#include <iostream.h>
#include <stdio.h>
#include <string.h>
#include <signal.h>
#include <setjmp.h>
#include <sys/types.h>
#include <sys/wait.h>
#include "FlexArrayTmpl.H"

#include "SockIOreader.hh"

#if defined(T3E) || defined(__hpux)
#define SIGNAL_CAST
#else
#define SIGNAL_CAST (SIG_PF)
#endif

// Globals
FlexArray<SockIOreader*> sock_io_readers;
void IOsigHandler(int sig);
void reaper(int sig);

// enable signals (needs a refcount)
class SigMgr {
  static int sigrefcount;
  static int nwatchers;
public:
  static void AddObserver(){
    nwatchers++;
  }
  static void RemoveObserver(){
    nwatchers--;
    // should check refcount status change
  }
  static void SigOn(){
    //puts("sigOn");
    sigrefcount++;
    if(sigrefcount>nwatchers){
      // error
      sigrefcount=nwatchers;
      puts("SigMgr: Error... the Signal refcount is > numwatchers");
      puts("correcting");
    }
    if(sigrefcount==nwatchers){
      // call the handlertest just in case
      //IOsigHandler((int)SIGIO);
      for(int i=0; i<sock_io_readers.getSize();i++){
	//printf("poll reader %u\n",i);
	sock_io_readers[i]->sigHandler(SIGIO);
      }
      signal(SIGIO,SIGNAL_CAST IOsigHandler); // reenable the signal handler
      signal(SIGURG,SIGNAL_CAST IOsigHandler);// reenable the signal handler
    }
  }
  // disable signals until elemental IO operation completes
  static void SigOff(){
    //puts("sigOff");
    sigrefcount--;
    if(sigrefcount<0){
      puts("SigMgr::SigOff(): Signal refcount < 0... correcting");
      sigrefcount=0;
    }
    signal(SIGIO,SIG_DFL); // prevent double-interrupt
    signal(SIGURG,SIG_DFL);
  }
};

int SigMgr::sigrefcount=0;
int SigMgr::nwatchers=0;

// If any IO event occurs, this will call handlers for all availible SockIOreaders
// to see if they have an event to take care of.
void IOsigHandler(int sig){
  //puts("SigHandler: IO Interrupt");
  SigMgr::SigOff();
  // So here we look at the global list of SockIOreaders and pass the event on
  for(int i=0; i<sock_io_readers.getSize();i++){
    //printf("poll reader %u\n",i);
    sock_io_readers[i]->sigHandler(sig);
  }
  SigMgr::SigOn();
}

// This gobbles up zombie children... kind of like Night of the Living Dead
void reaper(int sig){
  puts("Reaper: Child Interrupt");
#ifndef T3E
  // Eat dead children :b
  struct rusage status;
  int statptr;
  while(wait3(&statptr,WNOHANG,&status)>=0) {} // get all the deadsters
#endif
  
  signal(SIGCHLD,SIGNAL_CAST reaper); // reenable the signal handler
}

// Alarm handler to escape from hanging socket reads (crash in mid-send)
jmp_buf senv,tenv;
void timeout(int sig){
  signal(SIGALRM,SIGNAL_CAST timeout); // reset the handler
  longjmp(tenv,1); // jump to the error recovery vector
}

/*
void InterruptRecovery(int sig){
  SockIOwriter::halt(); // kill app on first opportunity
  if(SockIOwriter::sendInProgress()>0){
    signal(SIGALRM,SIGNAL_CAST timeout); // reset the handler
    longjmp(tenv,1);
  }
  else
    exit(0);
} 
*/

// kludge
int SockIOreader::blockingRead(void *buffer,int size){
  int nremaining,nreceived; 
  if(!connected_client) return 0;
  // read in 1k blocks (perhaps have 15-30sec timeout)
  // should be able to set variable blocksize
  for(nremaining=size;nremaining>0;nremaining-=nreceived) 
  {
	  nreceived=connected_client->read((char*)buffer,nremaining);
	  if (nreceived<1) // read error
		  return size-nremaining;
  }
  return size; // can return alt value if timeout occurs
}
//=======================================================================================

void SockIOreader::sigHandler(int sig){
  // do a select...
  RawPort *port = master_mux.select();
  if(port){
    if(connected_client)
      //pending++; // (if we didn't prefer new clients....) but....
      delete connected_client; // has preference for new clients!!
    // pref for new clients is good for error recovery. (eg. death of client program)
    puts("\nOpen New Client Port\n");
    connected_client = ServerPort.accept();
    mux.addInport(connected_client); // add to select mux list
    // close and reopent the file trunc
    delete scratchfile;
    scratchfile=new IEEEIO(scratchfilename,IObase::Write);
    delete scratchfile;
    scratchfile=new IEEEIO(scratchfilename,IObase::Append); // kludge to purge file
  }
  scratchfile->seek(scratchfile->nDatasets()-1);
  while(mux.select()>0){
    int dims[5];
    char name[128];
    int bufsize;
    void *current_buffer;
    blockingRead(&current_rec,sizeof(RecordHdr));
    switch(current_rec.recordtype){
    case 1: // data record
      blockingRead(&current_data_rec,sizeof(DataRecordHdr));
      blockingRead(dims,sizeof(int)*current_data_rec.rank);
      bufsize=current_data_rec.datasize;
      break;
    case 2: // annotation record
      // do nothing for now.
      bufsize=current_rec.recordsize;
      break;
    case 3: // attribrecord
      blockingRead(&current_att_rec,sizeof(AttributeRecordHdr));
      blockingRead(name,current_att_rec.namesize);
      bufsize=current_att_rec.datasize;
      break;
    }
    current_buffer = new char[bufsize];
    blockingRead(current_buffer,bufsize);
    // now commit it to disk
    switch(current_rec.recordtype){
    case 1:
      scratchfile->write(IObase::Int2DataType(current_data_rec.numbertype),
			 current_data_rec.rank,
			 dims,
			 current_buffer);
      break;
    case 2:
      scratchfile->writeAnnotation((char*)current_buffer);
      break;
    case 3:
      scratchfile->writeAttribute(name,IObase::Int2DataType(current_att_rec.numbertype),
				  bufsize/IObase::sizeOf(IObase::Int2DataType(current_att_rec.numbertype)),
				  current_buffer);
      break;
    }
    delete current_buffer;
    current_buffer=0;
  }
  if (current_ds > 0)
    scratchfile->seek(current_ds);
}

//------------------------core stuff.....................
SockIOreader::SockIOreader(CONST char *scratchfilenm,int port):IObase(scratchfilenm,IObase::Read),
  scratchfile(0),ServerPort(port),
  pending(0),connected_client(0){
    current_ds = -1;
    strcpy(scratchfilename,scratchfilenm);
    scratchfile=new IEEEIO(scratchfilename,IObase::Write);
    delete scratchfile;// kludge to purge file
    scratchfile=new IEEEIO(scratchfilename,IObase::Append);
    // sockport is open, now set up the select
    fprintf(stderr,"ServerPort validity=%u\n",ServerPort.isAlive());
    master_mux.addInport(&ServerPort);
    // the master mux should always return immediately 
    // (a non-blocking select())
    master_mux.setTimeout(0,0); // seconds and microseconds =0
    mux.setTimeout(0,0);
    // set signals for capturing events
    sock_io_readers.append(this); // append to handler list
    SigMgr::AddObserver();
    puts("Signals On");
    SigMgr::SigOn();
    signal(SIGCHLD,SIGNAL_CAST reaper); // reenable the signal reaper handler
    puts("construction completed");
}

SockIOreader::SockIOreader(CONST char *scratchfilenm,int port,int windowsize):
  IObase(scratchfilenm,IObase::Read),
  scratchfile(0),ServerPort(port,windowsize),
  pending(0),connected_client(0){
    current_ds = -1;
    strcpy(scratchfilename,scratchfilenm);
    scratchfile=new IEEEIO(scratchfilename,IObase::Write);
    delete scratchfile;// kludge to purge file
    scratchfile=new IEEEIO(scratchfilename,IObase::Append);
    // sockport is open, now set up the select
    fprintf(stderr,"ServerPort validity=%u\n",ServerPort.isAlive());
    master_mux.addInport(&ServerPort);
    // the master mux should always return immediately 
    // (a non-blocking select())
    master_mux.setTimeout(0,0); // seconds and microseconds =0
    mux.setTimeout(0,0);
    // set signals for capturing events
    sock_io_readers.append(this); // append to handler list
    SigMgr::AddObserver();
    puts("Signals On");
    SigMgr::SigOn();
    signal(SIGCHLD,SIGNAL_CAST reaper); // reenable the signal reaper handler
    puts("construction completed");
}

SockIOreader::~SockIOreader(){
  SigMgr::SigOff();
  SigMgr::RemoveObserver();
  // shut all of the sockets down
  if(connected_client) 
    delete connected_client; // need to remove from mux list
  connected_client=0;
}

// should check server status too
int SockIOreader::isValid() { 
  if(scratchfile && connected_client) return 1;
  return 0;
}

// could use overloading to differentiate type here... (but I'm going simple)
int SockIOreader::readInfo(IObase::DataType &typeID,int &rank,int *dims,int maxdims){
  // just hand this off to the datafile (and hope that APPEND mode works correctly)
  SigMgr::SigOff();
  int retval = scratchfile->readInfo(typeID,rank,dims,maxdims);
  SigMgr::SigOn();
  return retval;
}
int SockIOreader::read(void *data){
  SigMgr::SigOff();
  int retval = scratchfile->read(data);
  SigMgr::SigOn();
  return retval;
}
int SockIOreader::seek(int dataset_index){
  SigMgr::SigOff();
  current_ds=scratchfile->seek(dataset_index);
  int retval = current_ds;
  SigMgr::SigOn();
  return retval;
}
int SockIOreader::nDatasets(){
  SigMgr::SigOff();
  int retval = scratchfile->nDatasets(); // must not interrupt these operations...
  SigMgr::SigOn();
  return retval;
}
int SockIOreader::readAnnotationInfo(int number,int &length){ // returns length (-1 if none left)
  SigMgr::SigOff();
  scratchfile->seek(current_ds);
  int retval = scratchfile->readAnnotationInfo(number,length);
  SigMgr::SigOn();
  return retval;
}
int SockIOreader::readAnnotation(int number,char *annotation,int maxsize){
  SigMgr::SigOff();
  scratchfile->seek(current_ds);
  int retval = scratchfile->readAnnotation(number,annotation,maxsize);
  SigMgr::SigOn();
  return retval;
}
int SockIOreader::nAnnotations(){
  SigMgr::SigOff();
  scratchfile->seek(current_ds);
  int retval = scratchfile->nAnnotations();
  SigMgr::SigOn();
  return retval;
} 
int SockIOreader::readAttributeInfo(int number,char *name,IObase::DataType &typeID,Long &nelem,int maxnamelen){
  SigMgr::SigOff();
  scratchfile->seek(current_ds);
  int retval = scratchfile->readAttributeInfo(number,name,typeID,nelem,maxnamelen);
  SigMgr::SigOn();
  return retval;
}
int SockIOreader::readAttributeInfo(CONST char *name,IObase::DataType &typeID,Long &nelem){ // returns number
  SigMgr::SigOff();
  scratchfile->seek(current_ds);
  int retval = scratchfile->readAttributeInfo(name,typeID,nelem);
  SigMgr::SigOn();
  return retval;
}
int SockIOreader::readAttribute(int number,void *data){
  SigMgr::SigOff();
  scratchfile->seek(current_ds);
  int retval = scratchfile->readAttribute(number,data);
  SigMgr::SigOn();
  return retval;
}
int SockIOreader::nAttributes(){
  SigMgr::SigOff();
  scratchfile->seek(current_ds);
  int retval = scratchfile->nAttributes();
  SigMgr::SigOn();
  return retval;
}
//-----------------Chunking Utilities..................
int SockIOreader::readChunk(CONST int *chunkdims,CONST int *chunkorigin,void *data){
  SigMgr::SigOff();
  scratchfile->seek(current_ds);
  int retval = scratchfile->readChunk(chunkdims,chunkorigin,data);
  SigMgr::SigOn();
  return retval;
}