/**
 * This is a means to listen into the stream of log messages from the logv2 
 * logging system.
 *
 * Mark Koennecke, May 2016
 */
#include <sics.h>
#include <logv2.h>
#include <lld.h>

/*
  From logv2.c
*/
extern int subsystemFromText(const char *text);
/*=============================================================================*/
static int listenerList;
static int callbackRegistered = 0;

typedef struct {
  SConnection *pCon;
  char subsystem[64];
} ListenEntry;
/*-----------------------------------------------------------------------------*/
static void LogListenCallback(unsigned int severity, const char *timeStamp, 
			    const char *subsystem, 
			    const char *message, void *userData)
{
  ListenEntry current;
  int status, cleanupNeeded = 0;

  if(logFilter(severity,subsystem,message) == 1) {
    return;
  }


  status = LLDnodePtr2First(listenerList);
  while(status != 0){
    LLDnodeDataTo(listenerList,&current);
    if(strcmp(current.subsystem,subsystem) == 0) {
      if(SCisConnected(current.pCon)){
	SCPureSockWrite(current.pCon,(char *)message,eValue);
      } else {
	cleanupNeeded = 1;
      }
    }
    status = LLDnodePtr2Next(listenerList);
  }

  /*
    lld lists sometimes get confused when deleting nodes on the fly.
    This is why this has been put into a separate loop
  */
  if(cleanupNeeded){
    status = LLDnodePtr2First(listenerList);
    while(status != 0){
      LLDnodeDataTo(listenerList,&current);
      if(!SCisConnected(current.pCon)){
	SCDeleteConnection(current.pCon);
	LLDnodeDelete(listenerList);
      }
      status = LLDnodePtr2Next(listenerList);
    }
  }

}
/*-----------------------------------------------------------------------------*/
static int LogListenAction(SConnection * pCon, SicsInterp * pSics,
                            void *pData, int argc, char *argv[])
{
  ListenEntry listLog;

  if(argc < 2){ 
    SCWrite(pCon,"ERROR: need subsystem argument for loglisten", eError);
    return 0;
  }
  
  if(subsystemFromText(argv[1]) < 0){
    SCPrintf(pCon,eError, "ERROR: invalid subsystem %s specified", argv[1]);
    return 0;
  }


  listLog.pCon = SCCopyConnection(pCon);
  strncpy(listLog.subsystem,argv[1],sizeof(listLog.subsystem));
  LLDnodeAppendFrom(listenerList,&listLog);

  if(!callbackRegistered){
    RegisterLogCallback(LogListenCallback,NULL);
    callbackRegistered = 1;
  }

  SCSendOK(pCon);
  return 1;
}
/*-----------------------------------------------------------------------------*/
void LogListenInit(void)
{
  listenerList = LLDcreate(sizeof(ListenEntry));
  AddCmd("loglisten", LogListenAction);
}