///////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2002-2023, Open Design Alliance (the "Alliance").
// All rights reserved.
//
// This software and its documentation and related materials are owned by
// the Alliance. The software may only be incorporated into application
// programs owned by members of the Alliance, subject to a signed
// Membership Agreement and Supplemental Software License Agreement with the
// Alliance. The structure and organization of this software are the valuable
// trade secrets of the Alliance and its suppliers. The software is also
// protected by copyright law and international treaty provisions. Application
// programs incorporating this software must include the following statement
// with their copyright notices:
//
//   This application incorporates Open Design Alliance software pursuant to a
//   license agreement with Open Design Alliance.
//   Open Design Alliance Copyright (C) 2002-2021 by Open Design Alliance.
//   All rights reserved.
//
// By use of this software, its documentation or related materials, you
// acknowledge and accept the above terms.
///////////////////////////////////////////////////////////////////////////////

import * as THREE from "three";
import { IComponent } from "../IComponent";
import type { ThreejsViewer } from "../ThreejsViewer";

export class ObjectSelectionComponent implements IComponent {
  protected viewer: ThreejsViewer;
  protected raycaster: THREE.Raycaster;
  protected mouse: THREE.Vector2;
  protected selectionMaterial: THREE.MeshBasicMaterial;

  constructor(viewer: ThreejsViewer) {
    this.viewer = viewer;
    this.raycaster = new THREE.Raycaster();
    this.mouse = new THREE.Vector2();
    this.selectionMaterial = new THREE.MeshBasicMaterial({ color: "red" });

    this.viewer.addEventListener("pointerdown", this.onPointerDown);
    this.viewer.addEventListener("pointerup", this.onPointerUp);
  }

  dispose() {
    this.viewer.removeEventListener("pointerdown", this.onPointerDown);
    this.viewer.removeEventListener("pointerup", this.onPointerUp);
  }

  onPointerUp = (event: PointerEvent) => {
    const x = (event.offsetX / this.viewer.canvas.clientWidth) * 2 - 1;
    const y = -(event.offsetY / this.viewer.canvas.clientHeight) * 2 + 1;

    if (this.mouse.x === x && this.mouse.y === y) {
      this.raycaster.setFromCamera(this.mouse, this.viewer.camera);
      const intersects = this.raycaster.intersectObjects(this.viewer.scene.children, true);
      this.clearSelection();
      if (intersects.length > 0) {
        const object = intersects[0].object as THREE.Mesh;
        this.setSelectObject(object, true);
      }
    }
  };

  onPointerDown = (event: PointerEvent) => {
    this.mouse.x = (event.offsetX / this.viewer.canvas.clientWidth) * 2 - 1;
    this.mouse.y = -(event.offsetY / this.viewer.canvas.clientHeight) * 2 + 1;
  };

  clearSelection() {
    this.viewer.selectedObjects.forEach((object) => this.setSelectObject(object, false));
    this.viewer.selectedObjects.length = 0;
  }

  setSelectObject(object, selected) {
    if (selected) {
      const index = this.viewer.selectedObjects.findIndex((o) => o === object);
      if (index === -1) {
        this.viewer.selectedObjects.push(object);
        this.highlightObject(object, true);
        this.viewer.emit("selectobject", object);
      }
    } else {
      const index = this.viewer.selectedObjects.findIndex((o) => o === object);
      if (index !== -1) {
        this.viewer.selectedObjects.splice(index, 1);
        this.highlightObject(object, false);
        this.viewer.emit("deselectobject", object);
      }
    }
  }

  highlightObject(object, enable) {
    if (enable) {
      if (!object.originalMaterial) {
        object.originalMaterial = object.material;
        object.material = this.selectionMaterial;
      }
    } else {
      if (object.originalMaterial) {
        object.material = object.originalMaterial;
        delete object.originalMaterial;
      }
    }
  }
}