var _ = require('lodash');

var BpmnTreeWalker = require('./BpmnTreeWalker');

function importBpmnDiagram(diagram, definitions, done) {

  var canvas = diagram.get('canvas');

  var shapes = {};

  var visitor = {

    element: function(element, di, parent) {

      var shape;

      if (di.$type === 'bpmndi:BPMNShape') {
        var bounds = di.bounds;

        shape = {
          id: element.id, type: element.$type,
          x: bounds.x, y: bounds.y,
          width: bounds.width, height: bounds.height,
          parent: parent
        };

        canvas.addShape(shape);
      } else {

        var waypoints = _.collect(di.waypoint, function(p) {
          return { x: p.x, y: p.y };
        });

        shape = { id: element.id, type: element.$type, waypoints: waypoints };
        canvas.addConnection(shape);
      }

      shapes[element.id] = shape;

      return shape;
    },
    
    error: function(message, context) {
      console.warn('[import]', message, context);
    }
  };

  var walker = new BpmnTreeWalker(visitor);

  walker.handleDefinitions(definitions);

  done();
}

module.exports.importBpmnDiagram = importBpmnDiagram;