<?php
  namespace Foxx\ComputerScience\U1;

  /**
   * A simple game of rock, paper, scissors.
   * @author Foxx Azalea Pinkerton
   * @since 2022-09-26
   * @teacher Mr.Wachs
   */
  class RockPaperScissors {
    const OPTIONS = ['R', 'P', 'S'];
    const WINNING_COMBINATIONS = [
      ['R', 'S'],
      ['P', 'R'],
      ['S', 'P']
    ];
    const KEY = [
      'R' => 'Rock',
      'P' => 'Paper',
      'S' => 'Scissors'
    ];

    public function __construct() {
      // create a variable to store the user's choice
      $userChoice = readline("Rock (R), Paper (P), or Scissors (S): ");
      $userChoice = strtoupper($userChoice);

      // create a variable to store the computer's choice
      $computerChoice = $this->getComputerChoice();

      // create a variable to store the winner
      $winner = $this->getWinner($userChoice, $computerChoice);

      // display the winner
      echo "You chose " . self::KEY[$userChoice] . " and the computer chose " . self::KEY[$computerChoice] . ".\n";
      echo "The winner is $winner!\n";


    }

    /**
     * Gets the computer's choice.
     * @return string
     */
    private function getComputerChoice(): string {
      $randomNumber = rand(0, 2);
      $computerChoice = self::OPTIONS[$randomNumber];
      return $computerChoice;
    }

    /**
     * Gets the winner of the game.
     * @param string $userChoice
     * @param string $computerChoice
     * @return string
     */
    private function getWinner(string $userChoice, string $computerChoice): string {
      if ($userChoice == $computerChoice) {
        return "Tie";
      } else {
        $combination = [$userChoice, $computerChoice];
        if (in_array($combination, self::WINNING_COMBINATIONS)) {
          return "User";
        } else {
          return "Computer";
        }
      }
    }
  }