gleam_bson

-module(bson@encoder).
-compile([no_auto_import, nowarn_unused_vars]).

-export([encode/1]).
-export_type([entity/0]).

-type entity() :: {entity, bson@kind:kind(), bitstring()}.

-spec null() -> entity().
null() ->
    {entity, {kind, <<16#0A>>}, <<>>}.

-spec min() -> entity().
min() ->
    {entity, {kind, <<16#FF>>}, <<>>}.

-spec max() -> entity().
max() ->
    {entity, {kind, <<16#7F>>}, <<>>}.

-spec js(binary()) -> entity().
js(Value) ->
    Length = gleam@bit_string:byte_size(<<Value/binary>>) + 1,
    {entity, {kind, <<16#0D>>}, <<Length:32/little, Value/binary, 0>>}.

-spec string(binary()) -> entity().
string(Value) ->
    Length = gleam@bit_string:byte_size(<<Value/binary>>) + 1,
    {entity, {kind, <<16#02>>}, <<Length:32/little, Value/binary, 0>>}.

-spec double(float()) -> entity().
double(Value) ->
    {entity, {kind, <<16#01>>}, <<Value/little-float>>}.

-spec boolean(boolean()) -> entity().
boolean(Value) ->
    case Value of
        true ->
            {entity, {kind, <<16#08>>}, <<1>>};

        false ->
            {entity, {kind, <<16#08>>}, <<0>>}
    end.

-spec int32(integer()) -> entity().
int32(Value) ->
    {entity, {kind, <<16#10>>}, <<Value:32/little>>}.

-spec int64(integer()) -> entity().
int64(Value) ->
    {entity, {kind, <<16#12>>}, <<Value:64/little>>}.

-spec datetime(birl@time:date_time()) -> entity().
datetime(Value) ->
    {duration, Value@1} = birl@time:difference(
        Value,
        {date_time, 0, 0, none, none}
    ),
    Value@2 = Value@1 div 1000,
    {entity, {kind, <<16#09>>}, <<Value@2:64/little>>}.

-spec object_id(bson@object_id:object_id()) -> entity().
object_id(Value) ->
    {entity, {kind, <<16#07>>}, bson@object_id:to_bit_string(Value)}.

-spec timestamp(integer()) -> entity().
timestamp(Value) ->
    {entity, {kind, <<16#11>>}, <<Value:64/little>>}.

-spec md5(bson@md5:md5()) -> entity().
md5(Value) ->
    Value@1 = bson@md5:to_bit_string(Value),
    Length = gleam@bit_string:byte_size(Value@1),
    {entity,
        {kind, <<16#05>>},
        begin
            _pipe = [<<Length:32/little>>,
                erlang:element(2, {sub_kind, <<16#5>>}),
                Value@1],
            gleam@bit_string:concat(_pipe)
        end}.

-spec uuid(bson@uuid:uuid()) -> entity().
uuid(Value) ->
    Value@1 = bson@uuid:to_bit_string(Value),
    Length = gleam@bit_string:byte_size(Value@1),
    {entity,
        {kind, <<16#05>>},
        begin
            _pipe = [<<Length:32/little>>,
                erlang:element(2, {sub_kind, <<16#4>>}),
                Value@1],
            gleam@bit_string:concat(_pipe)
        end}.

-spec custom(bson@custom:custom()) -> entity().
custom(Value) ->
    {Code, Value@1} = bson@custom:to_bit_string_with_code(Value),
    Length = gleam@bit_string:byte_size(Value@1),
    {entity,
        {kind, <<16#05>>},
        begin
            _pipe = [<<Length:32/little>>, <<Code>>, Value@1],
            gleam@bit_string:concat(_pipe)
        end}.

-spec generic(bson@generic:generic()) -> entity().
generic(Value) ->
    Value@1 = bson@generic:to_bit_string(Value),
    Length = gleam@bit_string:byte_size(Value@1),
    {entity,
        {kind, <<16#05>>},
        begin
            _pipe = [<<Length:32/little>>,
                erlang:element(2, {sub_kind, <<16#0>>}),
                Value@1],
            gleam@bit_string:concat(_pipe)
        end}.

-spec regex(binary(), binary()) -> entity().
regex(Pattern, Options) ->
    {entity,
        {kind, <<16#0B>>},
        begin
            _pipe = [<<Pattern/binary, 0, Options/binary, 0>>],
            gleam@bit_string:concat(_pipe)
        end}.

-spec encode_kv({binary(), bson@value:value()}) -> bitstring().
encode_kv(Pair) ->
    Key = <<(erlang:element(1, Pair))/binary, 0>>,
    Value@15 = case erlang:element(2, Pair) of
        null ->
            null();

        min ->
            min();

        max ->
            max();

        {js, Value} ->
            js(Value);

        {str, Value@1} ->
            string(Value@1);

        {array, Value@2} ->
            array(Value@2);

        {int32, Value@3} ->
            int32(Value@3);

        {int64, Value@4} ->
            int64(Value@4);

        {double, Value@5} ->
            double(Value@5);

        {boolean, Value@6} ->
            boolean(Value@6);

        {document, Value@7} ->
            document(Value@7);

        {date_time, Value@8} ->
            datetime(Value@8);

        {object_id, Value@9} ->
            object_id(Value@9);

        {timestamp, Value@10} ->
            timestamp(Value@10);

        {binary, {md5, Value@11}} ->
            md5(Value@11);

        {binary, {uuid, Value@12}} ->
            uuid(Value@12);

        {binary, {custom, Value@13}} ->
            custom(Value@13);

        {binary, {generic, Value@14}} ->
            generic(Value@14);

        {regex, {Pattern, Options}} ->
            regex(Pattern, Options)
    end,
    case Value@15 of
        {entity, Kind, Value@16} ->
            _pipe = [erlang:element(2, Kind), Key, Value@16],
            gleam@bit_string:concat(_pipe)
    end.

-spec document(list({binary(), bson@value:value()})) -> entity().
document(Doc) ->
    Doc@1 = begin
        _pipe = Doc,
        _pipe@1 = gleam@list:map(_pipe, fun encode_kv/1),
        gleam@bit_string:concat(_pipe@1)
    end,
    Size = gleam@bit_string:byte_size(Doc@1) + 5,
    {entity,
        {kind, <<16#03>>},
        begin
            _pipe@2 = [<<Size:32/little>>, Doc@1, <<0>>],
            gleam@bit_string:concat(_pipe@2)
        end}.

-spec encode(list({binary(), bson@value:value()})) -> bitstring().
encode(Doc) ->
    case document(Doc) of
        {entity, _, Value} ->
            Value
    end.

-spec array(list(bson@value:value())) -> entity().
array(Value) ->
    case begin
        _pipe = gleam@list:index_map(
            Value,
            fun(Index, Item) -> {gleam@int:to_string(Index), Item} end
        ),
        document(_pipe)
    end of
        {entity, _, Value@1} ->
            {entity, {kind, <<16#04>>}, Value@1}
    end.