/**
 * @author Martin Karkowski
 * @email m.karkowski@zema.de
 * @create date 2021-11-23 11:21:57
 * @modify date 2021-11-23 11:21:57
 * @desc [description]
 */

import { rgetattr } from "./objectMethods";

const __sentinal = {
  unique: "value",
};

/**
 * Extracts the unique values of an map.
 *
 * @author M.Karkowski
 * @export
 * @template K
 * @template V
 * @param {Map<K, V>} map
 * @return {*}  {Set<V>}
 */
export function extractUniqueValues<D>(map: Map<any, any>, path = ""): Set<D> {
  return new Set(extractValues(map, path));
}

export function extractValues<D, K>(map: Map<K, any>, path = ""): Array<D> {
  const s = new Array<D>();

  for (const v of map.values()) {
    if (path) {
      const data: D | typeof __sentinal = rgetattr(v, path, __sentinal);
      if (data !== __sentinal) {
        if (Array.isArray(data)) {
          data.map((item) => s.push(item));
        } else {
          s.push(data as D);
        }
      }
    } else {
      if (Array.isArray(v)) {
        v.map((_v) => {
          s.push(_v as D);
        });
      } else {
        s.push(v as any as D);
      }
    }
  }

  return s;
}

/**
 *
 *
 * @author M.Karkowski
 * @export
 * @template D
 * @template K
 * @param {Map<K, any>} map
 * @param {string} [path=""]
 * @return {*}  {Map<K, D>}
 */
export function transformValues<D, K = any>(
  map: Map<K, any>,
  path = ""
): Map<K, D> {
  const m = new Map<K, D>();

  for (const [k, v] of map.entries()) {
    if (path) {
      const data: D | typeof __sentinal = rgetattr(v, path, __sentinal);
      if (data !== __sentinal) {
        m.set(k, data as D);
      }
    } else {
      m.set(k, v as any as D);
    }
  }

  return m;
}

/**
 * Reverses the given map.
 *
 * @author M.Karkowski
 * @export
 * @template K
 * @template V
 * @param {Map<K, V>} map
 * @return {*}  {Map<V, Set<K>>}
 */
export function reverse<K, V>(map: Map<K, V>): Map<V, Set<K>> {
  const m = new Map<V, Set<K>>();

  for (const [k, v] of map.entries()) {
    if (Array.isArray(v)) {
      for (const _v of v) {
        if (!m.has(_v)) {
          m.set(_v, new Set());
        }
        m.get(_v).add(k);
      }
    } else {
      if (!m.has(v)) {
        m.set(v, new Set());
      }
      m.get(v).add(k);
    }
  }

  return m;
}