import { match } from 'ts-pattern';

import type { Roi } from './Roi.js';
import type { RoiMapManager } from './RoiMapManager.js';
import { computeRois } from './computeRois.js';

export const RoiKind = {
  BLACK: 'black',
  WHITE: 'white',
  BW: 'bw',
} as const;
export type RoiKind = (typeof RoiKind)[keyof typeof RoiKind];

export interface GetRoisOptions {
  /**
   * Minimal surface of the ROIs to keep.
   * @default `0`
   */
  minSurface?: number;
  /**
   * Maximal surface of the ROIs to keep.
   * @default `Number.MAX_SAFE_INTEGER`
   */
  maxSurface?: number;
  /**
   * Kind of ROIs to keep.
   * @default `'white'`
   */
  kind?: RoiKind;
}

/**
 * Return an array of ROIs matching the options.
 * @param roiMapManager - The ROI map manager containing the ROIs.
 * @param options - Get ROIs options.
 * @returns The array of ROIs.
 */
export function getRois(
  roiMapManager: RoiMapManager,
  options: GetRoisOptions = {},
): Roi[] {
  const {
    minSurface = 0,
    maxSurface = Number.MAX_SAFE_INTEGER,
    kind = 'white',
  } = options;

  if (
    roiMapManager.blackRois.length === 0 &&
    roiMapManager.whiteRois.length === 0
  ) {
    computeRois(roiMapManager);
  }

  const rois = match(kind)
    .with('black', () => roiMapManager.blackRois)
    .with('white', () => roiMapManager.whiteRois)
    .with('bw', () => [...roiMapManager.whiteRois, ...roiMapManager.blackRois])
    .exhaustive();

  return rois.filter(
    (roi) => roi.surface >= minSurface && roi.surface <= maxSurface,
  );
}