-module(glsql@suggest).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/glsql/suggest.gleam").
-export([distance/2, closest/2]).

-file("src/glsql/suggest.gleam", 35).
-spec step_row(list(binary()), list(integer()), binary(), integer()) -> list(integer()).
step_row(B, Prev, Ac, I) ->
    Start = I + 1,
    {Row, _} = gleam@list:fold(
        B,
        {[Start], Prev},
        fun(State, Bc) ->
            {Acc, Prev_rest} = State,
            case {Acc, Prev_rest} of
                {[Left | _], [Diag, Up | Rest]} ->
                    Cost = case Ac =:= Bc of
                        true ->
                            0;

                        false ->
                            1
                    end,
                    Best = gleam@int:min(
                        gleam@int:min(Left + 1, Up + 1),
                        Diag + Cost
                    ),
                    {[Best | Acc], [Up | Rest]};

                {_, _} ->
                    State
            end
        end
    ),
    lists:reverse(Row).

-file("src/glsql/suggest.gleam", 19).
-spec distance(binary(), binary()) -> integer().
distance(A, B) ->
    A@1 = gleam@string:to_graphemes(A),
    B@1 = gleam@string:to_graphemes(B),
    First_row = begin
        _pipe = gleam@int:range(
            0,
            erlang:length(B@1) + 1,
            [],
            fun(Acc, I) -> [I | Acc] end
        ),
        lists:reverse(_pipe)
    end,
    Final = gleam@list:index_fold(
        A@1,
        First_row,
        fun(Prev, Ac, I@1) -> step_row(B@1, Prev, Ac, I@1) end
    ),
    case gleam@list:last(Final) of
        {ok, D} ->
            D;

        {error, nil} ->
            0
    end.

-file("src/glsql/suggest.gleam", 6).
-spec closest(binary(), list(binary())) -> gleam@option:option(binary()).
closest(Word, Candidates) ->
    Needle = string:lowercase(Word),
    Limit = gleam@int:min(2, string:length(Needle) - 1),
    _pipe = Candidates,
    _pipe@1 = gleam@list:map(
        _pipe,
        fun(C) -> {C, distance(Needle, string:lowercase(C))} end
    ),
    _pipe@2 = gleam@list:filter(
        _pipe@1,
        fun(Pair) -> erlang:element(2, Pair) =< Limit end
    ),
    _pipe@3 = gleam@list:sort(
        _pipe@2,
        fun(A, B) ->
            gleam@int:compare(erlang:element(2, A), erlang:element(2, B))
        end
    ),
    _pipe@4 = gleam@list:first(_pipe@3),
    _pipe@5 = gleam@option:from_result(_pipe@4),
    gleam@option:map(_pipe@5, fun(Pair@1) -> erlang:element(1, Pair@1) end).