/*
* This file is part of rasdaman community.
*
* Rasdaman community 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, either version 3 of the License, or
* (at your option) any later version.
*
* Rasdaman community 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 rasdaman community.  If not, see <http://www.gnu.org/licenses/>.
*
* Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2009 Peter Baumann /
rasdaman GmbH.
*
* For more information please see <http://www.rasdaman.org>
* or contact Peter Baumann via <baumann@rasdaman.com>.
*/
/*************************************************************
 *
 *
 * PURPOSE:
 *
 *
 * COMMENTS:
 * - why sometimes exit() and sometimes return on error?
 *   should be return or exception, always.
 *
 ************************************************************/

#include "srvrasmgrcomm.hh"
#include<stdio.h>
#include<errno.h>
#include<stdlib.h>
#include<unistd.h>
#include<sys/types.h>
#include<sys/socket.h>
#include<netinet/in.h>
#include<netdb.h>
#include<iostream>
#include<string.h>
#include "raslib/rminit.hh"


#include "debug.hh"


// exit code of the server when communication is impossible
// PB: Why 10 ? Anyway, should not use exit in a server, how often did I tell you, Walter Schatz!!!
const unsigned int EXIT_CODE = 10;

// max number of retries to connect to rasmgr in informRasMgr()
const unsigned int SRV_MAX_RETRY = 10000000;

// how many retries are attempted before a message is issued informRasMgr()
const unsigned int SRV_TALK_INTERVAL = 100000;


SrvRasmgrComm rasmgrComm;

SrvRasmgrComm::SrvRasmgrComm()
{
	timeout    = 0;
	serverName = 0;
	rasmgrHost = 0;
	rasmgrPort = -1;
}

// note: should make use of timeout as defined in cmd line,
// but that's a major undertaking -- PB 2005-sep-02

void SrvRasmgrComm::init(unsigned int timeOut, const char* instanceName, const char* nRasmgrHost, int nRasmgrPort)
{
	timeout    = timeOut;
	serverName = instanceName;
	rasmgrHost = nRasmgrHost;
	rasmgrPort = nRasmgrPort;
}

unsigned int SrvRasmgrComm::getTimeout()
{
	return timeout;
}

void SrvRasmgrComm::informRasmgrServerAvailable()
{
	informRasMGR(SERVER_AVAILABLE);
}

void SrvRasmgrComm::informRasmgrServerDown()
{
	informRasMGR(SERVER_DOWN);
}

void SrvRasmgrComm::informRasmgrServerStillAvailable() 
{
	// too verbose, blows up log file
	// RMInit::logOut << "informing rasmgr: server still available." << endl;
	informRasMGR(SERVER_REGULARSIG);
}
	  
void SrvRasmgrComm::informRasMGR(int what)
{ //what: 0 - going down
	//      1 - available
	//      2 - regular signal
	
//    cout<<"servername ="<<serverName<<" rasmgrhost="<<rasmgrHost<<"  port="<<rasmgrPort<<endl;
	
//    if(what == SERVER_AVAILABLE) accessControl.resetForNewClient(); 
	
	struct protoent* getprotoptr = getprotobyname("tcp");

	struct hostent *hostinfo = gethostbyname(rasmgrHost);
	if(hostinfo==NULL) 
	{ 
		RMInit::logOut << "Error: cannot locate rasmgr host '" << rasmgrHost << "': " << strerror(errno) << std::endl;
		return; 
	}

	sockaddr_in internetSocketAddress; 
	internetSocketAddress.sin_family = AF_INET;
	internetSocketAddress.sin_port=htons(rasmgrPort);
	internetSocketAddress.sin_addr=*(struct in_addr*)hostinfo->h_addr;    
	
	int sock;
	
	bool ok=false;
	long talkInterval=SRV_TALK_INTERVAL;
	long maxRetry=SRV_MAX_RETRY;
	long retry =0;
	// creating socket
	for(retry=0;retry<maxRetry;retry++)
	{
		sock=socket(PF_INET,SOCK_STREAM,getprotoptr->p_proto);
		//std::cout<<"Socket="<<sock<<" protocol(tcp)="<<getprotoptr->p_proto<<std::endl;
	   
		if(sock<0)
		{
			if( (retry%talkInterval) == 0)
			{
				std::cerr<< "Error: server '" << serverName << " cannot open socket to rasmgr (" << retry << " attempts, still retrying): " << strerror(errno) << std::endl; 
			RMInit::logOut << "Error: server '" << serverName << " cannot open socket to rasmgr (" << retry << " attempts, still retrying): " << strerror(errno) << std::endl; 
			} 
			continue;
		}

		if(connect(sock,(struct sockaddr*)&internetSocketAddress,sizeof(internetSocketAddress)) < 0)
		{ 
			if( (retry%talkInterval) == 0)
			{
				std::cerr << "Error: server '" << serverName << " cannot connect to rasmgr (" << retry << " attempts, still retrying): " << strerror(errno) << std::endl;
				RMInit::logOut << "Error: server '" << serverName << " cannot connect to rasmgr (" << retry << " attempts, still retrying): " << strerror(errno) << std::endl;
			}	       
			close(sock); //yes, some SO requieres this, like DEC from BLVA
			continue;
		} 
		ok = true;
		break;
	 }     
		 
	 if( !ok )
	 {
		 std::cerr << "Error: unable to contact rasmgr, server '" << serverName << "' herewith giving up." <<std::endl; 
		 RMInit::logOut << "Error: unable to contact rasmgr, server '" << serverName << "' herewith giving up." <<std::endl; 
		 if(sock)
			 close(sock);
		 exit( EXIT_CODE );
	 }    
	 
	 // creating the HTTP message
	 char message[200];
	 sprintf(message,"%s%d\r\n\r\n%s %d %ld ","POST rasservernewstatus HTTP/1.1\r\nUserAgent: RasServer/1.0\r\nContent-length: ",strlen(serverName)+3,serverName,what,0);
	
	 // writing message;
	 if(writeWholeMessage(sock,message,strlen(message)+1)<0)
	 { 
		std::cerr << "Error: cannot send message to rasmgr: " << strerror(errno) << std::endl;
		RMInit::logOut << "Error: cannot send message to rasmgr: " << strerror(errno) << std::endl;
	 	close(sock);
	 	exit( EXIT_CODE );
	 }
	 close(sock);
}

   
int SrvRasmgrComm::writeWholeMessage(int socket,char *destBuffer,int buffSize)
{
	// we write the whole message, including the ending '\0', which is already in
	// the buffSize provided by the caller
	int totalLength=0;
	int writeNow;
	while(1)
	{
		writeNow = write(socket,destBuffer+totalLength,buffSize-totalLength);
		if(writeNow == -1)
		{
			if(errno == EINTR)
				continue; // read was interrupted by signal (on bad SO's)
			return -1; // another error
		}
		totalLength+=writeNow;
	
		if( totalLength==buffSize )
			break; // THE END	    
	}

	return totalLength;
}