-module(parser_gleam@stream).
-compile(no_auto_import).

-export([stream/2, get/1, at_end/1, get_and_next/1, get_eq/1]).
-export_type([stream/1, it_and_next/1]).

-type stream(FBA) :: {stream, list(FBA), integer()}.

-type it_and_next(FBB) :: {it_and_next, FBB, stream(FBB)}.

-spec stream(list(FBE), gleam@option:option(integer())) -> stream(FBE).
stream(Buffer, Cursor) ->
    {stream,
     Buffer,
     begin
         _pipe = Cursor,
         gleam@option:unwrap(_pipe, 0)
     end}.

-spec get(stream(FBI)) -> gleam@option:option(FBI).
get(S) ->
    _pipe = erlang:element(2, S),
    _pipe@1 = gleam@list:at(_pipe, erlang:element(3, S)),
    gleam@option:from_result(_pipe@1).

-spec at_end(stream(any())) -> boolean().
at_end(S) ->
    erlang:element(3, S) >= gleam@list:length(erlang:element(2, S)).

-spec get_and_next(stream(FBP)) -> gleam@option:option(it_and_next(FBP)).
get_and_next(S) ->
    _pipe = get(S),
    gleam@option:map(
        _pipe,
        fun(Value) ->
            {it_and_next,
             Value,
             {stream, erlang:element(2, S), erlang:element(3, S) + 1}}
        end
    ).

-spec get_eq(fp_gl@eq:eq(FBT)) -> fp_gl@eq:eq(stream(FBT)).
get_eq(E) ->
    fp_gl@eq:from_equals(
        fun(X, Y) ->
            Ea = fp_gl@flist:get_eq(E),
            (erlang:element(3, X)
            =:= erlang:element(3, Y))
            andalso (erlang:element(2, Ea))(
                erlang:element(2, X),
                erlang:element(2, Y)
            )
        end
    ).