gchess

-module(move).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([to_string/1]).
-export_type([move/0]).

-type move() :: {normal,
        position:position(),
        position:position(),
        gleam@option:option(piece:piece()),
        gleam@option:option(piece:piece())} |
    {castle, position:position(), position:position()} |
    {en_passant, position:position(), position:position()}.

-spec to_string(move()) -> binary().
to_string(Move) ->
    From = position:to_string(erlang:element(2, Move)),
    To = position:to_string(erlang:element(3, Move)),
    Captured@2 = case Move of
        {normal, _, _, none, none} ->
            <<""/utf8>>;

        {normal, _, _, none, {some, Promotion}} ->
            <<" promoting to "/utf8, (piece:to_string(Promotion))/binary>>;

        {normal, _, _, {some, Captured}, none} ->
            <<" capturing "/utf8, (piece:to_string(Captured))/binary>>;

        {normal, _, _, {some, Captured@1}, {some, Promotion@1}} ->
            <<<<<<" capturing "/utf8, (piece:to_string(Captured@1))/binary>>/binary,
                    " and promoting to "/utf8>>/binary,
                (piece:to_string(Promotion@1))/binary>>;

        {castle, _, _} ->
            <<" castling"/utf8>>;

        {en_passant, _, _} ->
            <<" en passant"/utf8>>
    end,
    <<<<<<From/binary, ""/utf8>>/binary, To/binary>>/binary, Captured@2/binary>>.