multipartkit

-module(multipartkit@limit).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/multipartkit/limit.gleam").
-export([default_limits/0, new/4, max_body_bytes/1, max_part_bytes/1, max_parts/1, max_header_bytes/1]).
-export_type([limits/0, limit_config_error/0]).

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

-opaque limits() :: {limits, integer(), integer(), integer(), integer()}.

-type limit_config_error() :: {non_positive_limit, binary(), integer()}.

-file("src/multipartkit/limit.gleam", 36).
?DOC(
    " Conservative defaults used by `parse` and `parse_stream` when no explicit\n"
    " limits are supplied.\n"
).
-spec default_limits() -> limits().
default_limits() ->
    {limits, 10000000, 5000000, 100, 16384}.

-file("src/multipartkit/limit.gleam", 84).
-spec check_positive(binary(), integer()) -> {ok, nil} |
    {error, limit_config_error()}.
check_positive(Field, Value) ->
    gleam@bool:guard(
        Value < 1,
        {error, {non_positive_limit, Field, Value}},
        fun() -> {ok, nil} end
    ).

-file("src/multipartkit/limit.gleam", 66).
?DOC(
    " Construct a `Limits` value with validation. Each field must be `>= 1`;\n"
    " otherwise the returned `Error` names the first failing field.\n"
    "\n"
    " Use this in any path where the limit values come from configuration,\n"
    " CLI flags, request input, or other dynamic input. For trusted\n"
    " constants the direct `Limits(...)` constructor is also fine, but\n"
    " callers that want a stable surface ahead of the `Limits` type being\n"
    " closed (see the upcoming opaque-type work) should prefer `new`.\n"
    "\n"
    " Example:\n"
    "   import multipartkit/limit\n"
    "\n"
    "   case limit.new(\n"
    "     max_body_bytes: 5_000_000,\n"
    "     max_part_bytes: 2_000_000,\n"
    "     max_parts: 50,\n"
    "     max_header_bytes: 8_192,\n"
    "   ) {\n"
    "     Ok(limits) -> ...\n"
    "     Error(limit.NonPositiveLimit(field: f, given: g)) -> ...\n"
    "   }\n"
).
-spec new(integer(), integer(), integer(), integer()) -> {ok, limits()} |
    {error, limit_config_error()}.
new(Max_body_bytes, Max_part_bytes, Max_parts, Max_header_bytes) ->
    gleam@result:'try'(
        check_positive(<<"max_body_bytes"/utf8>>, Max_body_bytes),
        fun(_) ->
            gleam@result:'try'(
                check_positive(<<"max_part_bytes"/utf8>>, Max_part_bytes),
                fun(_) ->
                    gleam@result:'try'(
                        check_positive(<<"max_parts"/utf8>>, Max_parts),
                        fun(_) ->
                            gleam@result:'try'(
                                check_positive(
                                    <<"max_header_bytes"/utf8>>,
                                    Max_header_bytes
                                ),
                                fun(_) ->
                                    {ok,
                                        {limits,
                                            Max_body_bytes,
                                            Max_part_bytes,
                                            Max_parts,
                                            Max_header_bytes}}
                                end
                            )
                        end
                    )
                end
            )
        end
    ).

-file("src/multipartkit/limit.gleam", 93).
?DOC(" Total-input byte budget. See `Limits.max_body_bytes`.\n").
-spec max_body_bytes(limits()) -> integer().
max_body_bytes(Limits) ->
    erlang:element(2, Limits).

-file("src/multipartkit/limit.gleam", 98).
?DOC(" Per-part body byte budget. See `Limits.max_part_bytes`.\n").
-spec max_part_bytes(limits()) -> integer().
max_part_bytes(Limits) ->
    erlang:element(3, Limits).

-file("src/multipartkit/limit.gleam", 103).
?DOC(" Maximum number of parts. See `Limits.max_parts`.\n").
-spec max_parts(limits()) -> integer().
max_parts(Limits) ->
    erlang:element(4, Limits).

-file("src/multipartkit/limit.gleam", 108).
?DOC(" Per-part header-block byte budget. See `Limits.max_header_bytes`.\n").
-spec max_header_bytes(limits()) -> integer().
max_header_bytes(Limits) ->
    erlang:element(5, Limits).