import { connectPoints } from 'diagram-js/lib/layout/ManhattanLayout';
import Modeling from 'diagram-js/lib/features/modeling/Modeling';
import EventBus from 'diagram-js/lib/core/EventBus';
import { Connection } from 'diagram-js/lib/model/Types';

export function updateWaypointsByManhattan (connection: Connection, modeling: Modeling ): void {
  if (connection.source && connection.target) {
      const x0 = connection.source.x + connection.source.width / 2;
      const x1 = connection.target.x + connection.target.width / 2;
      const y0 = connection.source.y + connection.source.height / 2;
      const y1 = connection.target.y + connection.target.height / 2;
      const x2 = (Math.abs(x0-x1) < 5) ? x0 : x1;
      const y2 = (Math.abs(y0-y1) < 5) ? y0 : y1;
      const waypoints = connectPoints(
          { x: x0, y: y0 },
          { x: x2, y: y2 });

      const hasChanged = JSON.stringify(connection.waypoints) != JSON.stringify(waypoints);
      if (hasChanged) {
          modeling.updateWaypoints(connection, waypoints)
      }
  }
}

function ManhattanLayoutPlugin(eventBus: EventBus, modeling: Modeling) {
  eventBus.on('commandStack.connection.create.executed', (event) => {
    var connection = (event as any).element;
    if (connection) {
      updateWaypointsByManhattan(connection, modeling);
    }
  });


  eventBus.on("shape.move.end", (event) => {
      var shape = (event as any).shape;
      if (shape.incoming) {
        shape.incoming.forEach((element: Connection) => {
          updateWaypointsByManhattan(element, modeling);
        });
      }
  
      if (shape.outgoing) {
        shape.outgoing.forEach((element: Connection) => {
          updateWaypointsByManhattan(element, modeling);
        });
      }
  });
}

export default {
   __init__: [ 'manhattanLayoutPlugin' ],
     manhattanLayoutPlugin: [ 'type', ManhattanLayoutPlugin ]
};