import { connectPoints } from 'diagram-js/lib/layout/ManhattanLayout';

function ManhattanLayoutPlugin(eventBus, modeling) {
    eventBus.on('connection.changed', (event) => {
    var connection = event.element;

    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)
        }
    }
    });
}

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