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

// A custom DragSelectingTool for selecting and deselecting Parts during a drag.

/**
* @constructor
* @extends DragSelectingTool
* @class
* The RealtimeDragSelectingTool selects and deselects Parts within the {@link DragSelectingTool#box}
* during a drag, not just at the end of the drag.
*/
export class RealtimeDragSelectingTool extends go.DragSelectingTool {
  private _originalSelection: go.Set<go.Part> = null;
  private _temporarySelection: go.Set<go.Part> = null;

  /**
  * Remember the original collection of selected Parts.
  * @this {RealtimeDragSelectingTool}
  */
  public doActivate() {
    go.DragSelectingTool.prototype.doActivate.call(this);
    // keep a copy of the original Set of selected Parts
    this._originalSelection = this.diagram.selection.copy();
    // these Part.isSelected may have been temporarily modified
    this._temporarySelection = new go.Set(go.Part) as go.Set<go.Part>;
  };

  /**
  * Release any references to selected Parts.
  * @this {RealtimeDragSelectingTool}
  */
  public doDeactivate() {
    this._originalSelection = null;
    this._temporarySelection = null;
    go.DragSelectingTool.prototype.doDeactivate.call(this);
  };

  /**
  * Restore the selection which may have been modified during a drag.
  * @this {RealtimeDragSelectingTool}
  */
  public doCancel() {
    var orig = this._originalSelection;
    if (orig !== null) {
      orig.each(function (p) { p.isSelected = true; });
      this._temporarySelection.each(function (p) { if (!orig.contains(p)) p.isSelected = false; });
    }
    go.DragSelectingTool.prototype.doCancel.call(this);
  };

  /**
  * @this {RealtimeDragSelectingTool}
  */
  public doMouseMove() {
    if (this.isActive) {
      go.DragSelectingTool.prototype.doMouseMove.call(this);
      this.selectInRect(this.computeBoxBounds());
    }
  };

  /**
  * @this {RealtimeDragSelectingTool}
  */
  public doKeyDown() {
    if (this.isActive) {
      go.DragSelectingTool.prototype.doKeyDown.call(this);
      this.selectInRect(this.computeBoxBounds());
    }
  };

  /**
  * @this {RealtimeDragSelectingTool}
  */
  public doKeyUp() {
    if (this.isActive) {
      go.DragSelectingTool.prototype.doKeyUp.call(this);
      this.selectInRect(this.computeBoxBounds());
    }
  };

  /**
  * @expose
  * @this {RealtimeDragSelectingTool}
  * @param {Rect} r a rectangular bounds in document coordinates.
  */
  public selectInRect(r: go.Rect) {
    var diagram: any = this.diagram;
    var orig = this._originalSelection;
    var temp = this._temporarySelection;
    if (diagram === null || orig === null) return;
    var e = diagram.lastInput;
    diagram.raiseDiagramEvent("ChangingSelection");
    var found = diagram.findObjectsIn(r, null,
      function (p: go.Part) { return (p instanceof go.Part) && p.canSelect(); },
      this.isPartialInclusion,
      new go.Set(go.Part));
    if (e.control || e.meta) {  // toggle or deselect
      if (e.shift) {  // deselect only
        temp.each(function (p: go.Part) { if (!found.contains(p)) p.isSelected = orig.contains(p); });
        found.each(function (p: go.Part) { p.isSelected = false; temp.add(p); });
      } else {  // toggle selectedness of parts based on _originalSelection
        temp.each(function (p: go.Part) { if (!found.contains(p)) p.isSelected = orig.contains(p); });
        found.each(function (p: go.Part) { p.isSelected = !orig.contains(p); temp.add(p); });
      }
    } else if (e.shift) {  // extend selection only
      temp.each(function (p: go.Part) { if (!found.contains(p)) p.isSelected = orig.contains(p); });
      found.each(function (p: go.Part) { p.isSelected = true; temp.add(p); });
    } else {  // select found parts, and unselect all other previously selected parts
      temp.each(function (p: go.Part) { if (!found.contains(p)) p.isSelected = false; });
      orig.each(function (p: go.Part) { if (!found.contains(p)) p.isSelected = false; });
      found.each(function (p: go.Part) { p.isSelected = true; temp.add(p); });
    }
    diagram.raiseDiagramEvent("ChangedSelection");
  };

}