//
// Created by miti on 21/07/19.
//

#include "protobufReadWrite.h"

namespace protobufReadWrite {
    int read_protobuf_msg_from_fd(int accept_fd, google::protobuf::MessageLite &message)
    {
        ZeroCopyInputStream *raw_input;
        CodedInputStream *coded_input;
        uint32_t size;
        CodedInputStream::Limit limit;
        raw_input = new FileInputStream(accept_fd);
        coded_input = new CodedInputStream(raw_input);
        if (!coded_input->ReadVarint32(&size)) {
            printf("Error in reading size of msg");
            fflush(stdout);
            return -1;
        }
        //printf("size of msg was read to be %" PRIu32 " \n", size);
        fflush(stdout);
        limit = coded_input->PushLimit(size);
        if (!message.ParseFromCodedStream(coded_input)) {
            printf("Error in parsing msg");
            fflush(stdout);
            return -1;
        }
        coded_input->PopLimit(limit);
        delete raw_input;
        delete coded_input;
        return 0;
    }

    int write_protobuf_msg_to_fd(int accept_fd, google::protobuf::MessageLite &message)
    {
        ZeroCopyOutputStream *raw_output = new FileOutputStream(accept_fd);
        CodedOutputStream *coded_output = new CodedOutputStream(raw_output);
        coded_output->WriteVarint32(message.ByteSize());
        if (!message.SerializeToCodedStream(coded_output)) {
            printf("SerializeToCodedStream failed");
            fflush(stdout);
            return -1;
        }
        // As per this - https://stackoverflow.com/questions/22881876/protocol-buffers-how-to-serialize-and-deserialize-multiple-messages-into-a-file?noredirect=1&lq=1
        // TODO: There may be a better way to do this - 1) this happens with every accept now and 2) make it happen on the stack vs heap - destructor will be called on return from this function (main) and the items will then be written out. (We probably don't want that, actually)
        delete coded_output;
        delete raw_output;
        fflush(stdout);
        return 0;
    }
};