/**
 * @author Martin Karkowski
 * @email m.karkowski@zema.de
 * @create date 2021-06-24 17:58:16
 * @modify date 2021-06-24 17:58:16
 * @desc [description]
 */

import * as go from "gojs";

const make = go.GraphObject.make;

export function addNodeNextTo<N = any, L = any>(node: go.Node, newNodeOptions: N, newLinkOptions: L, mode: "from" | "to", direction: "n" | "e" | "s" | "w" = "s", offset = 100, movingOffset = 20) {
  // We get the Diagram of the Node.
  const diagram = node.diagram;
  // To position the 
  const nodeBox = node.actualBounds;
  const middleY = nodeBox.y + nodeBox.height / 2;
  const middleX = nodeBox.x + nodeBox.width / 2;


  diagram.startTransaction("add_node_and_link");

  // Add the new Node.
  diagram.model.addNodeData(newNodeOptions);
  const newNodeBox = diagram.findNodeForData(newNodeOptions).actualBounds;

  // New Node Location
  const location = new go.Point();

  // Define the Position
  switch (direction) {
    case "n":
      location.x = middleX - newNodeBox.width / 2;
      location.y = nodeBox.y - offset - newNodeBox.height / 2;
      break;
    case "s":
      location.x = middleX - newNodeBox.width / 2;
      location.y = nodeBox.y + nodeBox.height + offset - newNodeBox.height / 2;
      break;
    case "e":
      location.x = nodeBox.x + nodeBox.width + offset + newNodeBox.width / 2;
      location.y = middleY - newNodeBox.height / 2;
      break;
    case "w":
      location.x = nodeBox.x - offset - newNodeBox.width / 2;
      location.y = middleY - newNodeBox.height / 2;
      break;
  }


  const linkData = Object.assign(newLinkOptions, mode === "from" ? {
    from: diagram.model.getKeyForNodeData(node.data),
    to: diagram.model.getKeyForNodeData(newNodeOptions),
  } : {
    to: diagram.model.getKeyForNodeData(node.data),
    from: diagram.model.getKeyForNodeData(newNodeOptions),
  });

  diagram.findNodeForData(newNodeOptions).location = location;

  // Assign the Position
  const foundObjects = diagram.findObjectsNear(
    location,
    Math.max(newNodeBox.width, newNodeBox.height),
    // Filter Function, which only returns nodes and 
    // check if the node isnt the node we are considering
    x => {
      const p = x.part;
      return (p instanceof go.Node && p !== node) ?
        p : null;
    }
  );

  // If we will found new Objects => we will adapt theese nodes. with respect to there position
  if (foundObjects.size > 1) {
    const attribute: "width" | "height" = (direction == "n" || direction == "s") ? "width" : "height";

    let length = 0;
    for (const obj of foundObjects.toArray()) {
      length += (obj as go.Node).actualBounds[attribute];
    }
    length += movingOffset * (foundObjects.size - 1);

    const start = length / 2;
    let _offset = 0;

    // Iterate over the found elements
    for (const obj of foundObjects.toArray()) {
      // Location
      const locationForNode = obj.position.copy();

      switch (direction) {
        case "n":
        case "s":
          locationForNode.x = middleX - start + _offset;
          break;
        case "e":
        case "w":
          locationForNode.y = middleY - start + _offset;
          break;
      }

      // Adapt the Offset
      _offset += movingOffset + obj.actualBounds[attribute];

      // Adapt the Position
      diagram.findNodeForData(obj.data).location = locationForNode;
    }
  }

  // and add the link data to the model
  diagram.model.addLinkData(linkData);
  console.log(linkData);


  // Commit the Change
  diagram.commitTransaction("add_node_and_link");
}