-module(libero@format).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/libero/format.gleam").
-export([format_gleam/1]).

-if(?OTP_RELEASE >= 27).
-define(MODULEDOC(Str), -moduledoc(Str)).
-define(DOC(Str), -doc(Str)).
-else.
-define(MODULEDOC(Str), -compile([])).
-define(DOC(Str), -compile([])).
-endif.

?MODULEDOC(
    " Run `gleam format` on generated Gleam code.\n"
    "\n"
    " Writes code to a temp file, runs the formatter, reads back the result.\n"
    " Falls back to the original string if formatting fails.\n"
).

-file("src/libero/format.gleam", 58).
-spec run_executable(binary(), list(binary())) -> integer().
run_executable(Executable, Args) ->
    case libero_cli_ffi:find_executable(Executable) of
        none ->
            -1;

        {some, Path} ->
            libero_cli_ffi:run_executable(Path, Args)
    end.

-file("src/libero/format.gleam", 41).
-spec run_format(binary(), binary()) -> binary().
run_format(Tmp, Fallback) ->
    Exit_code = run_executable(<<"gleam"/utf8>>, [<<"format"/utf8>>, Tmp]),
    case Exit_code of
        0 ->
            _pipe = simplifile:read(Tmp),
            gleam@result:unwrap(_pipe, Fallback);

        _ ->
            gleam_stdlib:println_error(
                <<<<"warning: gleam format failed (exit code "/utf8,
                        (erlang:integer_to_binary(Exit_code))/binary>>/binary,
                    "), using unformatted output"/utf8>>
            ),
            Fallback
    end.

-file("src/libero/format.gleam", 99).
-spec find_env(list(binary()), binary()) -> gleam@option:option(binary()).
find_env(Entries, Prefix) ->
    case Entries of
        [] ->
            none;

        [Entry | Rest] ->
            case gleam_stdlib:string_starts_with(Entry, Prefix) of
                true ->
                    {some,
                        gleam@string:drop_start(Entry, string:length(Prefix))};

                false ->
                    find_env(Rest, Prefix)
            end
    end.

-file("src/libero/format.gleam", 91).
?DOC(" nolint: thrown_away_error -- env var lookup failure is expected (var not set)\n").
-spec get_env(binary()) -> gleam@option:option(binary()).
get_env(Name) ->
    Raw = os:getenv(),
    case gleam@dynamic@decode:run(
        Raw,
        gleam@dynamic@decode:list(
            {decoder, fun gleam@dynamic@decode:decode_string/1}
        )
    ) of
        {ok, Entries} ->
            find_env(Entries, <<Name/binary, "="/utf8>>);

        {error, _} ->
            none
    end.

-file("src/libero/format.gleam", 77).
-spec get_tmp_dir() -> binary().
get_tmp_dir() ->
    _pipe = get_env(<<"TMPDIR"/utf8>>),
    _pipe@1 = gleam@option:lazy_or(_pipe, fun() -> get_env(<<"TMP"/utf8>>) end),
    _pipe@2 = gleam@option:lazy_or(
        _pipe@1,
        fun() -> get_env(<<"TEMP"/utf8>>) end
    ),
    gleam@option:unwrap(_pipe@2, <<"/tmp"/utf8>>).

-file("src/libero/format.gleam", 18).
?DOC(
    " Format a string of Gleam code using `gleam format`.\n"
    " Returns the formatted code, or the original if formatting fails.\n"
    " nolint: thrown_away_error -- intentional fallback: formatting is best-effort\n"
).
-spec format_gleam(binary()) -> binary().
format_gleam(Code) ->
    Suffix = <<<<(erlang:integer_to_binary(
                gleam@int:absolute_value(erlang:unique_integer())
            ))/binary,
            "_"/utf8>>/binary,
        (erlang:integer_to_binary(rand:uniform(999999)))/binary>>,
    Tmp_dir = get_tmp_dir(),
    Tmp = <<<<<<Tmp_dir/binary, "/libero_fmt_"/utf8>>/binary, Suffix/binary>>/binary,
        ".gleam"/utf8>>,
    case simplifile:write(Tmp, Code) of
        {error, _} ->
            gleam_stdlib:println_error(
                <<"warning: could not write temp file for formatting, skipping gleam format"/utf8>>
            ),
            Code;

        {ok, _} ->
            Formatted = run_format(Tmp, Code),
            _ = simplifile_erl:delete(Tmp),
            Formatted
    end.