#!/usr/bin/env ruby

require_relative '../common'

class Day02 < Day
  WIN = 6
  DRAW = 3
  LOSE = 0

  class MovePart1
    def self.game
      {
        "X" => new("A", "C", 1),
        "Y" => new("B", "A", 2),
        "Z" => new("C", "B", 3)
      }
    end

    def self.score(input)
      game[input[2]].score(input[0])
    end

    def initialize(opponent_letter, beat_letter, score)
      @opponent_letter = opponent_letter
      @beat_letter = beat_letter
      @score = score
    end

    def score(played_letter)
      match_result = if @opponent_letter == played_letter
        Day02::DRAW
      elsif played_letter == @beat_letter
        Day02::WIN
      else
        Day02::LOSE
      end

      match_result + @score
    end
  end

  class MovePart2
    SCORES = {
      "A" => 1,
      "B" => 2,
      "C" => 3
    }

    def self.score(input)
      if input[2] == "X"
        Day02::LOSE + SCORES[SCORES.keys[SCORES.keys.index(input[0]) - 1]]
      elsif input[2] == "Y"
        Day02::DRAW + SCORES[input[0]]
      else
        Day02::WIN + SCORES[SCORES.keys[(SCORES.keys.index(input[0]) + 1) % SCORES.keys.size]]
      end
    end
  end

  def part1
    stdin.map { |i| MovePart1.score i }.sum
  end

  def part2
    stdin.map { |i| MovePart2.score i }.sum
  end
end

Day02.run