import { Vector } from "../math/vector.ts";

export class Mover {
  position: Vector;
  velocity: Vector;
  acceleration: Vector;
  maxSpeed: number;
  maxForce: number;
  _trailingPoint: number;
  protected _leadingPoint: number;

  get trailingPoint() {
    const desired = this.velocity.copy();
    desired.normalize();
    desired.mult(-this._trailingPoint);

    return Vector.add(this.position, desired);
  }
  get leadingPoint() {
    const desired = this.velocity.copy();
    desired.normalize();
    desired.mult(this._leadingPoint);

    return Vector.add(this.position, desired);
  }

  ctx?: CanvasRenderingContext2D;

  boundingBox: {
    pos: Vector;
    size: Vector;
  }

  constructor();
  constructor(random: boolean);
  constructor(pos?: Vector, vel?: Vector, acc?: Vector);
  constructor(posOrRandom?: Vector | boolean, vel?: Vector, acc?: Vector) {
    if (typeof posOrRandom === 'boolean' && posOrRandom) {
      this.position = Vector.random2D(new Vector());
      this.velocity = Vector.random2D(new Vector());
      this.acceleration = new Vector()
    } else {
      this.position = posOrRandom || new Vector();
      this.velocity = vel || new Vector();
      this.acceleration = acc || new Vector()
    }
    this.boundingBox = {
      size: new Vector(20, 10),
      pos: new Vector(this.position.x - 10, this.position.y - 5)
    }

    this.maxSpeed = 3;
    this.maxForce = .3;

    this._trailingPoint = 0;
    this._leadingPoint = 0;

    this.init();
  }

  init() {
    // 
  }

  move() {
    this.velocity.limit(this.maxSpeed);
    this.acceleration.limit(this.maxForce);
    this.velocity.add(this.acceleration);
    this.position.add(this.velocity);
    this.edges();
    this.draw();
  }

  edges() {
    if (!this.ctx) return;

    if (this.position.x > this.ctx.canvas.width) this.position.x = 0;
    if (this.position.y > this.ctx.canvas.height) this.position.y = 0;
    if (this.position.x < 0) this.position.x = this.ctx.canvas.width;
    if (this.position.y < 0) this.position.y = this.ctx.canvas.height;
  }

  draw() {
    if (!this.ctx) return;

    this.ctx.fillStyle = 'white'
    this.ctx.save();
    this.ctx.translate(this.position.x, this.position.y);
    this.ctx.rotate(this.velocity.heading() || 0);
    this.ctx.translate(-this.position.x, -this.position.y);
    // this.ctx.rotate(Math.PI)
    // this.ctx.rotate(.5);
    this.ctx.translate(-(this.boundingBox.size.x / 2), -(this.boundingBox.size.y / 2));
    this.ctx.fillRect(this.position.x, this.position.y, this.boundingBox.size.x, this.boundingBox.size.y);
    this.ctx.restore();
  }

  setContext(ctx: CanvasRenderingContext2D) {
    this.ctx = ctx;
  }

  applyForce(force: Vector) {
    this.acceleration.add(force);
  }

  static edges(point: Vector, width: number, height: number) {
    if (point.x > width) point.x = 0;
    if (point.y > height) point.y = 0;
    if (point.x < 0) point.x = width;
    if (point.y < 0) point.y = height;
  }
}