/*
 * =====================================================================================
 *
 *       Filename:  msg.cpp
 *
 *    Description:  
 *
 *        Version:  1.0
 *        Created:  2021年03月24日 16时48分42秒
 *       Revision:  none
 *       Compiler:  gcc
 *
 *         Author:  Li Chao (), 
 *   Organization:  
 *
 * =====================================================================================
 */
#include "msg.h"
#include "bh_util.h"

namespace bhome_msg {

const uint32_t kMsgTag = 0xf1e2d3c4;
const uint32_t kMsgPrefixLen = 4;

BHMsg InitMsg(MsgType type)
{
    BHMsg msg;
    msg.set_type(type);
    time_t tm = 0;
    msg.set_timestamp(time(&tm));
    return msg;
}

BHMsg MakeRequest(const MQId &src_id, const void *data, const size_t size)
{
    assert(data && size);
    BHMsg msg(InitMsg(kMsgTypeRequest));
    msg.set_body(data, size);
    msg.add_route()->set_mq_id(&src_id, sizeof(src_id));
    return msg;
}

BHMsg MakeReply(const void *data, const size_t size)
{
    assert(data && size);
    BHMsg msg(InitMsg(kMsgTypeReply));
    msg.set_body(data, size);
    return msg;
}

BHMsg MakeSubUnsub(const MQId &client, const std::vector<std::string> &topics, const MsgType sub_unsub)
{
    assert(sub_unsub == kMsgTypeSubscribe || sub_unsub == kMsgTypeUnsubscribe);
    BHMsg msg(InitMsg(sub_unsub));
    msg.add_route()->set_mq_id(&client, sizeof(client));
    DataSub subs;
    for (auto &t : topics) {
        subs.add_topics(t);
    }
    msg.set_body(subs.SerializeAsString());
    return msg;
}

BHMsg MakeSub(const MQId &client, const std::vector<std::string> &topics) { return MakeSubUnsub(client, topics, kMsgTypeSubscribe); }
BHMsg MakeUnsub(const MQId &client, const std::vector<std::string> &topics) { return MakeSubUnsub(client, topics, kMsgTypeUnsubscribe); }

BHMsg MakePub(const std::string &topic, const void *data, const size_t size)
{
    assert(data && size);
    BHMsg msg(InitMsg(kMsgTypePublish));
    DataPub pub;
    pub.set_topic(topic);
    pub.set_data(data, size);
    msg.set_body(pub.SerializeAsString());
    return msg;
}

void *Pack(SharedMemory &shm, const BHMsg &msg)
{
    uint32_t msg_size = msg.ByteSizeLong();
    void *p = shm.Alloc(4 + msg_size);
    if(p) {
        Put32(p, msg_size);
        if (!msg.SerializeToArray(static_cast<char*>(p) + kMsgPrefixLen, msg_size)) {
            shm.Dealloc(p);
            p = 0;
        }
    }
    return p;
}

bool MsgI::Unpack(BHMsg &msg) const
{
    void *p = ptr_.get();
    assert(p);
    uint32_t msg_size = Get32(p);
    return msg.ParseFromArray(static_cast<char*>(p) + kMsgPrefixLen, msg_size);
}

// with ref count;
bool MsgI::MakeRC(SharedMemory &shm, const BHMsg &msg)
{
    void *p = Pack(shm, msg);
    if(!p) {
        return false;
    }
    RefCount *rc = shm.New<RefCount>();
    if (!rc) {
        shm.Dealloc(p);
        return false;
    }
    MsgI(p, rc).swap(*this);
    return true;
}

bool MsgI::Make(SharedMemory &shm, const BHMsg &msg)
{
    void *p = Pack(shm, msg);
    if(!p) {
        return false;
    }
    MsgI(p, 0).swap(*this);
    return true;
}

int MsgI::Release(SharedMemory &shm) 
{
    if (IsCounted()) {
        const int n = count_->Dec();
        if (n != 0) {
            return n;
        }
    }
    // free data
    shm.Dealloc(ptr_);
    ptr_ = 0;
    shm.Delete(count_);
    count_ = 0;
    return 0;
}

} // namespace bhome_msg