-module(postgleam@codec@array).
-compile([no_auto_import, nowarn_unused_vars, nowarn_unused_function, nowarn_nomatch, inline]).
-define(FILEPATH, "src/postgleam/codec/array.gleam").
-export([array_oid_map/0, build_array_codec/2, register_arrays/1]).

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

-file("src/postgleam/codec/array.gleam", 31).
?DOC(" Hardcoded array OID -> element OID mapping for common types\n").
-spec array_oid_map() -> list({integer(), integer()}).
array_oid_map() ->
    [{1000, 16},
        {1005, 21},
        {1007, 23},
        {1016, 20},
        {1021, 700},
        {1022, 701},
        {1009, 25},
        {1015, 1043},
        {1001, 17},
        {2951, 2950},
        {199, 114},
        {3807, 3802},
        {1231, 1700},
        {1182, 1082},
        {1183, 1083},
        {1270, 1266},
        {1115, 1114},
        {1185, 1184},
        {1187, 1186},
        {1028, 26},
        {1003, 19},
        {1041, 869},
        {1040, 829},
        {1017, 600}].

-file("src/postgleam/codec/array.gleam", 120).
-spec encode_elements(
    list(gleam@option:option(postgleam@value:value())),
    fun((postgleam@value:value()) -> {ok, bitstring()} | {error, binary()}),
    bitstring()
) -> {ok, bitstring()} | {error, binary()}.
encode_elements(Elements, Elem_encode, Acc) ->
    case Elements of
        [] ->
            {ok, Acc};

        [none | Rest] ->
            encode_elements(
                Rest,
                Elem_encode,
                <<Acc/bitstring, 255, 255, 255, 255>>
            );

        [{some, Val} | Rest@1] ->
            case Elem_encode(Val) of
                {ok, Encoded} ->
                    Len = erlang:byte_size(Encoded),
                    encode_elements(
                        Rest@1,
                        Elem_encode,
                        <<Acc/bitstring, Len:32/big, Encoded/bitstring>>
                    );

                {error, E} ->
                    {error,
                        <<"array codec: element encode failed: "/utf8,
                            E/binary>>}
            end
    end.

-file("src/postgleam/codec/array.gleam", 87).
-spec encode_array(
    postgleam@value:value(),
    integer(),
    fun((postgleam@value:value()) -> {ok, bitstring()} | {error, binary()})
) -> {ok, bitstring()} | {error, binary()}.
encode_array(Val, Elem_oid, Elem_encode) ->
    case Val of
        {array, Elements} ->
            Len = erlang:length(Elements),
            case Len of
                0 ->
                    {ok, <<0:32/big, 0:32/big, Elem_oid:32/big>>};

                _ ->
                    Has_null = case gleam@list:any(
                        Elements,
                        fun(E) -> E =:= none end
                    ) of
                        true ->
                            1;

                        false ->
                            0
                    end,
                    Header = <<1:32/big,
                        Has_null:32/big,
                        Elem_oid:32/big,
                        Len:32/big,
                        1:32/big>>,
                    case encode_elements(Elements, Elem_encode, <<>>) of
                        {ok, Body} ->
                            {ok, <<Header/bitstring, Body/bitstring>>};

                        {error, E@1} ->
                            {error, E@1}
                    end
            end;

        _ ->
            {error, <<"array codec: expected Array value"/utf8>>}
    end.

-file("src/postgleam/codec/array.gleam", 164).
-spec decode_elements(
    bitstring(),
    integer(),
    fun((bitstring()) -> {ok, postgleam@value:value()} | {error, binary()}),
    list(gleam@option:option(postgleam@value:value()))
) -> {ok, list(gleam@option:option(postgleam@value:value()))} |
    {error, binary()}.
decode_elements(Data, Remaining, Elem_decode, Acc) ->
    case Remaining of
        0 ->
            {ok, Acc};

        _ ->
            case Data of
                <<-1:32/big-signed, Rest/bitstring>> ->
                    decode_elements(
                        Rest,
                        Remaining - 1,
                        Elem_decode,
                        [none | Acc]
                    );

                <<Len:32/big, Elem_data:Len/binary, Rest@1/bitstring>> ->
                    case Elem_decode(Elem_data) of
                        {ok, Val} ->
                            decode_elements(
                                Rest@1,
                                Remaining - 1,
                                Elem_decode,
                                [{some, Val} | Acc]
                            );

                        {error, E} ->
                            {error,
                                <<"array codec: element decode failed: "/utf8,
                                    E/binary>>}
                    end;

                _ ->
                    {error,
                        <<"array codec: unexpected end of array data"/utf8>>}
            end
    end.

-file("src/postgleam/codec/array.gleam", 146).
-spec decode_array(
    bitstring(),
    fun((bitstring()) -> {ok, postgleam@value:value()} | {error, binary()})
) -> {ok, postgleam@value:value()} | {error, binary()}.
decode_array(Data, Elem_decode) ->
    case Data of
        <<0:32/big, _:32/big, _:32/big>> ->
            {ok, {array, []}};

        <<1:32/big,
            _:32/big,
            _:32/big,
            Length:32/big,
            _:32/big,
            Rest/bitstring>> ->
            case decode_elements(Rest, Length, Elem_decode, []) of
                {ok, Elements} ->
                    {ok, {array, lists:reverse(Elements)}};

                {error, E} ->
                    {error, E}
            end;

        _ ->
            {error, <<"array codec: unsupported array format"/utf8>>}
    end.

-file("src/postgleam/codec/array.gleam", 17).
?DOC(
    " Build an array codec that wraps an element codec.\n"
    " The element codec is captured in closures for encode/decode.\n"
).
-spec build_array_codec(postgleam@codec:codec(), integer()) -> postgleam@codec:codec().
build_array_codec(Element_codec, Array_oid) ->
    Elem_oid = erlang:element(3, Element_codec),
    Elem_encode = erlang:element(5, Element_codec),
    Elem_decode = erlang:element(6, Element_codec),
    {codec,
        <<"array"/utf8>>,
        Array_oid,
        binary,
        fun(Val) -> encode_array(Val, Elem_oid, Elem_encode) end,
        fun(Data) -> decode_array(Data, Elem_decode) end}.

-file("src/postgleam/codec/array.gleam", 66).
-spec register_arrays_loop(
    list({integer(), integer()}),
    gleam@dict:dict(integer(), postgleam@codec:codec())
) -> gleam@dict:dict(integer(), postgleam@codec:codec()).
register_arrays_loop(Mappings, Reg) ->
    case Mappings of
        [] ->
            Reg;

        [{Array_oid, Elem_oid} | Rest] ->
            Reg@1 = case postgleam@codec@registry:lookup(Reg, Elem_oid) of
                {ok, Elem_codec} ->
                    Array_codec = build_array_codec(Elem_codec, Array_oid),
                    maps:put(Array_oid, Array_codec, Reg);

                {error, _} ->
                    Reg
            end,
            register_arrays_loop(Rest, Reg@1)
    end.

-file("src/postgleam/codec/array.gleam", 62).
?DOC(
    " Register array codecs into an existing registry.\n"
    " Looks up each element codec from the base registry, builds an array codec.\n"
).
-spec register_arrays(gleam@dict:dict(integer(), postgleam@codec:codec())) -> gleam@dict:dict(integer(), postgleam@codec:codec()).
register_arrays(Base) ->
    register_arrays_loop(array_oid_map(), Base).