using Match
using Test

plays = open("input") do f
    split.(eachsplit(read(f, String), "\n", keepempty = false))
end

translate(play) = @match play begin
    "A" || "X" => :rock
    "B" || "Y" => :paper
    "C" || "Z" => :scissors
end

weigth(play) = @match play begin
    :rock => 1
    :paper => 2
    :scissors => 3
end

function trumps(play)
    @match play begin
        :rock => :scissors
        :scissors => :paper
        :paper => :rock
        _ => error("Invalid play")
    end
end

function looses(play)
    @match play begin
        :rock => :paper
        :scissors => :rock
        :paper => :scissors
        _ => error("Invalid play")
    end
end

function points(my, other)
    if trumps(my) == other
        return 6
    elseif my == other
        return 3
    else
        return 0
    end
end

function fixed_play(oponent, my)
    oponent_hand = translate(oponent)
    my_hand = translate(my)
    points(my_hand, oponent_hand) + weigth(my_hand)
end

function reactive_play(oponent, my)
    oponent_hand = translate(oponent)
    my_hand = @match my begin
        "X" => trumps(oponent_hand) # I loose
        "Y" => oponent_hand
        "Z" => looses(oponent_hand) # I win
        _ => error("Invalid input")
    end
    points(my_hand, oponent_hand) + weigth(my_hand)
end


@testset "solutions" begin
    @test map(((op, my),) -> fixed_play(op, my), plays) |> sum == 12535
    @test map(((op, my),) -> reactive_play(op, my), plays) |> sum == 15457
end