"use strict"
/*
*  Copyright (C) 1998-2017 by Northwoods Software Corporation. All Rights Reserved.
*/

import * as go from "../release/go";

// A custom Tool for dragging a segment of an orthogonal link.

/**
* This OrthogonalLinkReshapingTool class allows for a Link's path to be modified by the user
* via the dragging of a tool handle along the link segment, which will move the whole segment.
* @constructor
* @extends LinkReshapingTool
* @class
*/
export class OrthogonalLinkReshapingTool extends go.LinkReshapingTool {
	public readonly name: string = "OrthogonalLinkReshaping";

  /**
  * For orthogonal, straight links, create the handles and set reshaping behavior.
  * @override
  * @param {Shape} pathshape
  * @return {Adornment}
  * @this {OrthogonalLinkReshapingTool}
  */
	public makeAdornment(pathshape: go.Shape): go.Adornment {
		var link = pathshape.part as go.Link;

		// add all normal handles first
		var adornment = super.makeAdornment.call(this, pathshape);

		// add long reshaping handles for orthogonal, straight links
		if (link !== null && link.isOrthogonal && link.curve !== go.Link.Bezier) {
			var firstindex = link.firstPickIndex;
			var lastindex = link.lastPickIndex;
			for (var i = firstindex + 1; i < lastindex - 1; i++) {
				this.makeSegmentDragHandle(link, adornment, i);
			}
		}
		return adornment;
	};

  /**
  * Once we finish a reshape, make sure any handles are properly updated.
  * @override
  * @this {OrthogonalLinkReshapingTool}
  */
	public doDeactivate() {
		// when we finish, recreate adornment to ensure proper reshaping behavior/cursor
		var link = this.adornedLink;
		if (link !== null && link.isOrthogonal && link.curve !== go.Link.Bezier) {
			var pathshape = link.path;
			var adornment = this.makeAdornment(pathshape);
			if (adornment !== null) {
				link.addAdornment(this.name, adornment);
				adornment.location = link.position;
			}
		}
		super.doDeactivate.call(this);
	};

  /**
  * Set the reshaping behavior for segment dragging handles.
  * @override
  * @param {Point} newpt
  * @this {OrthogonalLinkReshapingTool}
  */
	public reshape(newpt: go.Point) {
		var link: any = this.adornedLink;

		// identify if the handle being dragged is a segment dragging handle
		if (link !== null && link.isOrthogonal && link.curve !== go.Link.Bezier && this.handle.toMaxLinks === 999) {
			link.startRoute();
			var index = this.handle.segmentIndex; // for these handles, firstPickIndex + 1 <= index < lastPickIndex - 1
			var behavior = this.getReshapingBehavior(this.handle);
			if (behavior === go.LinkReshapingTool.Vertical) {
				// move segment vertically
				link.setPointAt(index, link.getPoint(index - 1).x, newpt.y);
				link.setPointAt(index + 1, link.getPoint(index + 2).x, newpt.y);
			} else if (behavior === go.LinkReshapingTool.Horizontal) {
				// move segment horizontally
				link.setPointAt(index, newpt.x, link.getPoint(index - 1).y);
				link.setPointAt(index + 1, newpt.x, link.getPoint(index + 2).y);
			}
			link.commitRoute();
		} else {
			super.reshape.call(this, newpt);
		}
	};

  /**
  * Create the segment dragging handles. 
  * There are two parts: one invisible handle that spans the segment, and a visible handle at the middle of the segment.
  * These are inserted at the front of the adornment such that the normal handles have priority.
  * @param {Link} link
  * @param {Adornment} adornment
  * @param {number} index
  * @this {OrthogonalLinkReshapingTool}
  */
	public makeSegmentDragHandle(link: go.Link, adornment: go.Adornment, index: number) {
		var a = link.getPoint(index);
		var b = link.getPoint(index + 1);
		var seglength = Math.max(Math.abs(a.x - b.x), Math.abs(a.y - b.y));
		// determine segment orientation
		var orient = "";
		if (this.isApprox(a.x, b.x) && this.isApprox(a.y, b.y)) {
			b = link.getPoint(index - 1);
			if (this.isApprox(a.x, b.x)) {
				orient = "vertical";
			} else if (this.isApprox(a.y, b.y)) {
				orient = "horizontal";
			}
		} else {
			if (this.isApprox(a.x, b.x)) {
				orient = "vertical";
			} else if (this.isApprox(a.y, b.y)) {
				orient = "horizontal";
			}
		}

		// first, make an invisible handle along the whole segment
		var h = new go.Shape();
		h.opacity = 0;
		h.segmentOrientation = go.Link.OrientAlong;
		h.segmentIndex = index;
		h.segmentFraction = 0.5;
		h.toMaxLinks = 999; // set this unsused property to easily identify that we have a segment dragging handle
		if (orient === "horizontal") {
			this.setReshapingBehavior(h, go.LinkReshapingTool.Vertical);
			h.cursor = 'n-resize';
		} else {
			this.setReshapingBehavior(h, go.LinkReshapingTool.Horizontal);
			h.cursor = 'w-resize';
		}
		h.geometryString = "M 0 0 L " + seglength + " 0";
		adornment.insertAt(0, h);

		// second, make a visible handle near the middle
		h = new go.Shape();
		h.fill = "#1B3471"; // different from other handles to make sure it stands out
		h.stroke = "dodgerblue";
		h.segmentOrientation = go.Link.OrientAlong;
		h.segmentIndex = index;
		h.segmentFraction = 0.5;
		h.toMaxLinks = 999; // set this unsused property to easily identify that we have a segment dragging handle
		if (orient === "horizontal") {
			this.setReshapingBehavior(h, go.LinkReshapingTool.Vertical);
			h.cursor = 'n-resize';
		} else {
			this.setReshapingBehavior(h, go.LinkReshapingTool.Horizontal);
			h.cursor = 'w-resize';
		}
		h.geometryString = "F M 0 0 L 12 0 L 12 4 L 0 4 Z X M 6 0 L 6 -3 X M 6 4 L 6 7";
		adornment.insertAt(0, h);
	};

  /**
  * Compare two numbers to ensure they are almost equal.
  * Used in this class for comparing coordinates of Points.
  * @param {number} x
  * @param {number} y
  * @return {boolean}
  */
	public isApprox(x: number, y: number): boolean {
		var d = x - y;
		return d < 0.5 && d > -0.5;
	}
}