// -*- indent-tabs-mode: nil; tab-width: 4; show-trailing-whitespace: t; c-indent-level: 4; c-basic-offset: 4; -*-
#include "rprotobuf.h"
#include "fieldtypes.h"
#include "RcppMacros.h"

#define SAME(x, y, tol) ((tol == 0.0 && x == y) || (((x - y) * (x - y) < tol* tol) ? 1 : 0))

namespace rprotobuf {

/* helpers */

/* this is only to be called for repeated fields */
int MESSAGE_GET_REPEATED_INT(const GPB::Message* message, const GPB::FieldDescriptor* field_desc,
			     int index) {
    const GPB::Reflection* ref = message->GetReflection();

    switch (field_desc->type()) {
        case TYPE_INT32:
        case TYPE_SINT32:
        case TYPE_SFIXED32:
            return (int)ref->GetRepeatedInt32(*message, field_desc, index);
        case TYPE_INT64:
        case TYPE_SINT64:
        case TYPE_SFIXED64:
            return (int)ref->GetRepeatedInt64(*message, field_desc, index);
        case TYPE_UINT32:
        case TYPE_FIXED32:
            return (int)ref->GetRepeatedUInt32(*message, field_desc, index);
        case TYPE_UINT64:
        case TYPE_FIXED64:
            return (int)ref->GetRepeatedUInt64(*message, field_desc, index);
        case TYPE_ENUM:
            return ref->GetRepeatedEnum(*message, field_desc, index)->number();
        default:
            Rcpp_error("cannot cast to int");
    }
    return 0;  // Unreachable for -Wall
}

/* this is only to be called for repeated fields */
double MESSAGE_GET_REPEATED_DOUBLE(const GPB::Message* message,
				   const GPB::FieldDescriptor* field_desc,
                                   int index) {
    const GPB::Reflection* ref = message->GetReflection();

    switch (field_desc->type()) {
        case TYPE_FLOAT:
            return (double)ref->GetRepeatedFloat(*message, field_desc, index);
        case TYPE_DOUBLE:
            return (double)ref->GetRepeatedDouble(*message, field_desc, index);
        default:
            Rcpp_error("cannot cast to double");
    }
    return 0;  // -Wall
}

#undef METHOD
#define METHOD(__NAME__) RCPP_PP_CAT(Message__, __NAME__)

/**
 * Clone a message
 *
 * @param xp external pointer to a message
 * @return a new message, clone of the input message
 */
RPB_FUNCTION_1(S4_Message, METHOD(clone), Rcpp::XPtr<GPB::Message> message) {
    /* cloning message as sheep */
    GPB::Message* sheep = message->New();
    sheep->CopyFrom(*message);

    return S4_Message(sheep);
}

/**
 * TRUE if the message has the specified field name.
 * FALSE otherwise.
 *
 *
 * @param xp external pointer to the Message
 * @param name name of the field
 */
RPB_FUNCTION_2(bool, METHOD(field_exists), Rcpp::XPtr<GPB::Message> message, std::string name) {
    const GPB::Descriptor* desc = message->GetDescriptor();
    const GPB::FieldDescriptor* field_desc = desc->FindFieldByName(name);
    return (field_desc != NULL);
}

/**
 * TRUE if the message has the field name and it is populated.
 * FALSE otherwise.
 *
 * @param xp external pointer to the Message
 * @param name name of the field
 */
RPB_FUNCTION_2(bool, METHOD(has_field), Rcpp::XPtr<GPB::Message> message, std::string name) {

    const GPB::Descriptor* desc = message->GetDescriptor();
    const GPB::FieldDescriptor* field_desc = desc->FindFieldByName(name);

    bool res = false;
    if (field_desc) {
        const GPB::Reflection* ref = message->GetReflection();
        if (field_desc->is_repeated()) {
            res = ref->FieldSize(*message, field_desc) > 0;
        } else {
            res = ref->HasField(*message, field_desc);
        }
    }
    return res;
}

/**
 * Check if all required fields are set
 *
 * @param xp external pointer to the Message
 */
RPB_FUNCTION_1(bool, METHOD(is_initialized), Rcpp::XPtr<GPB::Message> message) {
    return message->IsInitialized();
}

/**
 * Serialize a message to a file
 *
 * @param xp external pointer to a GPB::Message*
 * @param filename file name where to serialize
 */
RPB_FUNCTION_VOID_2(METHOD(serialize_to_file), Rcpp::XPtr<GPB::Message> message,
                    const char* filename) {

    /* open the file in binary mode to write */
    /* we make sure in the R side that filename is the full path of the file */
    int file = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0666);

    /* using partial to allow partially filled messages */
    // TODO(mstokely): Check return value and throw Rcpp::stop if 0?
    message->SerializePartialToFileDescriptor(file);

    close(file);
}

/**
 * Create a raw vector that contains the content of the serialized message
 *
 * @param xp xternal pointer to the message
 */
RPB_FUNCTION_1(Rcpp::RawVector, METHOD(get_payload), Rcpp::XPtr<GPB::Message> message) {

    /* create a raw vector of the appropriate size */
#if GOOGLE_PROTOBUF_VERSION < 3006001
    R_xlen_t size = message->ByteSize();
#else
    R_xlen_t size = message->ByteSizeLong();
#endif
    Rcpp::RawVector payload(size);

    /* fill the array */
    message->SerializePartialToArray(payload.begin(), size);

    return (payload);
}

RPB_XP_METHOD_VOID_0(METHOD(clear), GPB::Message, Clear)

/**
 * Clear a field of a message
 *
 * @param xp (GPB::Message*) external pointer
 * @param field name or tag of the field
 */
RPB_FUNCTION_VOID_2(METHOD(clear_field), Rcpp::XPtr<GPB::Message> m, SEXP field) {
    const GPB::FieldDescriptor* field_desc = getFieldDescriptor(m, field);
    const GPB::Reflection* ref = m->GetReflection();
    ref->ClearField(m, field_desc);
}

/**
 * Return a named list representation of the fields set in a message.
 *
 * @param xp external pointer to a Message
 * @return the message as an R list
 */
RPB_FUNCTION_1(Rcpp::List, METHOD(as_list), Rcpp::XPtr<GPB::Message> message) {

    const GPB::Descriptor* desc = message->GetDescriptor();
    int nf = desc->field_count();

    Rcpp::CharacterVector fieldNames(nf);
    Rcpp::List val(nf);
    /* TODO: not use getMessageField */
    for (int i = 0; i < nf; i++) {
        const GPB::FieldDescriptor* fd = desc->field(i);
        val[i] = getMessageField(message, Rcpp::CharacterVector::create(fd->name()));
        fieldNames[i] = std::string(fd->name());
    }
    val.names() = fieldNames;
    return val;
}

/**
 * The number of fields the message has. A field counts in these two situations:
 * - it is repeated and the array size is greater than 0
 * - it is not repeated and the message has it
 *
 * @param xp external pointer to the Message
 */
RPB_FUNCTION_1(int, METHOD(length), Rcpp::XPtr<GPB::Message> message) {
    const GPB::Descriptor* desc = message->GetDescriptor();
    const GPB::Reflection* ref = message->GetReflection();

    int nfields = desc->field_count();
    int res = 0;

    for (int i = 0; i < nfields; i++) {
        const GPB::FieldDescriptor* field_desc = desc->field(i);
        if (field_desc->is_repeated()) {
            if (ref->FieldSize(*message, field_desc) > 0) {
                res++;
            }
        } else {
            if (ref->HasField(*message, field_desc)) {
                res++;
            }
        }
    }
    return res;
}

/**
 * The number of extensions the message has.
 *
 * @param xp external pointer to the Message
 */
RPB_FUNCTION_1(int, METHOD(num_extensions), Rcpp::XPtr<GPB::Message> message) {
    const GPB::Reflection* ref = message->GetReflection();
    int nexts = 0;
    std::vector<const FieldDescriptor*> fields;
    ref->ListFields(*message, &fields);
    for (unsigned int i = 0; i < fields.size(); i++) {
        if (fields[i]->is_extension()) {
            nexts++;
        }
    }
    return nexts;
}

/**
 * Get the message descriptor of a Message.
 *
 * @param xp (GPB::Message*) external pointer
 * @return the descriptor, as a Descriptor R S4 object
 */
RPB_FUNCTION_1(S4_Descriptor, METHOD(descriptor), Rcpp::XPtr<GPB::Message> message) {
    return (message->GetDescriptor());
}

RPB_XP_METHOD_0(METHOD(as_character), GPB::Message, DebugString)
#if GOOGLE_PROTOBUF_VERSION < 3006001
  RPB_XP_METHOD_0(METHOD(bytesize), GPB::Message, ByteSize)
#else
  RPB_XP_METHOD_0(METHOD(bytesize), GPB::Message, ByteSizeLong)
#endif

RPB_FUNCTION_2(int, METHOD(field_size), Rcpp::XPtr<GPB::Message> message, SEXP field) {
    const GPB::FieldDescriptor* field_desc = getFieldDescriptor(message, field);

    int res = 0;
    if (field_desc->is_repeated()) {
        res = message->GetReflection()->FieldSize(*message, field_desc);
    } else {
        res = message->GetReflection()->HasField(*message, field_desc) ? 1 : 0;
    }
    return res;
}

RPB_FUNCTION_1(S4_FileDescriptor, METHOD(fileDescriptor), Rcpp::XPtr<GPB::Message> message) {
    return S4_FileDescriptor(message->GetDescriptor()->file());
}

RPB_FUNCTION_VOID_3(METHOD(set_field_size), Rcpp::XPtr<GPB::Message> message, SEXP field,
                    int target) {
    const GPB::FieldDescriptor* field_desc = getFieldDescriptor(message, field);
    const GPB::Reflection* ref = message->GetReflection();

    if (field_desc->is_repeated()) {
        int current = ref->FieldSize(*message, field_desc);

        if (target == 0) {
            ref->ClearField(message, field_desc);
        } else if (current > target) {
            while (current != target) {
                ref->RemoveLast(message, field_desc);
                current--;
            }
        } else if (current == target) {
            /* nothing to do */
        } else {/* current < target */

            while (current != target) {
                switch (field_desc->type()) {
                    case TYPE_INT32:
                    case TYPE_SINT32:
                    case TYPE_SFIXED32: {
                        ref->AddInt32(message, field_desc, (int32)0);
                        break;
                    }
                    case TYPE_INT64:
                    case TYPE_SINT64:
                    case TYPE_SFIXED64: {
                        ref->AddInt64(message, field_desc, (int64)0);
                        break;
                    }
                    case TYPE_UINT32:
                    case TYPE_FIXED32: {
                        ref->AddUInt32(message, field_desc, (uint32)0);
                        break;
                    }
                    case TYPE_UINT64:
                    case TYPE_FIXED64: {
                        ref->AddUInt32(message, field_desc, (uint64)0);
                        break;
                    }
                    case TYPE_DOUBLE: {
                        ref->AddDouble(message, field_desc, (double)0.0);
                        break;
                    }
                    case TYPE_FLOAT: {
                        ref->AddFloat(message, field_desc, (float)0.0);
                        break;
                    }
                    case TYPE_BOOL: {
                        ref->AddBool(message, field_desc, (bool)0);
                        break;
                    }
                    case TYPE_STRING:
                    case TYPE_BYTES: {
                        ref->AddString(message, field_desc, "");
                        break;
                    }
                    case TYPE_MESSAGE:
                    case TYPE_GROUP: {
                        /* fill with the prototype for that message type */
                        Rcpp_error("growing repeated messages not implemented, patches welcome");
                        break;
                    }
                    case TYPE_ENUM: {
                        /* fill with the prototype for that message type */
                        Rcpp_error("growing repeated enums not implemented yet, patches welcome");
                        break;
                    }
                } /* switch */

                current++;
            } /* while */
        }

    } else {
        if (target == 0) {
            if (ref->HasField(*message, field_desc)) {
                ref->ClearField(message, field_desc);
            }
        } else {
            if (!ref->HasField(*message, field_desc)) {
                switch (field_desc->type()) {
                    case TYPE_INT32:
                    case TYPE_SINT32:
                    case TYPE_SFIXED32: {
                        ref->SetInt32(message, field_desc, (int32)0);
                        break;
                    }
                    case TYPE_INT64:
                    case TYPE_SINT64:
                    case TYPE_SFIXED64: {
                        ref->SetInt64(message, field_desc, (int64)0);
                        break;
                    }
                    case TYPE_UINT32:
                    case TYPE_FIXED32: {
                        ref->SetUInt32(message, field_desc, (uint32)0);
                        break;
                    }
                    case TYPE_UINT64:
                    case TYPE_FIXED64: {
                        ref->SetUInt32(message, field_desc, (uint64)0);
                        break;
                    }
                    case TYPE_DOUBLE: {
                        ref->SetDouble(message, field_desc, (double)0.0);
                        break;
                    }
                    case TYPE_FLOAT: {
                        ref->SetFloat(message, field_desc, (float)0.0);
                        break;
                    }
                    case TYPE_BOOL: {
                        ref->SetBool(message, field_desc, (bool)0);
                        break;
                    }
                    case TYPE_STRING:
                    case TYPE_BYTES: {
                        ref->SetString(message, field_desc, "");
                        break;
                    }
                    case TYPE_MESSAGE:
                    case TYPE_GROUP: {
                        /* fill with the prototype for that message type */
                        Rcpp_error("not implemented yet, patches welcome");
                        break;
                    }
                    case TYPE_ENUM: {
                        /* fill with the prototype for that message type */
                        Rcpp_error("not implemented yet, patches welcome");
                        break;
                    }
                }
            }
        }
    }
}

/**
 * Returns the field names of the message.
 *
 * @param xp external pointer to a Message
 *
 * @return field names, as an R character vector (STRSXP)
 */
RPB_FUNCTION_1(Rcpp::CharacterVector, METHOD(fieldNames), Rcpp::XPtr<GPB::Message> message) {
    const GPB::Descriptor* desc = message->GetDescriptor();

    int nfields = desc->field_count();
    Rcpp::CharacterVector res(nfields);
    for (int i = 0; i < nfields; i++) {
        res[i] = std::string(desc->field(i)->name());
    }
    return (res);
}

/**
 * Returns the JSON representation of the message.
 *
 * @param xp external pointer to a Message
 * @param preserve_proto_field_names If FALSE (the default) convert field names to camelCase.
 * @param always_print_primitive_fields Whether to return the default value for missing primitive fields. (default false)
 *
 * @return JSON representation of the message as a single element R character vector (STRSXP)
 */
RPB_FUNCTION_3(Rcpp::CharacterVector, METHOD(as_json), Rcpp::XPtr<GPB::Message> message,
               bool preserve_proto_field_names,
               bool always_print_primitive_fields) {
#ifdef PROTOBUF_JSON_UTIL
    GPB::util::JsonPrintOptions opts;
    opts.add_whitespace = true;
    opts.preserve_proto_field_names = preserve_proto_field_names;
    #if GOOGLE_PROTOBUF_VERSION < 5026000
        opts.always_print_primitive_fields = always_print_primitive_fields;
    #endif

    std::string buf;
    #if GOOGLE_PROTOBUF_VERSION < 4022000
        GPB::util::Status status = GPB::util::MessageToJsonString(*message, &buf, opts);
    #else
        absl::Status status = GPB::util::MessageToJsonString(*message, &buf, opts);
    #endif
    if (!status.ok()) {
        Rcpp::stop(status.ToString().c_str());
    }
    Rcpp::CharacterVector res(1);
    res[0] = buf;
    return (res);
#else
    Rcpp::stop(
        "The protobuf library you are using is too old for using JSON utility functions, "
        "please upgrade to version 3 or above.");
#endif
}

bool identical_messages_(const GPB::Message* m1, const GPB::Message* m2, double tol) {
    const GPB::Descriptor* d1 = m1->GetDescriptor();
    const GPB::Descriptor* d2 = m2->GetDescriptor();

    /* first of all, check if this is the same message type */
    if (d1 != d2) {
        return false;
    }

    const GPB::Reflection* ref = m2->GetReflection();

    /* iterate field descriptors */
    int nf = d1->field_count();
    for (int i = 0; i < nf; i++) {
        const GPB::FieldDescriptor* field_desc = d1->field(i);

        if (field_desc->is_repeated()) {

            /* test if the size differs */
            int fs1 = ref->FieldSize(*m1, field_desc);
            int fs2 = ref->FieldSize(*m2, field_desc);
            if (fs1 != fs2) return false;
            /* skip the field if it's unset in both messages */
            if ((fs1 == 0) & (fs2 == 0)) continue;

            /* test all items */
            switch (field_desc->type()) {
                case TYPE_INT32:
                case TYPE_SINT32:
                case TYPE_SFIXED32: {
                    for (int j = 0; j < fs1; j++) {
                        if (ref->GetRepeatedInt32(*m1, field_desc, j) !=
                            ref->GetRepeatedInt32(*m2, field_desc, j))
                            return false;
                    }
                    break;
                }
                case TYPE_INT64:
                case TYPE_SINT64:
                case TYPE_SFIXED64: {
                    for (int j = 0; j < fs1; j++) {
                        if (ref->GetRepeatedInt64(*m1, field_desc, j) !=
                            ref->GetRepeatedInt64(*m2, field_desc, j))
                            return false;
                    }
                    break;
                }
                case TYPE_UINT32:
                case TYPE_FIXED32: {
                    for (int j = 0; j < fs1; j++) {
                        if (ref->GetRepeatedUInt32(*m1, field_desc, j) !=
                            ref->GetRepeatedUInt32(*m2, field_desc, j))
                            return false;
                    }
                    break;
                }
                case TYPE_UINT64:
                case TYPE_FIXED64: {
                    for (int j = 0; j < fs1; j++) {
                        if (ref->GetRepeatedUInt64(*m1, field_desc, j) !=
                            ref->GetRepeatedUInt64(*m2, field_desc, j))
                            return false;
                    }
                    break;
                }
                case TYPE_DOUBLE: {
                    for (int j = 0; j < fs1; j++) {
                        if (!SAME(ref->GetRepeatedDouble(*m1, field_desc, j),
                                  ref->GetRepeatedDouble(*m2, field_desc, j), tol))
                            return false;
                    }
                    break;
                }
                case TYPE_FLOAT: {
                    for (int j = 0; j < fs1; j++) {
                        if (!SAME(ref->GetRepeatedFloat(*m1, field_desc, j),
                                  ref->GetRepeatedFloat(*m2, field_desc, j), tol))
                            return false;
                    }
                    break;
                }
                case TYPE_BOOL: {
                    for (int j = 0; j < fs1; j++) {
                        if (ref->GetRepeatedBool(*m1, field_desc, j) !=
                            ref->GetRepeatedBool(*m2, field_desc, j))
                            return false;
                    }
                    break;
                }
                case TYPE_STRING:
                case TYPE_BYTES: {
                    for (int j = 0; j < fs1; j++) {
                        if (ref->GetRepeatedString(*m1, field_desc, j) !=
                            ref->GetRepeatedString(*m2, field_desc, j))
                            return false;
                    }
                    break;
                }
                case TYPE_ENUM: {
                    for (int j = 0; j < fs1; j++) {
                        if (ref->GetRepeatedEnum(*m1, field_desc, j) !=
                            ref->GetRepeatedEnum(*m2, field_desc, j))
                            return false;
                    }
                    break;
                }
                case TYPE_MESSAGE:
                case TYPE_GROUP: {
                    for (int j = 0; j < fs1; j++) {
                        const GPB::Message* mm1 = &ref->GetRepeatedMessage(*m1, field_desc, j);
                        const GPB::Message* mm2 = &ref->GetRepeatedMessage(*m2, field_desc, j);
                        if (!identical_messages_(mm1, mm2, tol)) {
                            return false;
                        }
                    }
                    break;
                }
                default:
                    Rcpp_error("unknown type");
            }

        } else {
            /* skip the field if it's unset in both messages */
            bool hf1 = ref->HasField(*m1, field_desc);
            bool hf2 = ref->HasField(*m2, field_desc);
            if (!hf1 & !hf2) continue;

            switch (field_desc->type()) {
                case TYPE_INT32:
                case TYPE_SINT32:
                case TYPE_SFIXED32: {
                    if (ref->GetInt32(*m1, field_desc) != ref->GetInt32(*m2, field_desc))
                        return false;
                    break;
                }
                case TYPE_INT64:
                case TYPE_SINT64:
                case TYPE_SFIXED64: {
                    if (ref->GetInt64(*m1, field_desc) != ref->GetInt64(*m2, field_desc))
                        return false;
                    break;
                }
                case TYPE_UINT32:
                case TYPE_FIXED32: {
                    if (ref->GetUInt32(*m1, field_desc) != ref->GetUInt32(*m2, field_desc))
                        return false;
                    break;
                }
                case TYPE_UINT64:
                case TYPE_FIXED64: {
                    if (ref->GetUInt64(*m1, field_desc) != ref->GetUInt64(*m2, field_desc))
                        return false;
                    break;
                }
                case TYPE_DOUBLE: {
                    if (ref->GetDouble(*m1, field_desc) != ref->GetDouble(*m2, field_desc))
                        return false;
                    break;
                }
                case TYPE_FLOAT: {
                    if (ref->GetFloat(*m1, field_desc) != ref->GetFloat(*m2, field_desc))
                        return false;
                    break;
                }
                case TYPE_BOOL: {
                    if (ref->GetBool(*m1, field_desc) != ref->GetBool(*m2, field_desc))
                        return false;
                    break;
                }
                case TYPE_STRING:
                case TYPE_BYTES: {
                    if (ref->GetString(*m1, field_desc) != ref->GetString(*m2, field_desc))
                        return false;
                    break;
                }
                case TYPE_ENUM: {
                    if (ref->GetEnum(*m1, field_desc) != ref->GetEnum(*m2, field_desc))
                        return false;
                    break;
                }
                case TYPE_MESSAGE:
                case TYPE_GROUP: {
                    const GPB::Message* mm1 = &ref->GetMessage(*m1, field_desc);
                    const GPB::Message* mm2 = &ref->GetMessage(*m2, field_desc);
                    if (!identical_messages_(mm1, mm2, tol)) {
                        return false;
                    }
                    break;
                }
                default:
                    Rcpp_error("unknown type");
            }
        }
    }
    /* finally */
    return true;
}

RPB_FUNCTION_2(bool, identical_messages, Rcpp::XPtr<const GPB::Message> m1,
	       Rcpp::XPtr<const GPB::Message> m2) {
    return identical_messages_(m1, m2, 0.0);
}

RPB_FUNCTION_3(bool, all_equal_messages, Rcpp::XPtr<const GPB::Message> m1,
	       Rcpp::XPtr<const GPB::Message> m2, double tol) {
    return identical_messages_(m1, m2, tol);
}

RPB_FUNCTION_VOID_4(METHOD(swap), Rcpp::XPtr<GPB::Message> message, SEXP field,
                    Rcpp::IntegerVector left, Rcpp::IntegerVector right) {
    GPB::FieldDescriptor* field_desc = getFieldDescriptor(message, field);
    const GPB::Reflection* ref = message->GetReflection();
    if (!field_desc->is_repeated()) {
        throw std::range_error("swap can only be used with repeated fields");
    }
    int n = LENGTH(left); /* we know that length(left) == length(right) */
    for (int i = 0; i < n; i++) {
        ref->SwapElements(message, field_desc, left[i], right[i]);
    }
}

/**
 * Creates a new message by merging two messages of the same type.
 *
 * @param xp1 external pointer to a GPB::Message*
 * @param xp2 external pointer to a GPB::Message*
 *
 * @return a new message, as an R object of "Message" S4 class
 */
RPB_FUNCTION_2(S4_Message, METHOD(merge), Rcpp::XPtr<GPB::Message> m1,
               Rcpp::XPtr<GPB::Message> m2) {
    GPB::Message* merged = m1->New();
    merged->MergeFrom(*m1);
    merged->MergeFrom(*m2);
    return S4_Message(merged);
}

/**
 * Add values to a repeated field.
 *
 * @param xp (GPB::Message*) external pointer
 * @param field field tag number or name
 * @param values values to append
 */
RPB_FUNCTION_VOID_3(METHOD(add_values), Rcpp::XPtr<GPB::Message> message, SEXP field, SEXP values) {
    const Reflection* ref = message->GetReflection();
    const GPB::FieldDescriptor* field_desc = getFieldDescriptor(message, field);

    if (values == R_NilValue || LENGTH(values) == 0) {
        return;
    }

    if (field_desc->is_repeated()) {
        /* first check */
        switch (field_desc->type()) {
            case TYPE_ENUM: {
                CHECK_values_for_enum(field_desc, values);
                break;
            }
            case TYPE_MESSAGE:
            case TYPE_GROUP: {
                CHECK_messages(field_desc, values);
                break;
            }
            default: {  // nothing
            }
        }

        int value_size = LENGTH(values);
        /* then add the values */
        switch (field_desc->type()) {
            // {{{ int32
            case TYPE_INT32:
            case TYPE_SINT32:
            case TYPE_SFIXED32: {
                switch (TYPEOF(values)) {
                    case INTSXP:
                    case REALSXP:
                    case LGLSXP:
                    case RAWSXP: {
                        for (int i = 0; i < value_size; i++) {
                            ref->AddInt32(message, field_desc, GET_int32(values, i));
                        }
                        break;
                    }
                    default:
                        Rcpp::stop("Cannot convert to int32");
                }
                break;
            }
            // }}}

            // {{{ int64
            case TYPE_INT64:
            case TYPE_SINT64:
            case TYPE_SFIXED64: {
                switch (TYPEOF(values)) {
                    case INTSXP:
                    case REALSXP:
                    case LGLSXP:
                    case RAWSXP:
                        for (int i = 0; i < value_size; i++) {
                            ref->AddInt64(message, field_desc, GET_int64(values, i));
                        }
			break;
                    default:
                        Rcpp::stop("Cannot convert to int64");
                }
                break;
            }
            // }}}

            // {{{ uint32
            case TYPE_UINT32:
            case TYPE_FIXED32: {
                switch (TYPEOF(values)) {
                    case INTSXP:
                    case REALSXP:
                    case LGLSXP:
                    case RAWSXP: {
                        for (int i = 0; i < value_size; i++) {
                            ref->AddUInt32(message, field_desc, GET_uint32(values, i));
                        }
                        break;
                    }
                    default:
                        Rcpp::stop("Cannot convert to uint32");
                }
                break;
            }
            // }}}

            // {{{ uint64
            case TYPE_UINT64:
            case TYPE_FIXED64: {
                switch (TYPEOF(values)) {
                    case INTSXP:
                    case REALSXP:
                    case LGLSXP:
                    case RAWSXP: {
                        for (int i = 0; i < value_size; i++) {
                            ref->AddUInt64(message, field_desc, GET_uint64(values, i));
                        }
                        break;
                    }
                    default:
                        Rcpp::stop("Cannot convert to int64");
                }
                break;
            }
            // }}}

            // {{{ double
            case TYPE_DOUBLE: {
                switch (TYPEOF(values)) {
                    case INTSXP:
                    case REALSXP:
                    case LGLSXP:
                    case RAWSXP: {
                        for (int i = 0; i < value_size; i++) {
                            ref->AddDouble(message, field_desc, GET_double(values, i));
                        }
                        break;
                    }
                    default:
                        Rcpp::stop("Cannot convert to double");
                }
                break;
            }
            // }}}

            // {{{ float
            case TYPE_FLOAT: {
                switch (TYPEOF(values)) {
                    case INTSXP:
                    case REALSXP:
                    case LGLSXP:
                    case RAWSXP: {
                        for (int i = 0; i < value_size; i++) {
                            ref->AddFloat(message, field_desc, GET_float(values, i));
                        }
                        break;
                    }
                    default:
                        Rcpp::stop("Cannot convert to float");
                }
                break;
            }
            // }}}

            // {{{ bool
            case TYPE_BOOL: {
                switch (TYPEOF(values)) {
                    case INTSXP:
                    case REALSXP:
                    case LGLSXP:
                    case RAWSXP: {
                        for (int i = 0; i < value_size; i++) {
                            ref->AddBool(message, field_desc, GET_bool(values, i));
                        }
                        break;
                    }
                    default:
                        Rcpp::stop("Cannot convert to bool");
                }
                break;
            }
            // }}}

            // {{{ string
            case TYPE_STRING: {
                if (TYPEOF(values) == STRSXP) {
                    for (int i = 0; i < value_size; i++) {
                        ref->AddString(message, field_desc,
                                       COPYSTRING(CHAR(STRING_ELT(values, i))));
                    }
                } else {
                    Rcpp::stop("Cannot convert to string");
                }
                break;
            }
            // }}}

            // {{{ bytes
            case TYPE_BYTES: {
                if (TYPEOF(values) == RAWSXP) {
                    ref->AddString(message, field_desc, GET_bytes(values, 0));
                } else if (TYPEOF(values) == VECSXP) {
                    for (int i = 0; i < value_size; i++) {
                        ref->AddString(message, field_desc, GET_bytes(values, i));
                    }
                } else {
                    Rcpp::stop("Cannot convert to bytes");
                }
                break;
            }
            // }}}

            // {{{ message
            case TYPE_MESSAGE:
            case TYPE_GROUP: {
                if (TYPEOF(values) == VECSXP) {
                    for (int i = 0; i < value_size; i++) {
                        GPB::Message* mess = GET_MESSAGE_POINTER_FROM_S4(VECTOR_ELT(values, i));
                        /* we already know it is of the correct
                           type because of premptive check above */

                        ref->AddMessage(message, field_desc)->CopyFrom(*mess);
                    }
                } else {
                    Rcpp::stop("type mismatch, expecting a list of 'Message' objects");
                }
                break;
            }
            // }}}

            // {{{ enum
            case TYPE_ENUM: {
                const GPB::EnumDescriptor* enum_desc = field_desc->enum_type();
                switch (TYPEOF(values)) {
                    // {{{ numbers
                    case INTSXP:
                    case REALSXP:
                    case LGLSXP:
                    case RAWSXP: {
                        for (int i = 0; i < value_size; i++) {
                            int val = GET_int(values, i);
                            ref->AddEnum(message, field_desc, enum_desc->FindValueByNumber(val));
                        }
                        break;
                    }
                    // }}}

                    // {{{ STRSXP
                    case STRSXP: {
                        for (int i = 0; i < value_size; i++) {
                            std::string val = CHAR(STRING_ELT(values, i));
                            const GPB::EnumValueDescriptor* evd = enum_desc->FindValueByName(val);
                            ref->AddEnum(message, field_desc, evd);
                        }
                        break;
                    }
                    // }}}

                    default:
                        Rcpp::stop("cannot set enum value");
                }
                break;
            }
            // }}}
            default: {
                // nothing
            }
        }
    } else {
        Rcpp::stop("add can only be used on repeated fields");
    }
}

/**
 * Fetch a subset of the values of a field.
 *
 * @param (GPB::Message*) external pointer
 * @param field name or tag number of the field
 * @param index
 */
RPB_FUNCTION_3(SEXP, METHOD(get_field_values), Rcpp::XPtr<GPB::Message> message, SEXP field,
               Rcpp::IntegerVector index) {
    GPB::FieldDescriptor* field_desc = getFieldDescriptor(message, field);
    if (!field_desc->is_repeated()) {
        Rcpp_error("fetch can only be used on repeated fields");
    }

    int n = index.size();
    switch (field_desc->type()) {
        case TYPE_INT32:
        case TYPE_SINT32:
        case TYPE_SFIXED32:
        case TYPE_INT64:
        case TYPE_SINT64:
        case TYPE_SFIXED64:
        case TYPE_UINT32:
        case TYPE_FIXED32:
        case TYPE_UINT64:
        case TYPE_FIXED64:
        case TYPE_ENUM: {
            Rcpp::IntegerVector res(n);
            for (int i = 0; i < n; i++) {
                res[i] = MESSAGE_GET_REPEATED_INT(message, field_desc, index[i]);
            }
            return res;
        }
        case TYPE_DOUBLE:
        case TYPE_FLOAT: {
            Rcpp::NumericVector res(n);
            for (int i = 0; i < n; i++) {
                res[i] = MESSAGE_GET_REPEATED_DOUBLE(message, field_desc, index[i]);
            }
            return res;
        }
        case TYPE_BOOL: {
            Rcpp::LogicalVector res(n);
            for (int i = 0; i < n; i++) {
                res[i] = MESSAGE_GET_REPEATED_DOUBLE(message, field_desc, index[i]);
            }
            return res;
        }
        case TYPE_STRING: {
            const GPB::Reflection* ref = message->GetReflection();
            Rcpp::CharacterVector res(n);
            for (int i = 0; i < n; i++) {
                res[i] = ref->GetRepeatedString(*message, field_desc, index[i]);
            }
            return res;
        }
        case TYPE_BYTES: {
            const GPB::Reflection* ref = message->GetReflection();
            Rcpp::List res(n);
            for (int i = 0; i < n; i++) {
                std::string s = ref->GetRepeatedString(*message, field_desc, index[i]);
                res[i] = std::vector<Rbyte>(s.begin(), s.end());
            }
            return res;
        }
        case TYPE_MESSAGE:
        case TYPE_GROUP: {
            const GPB::Reflection* ref = message->GetReflection();
            Rcpp::List res(n);
            for (int i = 0; i < n; i++) {
                res[i] = S4_Message(CLONE(&ref->GetRepeatedMessage(*message, field_desc, index[i])));
            }
            return res;
        }
        default:
            throw std::range_error("unknown type");
    }
    return R_NilValue;  // Unreachable.  For -Wall
}

/**
 * set the values of a repeated field
 *
 * @param xp (GPB::Message*) external pointer
 * @param field field tag number or name
 * @param index positions (0-based)
 * @param values new values
 */
RPB_FUNCTION_VOID_4(METHOD(set_field_values), Rcpp::XPtr<GPB::Message> message, SEXP field,
                    Rcpp::IntegerVector index, SEXP values) {
    const GPB::FieldDescriptor* field_desc = getFieldDescriptor(message, field);
    if (!field_desc->is_repeated()) {
        throw std::range_error("set can only be used on repeated fields");
    }

    const GPB::Reflection* ref = message->GetReflection();

    /* we know here that LENGTH(index) == LENGTH(values) */
    int n = index.size();
    switch (field_desc->type()) {
        case TYPE_INT32:
        case TYPE_SINT32:
        case TYPE_SFIXED32: {
            for (int i = 0; i < n; i++) {
                ref->SetRepeatedInt32(message, field_desc, index[i], GET_int32(values, i));
            }
            break;
        }
        case TYPE_INT64:
        case TYPE_SINT64:
        case TYPE_SFIXED64: {
            for (int i = 0; i < n; i++) {
                ref->SetRepeatedInt64(message, field_desc, index[i], GET_int64(values, i));
            }
            break;
        }
        case TYPE_UINT32:
        case TYPE_FIXED32: {
            for (int i = 0; i < n; i++) {
                ref->SetRepeatedUInt32(message, field_desc, GET_int(index, i),
                                       GET_uint32(values, i));
            }
            break;
        }
        case TYPE_UINT64:
        case TYPE_FIXED64: {
            for (int i = 0; i < n; i++) {
                ref->SetRepeatedUInt64(message, field_desc, index[i], GET_uint64(values, i));
            }
            break;
        }
        case TYPE_DOUBLE: {
            for (int i = 0; i < n; i++) {
                ref->SetRepeatedDouble(message, field_desc, index[i], GET_double(values, i));
            }
            break;
        }
        case TYPE_FLOAT: {
            for (int i = 0; i < n; i++) {
                ref->SetRepeatedFloat(message, field_desc, index[i], GET_float(values, i));
            }
            break;
        }
        case TYPE_BOOL: {
            for (int i = 0; i < n; i++) {
                ref->SetRepeatedBool(message, field_desc, index[i], GET_bool(values, i));
            }
            break;
        }
        case TYPE_STRING: {

            for (int i = 0; i < n; i++) {
                ref->SetRepeatedString(message, field_desc, index[i], GET_stdstring(values, i));
            }
            break;
        }
        case TYPE_BYTES: {

            for (int i = 0; i < n; i++) {
                ref->SetRepeatedString(message, field_desc, index[i], GET_bytes(values, i));
            }
            break;
        }
        case TYPE_ENUM: {
            CHECK_values_for_enum(field_desc, values);

            const GPB::EnumDescriptor* enum_desc = field_desc->enum_type();

            switch (TYPEOF(values)) {
                case INTSXP:
                case REALSXP:
                case LGLSXP:
                case RAWSXP: {
                    for (int i = 0; i < n; i++) {
                        int val = GET_int(values, i);
                        ref->SetRepeatedEnum(message, field_desc, i,
                                             enum_desc->FindValueByNumber(val));
                    }
                    break;
                }
                case STRSXP: {
                    Rcpp::CharacterVector vals(values);
                    std::string val;
                    for (int i = 0; i < n; i++) {
                        val = vals[i];
                        const GPB::EnumValueDescriptor* evd = enum_desc->FindValueByName(val);
                        ref->SetRepeatedEnum(message, field_desc, i, evd);
                    }
                    break;
                }
                default:
                    throw std::range_error("impossible to convert to a enum");
            }
	    break;
        }
        case TYPE_MESSAGE:
        case TYPE_GROUP: {
            CHECK_messages(field_desc, values);
            Rcpp::List vals(values);
            for (int i = 0; i < n; i++) {
                GPB::Message* mess = GET_MESSAGE_POINTER_FROM_S4(vals[i]);
                ref->MutableRepeatedMessage(message, field_desc, i)->CopyFrom(*mess);
            }
            break;
        }
        default:
            throw std::range_error("unknown type");
    }
}

//#undef METHOD

/**
 * Return the TextFormat of message
 * @param xp external pointer to the Message
 */
RPB_FUNCTION_1(std::string, METHOD(print_text_format),
               Rcpp::XPtr<GPB::Message> message) {
  std::string message_text;
  GPB::TextFormat::PrintToString(*message, &message_text);
  return message_text;
}

}
