-module(handles@internal@tokenizer).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch]).

-export([run/3]).
-export_type([token/0]).

-type token() :: {constant, integer(), binary()} |
    {property, integer(), list(binary())} |
    {if_block_start, integer(), list(binary())} |
    {if_block_end, integer()} |
    {unless_block_start, integer(), list(binary())} |
    {unless_block_end, integer()} |
    {each_block_start, integer(), list(binary())} |
    {each_block_end, integer()}.

-spec run(binary(), integer(), list(token())) -> {ok, list(token())} |
    {error, handles@error:tokenizer_error()}.
run(Input, Index, Tokens) ->
    case Input of
        <<"{{/if"/utf8, Rest/binary>> ->
            case begin
                _pipe = Rest,
                gleam@string:split_once(_pipe, <<"}}"/utf8>>)
            end of
                {ok, {<<""/utf8>>, Rest@1}} ->
                    run(Rest@1, Index + 7, [{if_block_end, Index + 2} | Tokens]);

                _ ->
                    {error, {unexpected_block_argument, Index + 2}}
            end;

        <<"{{#if"/utf8, Rest@2/binary>> ->
            case begin
                _pipe@1 = Rest@2,
                gleam@string:split_once(_pipe@1, <<"}}"/utf8>>)
            end of
                {ok, {Arg, Rest@3}} ->
                    case begin
                        _pipe@2 = Arg,
                        _pipe@3 = gleam@string:trim(_pipe@2),
                        _pipe@4 = gleam@string:trim(_pipe@3),
                        gleam@string:split(_pipe@4, <<"."/utf8>>)
                    end of
                        [<<""/utf8>>] ->
                            {error, {missing_block_argument, Index + 2}};

                        Path ->
                            run(
                                Rest@3,
                                (Index + 7) + gleam@string:length(Arg),
                                [{if_block_start, Index + 2, Path} | Tokens]
                            )
                    end;

                {error, _} ->
                    {error, {unbalanced_tag, Index + 2}}
            end;

        <<"{{/unless"/utf8, Rest@4/binary>> ->
            case begin
                _pipe@5 = Rest@4,
                gleam@string:split_once(_pipe@5, <<"}}"/utf8>>)
            end of
                {ok, {<<""/utf8>>, Rest@5}} ->
                    run(
                        Rest@5,
                        Index + 11,
                        [{unless_block_end, Index + 2} | Tokens]
                    );

                _ ->
                    {error, {unexpected_block_argument, Index + 2}}
            end;

        <<"{{#unless"/utf8, Rest@6/binary>> ->
            case begin
                _pipe@6 = Rest@6,
                gleam@string:split_once(_pipe@6, <<"}}"/utf8>>)
            end of
                {ok, {Arg@1, Rest@7}} ->
                    case begin
                        _pipe@7 = Arg@1,
                        _pipe@8 = gleam@string:trim(_pipe@7),
                        gleam@string:split(_pipe@8, <<"."/utf8>>)
                    end of
                        [<<""/utf8>>] ->
                            {error, {missing_block_argument, Index + 2}};

                        Path@1 ->
                            run(
                                Rest@7,
                                (Index + 11) + gleam@string:length(Arg@1),
                                [{unless_block_start, Index + 2, Path@1} |
                                    Tokens]
                            )
                    end;

                {error, _} ->
                    {error, {unbalanced_tag, Index + 2}}
            end;

        <<"{{/each"/utf8, Rest@8/binary>> ->
            case begin
                _pipe@9 = Rest@8,
                gleam@string:split_once(_pipe@9, <<"}}"/utf8>>)
            end of
                {ok, {<<""/utf8>>, Rest@9}} ->
                    run(
                        Rest@9,
                        Index + 9,
                        [{each_block_end, Index + 2} | Tokens]
                    );

                _ ->
                    {error, {unexpected_block_argument, Index + 2}}
            end;

        <<"{{#each"/utf8, Rest@10/binary>> ->
            case begin
                _pipe@10 = Rest@10,
                gleam@string:split_once(_pipe@10, <<"}}"/utf8>>)
            end of
                {ok, {Arg@2, Rest@11}} ->
                    case begin
                        _pipe@11 = Arg@2,
                        _pipe@12 = gleam@string:trim(_pipe@11),
                        gleam@string:split(_pipe@12, <<"."/utf8>>)
                    end of
                        [<<""/utf8>>] ->
                            {error, {missing_block_argument, Index + 2}};

                        Path@2 ->
                            run(
                                Rest@11,
                                (Index + 9) + gleam@string:length(Arg@2),
                                [{each_block_start, Index + 2, Path@2} | Tokens]
                            )
                    end;

                {error, _} ->
                    {error, {unbalanced_tag, Index + 2}}
            end;

        <<"{{/"/utf8, _/binary>> ->
            {error, {unexpected_block_kind, Index + 2}};

        <<"{{#"/utf8, _/binary>> ->
            {error, {unexpected_block_kind, Index + 2}};

        <<"{{"/utf8, Rest@12/binary>> ->
            case begin
                _pipe@13 = Rest@12,
                gleam@string:split_once(_pipe@13, <<"}}"/utf8>>)
            end of
                {ok, {Body, Rest@13}} ->
                    case begin
                        _pipe@14 = Body,
                        _pipe@15 = gleam@string:trim(_pipe@14),
                        gleam@string:split(_pipe@15, <<"."/utf8>>)
                    end of
                        [<<""/utf8>>] ->
                            {error, {missing_property_path, Index + 2}};

                        [<<""/utf8>>, <<""/utf8>>] ->
                            run(
                                Rest@13,
                                (Index + 4) + gleam@string:length(Body),
                                [{property, Index + 2, []} | Tokens]
                            );

                        Path@3 ->
                            run(
                                Rest@13,
                                (Index + 4) + gleam@string:length(Body),
                                [{property, Index + 2, Path@3} | Tokens]
                            )
                    end;

                {error, _} ->
                    {error, {unbalanced_tag, Index + 2}}
            end;

        _ ->
            case begin
                _pipe@16 = Input,
                gleam@string:split_once(_pipe@16, <<"{{"/utf8>>)
            end of
                {ok, {Str, Rest@14}} ->
                    run(
                        <<"{{"/utf8, Rest@14/binary>>,
                        Index + gleam@string:length(Str),
                        [{constant, Index, Str} | Tokens]
                    );

                _ ->
                    case Input of
                        <<""/utf8>> ->
                            {ok, lists:reverse(Tokens)};

                        Str@1 ->
                            {ok,
                                lists:reverse(
                                    [{constant, Index, Str@1} | Tokens]
                                )}
                    end
            end
    end.