/*
Copyright (c) 2003, 2011, Oracle and/or its affiliates. All rights
reserved.
Copyright (c) 2013, SkySQL Ab

Portions of this file contain modifications contributed and copyrighted by
SkySQL, Ab. Those modifications are gratefully acknowledged and are described
briefly in the source code.

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; version 2 of
the License.

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 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
*/
/*
SkySQL change details:
- Added support for GTID event handling for both MySQL and MariaDB

Author: Jan Lindström (jan.lindstrom@skysql.com

*/
#include <stdint.h>
#include <boost/array.hpp>
#include <vector>

#include "protocol.h"
#include "listener_exception.h"
#include <iostream>
#include <mysql.h>
#include <my_global.h>
#include <mysql_com.h>

using namespace mysql;
using namespace mysql::system;

namespace mysql { namespace system {

int proto_read_package_header(tcp::socket *socket, unsigned long *packet_length, unsigned char *packet_no)
{
  unsigned char buf[4];

  try {
    boost::asio::read(*socket, boost::asio::buffer(buf, 4),
                      boost::asio::transfer_at_least(4));
  } 
  catch (boost::system::system_error const& e)
  {
    throw(ListenerException("Read package header error: " + std::string(e.what()), __FILE__, __LINE__));
  }
  catch (boost::system::error_code const& e)
  {
    throw(ListenerException("Read package header error: " + e.message(), __FILE__, __LINE__));
  }
  catch (std::exception& e)
  {
    throw(ListenerException("Read package header error: " + std::string(e.what()), __FILE__, __LINE__));
  }

  *packet_length=  (unsigned long)(buf[0] &0xFF);
  *packet_length+= (unsigned long)((buf[1] &0xFF)<<8);
  *packet_length+= (unsigned long)((buf[2] &0xFF)<<16);
  *packet_no= (unsigned char)buf[3];

  return 0;
}

int proto_read_package_header(tcp::socket *socket, boost::asio::streambuf &buff, unsigned long *packet_length, unsigned char *packet_no)
{
  std::streamsize inbuff= buff.in_avail();
  if( inbuff < 0)
    inbuff= 0;

  if (4 > inbuff)
  {
    try {
      boost::asio::read(*socket, buff,
                        boost::asio::transfer_at_least(4-inbuff));
    } 
    catch (boost::system::system_error const& e)
    {
      throw(ListenerException("Read package header error: " + std::string(e.what()), __FILE__, __LINE__));
    }
    catch (boost::system::error_code const& e)
    {
      throw(ListenerException("Read package header error: " + e.message(), __FILE__, __LINE__));
    }
    catch (std::exception& e)
    {
      throw(ListenerException("Read package header error: " + std::string(e.what()), __FILE__, __LINE__));
    }
  }
  char ch;
  std::istream is(&buff);
  is.get(ch);
  *packet_length= (unsigned long)ch;
  is.get(ch);
  *packet_length+= (unsigned long)(ch<<8);
  is.get(ch);
  *packet_length+= (unsigned long)(ch<<16);
  is.get(ch);
  *packet_no= (unsigned char)ch;


  return 0;
}


int proto_get_one_package(tcp::socket *socket, boost::asio::streambuf &buff,
                          boost::uint8_t *packet_no)
{
  unsigned long packet_length;
  if (proto_read_package_header(socket, buff, &packet_length, packet_no))
    return 0;
  std::streamsize inbuffer= buff.in_avail();
  if (inbuffer < 0)
    inbuffer= 0;
  if (packet_length > inbuffer)
    boost::asio::read(*socket, buff,
                      boost::asio::transfer_at_least(packet_length-inbuffer));

  return packet_length;
}

void prot_parse_error_message(std::istream &is, struct st_error_package &err,
                              int packet_length)
{
  boost::uint8_t marker;

  Protocol_chunk<boost::uint16_t> prot_errno(err.error_code);
  Protocol_chunk<boost::uint8_t>  prot_marker(marker);
  Protocol_chunk<boost::uint8_t>  prot_sql_state(err.sql_state,5);

  is >> prot_errno
     >> prot_marker
     >> prot_sql_state;

    // TODO is the number of bytes read = is.tellg() ?

  int message_size= packet_length -2 -1 -5; // the remaining part of the package
  Protocol_chunk_string prot_message(err.message, message_size);
  is >> prot_message;
  err.message[message_size]= '\0';
}

void prot_parse_ok_message(std::istream &is, struct st_ok_package &ok, int packet_length)
{
 // TODO: Assure that zero length messages can be but on the input stream.

  //Protocol_chunk<boost::uint8_t>  prot_result_type(result_type);
  Protocol_chunk<boost::uint64_t> prot_affected_rows(ok.affected_rows);
  Protocol_chunk<boost::uint64_t> prot_insert_id(ok.insert_id);
  Protocol_chunk<boost::uint16_t> prot_server_status(ok.server_status);
  Protocol_chunk<boost::uint16_t> prot_warning_count(ok.warning_count);

  int message_size= packet_length -2  -prot_affected_rows.size()
                    -prot_insert_id.size() -prot_server_status.size()
                    -prot_warning_count.size();

  prot_affected_rows.set_length_encoded_binary(true);
  prot_insert_id.set_length_encoded_binary(true);

  is  >> prot_affected_rows
      >> prot_insert_id
      >> prot_server_status
      >> prot_warning_count;

  if (message_size > 0)
  {
    Protocol_chunk_string prot_message(ok.message, message_size);
    is >> prot_message;
    ok.message[message_size]= '\0';
  }
}

void prot_parse_eof_message(std::istream &is, struct st_eof_package &eof)
{
  Protocol_chunk<boost::uint16_t> proto_warning_count(eof.warning_count);
  Protocol_chunk<boost::uint16_t> proto_status_flags(eof.status_flags);

  is >> proto_warning_count
     >> proto_status_flags;
}

void proto_get_handshake_package(std::istream &is,
                                 struct st_handshake_package &p,
                                 int packet_length)
{
  boost::uint8_t filler;
  boost::uint8_t filler2[13];

  Protocol_chunk<boost::uint8_t>   proto_protocol_version(p.protocol_version);
  Protocol_chunk<boost::uint32_t>  proto_thread_id(p.thread_id);
  Protocol_chunk<boost::uint8_t>   proto_scramble_buffer(p.scramble_buff, 8);
  Protocol_chunk<boost::uint8_t>   proto_filler(filler);
  Protocol_chunk<boost::uint16_t>  proto_server_capabilities(p.server_capabilities);
  Protocol_chunk<boost::uint8_t>   proto_server_language(p.server_language);
  Protocol_chunk<boost::uint16_t>  proto_server_status(p.server_status);
  Protocol_chunk<boost::uint8_t>   proto_filler2(filler2,13);
  Protocol_chunk<boost::uint8_t>   proto_scramble_buffer2(p.scramble_buff2, 13);

  is  >> proto_protocol_version
      >> p.server_version_str
      >> proto_thread_id
      >> proto_scramble_buffer
      >> proto_filler
      >> proto_server_capabilities
      >> proto_server_language
      >> proto_server_status
      >> proto_filler2
      >> proto_scramble_buffer2;

  //assert(filler == 0);

  int remaining_bytes= packet_length - 9+13+13+8;
  boost::uint8_t extention_buffer[remaining_bytes];
  if (remaining_bytes > 0)
  {
    Protocol_chunk<boost::uint8_t> proto_extension(extention_buffer, remaining_bytes);
    is >> proto_extension;
  }

  //std::copy(&extention_buffer[0],&extention_buffer[remaining_bytes],std::ostream_iterator<char>(std::cout,","));
}

void write_packet_header(char *buff, boost::uint16_t size, boost::uint8_t packet_no)
{
  int3store(buff, size);
  buff[3]= (char)packet_no;
}


buffer_source &operator>>(buffer_source &src, Protocol &chunk)
{
  char ch;
  int ct= 0;
  char *ptr= (char*)chunk.data();

  while(ct < chunk.size() && src.m_ptr < src.m_size)
  {
    ptr[ct]= src.m_src[src.m_ptr];
    ++ct;
    ++src.m_ptr;
  }
  return src;
}

std::istream &operator>>(std::istream &is, Protocol &chunk)
{
 if (chunk.is_length_encoded_binary())
  {
    int ct= 0;
    is.read((char *)chunk.data(),1);
    unsigned char byte= *(unsigned char *)chunk.data();
    if (byte < 250)
    {
      chunk.collapse_size(1);
      return is;
    }
    else if (byte == 251)
    {
      // is this a row data packet? if so, then this column value is NULL
      chunk.collapse_size(1);
      ct= 1;
    }
    else if (byte == 252)
    {
      chunk.collapse_size(2);
      ct= 1;
    }
    else if(byte == 253)
    {
      chunk.collapse_size(3);
      ct= 1;
    }

    /* Read remaining bytes */
    //is.read((char *)chunk.data(), chunk.size()-1);
    char ch;
    char *ptr= (char*)chunk.data();
    while(ct < chunk.size())
    {
      is.get(ch);
      ptr[ct]= ch;
      ++ct;
    }
  }
  else
  {
    char ch;
    int ct= 0;
    char *ptr= (char*)chunk.data();
    int sz= chunk.size();
    while(ct < sz)
    {
      is.get(ch);
      ptr[ct]= ch;
      ++ct;
    }
  }

  return is;
}

std::istream &operator>>(std::istream &is, std::string &str)
{
  std::ostringstream out;
  char ch;
  int ct= 0;
  do
  {
    is.get(ch);
    out.put(ch);
    ++ct;
  } while (is.good() && ch != '\0');
  str.append(out.str());
  return is;
}

std::istream &operator>>(std::istream &is, Protocol_chunk_string &str)
{
  char ch;
  int ct= 0;
  int sz= str.m_str->size();
  for (ct=0; ct< sz && is.good(); ct++)
  {
    is.get(ch);
    str.m_str->at(ct)= ch;
  }
  
  return is;
}

std::istream &operator>>(std::istream &is, Protocol_chunk_string_len &lenstr)
{
  boost::uint8_t len;
  std::string *str= lenstr.m_storage;
  Protocol_chunk<boost::uint8_t> proto_str_len(len);
  is >> proto_str_len;
  Protocol_chunk_string   proto_str(*str, len);
  is >> proto_str;
  return is;
}

std::ostream &operator<<(std::ostream &os, Protocol &chunk)
{
  if (!os.bad())
    os.write((const char *) chunk.data(),chunk.size());
  return os;
}

Query_event *proto_query_event(std::istream &is, Log_event_header *header)
{
  boost::uint8_t db_name_len;
  boost::uint16_t var_size;
  // Length of query stored in the payload.
  boost::uint32_t query_len;
  Query_event *qev=new Query_event(header);

  Protocol_chunk<boost::uint32_t> proto_query_event_thread_id(qev->thread_id);
  Protocol_chunk<boost::uint32_t> proto_query_event_exec_time(qev->exec_time);
  Protocol_chunk<boost::uint8_t> proto_query_event_db_name_len(db_name_len);
  Protocol_chunk<boost::uint16_t> proto_query_event_error_code(qev->error_code);
  Protocol_chunk<boost::uint16_t> proto_query_event_var_size(var_size);

  is >> proto_query_event_thread_id
     >> proto_query_event_exec_time
     >> proto_query_event_db_name_len
     >> proto_query_event_error_code
     >> proto_query_event_var_size;

  //TODO : Implement it in a better way.

  /*
    Query length =
    Total event length (header->event_length) -
      (
        (LOG_EVENT_HEADER_SIZE - 1) +  //Shouldn't LOG_EVENT_HEADER_SIZE=19?
        Thread-id (pre-defined, 4) +
        Execution time (pre-defined, 4) +
        Placeholder to store database length (pre-defined, 1) +
        Error code (pre-defined, 2) +
        Placeholder to store length taken by status variable blk (pre-defined, 2) +
        Status variable block length (calculated, var_size) +
        Database name length (calculated, db_name_len) +
        Null terninator (pre-defined, 1) +
    )

    which gives :
  */

  query_len= header->event_length - (LOG_EVENT_HEADER_SIZE + 13 + var_size +
                                     db_name_len);

  qev->variables.reserve(var_size);
  Protocol_chunk_vector proto_payload(qev->variables, var_size);
  is >> proto_payload;

  Protocol_chunk_string proto_query_event_db_name(qev->db_name,
                                                  (unsigned long)db_name_len);

  Protocol_chunk_string proto_query_event_query_str
    (qev->query, (unsigned long)query_len);

  char zero_marker; // should always be 0;
  is >> proto_query_event_db_name
     >> zero_marker
     >> proto_query_event_query_str;
  // Following is not really required now,
  //qev->query.resize(qev->query.size() - 1); // Last character is a '\0' character.

  return qev;
}

Gtid_event *proto_gtid_event(std::istream &is, Log_event_header *header)
{
  Gtid_event *gev=new Gtid_event(header);
  boost::uint32_t gtid_length=0;

  if (header->type_code == GTID_EVENT_MARIADB) {
	  Protocol_chunk<boost::uint32_t> proto_gtid_event_domain_id(gev->domain_id);
	  gev->server_id = header->server_id;
	  Protocol_chunk<boost::uint64_t> proto_gtid_event_sequence_number(gev->sequence_number);

	  // In MariaDB GTIDs are just sequence number followed by domain id
	  is >> proto_gtid_event_sequence_number
	     >> proto_gtid_event_domain_id;
	  gev->m_gtid= Gtid(gev->domain_id, gev->server_id, gev->sequence_number);
  } else {
	  // In MySQL GTIDs consists two parts SID and global sequence
	  // number. SID is stored in encoded format, we will not try to
	  // understand that. Global sequence number is more meaningfull.
          unsigned char gtid_data[MYSQL_GTID_ENCODED_SIZE+1];
	  memset(gtid_data, 0, MYSQL_GTID_ENCODED_SIZE+1);
	  is.read((char *)gtid_data, MYSQL_GTID_ENCODED_SIZE);
	  unsigned char *buf = gtid_data;
	  buf++; // commit flag, ignore
	  memcpy(gev->m_mysql_gtid, (char *)buf, MYSQL_GTID_ENCODED_SIZE);
	  gev->sequence_number = uint8korr(buf+16);

	  gev->m_gtid= Gtid(gev->m_mysql_gtid, gev->sequence_number);
  }

  return gev;
}

Rotate_event *proto_rotate_event(std::istream &is, Log_event_header *header)
{
  Rotate_event *rev= new Rotate_event(header);

  boost::uint32_t file_name_length= header->event_length - 7 - LOG_EVENT_HEADER_SIZE;

  Protocol_chunk<boost::uint64_t > prot_position(rev->binlog_pos);
  Protocol_chunk_string prot_file_name(rev->binlog_file, file_name_length);
  is >> prot_position
     >> prot_file_name;

  return rev;
}

Incident_event *proto_incident_event(std::istream &is, Log_event_header *header)
{
  Incident_event *incident= new Incident_event(header);
  Protocol_chunk<boost::uint8_t> proto_incident_code(incident->type);
  Protocol_chunk_string_len      proto_incident_message(incident->message);

  is >> proto_incident_code
     >> proto_incident_message;

  return incident;
}

Row_event *proto_rows_event(std::istream &is, Log_event_header *header)
{
  Row_event *rev=new Row_event(header);

  union
  {
    boost::uint64_t integer;
    boost::uint8_t bytes[6];
  } table_id;

  table_id.integer=0L;
  Protocol_chunk<boost::uint8_t>  proto_table_id(&table_id.bytes[0], 6);
  Protocol_chunk<boost::uint16_t> proto_flags(rev->flags);
  Protocol_chunk<boost::uint64_t> proto_column_len(rev->columns_len);
  proto_column_len.set_length_encoded_binary(true);

  is >> proto_table_id
     >> proto_flags
     >> proto_column_len;

  rev->table_id=table_id.integer;
  int used_column_len=(int) ((rev->columns_len + 7) / 8);
  Protocol_chunk_vector proto_used_columns(rev->used_columns, used_column_len);
  rev->null_bits_len= used_column_len;

  is >> proto_used_columns;

  if (header->type_code == UPDATE_ROWS_EVENT)
  {
    Protocol_chunk_vector proto_columns_before_image(rev->columns_before_image, used_column_len);
    is >> proto_columns_before_image;
  }

  int bytes_read=proto_table_id.size() + proto_flags.size() + proto_column_len.size() + used_column_len;
  if (header->type_code == UPDATE_ROWS_EVENT)
    bytes_read+=used_column_len;

  unsigned long row_len= header->event_length - bytes_read - LOG_EVENT_HEADER_SIZE + 1;
  //std::cout << "Bytes read: " << bytes_read << " Bytes expected: " << rev->row_len << std::endl;
  Protocol_chunk_vector proto_row(rev->row, row_len);
  is >> proto_row;

  return rev;
}

Int_var_event *proto_intvar_event(std::istream &is, Log_event_header *header)
{
  Int_var_event *event= new Int_var_event(header);

  Protocol_chunk<boost::uint8_t>  proto_type(event->type);
  Protocol_chunk<boost::uint64_t> proto_value(event->value);
  is >> proto_type
     >> proto_value;

  return event;
}

User_var_event *proto_uservar_event(std::istream &is, Log_event_header *header)
{
  User_var_event *event= new User_var_event(header);

  boost::uint32_t name_len;
  Protocol_chunk<boost::uint32_t> proto_name_len(name_len);

  is >> proto_name_len;

  Protocol_chunk_string proto_name(event->name, name_len);
  Protocol_chunk<boost::uint8_t>  proto_null(event->is_null);

  is >> proto_name >> proto_null;
  if (event->is_null)
  {
    event->type = User_var_event::STRING_TYPE;
    event->charset = 63;                        // Binary charset
  }
  else
  {
    boost::uint32_t value_len;
    Protocol_chunk<boost::uint8_t> proto_type(event->type);
    Protocol_chunk<boost::uint32_t> proto_charset(event->charset);
    Protocol_chunk<boost::uint32_t> proto_val_len(value_len);
    is >> proto_type >> proto_charset >> proto_val_len;
    Protocol_chunk_string proto_value(event->value, value_len);
    is >> proto_value;
  }

  return event;
}

Table_map_event *proto_table_map_event(std::istream &is, Log_event_header *header)
{
  Table_map_event *tmev=new Table_map_event(header);
  boost::uint64_t columns_len= 0;
  boost::uint64_t metadata_len= 0;
  union
  {
    boost::uint64_t integer;
    boost::uint8_t bytes[6];
  } table_id;
  char zero_marker= 0;

  table_id.integer=0L;
  Protocol_chunk<boost::uint8_t> proto_table_id(&table_id.bytes[0], 6);
  Protocol_chunk<boost::uint16_t> proto_flags(tmev->flags);
  Protocol_chunk_string_len proto_db_name(tmev->db_name);
  Protocol_chunk<boost::uint8_t> proto_marker(zero_marker); // Should be '\0'
  Protocol_chunk_string_len proto_table_name(tmev->table_name);
  Protocol_chunk<boost::uint64_t> proto_columns_len(columns_len);
  proto_columns_len.set_length_encoded_binary(true);

  is >> proto_table_id
     >> proto_flags
     >> proto_db_name
     >> proto_marker
     >> proto_table_name
     >> proto_marker
     >> proto_columns_len;
  tmev->table_id=table_id.integer;
  Protocol_chunk_vector proto_columns(tmev->columns, columns_len);
  Protocol_chunk<boost::uint64_t> proto_metadata_len(metadata_len);
  proto_metadata_len.set_length_encoded_binary(true);

  is >> proto_columns
     >> proto_metadata_len;
  Protocol_chunk_vector proto_metadata(tmev->metadata, (unsigned long)metadata_len);
  is >> proto_metadata;
  unsigned long null_bits_len=(int) ((tmev->columns.size() + 7) / 8);

  Protocol_chunk_vector proto_null_bits(tmev->null_bits, null_bits_len);

  is >> proto_null_bits;
  return tmev;
}

std::istream &operator>>(std::istream &is, Protocol_chunk_vector &chunk)
{
  unsigned long size= chunk.m_size;
  for(int i=0; i< size; i++)
  {
    char ch;
    is.get(ch);
    chunk.m_vec->push_back(ch);
  }
  return is;
}


} } // end namespace mysql::system