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

-export([parse_text/1, parse_paragraph/1, parse_block_state/1, parse_blocks/1]).
-export_type([parser_state/0, block_parse_state/0]).

-type parser_state() :: outside_block |
    {paragraph_builder, list(binary())} |
    {code_block_builder,
        binary(),
        gleam@option:option(binary()),
        gleam@option:option(binary()),
        list(binary())}.

-opaque block_parse_state() :: {paragraph, list(binary())} |
    horizontal_break |
    {heading, integer(), gleam@option:option(list(binary()))} |
    {code_block,
        gleam@option:option(binary()),
        gleam@option:option(binary()),
        list(binary())}.

-spec parse_text(list(binary())) -> list(commonmark@ast:inline_node()).
parse_text(Text) ->
    Len = erlang:length(Text) - 1,
    _assert_subject = gleam@regex:from_string(<<"(  |\\\\)$"/utf8>>),
    {ok, Hard_break_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"/utf8>>,
                        function => <<"parse_text"/utf8>>,
                        line => 23})
    end,
    _pipe = Text,
    _pipe@5 = gleam@list:index_map(
        _pipe,
        fun(L, I) -> case gleam@regex:check(Hard_break_regex, L) of
                _ when I =:= Len ->
                    [{text,
                            begin
                                _pipe@1 = L,
                                gleam@string:trim(_pipe@1)
                            end}];

                true ->
                    [{text,
                            begin
                                _pipe@2 = L,
                                _pipe@3 = gleam@string:drop_right(_pipe@2, 1),
                                gleam@string:trim(_pipe@3)
                            end},
                        hard_line_break];

                _ ->
                    [{text,
                            begin
                                _pipe@4 = L,
                                gleam@string:trim(_pipe@4)
                            end},
                        soft_line_break]
            end end
    ),
    gleam@list:concat(_pipe@5).

-spec parse_paragraph(list(binary())) -> commonmark@ast:block_node().
parse_paragraph(Lines) ->
    _pipe = Lines,
    _pipe@1 = parse_text(_pipe),
    {paragraph, _pipe@1}.

-spec parse_block_state(block_parse_state()) -> list(commonmark@ast:block_node()).
parse_block_state(State) ->
    case State of
        {paragraph, Lines} ->
            [begin
                    _pipe = Lines,
                    _pipe@1 = lists:reverse(_pipe),
                    _pipe@2 = parse_text(_pipe@1),
                    {paragraph, _pipe@2}
                end];

        {code_block, Info, Full_info, Lines@1} ->
            [{code_block,
                    Info,
                    Full_info,
                    begin
                        _pipe@3 = Lines@1,
                        _pipe@4 = lists:reverse(_pipe@3),
                        gleam@string:join(_pipe@4, <<"\n"/utf8>>)
                    end}];

        horizontal_break ->
            [horizontal_break];

        {heading, Level, {some, Contents}} ->
            [{heading, Level, parse_text(Contents)}];

        {heading, Level@1, none} ->
            [{heading, Level@1, parse_text([])}]
    end.

-spec do_parse_blocks(parser_state(), list(block_parse_state()), list(binary())) -> list(block_parse_state()).
do_parse_blocks(State, Acc, Lines) ->
    _assert_subject = gleam@regex:from_string(
        <<"^ {0,3}(?:\\*[* \t]*\\*[* \t]*\\*|-[- \t]*-[- \t]*-|_[_ \t]*_[_ \t]*_)[ \t]*$"/utf8>>
    ),
    {ok, Hr_regex} = case _assert_subject of
        {ok, _} -> _assert_subject;
        _assert_fail ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Assertion pattern match failed"/utf8>>,
                        value => _assert_fail,
                        module => <<"commonmark/internal/parser"/utf8>>,
                        function => <<"do_parse_blocks"/utf8>>,
                        line => 62})
    end,
    _assert_subject@1 = gleam@regex:from_string(
        <<"^ {0,3}(#{1,6})([ \t]+.*?)?(?:(?<=[ \t])#*)?[ \t]*$"/utf8>>
    ),
    {ok, Atx_header_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"/utf8>>,
                        function => <<"do_parse_blocks"/utf8>>,
                        line => 66})
    end,
    _assert_subject@2 = gleam@regex:from_string(
        <<"^ {0,3}([-=])+[ \t]*$"/utf8>>
    ),
    {ok, Setext_header_regex} = case _assert_subject@2 of
        {ok, _} -> _assert_subject@2;
        _assert_fail@2 ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Assertion pattern match failed"/utf8>>,
                        value => _assert_fail@2,
                        module => <<"commonmark/internal/parser"/utf8>>,
                        function => <<"do_parse_blocks"/utf8>>,
                        line => 68})
    end,
    _assert_subject@3 = case State of
        {code_block_builder, Break, _, _, _} ->
            gleam@regex:from_string(
                <<<<"^ {0,3}"/utf8, Break/binary>>/binary, "+[ \t]*$"/utf8>>
            );

        _ ->
            gleam@regex:from_string(
                <<"^ {0,3}([~`]{3,})[ \t]*(([^\\s]+).*?)?[ \t]*$"/utf8>>
            )
    end,
    {ok, Fenced_code_regex} = case _assert_subject@3 of
        {ok, _} -> _assert_subject@3;
        _assert_fail@3 ->
            erlang:error(#{gleam_error => let_assert,
                        message => <<"Assertion pattern match failed"/utf8>>,
                        value => _assert_fail@3,
                        module => <<"commonmark/internal/parser"/utf8>>,
                        function => <<"do_parse_blocks"/utf8>>,
                        line => 70})
    end,
    L = begin
        _pipe = gleam@list:first(Lines),
        gleam@result:unwrap(_pipe, <<""/utf8>>)
    end,
    case {State,
        Lines,
        gleam@regex:check(Hr_regex, L),
        gleam@regex:scan(Atx_header_regex, L),
        gleam@regex:scan(Setext_header_regex, L),
        gleam@regex:scan(Fenced_code_regex, L)} of
        {{paragraph_builder, Lines@1}, [], _, _, _, _} ->
            _pipe@1 = [{paragraph, Lines@1} | Acc],
            lists:reverse(_pipe@1);

        {{code_block_builder, _, Info, Full_info, Contents},
            [<<""/utf8>>],
            _,
            _,
            _,
            _} ->
            _pipe@2 = [{code_block, Info, Full_info, [<<""/utf8>> | Contents]} |
                Acc],
            lists:reverse(_pipe@2);

        {{code_block_builder, _, Info, Full_info, Contents}, [], _, _, _, _} ->
            _pipe@2 = [{code_block, Info, Full_info, [<<""/utf8>> | Contents]} |
                Acc],
            lists:reverse(_pipe@2);

        {outside_block, [], _, _, _, _} ->
            _pipe@3 = Acc,
            lists:reverse(_pipe@3);

        {{paragraph_builder, Bs}, [<<"  "/utf8>> | Ls], _, _, _, _} ->
            do_parse_blocks(outside_block, [{paragraph, Bs} | Acc], Ls);

        {{paragraph_builder, Bs}, [<<"\\"/utf8>> | Ls], _, _, _, _} ->
            do_parse_blocks(outside_block, [{paragraph, Bs} | Acc], Ls);

        {{paragraph_builder, Bs}, [<<""/utf8>> | Ls], _, _, _, _} ->
            do_parse_blocks(outside_block, [{paragraph, Bs} | Acc], Ls);

        {outside_block, [<<"  "/utf8>> | Ls@1], _, _, _, _} ->
            do_parse_blocks(outside_block, Acc, Ls@1);

        {outside_block, [<<"\\"/utf8>> | Ls@1], _, _, _, _} ->
            do_parse_blocks(outside_block, Acc, Ls@1);

        {outside_block, [<<""/utf8>> | Ls@1], _, _, _, _} ->
            do_parse_blocks(outside_block, Acc, Ls@1);

        {{paragraph_builder, Bs@1},
            [_ | Ls@2],
            _,
            _,
            _,
            [{match, _, [{some, Exit}]}]} ->
            do_parse_blocks(
                {code_block_builder, Exit, none, none, []},
                [{paragraph, Bs@1} | Acc],
                Ls@2
            );

        {{paragraph_builder, Bs@2},
            [_ | Ls@3],
            _,
            _,
            _,
            [{match, _, [{some, Exit@1}, Full_info@1, Info@1]}]} ->
            do_parse_blocks(
                {code_block_builder, Exit@1, Info@1, Full_info@1, []},
                [{paragraph, Bs@2} | Acc],
                Ls@3
            );

        {outside_block, [_ | Ls@4], _, _, _, [{match, _, [{some, Exit@2}]}]} ->
            do_parse_blocks(
                {code_block_builder, Exit@2, none, none, []},
                Acc,
                Ls@4
            );

        {outside_block,
            [_ | Ls@5],
            _,
            _,
            _,
            [{match, _, [{some, Exit@3}, Full_info@2, Info@2]}]} ->
            do_parse_blocks(
                {code_block_builder, Exit@3, Info@2, Full_info@2, []},
                Acc,
                Ls@5
            );

        {{code_block_builder, _, Info@3, Full_info@3, Bs@3},
            [_ | Ls@6],
            _,
            _,
            _,
            [{match, _, _}]} ->
            do_parse_blocks(
                outside_block,
                [{code_block, Info@3, Full_info@3, [<<""/utf8>> | Bs@3]} | Acc],
                Ls@6
            );

        {{code_block_builder, Break@1, Info@4, Full_info@4, Bs@4},
            [L@1 | Ls@7],
            _,
            _,
            _,
            _} ->
            do_parse_blocks(
                {code_block_builder, Break@1, Info@4, Full_info@4, [L@1 | Bs@4]},
                Acc,
                Ls@7
            );

        {{paragraph_builder, Bs@5},
            [_ | Ls@8],
            _,
            _,
            [{match, _, [{some, <<"="/utf8>>}]}],
            _} ->
            do_parse_blocks(
                outside_block,
                [{heading, 1, {some, lists:reverse(Bs@5)}} | Acc],
                Ls@8
            );

        {{paragraph_builder, Bs@6},
            [_ | Ls@9],
            _,
            _,
            [{match, _, [{some, <<"-"/utf8>>}]}],
            _} ->
            do_parse_blocks(
                outside_block,
                [{heading, 2, {some, lists:reverse(Bs@6)}} | Acc],
                Ls@9
            );

        {{paragraph_builder, Bs@7}, [_ | Ls@10], true, _, _, _} ->
            do_parse_blocks(
                outside_block,
                [horizontal_break, {paragraph, Bs@7} | Acc],
                Ls@10
            );

        {outside_block, [_ | Ls@11], true, _, _, _} ->
            do_parse_blocks(outside_block, [horizontal_break | Acc], Ls@11);

        {outside_block, [_ | Ls@12], _, [{match, _, [{some, Heading}]}], _, _} ->
            do_parse_blocks(
                outside_block,
                [{heading, gleam@string:length(Heading), none} | Acc],
                Ls@12
            );

        {outside_block,
            [_ | Ls@13],
            _,
            [{match, _, [{some, Heading@1}, {some, Contents@1}]}],
            _,
            _} ->
            do_parse_blocks(
                outside_block,
                [{heading, gleam@string:length(Heading@1), {some, [Contents@1]}} |
                    Acc],
                Ls@13
            );

        {{paragraph_builder, Bs@8},
            [_ | Ls@14],
            _,
            [{match, _, [{some, Heading@2}]}],
            _,
            _} ->
            do_parse_blocks(
                outside_block,
                [{heading, gleam@string:length(Heading@2), none},
                    {paragraph, Bs@8} |
                    Acc],
                Ls@14
            );

        {{paragraph_builder, Bs@9},
            [_ | Ls@15],
            _,
            [{match, _, [{some, Heading@3}, {some, Contents@2}]}],
            _,
            _} ->
            do_parse_blocks(
                outside_block,
                [{heading, gleam@string:length(Heading@3), {some, [Contents@2]}},
                    {paragraph, Bs@9} |
                    Acc],
                Ls@15
            );

        {outside_block, [Line | Ls@16], _, _, _, _} ->
            do_parse_blocks({paragraph_builder, [Line]}, Acc, Ls@16);

        {{paragraph_builder, Bs@10}, [Line@1 | Ls@17], _, _, _, _} ->
            do_parse_blocks({paragraph_builder, [Line@1 | Bs@10]}, Acc, Ls@17)
    end.

-spec parse_blocks(list(binary())) -> list(block_parse_state()).
parse_blocks(Lines) ->
    do_parse_blocks(outside_block, [], Lines).