Diffblue Cover Tennis Kata 2

TennisScore.java

// Original: https://github.com/emilybache/Tennis-Refactoring-Kata/blob/master/java/src/main/java/TennisGame1.java

package com.example.tennis;

public class TennisScore {

  public static class GamesWon {
    final int player1;
    final int player2;

    public GamesWon(final int player1Won, final int player2Won) {
      player1 = player1Won;
      player2 = player2Won;
    }
  }

  public String announceScore(final GamesWon gamesWon) {
    if (gamesWon.player1 < 0) {
      throw new IllegalArgumentException(
          String.format(
              "Number of games won cannot be negative, got %d for player 1", gamesWon.player1
          )
      );
    }
    if (gamesWon.player2 < 0) {
      throw new IllegalArgumentException(
          String.format(
              "Number of games won cannot be negative, got %d for player 2", gamesWon.player2
          )
      );
    }
    String score = "";
    int tempScore = 0;
    if (gamesWon.player1 == gamesWon.player2) {
      switch (gamesWon.player1) {
        case 0:
          score = "Love-All";
          break;
        case 1:
          score = "Fifteen-All";
          break;
        case 2:
          score = "Thirty-All";
          break;
        default:
          score = "Deuce";
          break;
      }
    }
    else if (gamesWon.player1 >= 4 || gamesWon.player2 >= 4) {
      int minusResult = gamesWon.player1 - gamesWon.player2;
      if (minusResult == 1) score ="Advantage player1";
      else if (minusResult == -1) score ="Advantage player2";
      else if (minusResult >= 2) score = "Win for player1";
      else score ="Win for player2";
    }
    else {
      for (int i = 1; i < 3; i++) {
        if (i == 1) tempScore = gamesWon.player1;
        else { score += "-"; tempScore = gamesWon.player2;}
        switch(tempScore) {
          case 0:
            score += "Love";
            break;
          case 1:
            score += "Fifteen";
            break;
          case 2:
            score += "Thirty";
            break;
          case 3:
            score += "Forty";
            break;
        }
      }
    }
    return score;
  }
}