import type { PropertyBag } from '../model/Properties';
import { defaultsFor } from './PropertySchema';

const DEFAULTS = defaultsFor('camera');

/** Axis-aligned rectangle in world units. */
export interface WorldRect {
  left: number;
  top: number;
  right: number;
  bottom: number;
}

/**
 * The world region a camera shows: its view size divided by its zoom. Drawn as a frame in edit mode,
 * and the only region rendered in play mode.
 */
export function cameraFrame(props: PropertyBag): { w: number; h: number } {
  const zoom = Math.max(0.01, Number(props.zoom ?? DEFAULTS.zoom));
  return {
    w: Number(props.width ?? DEFAULTS.width) / zoom,
    h: Number(props.height ?? DEFAULTS.height) / zoom,
  };
}

export function rectAround(cx: number, cy: number, w: number, h: number): WorldRect {
  return { left: cx - w / 2, top: cy - h / 2, right: cx + w / 2, bottom: cy + h / 2 };
}

export function rectsIntersect(a: WorldRect, b: WorldRect): boolean {
  return a.left < b.right && a.right > b.left && a.top < b.bottom && a.bottom > b.top;
}