import { vec2 } from 'gl-matrix';
import {
  Circle,
  CommandExecutors,
  CommandReceiver,
  GameObject,
  serializesTo,
} from 'shared';
import { BoundingBox } from '../physics/bounding-boxes/bounding-box';
import { BoundingBoxBase } from '../physics/bounding-boxes/bounding-box-base';
import { moveCircle } from '../physics/functions/move-circle';
import { PhysicalContainer } from '../physics/containers/physical-container';
import { DynamicPhysical } from '../physics/physicals/dynamic-physical';
import { ReactToCollisionCommand } from '../commands/react-to-collision';

@serializesTo(Circle)
export class CirclePhysical extends CommandReceiver implements Circle, DynamicPhysical {
  readonly canCollide = true;
  readonly canMove = true;

  public velocity = vec2.create();
  public lastNormal = vec2.fromValues(0, 1);

  private _boundingBox: BoundingBox;

  protected commandExecutors: CommandExecutors = {
    [ReactToCollisionCommand.type]: this.onCollision.bind(this),
  };

  constructor(
    private _center: vec2,
    private _radius: number,
    public owner: GameObject,
    private readonly container: PhysicalContainer,
    private restitution = 0,
  ) {
    super();
    this._boundingBox = new BoundingBox();
    this.recalculateBoundingBox();
  }

  public get boundingBox(): BoundingBoxBase {
    return this._boundingBox;
  }

  public get center(): vec2 {
    return this._center;
  }

  public set center(value: vec2) {
    this._center = value;
    this.recalculateBoundingBox();
  }

  public onCollision(c: ReactToCollisionCommand) {
    this.owner.handleCommand(c);
  }

  public get gameObject(): GameObject {
    return this.owner;
  }

  public get radius(): number {
    return this._radius;
  }

  public set radius(value: number) {
    this._radius = value;
    this.recalculateBoundingBox();
  }

  public distance(target: vec2): number {
    return vec2.distance(target, this.center) - this.radius;
  }

  private recalculateBoundingBox() {
    this._boundingBox.xMin = this.center.x - this._radius;
    this._boundingBox.xMax = this.center.x + this._radius;
    this._boundingBox.yMin = this.center.y - this._radius;
    this._boundingBox.yMax = this.center.y + this._radius;
  }

  public applyForce(force: vec2, timeInSeconds: number) {
    vec2.add(
      this.velocity,
      this.velocity,
      vec2.scale(vec2.create(), force, timeInSeconds),
    );
  }

  public stepManually(
    deltaTimeInSeconds: number,
  ): { hitObject: GameObject | undefined; velocity: vec2 } {
    let delta = vec2.scale(vec2.create(), this.velocity, deltaTimeInSeconds);

    this.radius += vec2.length(delta);
    const intersecting = this.container
      .findIntersecting(this.boundingBox)
      .filter((b) => b.gameObject !== this.gameObject && b.canCollide);
    this.radius -= vec2.length(delta);

    let { normal, hitSurface, hitObject } = moveCircle(this, delta, intersecting);

    if (hitSurface) {
      vec2.copy(this.lastNormal, normal!);

      vec2.subtract(
        this.velocity,
        this.velocity,
        vec2.scale(
          normal!,
          normal!,
          (1 + this.restitution) * vec2.dot(normal!, this.velocity),
        ),
      );

      if (vec2.length(this.velocity) > 50) {
        delta = vec2.scale(vec2.create(), this.velocity, deltaTimeInSeconds);
        moveCircle(this, delta, intersecting);
      }
    }

    const lastVelocity = vec2.clone(this.velocity);
    vec2.zero(this.velocity);

    return { hitObject, velocity: lastVelocity };
  }

  public toArray(): Array<any> {
    const { center, radius } = this;
    return [center, radius];
  }
}
