-module(dream@http@params).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/dream/http/params.gleam").
-export([require_int/2, require_string/2, require_form/1, require_field/2, require_field_int/2, field_optional/2]).

-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(
    " Parameter validation and extraction utilities\n"
    "\n"
    " This module provides safe parameter extraction from HTTP requests,\n"
    " returning Result types with dream.Error instead of crashing on missing or invalid data.\n"
    "\n"
    " Use these helpers to validate path parameters and form data in controllers,\n"
    " then pipe the results through your business logic using gleam/result.\n"
).

-file("src/dream/http/params.gleam", 113).
-spec parse_int_field(binary(), binary()) -> {ok, integer()} |
    {error, dream@http@error:error()}.
parse_int_field(Value, Name) ->
    case gleam_stdlib:parse_int(Value) of
        {ok, I} ->
            {ok, I};

        {error, _} ->
            {error,
                {bad_request,
                    <<<<"Field '"/utf8, Name/binary>>/binary,
                        "' must be an integer"/utf8>>}}
    end.

-file("src/dream/http/params.gleam", 120).
-spec result_string_to_error({ok, ADRS} | {error, binary()}) -> {ok, ADRS} |
    {error, dream@http@error:error()}.
result_string_to_error(Result) ->
    case Result of
        {ok, Value} ->
            {ok, Value};

        {error, Msg} ->
            {error, {bad_request, Msg}}
    end.

-file("src/dream/http/params.gleam", 32).
?DOC(
    " Require a path parameter as an integer\n"
    "\n"
    " Returns a Result with dream.Error if the parameter is missing\n"
    " or cannot be converted to an integer.\n"
    "\n"
    " ## Examples\n"
    "\n"
    " ```gleam\n"
    " // Using with gleam/result pipeline\n"
    " let result = {\n"
    "   use id <- result.try(params.require_int(request, \"id\"))\n"
    "   // ... rest of logic with id : Int\n"
    " }\n"
    " ```\n"
).
-spec require_int(dream@http@request:request(), binary()) -> {ok, integer()} |
    {error, dream@http@error:error()}.
require_int(Req, Name) ->
    _pipe = dream@http@request:get_int_param(Req, Name),
    result_string_to_error(_pipe).

-file("src/dream/http/params.gleam", 47).
?DOC(
    " Require a path parameter as a string\n"
    "\n"
    " Returns a Result with dream.Error if the parameter is missing.\n"
    "\n"
    " ## Examples\n"
    "\n"
    " ```gleam\n"
    " use name <- result.try(params.require_string(request, \"name\"))\n"
    " // ... rest of logic with name : String\n"
    " ```\n"
).
-spec require_string(dream@http@request:request(), binary()) -> {ok, binary()} |
    {error, dream@http@error:error()}.
require_string(Req, Name) ->
    _pipe = dream@http@request:get_string_param(Req, Name),
    result_string_to_error(_pipe).

-file("src/dream/http/params.gleam", 192).
-spec decode_url_component(binary()) -> binary().
decode_url_component(Component) ->
    With_spaces = gleam@string:replace(Component, <<"+"/utf8>>, <<" "/utf8>>),
    case gleam_stdlib:percent_decode(With_spaces) of
        {ok, Decoded} ->
            Decoded;

        {error, _} ->
            With_spaces
    end.

-file("src/dream/http/params.gleam", 177).
-spec parse_form_pair(binary()) -> gleam@option:option({binary(), binary()}).
parse_form_pair(Pair) ->
    case gleam@string:split(Pair, <<"="/utf8>>) of
        [Key, Value] ->
            Decoded_key = decode_url_component(Key),
            Decoded_value = decode_url_component(Value),
            {some, {Decoded_key, Decoded_value}};

        [Key@1] ->
            Decoded_key@1 = decode_url_component(Key@1),
            {some, {Decoded_key@1, <<""/utf8>>}};

        _ ->
            none
    end.

-file("src/dream/http/params.gleam", 167).
-spec add_parsed_pair(binary(), list({binary(), binary()})) -> list({binary(),
    binary()}).
add_parsed_pair(Pair, Rest_parsed) ->
    case parse_form_pair(Pair) of
        {some, Kv} ->
            [Kv | Rest_parsed];

        none ->
            Rest_parsed
    end.

-file("src/dream/http/params.gleam", 157).
-spec parse_form_pairs(list(binary())) -> list({binary(), binary()}).
parse_form_pairs(Pairs) ->
    case Pairs of
        [] ->
            [];

        [Pair | Rest] ->
            Rest_parsed = parse_form_pairs(Rest),
            add_parsed_pair(Pair, Rest_parsed)
    end.

-file("src/dream/http/params.gleam", 150).
-spec parse_form_body(binary()) -> list({binary(), binary()}).
parse_form_body(Body) ->
    case Body of
        <<""/utf8>> ->
            [];

        _ ->
            parse_form_pairs(gleam@string:split(Body, <<"&"/utf8>>))
    end.

-file("src/dream/http/params.gleam", 63).
?DOC(
    " Require and parse form data from request body\n"
    "\n"
    " Returns a Result containing the parsed form data as key-value pairs.\n"
    " Returns an error if the body is empty or invalid.\n"
    "\n"
    " ## Examples\n"
    "\n"
    " ```gleam\n"
    " use form <- result.try(params.require_form(request))\n"
    " use title <- result.try(params.require_field(form, \"title\"))\n"
    " ```\n"
).
-spec require_form(dream@http@request:request()) -> {ok,
        list({binary(), binary()})} |
    {error, dream@http@error:error()}.
require_form(Req) ->
    case erlang:element(11, Req) of
        <<""/utf8>> ->
            {error, {bad_request, <<"Request body is empty"/utf8>>}};

        Body ->
            {ok, parse_form_body(Body)}
    end.

-file("src/dream/http/params.gleam", 203).
-spec get_form_field(list({binary(), binary()}), binary()) -> gleam@option:option(binary()).
get_form_field(Form_data, Name) ->
    _pipe = gleam@list:key_find(Form_data, Name),
    gleam@option:from_result(_pipe).

-file("src/dream/http/params.gleam", 80).
?DOC(
    " Require a field from form data\n"
    "\n"
    " Returns an error if the field is missing or empty.\n"
    "\n"
    " ## Examples\n"
    "\n"
    " ```gleam\n"
    " use form <- result.try(params.require_form(request))\n"
    " use title <- result.try(params.require_field(form, \"title\"))\n"
    " ```\n"
).
-spec require_field(list({binary(), binary()}), binary()) -> {ok, binary()} |
    {error, dream@http@error:error()}.
require_field(Form, Name) ->
    case get_form_field(Form, Name) of
        {some, <<""/utf8>>} ->
            {error,
                {bad_request,
                    <<<<"Field '"/utf8, Name/binary>>/binary,
                        "' cannot be empty"/utf8>>}};

        {some, Value} ->
            {ok, Value};

        none ->
            {error,
                {bad_request, <<"Missing required field: "/utf8, Name/binary>>}}
    end.

-file("src/dream/http/params.gleam", 102).
?DOC(
    " Require a field from form data as an integer\n"
    "\n"
    " Returns an error if the field is missing, empty, or not a valid integer.\n"
    "\n"
    " ## Examples\n"
    "\n"
    " ```gleam\n"
    " use form <- result.try(params.require_form(request))\n"
    " use priority <- result.try(params.require_field_int(form, \"priority\"))\n"
    " ```\n"
).
-spec require_field_int(list({binary(), binary()}), binary()) -> {ok, integer()} |
    {error, dream@http@error:error()}.
require_field_int(Form, Name) ->
    Result = begin
        gleam@result:'try'(
            require_field(Form, Name),
            fun(Value) -> parse_int_field(Value, Name) end
        )
    end,
    Result.

-file("src/dream/http/params.gleam", 137).
?DOC(
    " Extract an optional field from form data\n"
    "\n"
    " Returns None if the field is missing or empty, Some(value) otherwise.\n"
    " This never returns an error - use this for truly optional fields.\n"
    "\n"
    " ## Examples\n"
    "\n"
    " ```gleam\n"
    " let description = params.field_optional(form, \"description\")\n"
    " ```\n"
).
-spec field_optional(list({binary(), binary()}), binary()) -> gleam@option:option(binary()).
field_optional(Form, Name) ->
    case get_form_field(Form, Name) of
        {some, <<""/utf8>>} ->
            none;

        {some, Value} ->
            {some, Value};

        none ->
            none
    end.