-module(prequel@internals@parser).
-compile([no_auto_import, nowarn_unused_vars]).

-export([parse/1]).

-spec 'try'(
    {ok, {HYR, list({prequel@internals@token:token(), prequel@span:span()})}} |
        {error, prequel@error@parse_error:parse_error()},
    fun((HYR, list({prequel@internals@token:token(), prequel@span:span()})) -> {ok,
            {HYU, list({prequel@internals@token:token(), prequel@span:span()})}} |
        {error, prequel@error@parse_error:parse_error()})
) -> {ok, {HYU, list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
'try'(Result, Do) ->
    case Result of
        {ok, {A, Tokens}} ->
            Do(A, Tokens);

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

-spec fail(prequel@error@parse_error:parse_error()) -> {ok,
        {any(), list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
fail(Error) ->
    {error, Error}.

-spec succeed(HYZ, list({prequel@internals@token:token(), prequel@span:span()})) -> {ok,
        {HYZ, list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
succeed(Result, Tokens) ->
    {ok, {Result, Tokens}}.

-spec totality_from_string(binary()) -> {ok, prequel@ast:totality()} |
    {error, nil}.
totality_from_string(String) ->
    case String of
        <<"total"/utf8>> ->
            {ok, total};

        <<"partial"/utf8>> ->
            {ok, partial};

        _ ->
            {error, nil}
    end.

-spec overlapping_from_string(binary()) -> {ok, prequel@ast:overlapping()} |
    {error, nil}.
overlapping_from_string(String) ->
    case String of
        <<"overlapped"/utf8>> ->
            {ok, overlapped};

        <<"disjoint"/utf8>> ->
            {ok, disjoint};

        _ ->
            {error, nil}
    end.

-spec parse_attribute_type(
    list({prequel@internals@token:token(), prequel@span:span()})
) -> {ok,
        {prequel@ast:type(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
parse_attribute_type(Tokens) ->
    _pipe = no_type,
    succeed(_pipe, Tokens).

-spec parse_number(binary(), prequel@span:span(), prequel@span:span()) -> {ok,
        integer()} |
    {error, prequel@error@parse_error:parse_error()}.
parse_number(Raw_number, Raw_number_span, Enclosing_span) ->
    _pipe = gleam@int:parse(Raw_number),
    gleam@result:replace_error(
        _pipe,
        {internal_error,
            {some, <<"TODO: add hint"/utf8>>},
            {some, Enclosing_span},
            Raw_number_span,
            <<"This was assumed to be a number"/utf8>>}
    ).

-spec parse_cardinality(
    list({prequel@internals@token:token(), prequel@span:span()}),
    boolean(),
    prequel@span:span(),
    prequel@span:span()
) -> {ok,
        {prequel@ast:cardinality(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
parse_cardinality(Tokens, Lenient, Enclosing_span, Preceding_span) ->
    case Tokens of
        [{open_parens, Start},
            {{number, Raw_lower}, Raw_lower_span},
            {minus, _},
            {{number, Raw_upper}, Raw_upper_span},
            {close_parens, End} |
            Tokens@1] ->
            Result = parse_number(Raw_lower, Raw_lower_span, Enclosing_span),
            gleam@result:'try'(
                Result,
                fun(Lower) ->
                    Result@1 = parse_number(
                        Raw_upper,
                        Raw_upper_span,
                        Enclosing_span
                    ),
                    gleam@result:'try'(
                        Result@1,
                        fun(Upper) ->
                            _pipe = {bounded,
                                prequel@span:merge(Start, End),
                                Lower,
                                Upper},
                            succeed(_pipe, Tokens@1)
                        end
                    )
                end
            );

        [{open_parens, Start@1},
            {{number, Raw_lower@1}, Raw_lower_span@1},
            {minus, _},
            {{word, <<"N"/utf8>>}, _},
            {close_parens, End@1} |
            Tokens@2] ->
            Result@2 = parse_number(
                Raw_lower@1,
                Raw_lower_span@1,
                Enclosing_span
            ),
            gleam@result:'try'(
                Result@2,
                fun(Lower@1) ->
                    _pipe@1 = {unbounded,
                        prequel@span:merge(Start@1, End@1),
                        Lower@1},
                    succeed(_pipe@1, Tokens@2)
                end
            );

        [{open_parens, _},
            {{number, _}, _},
            {minus, _},
            {{word, _}, Span},
            {close_parens, _} |
            _] ->
            _pipe@2 = {wrong_letter_in_unbounded_cardinality,
                {some, <<"TODO: add hint"/utf8>>},
                Enclosing_span,
                Span},
            fail(_pipe@2);

        [{open_parens, Start@2},
            {{number, _}, _},
            {minus, _},
            {{number, _}, End@2} |
            _] ->
            _pipe@3 = {incomplete_cardinality,
                {some, <<"TODO: add hint"/utf8>>},
                Enclosing_span,
                prequel@span:merge(Start@2, End@2),
                <<"a closed parentheses"/utf8>>},
            fail(_pipe@3);

        [{open_parens, Start@2},
            {{number, _}, _},
            {minus, _},
            {{word, _}, End@2} |
            _] ->
            _pipe@3 = {incomplete_cardinality,
                {some, <<"TODO: add hint"/utf8>>},
                Enclosing_span,
                prequel@span:merge(Start@2, End@2),
                <<"a closed parentheses"/utf8>>},
            fail(_pipe@3);

        [{open_parens, Start@3}, {{number, _}, _}, {minus, End@3} | _] ->
            _pipe@4 = {incomplete_cardinality,
                {some, <<"TODO: add hint"/utf8>>},
                Enclosing_span,
                prequel@span:merge(Start@3, End@3),
                <<"an upper bound"/utf8>>},
            fail(_pipe@4);

        [{open_parens, Start@4}, {{number, _}, End@4} | _] ->
            _pipe@5 = {incomplete_cardinality,
                {some, <<"TODO: add hint"/utf8>>},
                Enclosing_span,
                prequel@span:merge(Start@4, End@4),
                <<"an upper bound"/utf8>>},
            fail(_pipe@5);

        [{open_parens, Span@1} | _] ->
            _pipe@6 = {incomplete_cardinality,
                {some, <<"TODO: add hint"/utf8>>},
                Enclosing_span,
                Span@1,
                <<"a lower bound"/utf8>>},
            fail(_pipe@6);

        [{{number, _}, Span@2} | _] ->
            _pipe@7 = {incomplete_cardinality,
                {some, <<"TODO: add hint"/utf8>>},
                Enclosing_span,
                Span@2,
                <<"an open parentheses"/utf8>>},
            fail(_pipe@7);

        [_ | _] when Lenient ->
            _pipe@8 = {bounded, Preceding_span, 1, 1},
            succeed(_pipe@8, Tokens);

        [{Token, Span@3} | _] ->
            _pipe@9 = {wrong_cardinality_annotation,
                {some, <<"TODO: add hint"/utf8>>},
                Enclosing_span,
                Preceding_span,
                prequel@internals@token:to_string(Token),
                Span@3},
            fail(_pipe@9);

        [] ->
            _pipe@10 = {unexpected_end_of_file,
                {some, <<"TODO: add hint"/utf8>>},
                {some, Enclosing_span},
                Preceding_span,
                <<"the cardinality of this element"/utf8>>},
            fail(_pipe@10)
    end.

-spec parse_attribute(
    list({prequel@internals@token:token(), prequel@span:span()}),
    prequel@span:span(),
    prequel@span:span()
) -> {ok,
        {prequel@ast:attribute(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
parse_attribute(Tokens, Enclosing_span, Lollipop_span) ->
    case Tokens of
        [{{word, Name}, Name_span}, {colon, Colon_span} | Tokens@1] ->
            'try'(
                parse_attribute_type(Tokens@1),
                fun(Type_, Tokens@2) ->
                    'try'(
                        parse_cardinality(
                            Tokens@2,
                            Type_ /= no_type,
                            Enclosing_span,
                            Colon_span
                        ),
                        fun(Cardinality, Tokens@3) ->
                            _pipe = {attribute,
                                Name_span,
                                Name,
                                Cardinality,
                                Type_},
                            succeed(_pipe, Tokens@3)
                        end
                    )
                end
            );

        [{{word, Name@1}, Name_span@1} | Tokens@4] ->
            _pipe@1 = {attribute,
                Name_span@1,
                Name@1,
                {bounded, Name_span@1, 1, 1},
                no_type},
            succeed(_pipe@1, Tokens@4);

        [{Token, Span} | _] ->
            _pipe@2 = {wrong_attribute_name,
                {some, <<"TODO: add hint"/utf8>>},
                Enclosing_span,
                Lollipop_span,
                prequel@internals@token:to_string(Token),
                Span},
            fail(_pipe@2);

        [] ->
            _pipe@3 = {unexpected_end_of_file,
                {some, <<"TODO: add hint"/utf8>>},
                {some, Enclosing_span},
                Lollipop_span,
                <<"this attribute"/utf8>>},
            fail(_pipe@3)
    end.

-spec parse_multi_attribute_key(
    list({prequel@internals@token:token(), prequel@span:span()}),
    prequel@span:span(),
    prequel@span:span(),
    prequel@span:span(),
    prequel@span:span(),
    list(binary())
) -> {ok,
        {prequel@ast:key(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
parse_multi_attribute_key(
    Tokens,
    Entity_span,
    Lollipop_span,
    Last_ampersand_span,
    First_word_span,
    Keys
) ->
    case Tokens of
        [{{word, Key}, _}, {ampersand, Last_ampersand_span@1} | Tokens@1] ->
            parse_multi_attribute_key(
                Tokens@1,
                Entity_span,
                Lollipop_span,
                Last_ampersand_span@1,
                First_word_span,
                [Key | Keys]
            );

        [{{word, _}, Last_word_span}, {colon, Colon_span} | _] ->
            _pipe = {type_annotation_on_composed_key,
                {some, <<"TODO: add hint"/utf8>>},
                Entity_span,
                prequel@span:merge(First_word_span, Last_word_span),
                Colon_span},
            fail(_pipe);

        [{{word, Key@1}, Last_word_span@1} | Tokens@2] ->
            _pipe@1 = prequel@span:merge(First_word_span, Last_word_span@1),
            _pipe@2 = {composed_key,
                _pipe@1,
                non_empty_list:reverse(non_empty_list:new(Key@1, Keys))},
            succeed(_pipe@2, Tokens@2);

        [{Token, Span} | _] ->
            _pipe@3 = {incomplete_composed_key,
                {some, <<"TODO: add hint"/utf8>>},
                prequel@span:merge(Lollipop_span, Last_ampersand_span),
                Entity_span,
                prequel@internals@token:to_string(Token),
                Span},
            fail(_pipe@3);

        [] ->
            _pipe@4 = {unexpected_end_of_file,
                {some, <<"TODO: add hint"/utf8>>},
                {some, Entity_span},
                Lollipop_span,
                <<"this key"/utf8>>},
            fail(_pipe@4)
    end.

-spec do_parse_key(
    list({prequel@internals@token:token(), prequel@span:span()}),
    prequel@span:span(),
    prequel@span:span()
) -> {ok,
        {prequel@ast:key(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
do_parse_key(Tokens, Entity_span, Lollipop_span) ->
    case Tokens of
        [{{word, Key}, First_word_span},
            {ampersand, Last_ampersand_span} |
            Tokens@1] ->
            'try'(
                parse_multi_attribute_key(
                    Tokens@1,
                    Entity_span,
                    Lollipop_span,
                    Last_ampersand_span,
                    First_word_span,
                    [Key]
                ),
                fun(Key@1, Tokens@2) -> succeed(Key@1, Tokens@2) end
            );

        [{{word, Key@2}, Span}, {colon, _} | Tokens@3] ->
            'try'(
                parse_attribute_type(Tokens@3),
                fun(Type_, Tokens@4) ->
                    succeed({single_key, Span, Key@2, {some, Type_}}, Tokens@4)
                end
            );

        [{{word, Key@3}, Span@1} | Tokens@5] ->
            succeed({single_key, Span@1, Key@3, none}, Tokens@5);

        [{Token, Span@2} | _] ->
            _pipe = {wrong_key_name,
                {some, <<"TODO: add hint"/utf8>>},
                Entity_span,
                Lollipop_span,
                prequel@internals@token:to_string(Token),
                Span@2},
            fail(_pipe);

        [] ->
            _pipe@1 = {unexpected_end_of_file,
                {some, <<"TODO: add hint"/utf8>>},
                {some, Entity_span},
                Lollipop_span,
                <<"this key"/utf8>>},
            fail(_pipe@1)
    end.

-spec parse_key(
    list({prequel@internals@token:token(), prequel@span:span()}),
    prequel@span:span(),
    prequel@span:span()
) -> {ok,
        {prequel@ast:key(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
parse_key(Tokens, Entity_span, Lollipop_span) ->
    do_parse_key(Tokens, Entity_span, Lollipop_span).

-spec do_parse_inner_relationship_body(
    list({prequel@internals@token:token(), prequel@span:span()}),
    prequel@span:span(),
    prequel@span:span(),
    list(prequel@ast:attribute())
) -> {ok,
        {list(prequel@ast:attribute()),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
do_parse_inner_relationship_body(
    Tokens,
    Relationship_span,
    Entity_span,
    Attributes
) ->
    case Tokens of
        [{close_bracket, _} | Tokens@1] ->
            _pipe = gleam@list:reverse(Attributes),
            succeed(_pipe, Tokens@1);

        [{circle_lollipop, Span} | Tokens@2] ->
            'try'(
                parse_attribute(Tokens@2, Relationship_span, Span),
                fun(Attribute, Tokens@3) ->
                    do_parse_inner_relationship_body(
                        Tokens@3,
                        Relationship_span,
                        Entity_span,
                        [Attribute | Attributes]
                    )
                end
            );

        [{star_lollipop, Lollipop_span} | _] ->
            _pipe@1 = {key_inside_relationship,
                {some, <<"TODO: add hint"/utf8>>},
                Relationship_span,
                Lollipop_span},
            fail(_pipe@1);

        [{minus, Minus_span}, {{word, <<"o"/utf8>>}, O_span} | _] ->
            _pipe@2 = {possible_circle_lollipop_typo,
                {some, <<"TODO: add hint"/utf8>>},
                Relationship_span,
                prequel@span:merge(Minus_span, O_span)},
            fail(_pipe@2);

        [{_, Token_span} | _] ->
            _pipe@3 = {unexpected_token_in_binary_relationship,
                {some, <<"TODO: add hint"/utf8>>},
                Relationship_span,
                Token_span},
            fail(_pipe@3);

        [] ->
            _pipe@4 = {unexpected_end_of_file,
                {some, <<"TODO: add hint"/utf8>>},
                {some, Entity_span},
                Relationship_span,
                <<"the body of this relationship"/utf8>>},
            fail(_pipe@4)
    end.

-spec parse_inner_relationship_body(
    list({prequel@internals@token:token(), prequel@span:span()}),
    prequel@span:span(),
    prequel@span:span()
) -> {ok,
        {list(prequel@ast:attribute()),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
parse_inner_relationship_body(Tokens, Relationship_span, Entity_span) ->
    do_parse_inner_relationship_body(Tokens, Relationship_span, Entity_span, []).

-spec parse_inner_relationship(
    list({prequel@internals@token:token(), prequel@span:span()}),
    binary(),
    prequel@span:span(),
    prequel@span:span()
) -> {ok,
        {prequel@ast:relationship(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
parse_inner_relationship(Tokens, Entity_name, Entity_span, Lollipop_span) ->
    case Tokens of
        [{{word, Relationship_name}, Relationship_span},
            {colon, Colon_span} |
            Tokens@1] ->
            'try'(
                parse_cardinality(Tokens@1, false, Entity_span, Colon_span),
                fun(One_cardinality, Tokens@2) -> case Tokens@2 of
                        [{{word, Other_name}, Other_name_span} | Tokens@3] ->
                            'try'(
                                parse_cardinality(
                                    Tokens@3,
                                    false,
                                    Entity_span,
                                    Other_name_span
                                ),
                                fun(Other_cardinality, Tokens@4) ->
                                    One_entity = {relationship_entity,
                                        Entity_span,
                                        Entity_name,
                                        One_cardinality},
                                    Other_entity = begin
                                        _pipe = {relationship_entity,
                                            Other_name_span,
                                            Other_name,
                                            Other_cardinality},
                                        non_empty_list:single(_pipe)
                                    end,
                                    case Tokens@4 of
                                        [{open_bracket, _} | Tokens@5] ->
                                            'try'(
                                                parse_inner_relationship_body(
                                                    Tokens@5,
                                                    Relationship_span,
                                                    Entity_span
                                                ),
                                                fun(Attributes, Tokens@6) ->
                                                    _pipe@1 = {relationship,
                                                        Relationship_span,
                                                        Relationship_name,
                                                        One_entity,
                                                        Other_entity,
                                                        Attributes},
                                                    succeed(_pipe@1, Tokens@6)
                                                end
                                            );

                                        _ ->
                                            _pipe@2 = Relationship_span,
                                            _pipe@3 = {relationship,
                                                _pipe@2,
                                                Relationship_name,
                                                One_entity,
                                                Other_entity,
                                                []},
                                            succeed(_pipe@3, Tokens@4)
                                    end
                                end
                            );

                        [{Token, Span} | _] ->
                            _pipe@4 = {wrong_entity_name,
                                {some, <<"TODO: add hint"/utf8>>},
                                {some, Entity_span},
                                erlang:element(2, One_cardinality),
                                prequel@internals@token:to_string(Token),
                                Span,
                                <<"the first cardinality annotation"/utf8>>},
                            fail(_pipe@4);

                        [] ->
                            _pipe@5 = {unexpected_end_of_file,
                                {some, <<"TODO: add hint"/utf8>>},
                                {some, Entity_span},
                                Lollipop_span,
                                <<"this relationship"/utf8>>},
                            fail(_pipe@5)
                    end end
            );

        [{{word, _}, Name_span} | _] ->
            _pipe@6 = {missing_cardinality_annotation,
                {some, <<"TODO: add hint"/utf8>>},
                Entity_span,
                Name_span},
            fail(_pipe@6);

        [{Token@1, Span@1} | _] ->
            _pipe@7 = {wrong_relationship_name,
                {some, <<"TODO: add hint"/utf8>>},
                {some, Entity_span},
                Lollipop_span,
                prequel@internals@token:to_string(Token@1),
                Span@1},
            fail(_pipe@7);

        [] ->
            _pipe@8 = {unexpected_end_of_file,
                {some, <<"TODO: add hint"/utf8>>},
                {some, Entity_span},
                Lollipop_span,
                <<"this relationship"/utf8>>},
            fail(_pipe@8)
    end.

-spec parse_relationship_entity(
    list({prequel@internals@token:token(), prequel@span:span()}),
    prequel@span:span(),
    prequel@span:span()
) -> {ok,
        {prequel@ast:relationship_entity(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
parse_relationship_entity(Tokens, Relationship_span, Lollipop_span) ->
    case Tokens of
        [{{word, Name}, Name_span}, {colon, Colon_span} | Tokens@1] ->
            'try'(
                parse_cardinality(
                    Tokens@1,
                    false,
                    Relationship_span,
                    Colon_span
                ),
                fun(Cardinality, Tokens@2) ->
                    _pipe = {relationship_entity, Name_span, Name, Cardinality},
                    succeed(_pipe, Tokens@2)
                end
            );

        [{{word, _}, Name_span@1} | _] ->
            _pipe@1 = {missing_cardinality_annotation,
                {some, <<"TODO: add hint"/utf8>>},
                Relationship_span,
                Name_span@1},
            fail(_pipe@1);

        [{Token, Span} | _] ->
            _pipe@2 = {wrong_entity_name,
                {some, <<"TODO: add hint"/utf8>>},
                {some, Relationship_span},
                Lollipop_span,
                prequel@internals@token:to_string(Token),
                Span,
                <<"the `->` lollipop"/utf8>>},
            fail(_pipe@2);

        [] ->
            _pipe@3 = {unexpected_end_of_file,
                {some, <<"TODO: add hint"/utf8>>},
                {some, Relationship_span},
                Lollipop_span,
                <<"this entity"/utf8>>},
            fail(_pipe@3)
    end.

-spec do_parse(
    list({prequel@internals@token:token(), prequel@span:span()}),
    list(prequel@ast:entity()),
    list(prequel@ast:relationship())
) -> {ok,
        {prequel@ast:module_(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
do_parse(Tokens, Entities, Relationships) ->
    case Tokens of
        [] ->
            _pipe = {module,
                gleam@list:reverse(Entities),
                gleam@list:reverse(Relationships)},
            succeed(_pipe, []);

        [{{word, <<"entity"/utf8>>}, Entity_keyword_span} | Tokens@1] ->
            'try'(
                parse_entity(Tokens@1, Entity_keyword_span),
                fun(Entity, Tokens@2) ->
                    do_parse(Tokens@2, [Entity | Entities], Relationships)
                end
            );

        [{{word, <<"relationship"/utf8>>}, Relationship_span} | Tokens@3] ->
            'try'(
                parse_relationship(Tokens@3, Relationship_span),
                fun(Relationship, Tokens@4) ->
                    do_parse(Tokens@4, Entities, [Relationship | Relationships])
                end
            );

        [{_, Span} | _] ->
            _pipe@1 = {unexpected_token_in_top_level,
                {some, <<"TODO: add hint"/utf8>>},
                Span},
            fail(_pipe@1)
    end.

-spec parse(list({prequel@internals@token:token(), prequel@span:span()})) -> {ok,
        prequel@ast:module_()} |
    {error, prequel@error@parse_error:parse_error()}.
parse(Tokens) ->
    case do_parse(Tokens, [], []) of
        {ok, {Module, _}} ->
            {ok, Module};

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

-spec do_parse_entity_body(
    list({prequel@internals@token:token(), prequel@span:span()}),
    binary(),
    prequel@span:span(),
    list(prequel@ast:key()),
    list(prequel@ast:attribute()),
    list(prequel@ast:relationship()),
    gleam@option:option(prequel@ast:hierarchy())
) -> {ok,
        {prequel@ast:entity(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
do_parse_entity_body(
    Tokens,
    Entity_name,
    Entity_span,
    Keys,
    Attributes,
    Inner_relationships,
    Children
) ->
    case Tokens of
        [{close_bracket, _} | Tokens@1] ->
            _pipe = {entity,
                Entity_span,
                Entity_name,
                gleam@list:reverse(Keys),
                gleam@list:reverse(Attributes),
                gleam@list:reverse(Inner_relationships),
                Children},
            succeed(_pipe, Tokens@1);

        [{circle_lollipop, Lollipop_span} | Tokens@2] ->
            'try'(
                parse_attribute(Tokens@2, Entity_span, Lollipop_span),
                fun(Attribute, Tokens@3) ->
                    do_parse_entity_body(
                        Tokens@3,
                        Entity_name,
                        Entity_span,
                        Keys,
                        [Attribute | Attributes],
                        Inner_relationships,
                        Children
                    )
                end
            );

        [{star_lollipop, Lollipop_span@1} | Tokens@4] ->
            'try'(
                parse_key(Tokens@4, Entity_span, Lollipop_span@1),
                fun(Key, Tokens@5) ->
                    do_parse_entity_body(
                        Tokens@5,
                        Entity_name,
                        Entity_span,
                        [Key | Keys],
                        Attributes,
                        Inner_relationships,
                        Children
                    )
                end
            );

        [{arrow_lollipop, Lollipop_span@2} | Tokens@6] ->
            'try'(
                parse_inner_relationship(
                    Tokens@6,
                    Entity_name,
                    Entity_span,
                    Lollipop_span@2
                ),
                fun(Relationship, Tokens@7) ->
                    do_parse_entity_body(
                        Tokens@7,
                        Entity_name,
                        Entity_span,
                        Keys,
                        Attributes,
                        [Relationship | Inner_relationships],
                        Children
                    )
                end
            );

        [{{word, <<"total"/utf8>> = Totality_string}, Totality_span} | Tokens@8] ->
            Error = {internal_error,
                {some, <<"TODO: add hint"/utf8>>},
                {some, Entity_span},
                Totality_span,
                <<"A call to `totality_from_string` failed despite this being assumed a correct totality"/utf8>>},
            Result = gleam@result:replace_error(
                totality_from_string(Totality_string),
                Error
            ),
            gleam@result:'try'(
                Result,
                fun(Totality) ->
                    'try'(
                        parse_hierarchy(
                            Tokens@8,
                            Entity_span,
                            Totality_span,
                            Children,
                            Totality
                        ),
                        fun(Hierarchy, Tokens@9) ->
                            do_parse_entity_body(
                                Tokens@9,
                                Entity_name,
                                Entity_span,
                                Keys,
                                Attributes,
                                Inner_relationships,
                                {some, Hierarchy}
                            )
                        end
                    )
                end
            );

        [{{word, <<"partial"/utf8>> = Totality_string}, Totality_span} |
            Tokens@8] ->
            Error = {internal_error,
                {some, <<"TODO: add hint"/utf8>>},
                {some, Entity_span},
                Totality_span,
                <<"A call to `totality_from_string` failed despite this being assumed a correct totality"/utf8>>},
            Result = gleam@result:replace_error(
                totality_from_string(Totality_string),
                Error
            ),
            gleam@result:'try'(
                Result,
                fun(Totality) ->
                    'try'(
                        parse_hierarchy(
                            Tokens@8,
                            Entity_span,
                            Totality_span,
                            Children,
                            Totality
                        ),
                        fun(Hierarchy, Tokens@9) ->
                            do_parse_entity_body(
                                Tokens@9,
                                Entity_name,
                                Entity_span,
                                Keys,
                                Attributes,
                                Inner_relationships,
                                {some, Hierarchy}
                            )
                        end
                    )
                end
            );

        [{minus, Minus_span}, {{word, <<"o"/utf8>>}, O_span} | _] ->
            _pipe@1 = {possible_circle_lollipop_typo,
                {some, <<"TODO: add hint"/utf8>>},
                Entity_span,
                prequel@span:merge(Minus_span, O_span)},
            fail(_pipe@1);

        [{minus, Minus_span@1}, {{word, <<"*"/utf8>>}, Star_span} | _] ->
            _pipe@2 = {possible_star_lollipop_typo,
                {some, <<"TODO: add hint"/utf8>>},
                Entity_span,
                prequel@span:merge(Minus_span@1, Star_span)},
            fail(_pipe@2);

        [{minus, Minus_span@2}, {{word, <<">"/utf8>>}, Arrow_span} | _] ->
            _pipe@3 = {possible_arrow_lollipop_typo,
                {some, <<"TODO: add hint"/utf8>>},
                Entity_span,
                prequel@span:merge(Minus_span@2, Arrow_span)},
            fail(_pipe@3);

        [{{word, First}, First_span}, {{word, Second}, Second_span} | _] when (((First =:= <<"overlapped"/utf8>>) orelse (First =:= <<"overlapping"/utf8>>)) orelse (First =:= <<"disjoint"/utf8>>)) andalso ((Second =:= <<"total"/utf8>>) orelse (Second =:= <<"partial"/utf8>>)) ->
            _pipe@4 = {wrong_order_of_hierarchy_qualifiers,
                {some, <<"TODO: add hint"/utf8>>},
                Entity_span,
                prequel@span:merge(First_span, Second_span),
                First,
                Second},
            fail(_pipe@4);

        [{{word, <<"hierarchy"/utf8>>}, Span} | _] ->
            _pipe@5 = {unqualified_hierarchy,
                {some, <<"TODO: add hint"/utf8>>},
                Entity_span,
                Span},
            fail(_pipe@5);

        [{_, Token_span} | _] ->
            _pipe@6 = {unexpected_token_in_entity_body,
                {some, <<"TODO: add hint"/utf8>>},
                Entity_span,
                Token_span},
            fail(_pipe@6);

        [] ->
            _pipe@7 = {unexpected_end_of_file,
                {some, <<"TODO: add hint"/utf8>>},
                none,
                Entity_span,
                <<"the body of this entity"/utf8>>},
            fail(_pipe@7)
    end.

-spec parse_entity_body(
    list({prequel@internals@token:token(), prequel@span:span()}),
    binary(),
    prequel@span:span()
) -> {ok,
        {prequel@ast:entity(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
parse_entity_body(Tokens, Entity_name, Entity_span) ->
    do_parse_entity_body(Tokens, Entity_name, Entity_span, [], [], [], none).

-spec parse_entity(
    list({prequel@internals@token:token(), prequel@span:span()}),
    prequel@span:span()
) -> {ok,
        {prequel@ast:entity(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
parse_entity(Tokens, Entity_keyword_span) ->
    case Tokens of
        [{{word, Entity_name}, Entity_span}, {open_bracket, _} | Tokens@1] ->
            parse_entity_body(Tokens@1, Entity_name, Entity_span);

        [{{word, Entity_name@1}, Entity_span@1} | Tokens@2] ->
            _pipe = {entity, Entity_span@1, Entity_name@1, [], [], [], none},
            succeed(_pipe, Tokens@2);

        [{Token, Span} | _] ->
            _pipe@1 = {wrong_entity_name,
                {some, <<"TODO: add hint"/utf8>>},
                none,
                Entity_keyword_span,
                prequel@internals@token:to_string(Token),
                Span,
                <<"the `entity` keyword"/utf8>>},
            fail(_pipe@1);

        [] ->
            _pipe@2 = {unexpected_end_of_file,
                {some, <<"TODO: add hint"/utf8>>},
                none,
                Entity_keyword_span,
                <<"this entity"/utf8>>},
            fail(_pipe@2)
    end.

-spec do_parse_hierarchy_body(
    list({prequel@internals@token:token(), prequel@span:span()}),
    list(prequel@ast:entity()),
    prequel@span:span(),
    prequel@span:span()
) -> {ok,
        {non_empty_list:non_empty_list(prequel@ast:entity()),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
do_parse_hierarchy_body(Tokens, Entities, Entity_span, Hierarchy_span) ->
    case Tokens of
        [{close_bracket, _} | Tokens@1] ->
            Error = {empty_hierarchy,
                {some, <<"TODO: add hint"/utf8>>},
                Entity_span,
                Hierarchy_span},
            _pipe = Entities,
            _pipe@1 = gleam@list:reverse(_pipe),
            _pipe@2 = non_empty_list:from_list(_pipe@1),
            _pipe@3 = gleam@result:replace_error(_pipe@2, Error),
            gleam@result:'try'(
                _pipe@3,
                fun(_capture) -> succeed(_capture, Tokens@1) end
            );

        [{{word, <<"entity"/utf8>>}, Span} | Tokens@2] ->
            'try'(
                parse_entity(Tokens@2, Span),
                fun(Entity, Tokens@3) ->
                    do_parse_hierarchy_body(
                        Tokens@3,
                        [Entity | Entities],
                        Entity_span,
                        Hierarchy_span
                    )
                end
            );

        [{_, Span@1} | _] ->
            _pipe@4 = {unexpected_token_in_hierarchy_body,
                {some, <<"TODO: add hint"/utf8>>},
                Hierarchy_span,
                Span@1},
            fail(_pipe@4);

        [] ->
            _pipe@5 = {unexpected_end_of_file,
                {some, <<"TODO: add hint"/utf8>>},
                {some, Entity_span},
                Hierarchy_span,
                <<"this hierarchy"/utf8>>},
            fail(_pipe@5)
    end.

-spec parse_hierarchy_body(
    list({prequel@internals@token:token(), prequel@span:span()}),
    prequel@span:span(),
    prequel@span:span()
) -> {ok,
        {non_empty_list:non_empty_list(prequel@ast:entity()),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
parse_hierarchy_body(Tokens, Entity_span, Hierarchy_span) ->
    do_parse_hierarchy_body(Tokens, [], Entity_span, Hierarchy_span).

-spec parse_hierarchy(
    list({prequel@internals@token:token(), prequel@span:span()}),
    prequel@span:span(),
    prequel@span:span(),
    gleam@option:option(prequel@ast:hierarchy()),
    prequel@ast:totality()
) -> {ok,
        {prequel@ast:hierarchy(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
parse_hierarchy(Tokens, Entity_span, Totality_span, Entity_children, Totality) ->
    case Tokens of
        [{{word, <<"overlapped"/utf8>> = Word}, Word_span},
            {{word, <<"hierarchy"/utf8>>}, Final_span},
            {open_bracket, _} |
            Tokens@1] ->
            Error = {internal_error,
                {some, <<"TODO: add hint"/utf8>>},
                {some, Entity_span},
                Word_span,
                <<"A call to `overlapping_from_string` failed despite this being assumed a correct overlapping"/utf8>>},
            Result = gleam@result:replace_error(
                overlapping_from_string(Word),
                Error
            ),
            gleam@result:'try'(
                Result,
                fun(Overlapping) ->
                    Hierarchy_span = prequel@span:merge(
                        Totality_span,
                        Final_span
                    ),
                    case Entity_children of
                        {some, First_hierarchy} ->
                            _pipe = {more_than_one_hierarchy,
                                {some, <<"TODO: add hint"/utf8>>},
                                Entity_span,
                                erlang:element(2, First_hierarchy),
                                Hierarchy_span},
                            fail(_pipe);

                        none ->
                            'try'(
                                parse_hierarchy_body(
                                    Tokens@1,
                                    Entity_span,
                                    Hierarchy_span
                                ),
                                fun(Entities, Tokens@2) ->
                                    _pipe@1 = {hierarchy,
                                        Hierarchy_span,
                                        Overlapping,
                                        Totality,
                                        Entities},
                                    succeed(_pipe@1, Tokens@2)
                                end
                            )
                    end
                end
            );

        [{{word, <<"disjoint"/utf8>> = Word}, Word_span},
            {{word, <<"hierarchy"/utf8>>}, Final_span},
            {open_bracket, _} |
            Tokens@1] ->
            Error = {internal_error,
                {some, <<"TODO: add hint"/utf8>>},
                {some, Entity_span},
                Word_span,
                <<"A call to `overlapping_from_string` failed despite this being assumed a correct overlapping"/utf8>>},
            Result = gleam@result:replace_error(
                overlapping_from_string(Word),
                Error
            ),
            gleam@result:'try'(
                Result,
                fun(Overlapping) ->
                    Hierarchy_span = prequel@span:merge(
                        Totality_span,
                        Final_span
                    ),
                    case Entity_children of
                        {some, First_hierarchy} ->
                            _pipe = {more_than_one_hierarchy,
                                {some, <<"TODO: add hint"/utf8>>},
                                Entity_span,
                                erlang:element(2, First_hierarchy),
                                Hierarchy_span},
                            fail(_pipe);

                        none ->
                            'try'(
                                parse_hierarchy_body(
                                    Tokens@1,
                                    Entity_span,
                                    Hierarchy_span
                                ),
                                fun(Entities, Tokens@2) ->
                                    _pipe@1 = {hierarchy,
                                        Hierarchy_span,
                                        Overlapping,
                                        Totality,
                                        Entities},
                                    succeed(_pipe@1, Tokens@2)
                                end
                            )
                    end
                end
            );

        [{{word, <<"overlapped"/utf8>>}, _},
            {{word, <<"hierarchy"/utf8>>}, Hierarchy_span@1} |
            _] ->
            _pipe@2 = {empty_hierarchy,
                {some, <<"TODO: add hint"/utf8>>},
                Entity_span,
                prequel@span:merge(Totality_span, Hierarchy_span@1)},
            fail(_pipe@2);

        [{{word, <<"disjoint"/utf8>>}, _},
            {{word, <<"hierarchy"/utf8>>}, Hierarchy_span@1} |
            _] ->
            _pipe@2 = {empty_hierarchy,
                {some, <<"TODO: add hint"/utf8>>},
                Entity_span,
                prequel@span:merge(Totality_span, Hierarchy_span@1)},
            fail(_pipe@2);

        [{{word, <<"overlapped"/utf8>>}, Overlapping_span} | _] ->
            _pipe@3 = {missing_hierarchy_keyword,
                {some, <<"TODO: add hint"/utf8>>},
                Entity_span,
                prequel@span:merge(Totality_span, Overlapping_span)},
            fail(_pipe@3);

        [{{word, <<"disjoint"/utf8>>}, Overlapping_span} | _] ->
            _pipe@3 = {missing_hierarchy_keyword,
                {some, <<"TODO: add hint"/utf8>>},
                Entity_span,
                prequel@span:merge(Totality_span, Overlapping_span)},
            fail(_pipe@3);

        [{Token, Span} | _] ->
            _pipe@4 = {wrong_hierarchy_overlapping,
                {some, <<"TODO: add hint"/utf8>>},
                Entity_span,
                Totality_span,
                prequel@internals@token:to_string(Token),
                Span},
            fail(_pipe@4);

        [] ->
            _pipe@5 = {unexpected_end_of_file,
                {some, <<"TODO: add hint"/utf8>>},
                {some, Entity_span},
                Totality_span,
                <<"this hierarchy"/utf8>>},
            fail(_pipe@5)
    end.

-spec do_parse_relationship_body(
    list({prequel@internals@token:token(), prequel@span:span()}),
    binary(),
    prequel@span:span(),
    list(prequel@ast:relationship_entity()),
    list(prequel@ast:attribute())
) -> {ok,
        {prequel@ast:relationship(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
do_parse_relationship_body(
    Tokens,
    Relationship_name,
    Relationship_span,
    Entities,
    Attributes
) ->
    case Tokens of
        [{close_bracket, _} | Tokens@1] ->
            case Entities of
                [One_entity, Other_entity | Other_entities] ->
                    _pipe = {relationship,
                        Relationship_span,
                        Relationship_name,
                        One_entity,
                        non_empty_list:new(Other_entity, Other_entities),
                        Attributes},
                    succeed(_pipe, Tokens@1);

                [One_entity@1] ->
                    _pipe@1 = {relationship_body_with_just_one_entity,
                        {some, <<"TODO: add hint"/utf8>>},
                        Relationship_span,
                        Relationship_name,
                        erlang:element(2, One_entity@1)},
                    fail(_pipe@1);

                [] ->
                    _pipe@2 = {relationship_body_with_no_entities,
                        {some, <<"TODO: add hint"/utf8>>},
                        Relationship_span},
                    fail(_pipe@2)
            end;

        [{circle_lollipop, Lollipop_span} | Tokens@2] ->
            'try'(
                parse_attribute(Tokens@2, Relationship_span, Lollipop_span),
                fun(Attribute, Tokens@3) ->
                    do_parse_relationship_body(
                        Tokens@3,
                        Relationship_name,
                        Relationship_span,
                        Entities,
                        [Attribute | Attributes]
                    )
                end
            );

        [{arrow_lollipop, Lollipop_span@1} | Tokens@4] ->
            'try'(
                parse_relationship_entity(
                    Tokens@4,
                    Relationship_span,
                    Lollipop_span@1
                ),
                fun(Entity, Tokens@5) ->
                    do_parse_relationship_body(
                        Tokens@5,
                        Relationship_name,
                        Relationship_span,
                        [Entity | Entities],
                        Attributes
                    )
                end
            );

        [{star_lollipop, Lollipop_span@2} | _] ->
            _pipe@3 = {key_inside_relationship,
                {some, <<"TODO: add hint"/utf8>>},
                Relationship_span,
                Lollipop_span@2},
            fail(_pipe@3);

        [{minus, Minus_span}, {{word, <<"o"/utf8>>}, O_span} | _] ->
            _pipe@4 = {possible_circle_lollipop_typo,
                {some, <<"TODO: add hint"/utf8>>},
                Relationship_span,
                prequel@span:merge(Minus_span, O_span)},
            fail(_pipe@4);

        [{minus, Minus_span@1}, {{word, <<">"/utf8>>}, Arrow_span} | _] ->
            _pipe@5 = {possible_arrow_lollipop_typo,
                {some, <<"TODO: add hint"/utf8>>},
                Relationship_span,
                prequel@span:merge(Minus_span@1, Arrow_span)},
            fail(_pipe@5);

        [{_, Span} | _] ->
            _pipe@6 = {unexpected_token_in_relationship_body,
                {some, <<"TODO: add hint"/utf8>>},
                Relationship_span,
                Span},
            fail(_pipe@6);

        [] ->
            _pipe@7 = {unexpected_end_of_file,
                {some, <<"TODO: add hint"/utf8>>},
                none,
                Relationship_span,
                <<"this relationship"/utf8>>},
            fail(_pipe@7)
    end.

-spec parse_relationship_body(
    list({prequel@internals@token:token(), prequel@span:span()}),
    binary(),
    prequel@span:span()
) -> {ok,
        {prequel@ast:relationship(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
parse_relationship_body(Tokens, Relationship_name, Name_span) ->
    do_parse_relationship_body(Tokens, Relationship_name, Name_span, [], []).

-spec parse_relationship(
    list({prequel@internals@token:token(), prequel@span:span()}),
    prequel@span:span()
) -> {ok,
        {prequel@ast:relationship(),
            list({prequel@internals@token:token(), prequel@span:span()})}} |
    {error, prequel@error@parse_error:parse_error()}.
parse_relationship(Tokens, Relationship_keyword_span) ->
    case Tokens of
        [{{word, Relationship_name}, Relationship_span},
            {open_bracket, _} |
            Tokens@1] ->
            parse_relationship_body(
                Tokens@1,
                Relationship_name,
                Relationship_span
            );

        [{{word, _}, Name_span} | _] ->
            _pipe = {relationship_body_with_no_entities,
                {some, <<"TODO: add hint"/utf8>>},
                Name_span},
            fail(_pipe);

        [{Token, Span} | _] ->
            _pipe@1 = {wrong_relationship_name,
                {some, <<"TODO: add hint"/utf8>>},
                none,
                Relationship_keyword_span,
                prequel@internals@token:to_string(Token),
                Span},
            fail(_pipe@1);

        [] ->
            _pipe@2 = {unexpected_end_of_file,
                {some, <<"TODO: add hint"/utf8>>},
                none,
                Relationship_keyword_span,
                <<"this relationship"/utf8>>},
            fail(_pipe@2)
    end.