import {Entity, EntityAccessor} from "../utils/entity";
import {Part} from "./part";
import {RNG} from "../utils/rng";

export type Region = Entity & {
  // aligning axes of the region
  axes: RegionAxis[];
  
  // current children; expect no overlapped positions
  children: EntityAccessor<Part>[];
}

export type RegionAxis = {
  name: string;
  min?: number;
  max?: number;
  align?: 'start' | 'end' | 'center';
}

/**
 * for each axis, try to remove gaps in positions.
 * - if min exists and align is start, and there are parts at (for example) min+2 and min+4, then move them to min and min+1
 * - if max exists and align is end, and there are parts at (for example) max-2 and max-4, then move them to max-1 and max-3
 * - for center, move parts to the center, possibly creating parts placed at 0.5 positions
 * - sort children so that they're in ascending order on each axes.
 * @param region
 */
export function applyAlign(region: Region){
  for (const axis of region.axes) {
    // TODO implement this
  }
}

/**
 * shuffle on each axis. for each axis, try to swap position.
 * @param region
 * @param rng
 */
export function shuffle(region: Region, rng: RNG){
  // TODO implement this
}