-module(gleambox).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([get_headers/1, get_header/2, get_body/1, get_from/1, get_to/1, get_date/1, get_subject/1, get_message_id/1, get_references/1, parse/1]).
-export_type([m_box/0]).

-type m_box() :: {m_box, gleam@dict:dict(binary(), binary()), binary()}.

-spec get_headers(m_box()) -> gleam@dict:dict(binary(), binary()).
get_headers(Mbox) ->
    erlang:element(2, Mbox).

-spec get_header(m_box(), binary()) -> {ok, binary()} | {error, nil}.
get_header(Mbox, Key) ->
    _pipe = erlang:element(2, Mbox),
    gleam@dict:get(_pipe, Key).

-spec get_body(m_box()) -> binary().
get_body(Mbox) ->
    erlang:element(3, Mbox).

-spec get_from(m_box()) -> {ok, binary()} | {error, nil}.
get_from(Mbox) ->
    get_header(Mbox, <<"From"/utf8>>).

-spec get_to(m_box()) -> {ok, binary()} | {error, nil}.
get_to(Mbox) ->
    get_header(Mbox, <<"To"/utf8>>).

-spec get_date(m_box()) -> {ok, binary()} | {error, nil}.
get_date(Mbox) ->
    get_header(Mbox, <<"Date"/utf8>>).

-spec get_subject(m_box()) -> {ok, binary()} | {error, nil}.
get_subject(Mbox) ->
    get_header(Mbox, <<"Subject"/utf8>>).

-spec get_message_id(m_box()) -> {ok, binary()} | {error, nil}.
get_message_id(Mbox) ->
    get_header(Mbox, <<"Message-ID"/utf8>>).

-spec get_references(m_box()) -> list(binary()).
get_references(Mbox) ->
    _pipe = get_header(Mbox, <<"References"/utf8>>),
    _pipe@1 = gleam@result:unwrap(_pipe, <<"Error"/utf8>>),
    gleam@string:split(_pipe@1, <<" "/utf8>>).

-spec parse_body(binary()) -> binary().
parse_body(Mboxcontents) ->
    _pipe = Mboxcontents,
    _pipe@1 = gleam@string:split_once(_pipe, <<"\n\n"/utf8>>),
    _pipe@2 = gleam@result:unwrap(_pipe@1, {<<""/utf8>>, <<""/utf8>>}),
    gleam@pair:second(_pipe@2).

-spec get_header_dict(binary()) -> {binary(), binary()}.
get_header_dict(S) ->
    _pipe = S,
    _pipe@1 = gleam@string:split_once(_pipe, <<": "/utf8>>),
    gleam@result:unwrap(_pipe@1, {<<""/utf8>>, <<""/utf8>>}).

-spec remove_dead_space(binary(), binary()) -> binary().
remove_dead_space(Acc, Matched_content) ->
    _assert_subject = gleam@regex:from_string(<<"\\s+"/utf8>>),
    {ok, Dead_space} = case _assert_subject of
        {ok, _} -> _assert_subject;
        _assert_fail ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Assertion pattern match failed"/utf8>>,
                        value => _assert_fail,
                        module => <<"gleambox"/utf8>>,
                        function => <<"remove_dead_space"/utf8>>,
                        line => 98})
    end,
    _pipe = Matched_content,
    _pipe@1 = gleam@regex:split(Dead_space, _pipe),
    _pipe@2 = gleam@string:join(_pipe@1, <<" "/utf8>>),
    gleam@string:replace(Acc, Matched_content, _pipe@2).

-spec fix_multiline_values(binary()) -> binary().
fix_multiline_values(S) ->
    _assert_subject = gleam@regex:compile(
        <<": [^\n]+\n\\s+[^\n]+$"/utf8>>,
        {options, true, true}
    ),
    {ok, Multi_line_value} = case _assert_subject of
        {ok, _} -> _assert_subject;
        _assert_fail ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Assertion pattern match failed"/utf8>>,
                        value => _assert_fail,
                        module => <<"gleambox"/utf8>>,
                        function => <<"fix_multiline_values"/utf8>>,
                        line => 86})
    end,
    _pipe = S,
    _pipe@1 = gleam@regex:scan(Multi_line_value, _pipe),
    _pipe@2 = gleam@list:map(
        _pipe@1,
        fun(Match) -> erlang:element(2, Match) end
    ),
    _pipe@3 = gleam@list:scan(_pipe@2, S, fun remove_dead_space/2),
    _pipe@4 = gleam@list:first(_pipe@3),
    gleam@result:unwrap(_pipe@4, <<"bar"/utf8>>).

-spec parse_headers(binary()) -> gleam@dict:dict(binary(), binary()).
parse_headers(Mboxcontents) ->
    _pipe = Mboxcontents,
    _pipe@1 = gleam@string:split_once(_pipe, <<"\n\n"/utf8>>),
    _pipe@2 = gleam@result:unwrap(_pipe@1, {<<""/utf8>>, <<""/utf8>>}),
    _pipe@3 = gleam@pair:first(_pipe@2),
    _pipe@4 = fix_multiline_values(_pipe@3),
    _pipe@5 = gleam@string:split(_pipe@4, <<"\n"/utf8>>),
    _pipe@6 = gleam@list:map(_pipe@5, fun get_header_dict/1),
    maps:from_list(_pipe@6).

-spec parse(binary()) -> m_box().
parse(Mboxcontents) ->
    {m_box, parse_headers(Mboxcontents), parse_body(Mboxcontents)}.