/* Copyright (c) 2016, 2021, Oracle and/or its affiliates.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License, version 2.0, for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

#include <stdlib.h>
#include <string.h>
#include "gcs_message_stages.h"
#include <assert.h>
#include "gcs_internal_message.h"
#include "gcs_logging.h"
#include <mysql/gcs/xplatform/byteorder.h>
#include <sstream>
#include <iostream>
#include <map>

/*
  There will be a compile warning on os << type_code if no explicit type cast.
  the function is added to eliminate the warnings.
 */
template <class OSTREAM>
static inline
OSTREAM& operator << (OSTREAM& os, Gcs_message_stage::enum_type_code type_code)
{
  return os << static_cast<int>(type_code);
}


const unsigned short Gcs_message_stage::WIRE_HD_LEN_SIZE= 2;
const unsigned short Gcs_message_stage::WIRE_HD_TYPE_SIZE= 4;

const unsigned short Gcs_message_stage::WIRE_HD_LEN_OFFSET= 0;
const unsigned short Gcs_message_stage::WIRE_HD_TYPE_OFFSET=
  Gcs_message_stage::WIRE_HD_LEN_SIZE;

bool
Gcs_message_pipeline::outgoing(Gcs_packet &p)
{
  bool error= false;
  std::vector<Gcs_message_stage::enum_type_code>::iterator it;
  std::map<Gcs_message_stage::enum_type_code, Gcs_message_stage *>::iterator mit;
  for (it= m_pipeline.begin(); !error && it != m_pipeline.end(); it++)
  {
    if ((mit= m_stage_reg.find(*it)) != m_stage_reg.end())
      error= (*mit).second->apply(p);
    else
    {
      MYSQL_GCS_LOG_ERROR("Unable to deliver outgoing message. "
        << "Request for an unknown/invalid message handler! ("
        << *it << ")");
      error= true;
    }
  }
  return error;
}

bool
Gcs_message_pipeline::incoming(Gcs_packet &p)
{
  bool error;
  Gcs_message_stage::enum_type_code stage_type_code;
  std::map<Gcs_message_stage::enum_type_code, Gcs_message_stage *>::iterator mit;

  for (error= false; p.get_dyn_headers_length() > 0 && !error; )
  {
    // decode just the type code
    unsigned int i_stage_type_code;
    memcpy(&i_stage_type_code,
           p.get_payload() + Gcs_message_stage::WIRE_HD_TYPE_OFFSET,
           Gcs_message_stage::WIRE_HD_TYPE_SIZE);
    i_stage_type_code= le32toh(i_stage_type_code);
    stage_type_code= (Gcs_message_stage::enum_type_code) i_stage_type_code;

    if ((mit= m_stage_reg.find(stage_type_code)) != m_stage_reg.end())
      // apply the stage, which removes the header as well
      error= mit->second->revert(p);
    else
    {
      MYSQL_GCS_LOG_ERROR("Unable to deliver incoming message. "
        << "Request for an unknown/invalid message handler! ("
        << stage_type_code << ")");
      error= true;
    }
  }

  return error;
}

void Gcs_message_pipeline::register_stage(Gcs_message_stage *s)
{
  std::map<Gcs_message_stage::enum_type_code, Gcs_message_stage *>::iterator it;
  it = m_stage_reg.find(s->type_code());
  if (it != m_stage_reg.end())
  {
    /*
      If there is a previous registered stage, it is removed first.
    */
    delete (*it).second;
    m_stage_reg.erase(it);
  }
  m_stage_reg[s->type_code()]= s;
}

Gcs_message_pipeline::~Gcs_message_pipeline()
{
  std::map<Gcs_message_stage::enum_type_code, Gcs_message_stage *>::iterator it;
  for (it=m_stage_reg.begin(); it != m_stage_reg.end(); it++)
  {
    Gcs_message_stage *s= (*it).second;
    delete s;
  }
  m_pipeline.clear();
}
