const e1 = EIGHT.Geometric3.e1()
const e2 = EIGHT.Geometric3.e2()
const e3 = EIGHT.Geometric3.e3()

export interface Bivector extends EIGHT.Renderable {
  a: EIGHT.Geometric3;
  b: EIGHT.Geometric3;
}

export default function bivector(contextManager: EIGHT.ContextManager): Bivector {
  let sceneName: string;
  const arrow = new EIGHT.Arrow({contextManager});
  const darea = new EIGHT.Parallelepiped(contextManager);
  darea.a = e1
  darea.b = e2
  darea.c = 0.01 * e3

  darea.opacity = 0.5
  darea.transparent = true;
  const color = EIGHT.Color.blueviolet.clone().scale(0.05)
  darea.colors[0] = color
  darea.colors[1] = color
  darea.colors[2] = color
  darea.colors[3] = color
  darea.colors[4] = color
  darea.colors[5] = color

  let refCount = 0;
  const addRef = function(): number {
    refCount++;
    return refCount;
  }
  const release = function(): number {
    refCount--;
    if (refCount === 0) {

    }
    return refCount;
  }
  const render = function(ambients: EIGHT.Facet[]): void {
    // TODO: We really need a parameter that tells us whether
    // this is the non-transparent pass (1st), or transparent pass (2nd)
    arrow.h = darea.a;
    arrow.X = darea.X - 0.5 * darea.a - 0.5 * darea.b
    arrow.color = EIGHT.Color.red;
    arrow.render(ambients);

    arrow.h = darea.b;
    arrow.X = darea.X + 0.5 * darea.a - 0.5 * darea.b
    arrow.color = EIGHT.Color.blue;
    arrow.render(ambients);

    darea.render(ambients);
  }
  const that: Bivector = {
    a: darea.a,
    b: darea.b,
    get name(): string {
       return sceneName;
    },
    get transparent(): boolean {
      return false;
    },
    addRef,
    release,
    render
  }
  return Object.freeze(that);
}