#include <utility>
#include <cmath>

struct Square
{
    char file; // engelskt namn på kolumnen
    int rank;  // engelskt namn på raden
    std::pair<size_t, size_t> diff(Square s) const
    {
        return { abs(s.file - file), abs(s.rank - rank) };
    }
};

#include "catch.hpp"

TEST_CASE("Pawn movement")
{
    Chess_Piece pawn { {'A', 2}, new Pawn_Behavior };
    pawn.move({'A', 4});
    CHECK(pawn.position().rank == 4);
    pawn.move({'A', 6}); // felaktig
    CHECK(pawn.position().rank == 4);
    pawn.move({'B', 4});
    CHECK(pawn.position().rank == 4);
    CHECK(pawn.position().file == 'A');
}

TEST_CASE("Rook movement")
{
    Chess_Piece rook { {'A', 1}, new Rook_Behavior };
    rook.move({'A', 4});
    CHECK(rook.position().rank == 4);
    rook.move({'D', 4});
    CHECK(rook.position().rank == 4);
    CHECK(rook.position().file == 'D');
    rook.move({'B', 5}); // felaktig
    CHECK(rook.position().rank == 4);
}

TEST_CASE("Queen movement")
{
    Chess_Piece queen { {'D', 1}, new Queen_Behavior };
    queen.move({'A', 4});
    CHECK(queen.position().rank == 4);
    queen.move({'A', 6});
    CHECK(queen.position().rank == 6);
    queen.move({'B', 6});
    CHECK(queen.position().rank == 6);
    CHECK(queen.position().file == 'B');
}