/*
 * SortCandidatesUtil
 *
 * Created on 10.08.2009
 * Copyright (c) 2009 Kiesraad
 */
package de.ivu.wahl.result.determination;

import de.ivu.wahl.result.Candidate;
import de.ivu.wahl.result.Util;

import java.util.Comparator;
import java.util.List;

/**
 * Utility class that provides Comparators to sort CandidateForSorting
 *
 * @author , IVU Traffic Technologies AG
 */
final class SortCandidatesUtil {
  private SortCandidatesUtil() {
    // hide constructor
  }

  /**
   * Comparator<CandidateForSorting> Sorts candidates with priority seat by number of votes and the
   * result of drawing lots
   */
  static final Comparator<CandidateForSorting> COMPARATOR_FOR_PREF_SEATS = Comparator
          .comparingLong(CandidateForSorting::getNumberOfVotes).thenComparing(CandidateForSorting::o2).reversed();

  static final Comparator<CandidateForSorting> COMPARE_BY_POSITION_IN_LIST = Comparator.comparing(
          CandidateForSorting::getListPositionAndDistrictNumber);

  static Comparator<CandidateForSorting> sortByPositionOnP2List(P2List p2List) {
    final List<Candidate> candidates = Util.createUnmodifiableCopy(p2List.getCandidates());
    return (x, y) -> {
      int ix = candidates.indexOf(x.getCandidate());
      int iy = candidates.indexOf(y.getCandidate());
      return ix == -1 ? (iy == -1 ? 0 : 1) : (iy == -1 ? -1 : (ix - iy));
    };
  }

  /**
   * Comparator to determine the new list order on a P2List.
   *
   * @author , IVU Traffic Technologies AG
   */
  public final static class NewOrderOnP2ListComparator implements Comparator<CandidateForSorting> {
    private final P2List _p2List;
    private final Comparator<CandidateForSorting> sortByPositionOnP2List;

    NewOrderOnP2ListComparator(P2List p2List) {
      this._p2List = p2List;
      this.sortByPositionOnP2List = SortCandidatesUtil.sortByPositionOnP2List(p2List);
    }

    public int compare(CandidateForSorting x, CandidateForSorting y) {
      int result = Long.signum(y.o1() - x.o1());
      if (result != 0) {
        return result;
      }
      result = Integer.signum(y.o2() - x.o2());
      if (result != 0) {
        return result;
      }
      result = Long.signum(y.o3(_p2List) - x.o3(_p2List));
      if (result != 0) {
        return result;
      }
      return sortByPositionOnP2List.compare(x, y);
    }
  }

}
