class RockPaperScissors

    require_relative 'RPSrb/Version.rb'

    # make choices constant (2d list)
    CHOICES = [['r', 'rock'], ['p', 'paper'], ['s', 'scissors']]


    # define an entry to symbol dictionary
    NTRY_TO_SYM = {
        CHOICES[0][0] => :ROCK    , CHOICES[0][1] => :ROCK    ,
        CHOICES[1][0] => :PAPER   , CHOICES[1][1] => :PAPER   ,
        CHOICES[2][0] => :SCISSORS, CHOICES[2][1] => :SCISSORS
    }

    # define what our valid entries out
    VALID_ENTRIES = NTRY_TO_SYM.keys

    # define possible computer choices
    COMPUTER_CHOICES = NTRY_TO_SYM.values

    # define winners 2d array
    WINNERS = [
        [:SCISSORS, :PAPER   ],
        [:PAPER   , :ROCK    ],
        [:ROCK    , :SCISSORS]
    ]

    # map array for losers
    LOSERS = WINNERS.map { |winning_choice,losing_choice| [losing_choice,winning_choice] }

    class << self
        # define entry point for game
        protected
        def continue(str1,str2,str3)
            puts  str1
            print str2
            gets
            puts  str3
        end
    end

    continue("\nYou are about to enter a rock-paper-scissors best of 3 match.", "\nPress the return/enter key to continue...", "")

    # define constructor for class
    protected
    def initialize
        @player_score = @computer_score = @ties = 0
    end

    # define play game method
    public
    def play(winning_score)
        while @player_score < winning_score && @computer_score < winning_score
            puts "\nPlayer score: #{@player_score}, " +
                "Computer score: #{@computer_score}, Ties: #{@ties}.\n"
            player = player_choice
            computer = COMPUTER_CHOICES.sample # chooses a random option
            puts "\nPlayer chooses #{player.to_s.downcase}."
            puts "Computer chooses #{computer.to_s.downcase}.\n"
            case player_outcome [player, computer]
            when :WIN
                printf "\n%s beats %s, player wins the round. \n\n" % [player.to_s.capitalize, computer.to_s.downcase]
                @player_score += 1
            when :LOSE
                printf "\n%s beats %s, computer wins the round.\n\n" % [computer.to_s.capitalize, player.to_s.downcase]
                @computer_score += 1
            else
                puts "\nTie, choose again\n"
                @ties += 1
            end
        end
        printf "\nFinal score:\nplayer: %i, computer: %i; (ties: %i).\n\n" % [@player_score, @computer_score, @ties]
        case final_outcome(@player_score, @computer_score)
        when :WIN
            puts "Player wins!\n"
        when :LOSE
            puts "Computer wins!\n"
        end
        print "\n[press the enter/return key to exit game]"
        gets
        puts
    end  

    # make player choice method
    private
    def player_choice
        loop do
            print "\nChoose: Rock (r), Paper (p), or Scissors (s): "
            choice = gets.chomp.downcase
            if NTRY_TO_SYM.key?(choice)
                return NTRY_TO_SYM[choice]
            elsif choice != VALID_ENTRIES
                puts "\nThat entry is invalid. Please re-enter.\n"
            else
                return nil
            end
        end
    end

    # define player outcome
    private
    def player_outcome(plays)
        return :WIN  if WINNERS.include?(plays)
        return :LOSE if LOSERS.include?(plays)
        return :TIE  if !:WIN | !:LOSE
    end
    
    # define final outcome function
    private
    def final_outcome(pl, co)
        return :WIN  if pl > co
        return :LOSE if pl < co
    end

end

require 'exec.rb'