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

-export([get_raw_sections/2]).
-export_type([raw_tag/0, raw_section/0]).

-type raw_tag() :: {raw_tag,
        binary(),
        integer(),
        integer(),
        boolean(),
        boolean(),
        binary()}.

-type raw_section() :: {raw_text_section, binary(), integer(), integer()} |
    {raw_tag_section, raw_tag()}.

-spec get_attrs_text(binary()) -> {binary(), binary()}.
get_attrs_text(S) ->
    grapheme_util:get_chars_matching_func(
        S,
        <<""/utf8>>,
        fun grapheme_util:is_not_gt/1
    ).

-spec get_tags_rec(
    binary(),
    integer(),
    gleam@set:set(binary()),
    list(raw_tag())
) -> {ok, list(raw_tag())} | {error, tagg_error:tagg_error()}.
get_tags_rec(S, I, Custom_tag_names, Acc) ->
    case S of
        <<"<!"/utf8, Rest/binary>> ->
            get_tags_rec(Rest, I + 2, Custom_tag_names, Acc);

        <<"</"/utf8, Rest@1/binary>> ->
            Start = I,
            I@1 = I + 2,
            {Tag_name, Rest@2, Num_graphemes} = grapheme_util:get_name_ignore_ws(
                Rest@1
            ),
            I@2 = I@1 + Num_graphemes,
            case gleam@set:contains(Custom_tag_names, Tag_name) of
                true ->
                    case Rest@2 of
                        <<">"/utf8, Rest@3/binary>> ->
                            get_tags_rec(
                                Rest@3,
                                I@2 + 1,
                                Custom_tag_names,
                                [{raw_tag,
                                        Tag_name,
                                        Start,
                                        I@2,
                                        true,
                                        false,
                                        <<""/utf8>>} |
                                    Acc]
                            );

                        _ ->
                            {error,
                                {tag_not_closed_error,
                                    <<"Closing tag not closed for tag: "/utf8,
                                        Tag_name/binary>>}}
                    end;

                false ->
                    get_tags_rec(Rest@2, I@2, Custom_tag_names, Acc)
            end;

        <<"<"/utf8, Rest@4/binary>> ->
            Start@1 = I,
            I@3 = I + 1,
            {Tag_name@1, Rest@5, Num_graphemes@1} = grapheme_util:get_name_ignore_ws(
                Rest@4
            ),
            I@4 = I@3 + Num_graphemes@1,
            case gleam@set:contains(Custom_tag_names, Tag_name@1) of
                true ->
                    {Attrs_text, Rest@6} = get_attrs_text(Rest@5),
                    I@5 = I@4 + gleam@string:length(Attrs_text),
                    case Rest@6 of
                        <<">"/utf8, Rest@7/binary>> ->
                            case gleam@string:ends_with(
                                Attrs_text,
                                <<"/"/utf8>>
                            ) of
                                true ->
                                    get_tags_rec(
                                        Rest@7,
                                        I@5 + 1,
                                        Custom_tag_names,
                                        [{raw_tag,
                                                Tag_name@1,
                                                Start@1,
                                                I@5,
                                                false,
                                                true,
                                                gleam@string:drop_right(
                                                    Attrs_text,
                                                    1
                                                )} |
                                            Acc]
                                    );

                                false ->
                                    get_tags_rec(
                                        Rest@7,
                                        I@5 + 1,
                                        Custom_tag_names,
                                        [{raw_tag,
                                                Tag_name@1,
                                                Start@1,
                                                I@5,
                                                false,
                                                false,
                                                Attrs_text} |
                                            Acc]
                                    )
                            end;

                        _ ->
                            {error,
                                {tag_not_closed_error,
                                    <<"Closing tag not closed for tag: "/utf8,
                                        Tag_name@1/binary>>}}
                    end;

                false ->
                    get_tags_rec(Rest@5, I@4, Custom_tag_names, Acc)
            end;

        _ ->
            case gleam@string:pop_grapheme(S) of
                {ok, {_, Rest@8}} ->
                    get_tags_rec(Rest@8, I + 1, Custom_tag_names, Acc);

                {error, _} ->
                    {ok, Acc}
            end
    end.

-spec get_tags(binary(), gleam@set:set(binary())) -> {ok, list(raw_tag())} |
    {error, tagg_error:tagg_error()}.
get_tags(S, Custom_tag_names) ->
    case get_tags_rec(S, 0, Custom_tag_names, []) of
        {ok, Tags} ->
            {ok, lists:reverse(Tags)};

        {error, Err} ->
            {error, Err}
    end.

-spec get_raw_sections_rec(
    list(raw_tag()),
    binary(),
    integer(),
    list(raw_section())
) -> list(raw_section()).
get_raw_sections_rec(Tags, S, I, Acc) ->
    case gleam@list:first(Tags) of
        {ok, Tag} ->
            case I < erlang:element(3, Tag) of
                true ->
                    Text_len = erlang:element(3, Tag) - I,
                    Tag_len = (erlang:element(4, Tag) - erlang:element(3, Tag))
                    + 1,
                    get_raw_sections_rec(
                        gleam@list:drop(Tags, 1),
                        gleam@string:drop_left(S, Text_len + Tag_len),
                        erlang:element(4, Tag) + 1,
                        [{raw_tag_section, Tag},
                            {raw_text_section,
                                gleam@string:slice(S, 0, Text_len),
                                I,
                                erlang:element(3, Tag) - 1} |
                            Acc]
                    );

                false ->
                    get_raw_sections_rec(
                        gleam@list:drop(Tags, 1),
                        gleam@string:drop_left(
                            S,
                            (erlang:element(4, Tag) - erlang:element(3, Tag)) + 1
                        ),
                        erlang:element(4, Tag) + 1,
                        [{raw_tag_section, Tag} | Acc]
                    )
            end;

        {error, _} ->
            case gleam@string:is_empty(S) of
                true ->
                    Acc;

                false ->
                    [{raw_text_section, S, I, (I + gleam@string:length(S)) - 1} |
                        Acc]
            end
    end.

-spec get_raw_sections(binary(), gleam@set:set(binary())) -> {ok,
        list(raw_section())} |
    {error, tagg_error:tagg_error()}.
get_raw_sections(S, Custom_tag_names) ->
    case get_tags(S, Custom_tag_names) of
        {ok, Tags} ->
            {ok,
                lists:reverse(
                    begin
                        _pipe = Tags,
                        get_raw_sections_rec(_pipe, S, 0, [])
                    end
                )};

        {error, Err} ->
            {error, Err}
    end.