-module(commonmark@internal@parser@helpers).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([ol_marker/1, ul_marker/1, trim_indent/2, determine_indent/1, parse_autolink/1, indent_pattern/1]).

-spec ol_marker(binary()) -> commonmark@ast:ordered_list_marker().
ol_marker(Marker) ->
    case Marker of
        <<"."/utf8>> ->
            period_list_marker;

        <<")"/utf8>> ->
            bracket_list_marker;

        _ ->
            erlang:error(#{gleam_error => panic,
                    message => (<<"Invalid ordered list marker: "/utf8,
                        Marker/binary>>),
                    module => <<"commonmark/internal/parser/helpers"/utf8>>,
                    function => <<"ol_marker"/utf8>>,
                    line => 13})
    end.

-spec ul_marker(binary()) -> commonmark@ast:unordered_list_marker().
ul_marker(Marker) ->
    case Marker of
        <<"*"/utf8>> ->
            asterisk_list_marker;

        <<"-"/utf8>> ->
            dash_list_marker;

        <<"+"/utf8>> ->
            plus_list_marker;

        _ ->
            erlang:error(#{gleam_error => panic,
                    message => (<<"Invalid unordered list marker: "/utf8,
                        Marker/binary>>),
                    module => <<"commonmark/internal/parser/helpers"/utf8>>,
                    function => <<"ul_marker"/utf8>>,
                    line => 22})
    end.

-spec do_trim_indent(binary(), integer(), integer()) -> binary().
do_trim_indent(Line, N, Removed) ->
    case Line of
        _ when Removed >= N ->
            Line;

        <<" "/utf8, Rest/binary>> ->
            do_trim_indent(Rest, N, Removed + 1);

        <<"\t"/utf8, Rest@1/binary>> ->
            Next_tab_stop = Removed + (4 - (Removed rem 4)),
            do_trim_indent(Rest@1, N, Removed + Next_tab_stop);

        _ ->
            Line
    end.

-spec trim_indent(binary(), integer()) -> binary().
trim_indent(Line, N) ->
    do_trim_indent(Line, N, 0).

-spec determine_indent(gleam@option:option(binary())) -> integer().
determine_indent(Indent) ->
    case Indent of
        none ->
            0;

        {some, S} ->
            gleam@string:length(S)
    end.

-spec parse_autolink(binary()) -> commonmark@ast:inline_node().
parse_autolink(Href) ->
    _assert_subject = gleam@regex:from_string(
        <<"^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?(?:\\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$"/utf8>>
    ),
    {ok, Email_regex} = 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 => <<"commonmark/internal/parser/helpers"/utf8>>,
                        function => <<"parse_autolink"/utf8>>,
                        line => 62})
    end,
    _assert_subject@1 = gleam@regex:from_string(
        <<"^[a-zA-Z][-a-zA-Z+.]{1,31}:"/utf8>>
    ),
    {ok, Uri_regex} = case _assert_subject@1 of
        {ok, _} -> _assert_subject@1;
        _assert_fail@1 ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Assertion pattern match failed"/utf8>>,
                        value => _assert_fail@1,
                        module => <<"commonmark/internal/parser/helpers"/utf8>>,
                        function => <<"parse_autolink"/utf8>>,
                        line => 66})
    end,
    case {gleam@regex:check(Email_regex, Href),
        gleam@regex:check(Uri_regex, Href)} of
        {true, _} ->
            {email_autolink, Href};

        {_, true} ->
            {uri_autolink, Href};

        {false, false} ->
            {plain_text, <<<<"<"/utf8, Href/binary>>/binary, ">"/utf8>>}
    end.

-spec indent_pattern(integer()) -> binary().
indent_pattern(Indent) ->
    case Indent of
        0 ->
            <<""/utf8>>;

        I when I >= 4 ->
            <<"(?: {0,3}\t|    )"/utf8, (indent_pattern(I - 4))/binary>>;

        I@1 ->
            <<<<" {"/utf8, (gleam@int:to_string(I@1))/binary>>/binary,
                "}"/utf8>>
    end.