type)) {
      type = attrs.type.replace(/^custom:/, '');

      businessObject = {};

      size = self._getCustomElementSize(type);

      return self.baseCreate(elementType,
        assign({ type: elementType, businessObject: businessObject }, attrs, size));
    }

    return self.createBpmnElement(elementType, attrs);
  };
}

inherits(CustomElementFactory, BpmnElementFactory);

CustomElementFactory.$inject = [ 'injector' ];


/**
 * Sets the *width* and *height* for custom shapes.
 *
 * The following example shows an interface on how
 * to setup the custom element's dimensions.
 *
 * @example
 *
 *  var shapes = {
 *     triangle: { width: 40, height: 40 },
 *     rectangle: { width: 100, height: 20 }
 *  };
 *
 *   return shapes[type];
 *
 *
 * @param  {string} type
 *
 * @return {Bounds} { width, height}
 */
CustomElementFactory.prototype._getCustomElementSize = function(type) {
  if (!type) {
    return { width: 100, height: 80 };
  }

  var shapes = {
    triangle: { width: 40, height: 40 },
    circle: { width: 140, height: 140 }
  };

  return shapes[type];
};