import type { ICircle, IRectangle2 } from '../interfaces';
import { ptsDistanceSq } from '../utils';

export class Circle implements IRectangle2, ICircle {
  constructor(
    public cx: number,
    public cy: number,
    public radius: number
  ) {}

  get x() {
    return this.cx - this.radius;
  }

  get x2() {
    return this.cx + this.radius;
  }

  get width() {
    return this.radius * 2;
  }

  get y() {
    return this.cy - this.radius;
  }

  get y2() {
    return this.cy + this.radius;
  }

  get height() {
    return this.radius * 2;
  }

  static from(r: ICircle) {
    return new Circle(r.cx, r.cy, r.radius);
  }

  containsPt(x: number, y: number) {
    return ptsDistanceSq(this.cx, this.cy, x, y) < this.radius * this.radius;
  }

  distSquare(tempX: number, tempY: number) {
    const dist = ptsDistanceSq(this.cx, this.cy, tempX, tempY);
    if (dist < this.radius * this.radius) {
      // inside
      return 0;
    }
    const offset = Math.sqrt(dist) - this.radius;
    return offset * offset;
  }

  draw(ctx: CanvasRenderingContext2D) {
    ctx.ellipse(this.cx, this.cy, this.radius, this.radius, 0, 0, Math.PI * 2);
  }
}