css_select

-module(css_select@parser).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/css_select/parser.gleam").
-export([new/0, parse/2]).
-export_type([parser/0, parse_error/0]).

-if(?OTP_RELEASE >= 27).
-define(MODULEDOC(Str), -moduledoc(Str)).
-define(DOC(Str), -doc(Str)).
-else.
-define(MODULEDOC(Str), -compile([])).
-define(DOC(Str), -compile([])).
-endif.

-opaque parser() :: {parser,
        splitter:splitter(),
        splitter:splitter(),
        splitter:splitter()}.

-type parse_error() :: {parse_error, binary()}.

-file("src/css_select/parser.gleam", 32).
?DOC(
    " Create a new parser instance with pre-built splitters.\n"
    "\n"
    " Use this when parsing multiple selectors to avoid the overhead\n"
    " of creating splitters on each call.\n"
    "\n"
    " ```gleam\n"
    " let parser = parser.new()\n"
    " parser.parse_simple_selector_with_parser(parser, \"div#foo\")\n"
    " parser.parse_simple_selector_with_parser(parser, \".bar\")\n"
    " ```\n"
).
-spec new() -> parser().
new() ->
    {parser,
        splitter:new([<<"."/utf8>>, <<"#"/utf8>>, <<"["/utf8>>, <<":"/utf8>>]),
        splitter:new(
            [<<"^="/utf8>>,
                <<"$="/utf8>>,
                <<"*="/utf8>>,
                <<"="/utf8>>,
                <<"]"/utf8>>]
        ),
        splitter:new([<<"\""/utf8>>])}.

-file("src/css_select/parser.gleam", 120).
-spec parse_attr_value(binary(), parser()) -> {binary(), binary()}.
parse_attr_value(Input, Parser) ->
    case Input of
        <<"\""/utf8, Rest/binary>> ->
            {Parts, _, Remaining} = splitter_ffi:split(
                erlang:element(4, Parser),
                Rest
            ),
            case Remaining of
                <<"\""/utf8, After/binary>> ->
                    {Parts, After};

                _ ->
                    {Parts, Remaining}
            end;

        _ ->
            splitter_ffi:split_before(erlang:element(3, Parser), Input)
    end.

-file("src/css_select/parser.gleam", 106).
-spec parse_attr_with_op(
    fun((binary(), binary()) -> css_select@selector:attribute_selector()),
    binary(),
    binary(),
    parser()
) -> {css_select@selector:attribute_selector(), binary()}.
parse_attr_with_op(Constructor, Key, Input, Parser) ->
    {Value, After_value} = parse_attr_value(Input, Parser),
    case After_value of
        <<"]"/utf8, Remaining/binary>> ->
            {Constructor(Key, Value), Remaining};

        _ ->
            {Constructor(Key, Value), After_value}
    end.

-file("src/css_select/parser.gleam", 90).
-spec parse_bracket_attr(binary(), parser()) -> {css_select@selector:attribute_selector(),
    binary()}.
parse_bracket_attr(Input, Parser) ->
    {Key, Op_and_rest} = splitter_ffi:split_before(
        erlang:element(3, Parser),
        Input
    ),
    case Op_and_rest of
        <<"]"/utf8, Remaining/binary>> ->
            {{attribute_exists, Key}, Remaining};

        <<"^="/utf8, Rest/binary>> ->
            parse_attr_with_op(
                fun(Field@0, Field@1) -> {attribute_prefix, Field@0, Field@1} end,
                Key,
                Rest,
                Parser
            );

        <<"$="/utf8, Rest@1/binary>> ->
            parse_attr_with_op(
                fun(Field@0, Field@1) -> {attribute_suffix, Field@0, Field@1} end,
                Key,
                Rest@1,
                Parser
            );

        <<"*="/utf8, Rest@2/binary>> ->
            parse_attr_with_op(
                fun(Field@0, Field@1) -> {attribute_includes, Field@0, Field@1} end,
                Key,
                Rest@2,
                Parser
            );

        <<"="/utf8, Rest@3/binary>> ->
            parse_attr_with_op(
                fun(Field@0, Field@1) -> {attribute_equal, Field@0, Field@1} end,
                Key,
                Rest@3,
                Parser
            );

        _ ->
            {{attribute_exists, Key}, Op_and_rest}
    end.

-file("src/css_select/parser.gleam", 64).
-spec parse_attrs(binary(), parser()) -> list(css_select@selector:attribute_selector()).
parse_attrs(Input, Parser) ->
    case Input of
        <<""/utf8>> ->
            [];

        <<"."/utf8, Rest/binary>> ->
            {Name, Remaining} = splitter_ffi:split_before(
                erlang:element(2, Parser),
                Rest
            ),
            [{class, Name} | parse_attrs(Remaining, Parser)];

        <<"#"/utf8, Rest@1/binary>> ->
            {Name@1, Remaining@1} = splitter_ffi:split_before(
                erlang:element(2, Parser),
                Rest@1
            ),
            [{id, Name@1} | parse_attrs(Remaining@1, Parser)];

        <<":"/utf8, Rest@2/binary>> ->
            {Name@2, Remaining@2} = splitter_ffi:split_before(
                erlang:element(2, Parser),
                Rest@2
            ),
            [{psuedo, Name@2} | parse_attrs(Remaining@2, Parser)];

        <<"["/utf8, Rest@3/binary>> ->
            {Attr, Remaining@3} = parse_bracket_attr(Rest@3, Parser),
            [Attr | parse_attrs(Remaining@3, Parser)];

        _ ->
            []
    end.

-file("src/css_select/parser.gleam", 49).
?DOC(
    " Parse a CSS selector string using a pre-created `Parser`.\n"
    "\n"
    " This avoids the overhead of creating splitters on each call.\n"
    " Create a `Parser` once with `new()` and reuse it for all parsing.\n"
).
-spec parse(parser(), binary()) -> {ok, css_select@selector:selector()} |
    {error, parse_error()}.
parse(Parser, Input) ->
    {Tag_part, Rest} = splitter_ffi:split_before(
        erlang:element(2, Parser),
        Input
    ),
    Tag = case Tag_part of
        <<""/utf8>> ->
            any;

        _ ->
            {tag, Tag_part}
    end,
    Attrs = parse_attrs(Rest, Parser),
    {ok, {element_selector, Tag, Attrs}}.