// dialproc.cxx
//
// David Adams
// August 2002
//
// Main program for looping over events in an event dataset, applying
// a task to each and returning a result which is a VirtualEventDataset.
//
// Communication is via files:
//   Input:
//     task.xml - task (contains input empty result)
//     dataset.xml - input dataset
//                   (library defines symbol task)
//   Output:
//     pid - process ID
//     result.xml - result (output datset)
//

#include <string>
#include <iostream>
#include <fstream>
#include <dlfcn.h>
#include <unistd.h>
#include "dataset_util/Environment.h"
#include "dataset_xml/XmlParser.h"
#include "dataset_id/EventId.h"
#include "dataset_id/UniqueIdGenerator.h"
#include "dataset_credential/GssCredentialManager.h"
#include "dataset_base/Dataset.h"
#include "dataset_base/DatasetCreator.h"
#include "dataset_base/VirtualEventDataset.h"
#include "dataset_base/DatasetRepository.h"
#include "dial_task/Task.h"
#include "dial_com/dial_init.h"
#include "dial_com/registrations.h"

using std::string;
using std::ofstream;
using std::cerr;
using std::endl;
using dset::GssCredentialManager;
using dset::ContentBlock;
using dset::Content;
using dset::Dataset;
using dset::DatasetCreator;
using dset::DatasetRepository;
using dset::VirtualEventDataset;
using dial::Task;

typedef int (*TaskFun) (const EventId& eid, dset::Dataset& res);

int main(int, char*) {

  if ( dial::dial_init() ) return 101;

  // Set to true to wait for debugger.
  bool waiting = false;
  while ( waiting ) {
    sleep(2);
  }

  // Set the credential for this thread.
  // This is needed to find owner for task.
  int cstat = GssCredentialManager::set_default();
  if ( cstat != 0 ) {
    cerr << "Unable to find credential" << endl;
    return 18;
  }
  if ( GssCredentialManager::owner().size() == 0 ) {
    cerr << "Unable to find credential owner" << endl;
    return 19;
  }


  ofstream out("out.txt");
  out << "Begin processing task" << endl;

  // Check that we have a global dataset ID generator.
  // Otherwise we will not be able to write out the result dataset.
  if ( ! Dataset::id_generator().is_global() ) {
    out << endl;
    out << "Dataset ID generator is not global" << endl;
    out << "  DIAL_UIDS = "
        << Environment::current().value("DIAL_UIDS") << endl;
    return 2;
  }

  // Open the task library.
  TaskFun task;
  {
    Text tskloc("taskdir");
    string dir = tskloc.line(0);
    string libname = dir + "/" + "task.so";
    void* handle = dlopen(libname.c_str(), RTLD_NOW);
    if ( ! handle ) {
      out << "Unable to open task library " << libname << endl;
      out << dlerror() << endl;
      return 3;
    }
    task = (TaskFun) dlsym(handle, "task");
    if ( task == 0 ) {
      out << "Unable to load symbol" << endl;
      out << dlerror() << endl;
       return 4;
    }
  }
  
  // Write the DTD.
  DtdRegistry::instance("dataset").write();
  DtdRegistry::instance("dial").write();
  
  XmlParser parser;

  DatasetRepository& drep = DatasetRepository::default_instance();

  const XmlElement* pxdst = parser.parse("dataset.xml");
  if ( pxdst == 0 ) {
    out << "Unable to parse dataset.xml" << endl;
    return 5;
  }
  const Dataset* pdst = DatasetCreator::create(*pxdst, &drep);
  if ( pdst == 0 ) {
    out << "Unable to create dataset from dataset.xml" << endl;
    out << endl;
    DatasetCreator::display(out);
    out << endl;
    out << endl;
    out << *pxdst << endl;
    return 6;
  }
  const Dataset& dst = *pdst;
  out << endl;
  out << "Input dataset: " << endl;
  out << dst << endl;

  // Loop over events and fill result.
  if ( dst.content().size() != 1 ) return 7;
  const ContentBlock& blk = dst.content().front();
  EventIdList eids;
  Content con(blk.dataset_type(), blk.name(), blk.content_ids(), eids);
  Dataset* pres2 = new VirtualEventDataset(con);
  Dataset& res2 = *pres2;
  out << endl << "Input result:" << endl;
  out << res2 << endl;
  out << endl << "Begin event loop" << endl;
  out << res2 << endl << endl;
  int rstat = 0;
  if ( dst.is_event_dataset() ) {
    for ( EventIdList::const_iterator ieid=dst.event_ids().begin();
          ieid!=dst.event_ids().end(); ++ieid ) {
      const EventId& eid = *ieid;
      out << eid << endl;
      rstat = task(eid, res2);
  out << endl << "Merged" << endl << endl;
  out << res2 << endl << endl;
      out << eid << " returns " << rstat << endl;
      if ( rstat != 0 ) break;
    }
    res2.lock();
  } else {
    out << "Warning: This is not an event dataset--no event loop."
        << endl;
  }

  out << endl;
  out << "Output result:" << endl;
  out << res2 << endl;

  // Write the result.
  const XmlElement* pxres2 = res2.xml();
  if ( pxres2 == 0 ) return 9;
  int stat = parser.write("result.xml", *pxres2);
  if ( stat != 0 ) return 10;
  out << "Output result:" << endl;
  out << res2 << endl;

  return 0;
}