#include <algorithm>
#include <cassert>
#include <cstddef>
#include <cstdlib>
#include <cstring>
#include <iomanip>
#include <map>
#include <sstream>
#include <string>
#include <vector>

#include "util_Table.h"
#include "cctk.h"
#include "cctk_Arguments.h"
#include "cctk_Parameters.h"
#include "cctk_Version.h"

#include "CactusBase/IOUtil/src/ioGH.h"
#include "CactusBase/IOUtil/src/ioutil_CheckpointRecovery.h"

#include "CarpetTimers.hh"

#include "CarpetIONirvana.hh"

#include "defs.hh"
#include "gh.hh"



namespace CarpetIONirvana
{

using namespace std;
using namespace Carpet;
using namespace Nirvana;


// Variable definitions

// when was the last checkpoint written ?
static int last_checkpoint_iteration = -1;
static CCTK_REAL last_checkpoint_walltime;


// registered GH extension setup routine
static void* SetupGH (tFleshConfig* const fleshconfig,
                      const int convLevel, cGH* const cctkGH);

// callbacks for CarpetIOHDF5's I/O method
static int OutputGH (const cGH* const cctkGH);
static int OutputVarAs (const cGH* const cctkGH, const char* const varname,
                        const char* const alias);
static int TimeToOutput (const cGH* const cctkGH, const int vindex);
static int TriggerOutput (const cGH* const cctkGH, const int vindex);

// general checkpoint routine
static void Checkpoint (const cGH* const cctkGH, int called_from);

// callback for I/O parameter parsing routine
static void GetVarIndex (int vindex, const char* optstring, void* arg);

static void CheckSteerableParameters (const cGH *const cctkGH,
                                      CarpetIONirvanaGH *myGH);


//////////////////////////////////////////////////////////////////////////////
// public routines
//////////////////////////////////////////////////////////////////////////////

int CarpetIONirvana_Startup (void)
{
  CCTK_RegisterBanner ("Carpet Data Nirvana I/O");

  const int GHExtension = CCTK_RegisterGHExtension (CCTK_THORNSTRING);
  CCTK_RegisterGHExtensionSetupGH (GHExtension, SetupGH);

  /*IONirvana<0>::Startup();
  IONirvana<1>::Startup();
  IONirvana<2>::Startup();*/

  return (0);
}


// Called at basegrid during regular startup
void CarpetIONirvana_Init (CCTK_ARGUMENTS)
{
  DECLARE_CCTK_ARGUMENTS;

  *this_iteration = -1;
  *next_output_iteration = 0;
  *next_output_time = cctk_time;

  for (int d=0; d<3; ++d) {
    this_iteration_slice[d]        = 0;
    last_output_iteration_slice[d] = 0;
    last_output_time_slice[d]      = cctk_time;
  }
}




hid_t CCTKtoHDF5_Datatype (const cGH* const cctkGH,
                           int cctk_type, bool single_precision)
{
  hid_t retval;

  const CarpetIONirvanaGH *myGH =
    (CarpetIONirvanaGH *) CCTK_GHExtension (cctkGH, CCTK_THORNSTRING);

  /*switch (cctk_type) {

    case CCTK_VARIABLE_CHAR:      retval = HDF5_CHAR; break;

    case CCTK_VARIABLE_INT:       retval = HDF5_INT; break;
#ifdef CCTK_INT1
    case CCTK_VARIABLE_INT1:      retval = H5T_NATIVE_CHAR; break;
#endif
#ifdef CCTK_INT2
    case CCTK_VARIABLE_INT2:      retval = H5T_NATIVE_SHORT; break;
#endif
#ifdef CCTK_INT4
    case CCTK_VARIABLE_INT4:      retval = H5T_NATIVE_INT; break;
#endif
#ifdef CCTK_INT8
    case CCTK_VARIABLE_INT8:      retval = H5T_NATIVE_LLONG; break;
#endif

    case CCTK_VARIABLE_REAL:      retval = HDF5_REAL;
#ifdef CCTK_REAL4
                                  if (single_precision) {
                                    retval = H5T_NATIVE_FLOAT;
                                  }
#endif
                                  break;

    case CCTK_VARIABLE_COMPLEX:   retval = myGH->HDF5_COMPLEX;
#ifdef CCTK_REAL4
                                  if (single_precision) {
                                    retval = myGH->HDF5_COMPLEX8;
                                  }
#endif
                                  break;

#ifdef CCTK_REAL4
    case CCTK_VARIABLE_REAL4:     retval = H5T_NATIVE_FLOAT; break;
    case CCTK_VARIABLE_COMPLEX8:  retval = myGH->HDF5_COMPLEX8; break;
#endif
#ifdef CCTK_REAL8
    case CCTK_VARIABLE_REAL8:     retval = H5T_NATIVE_DOUBLE; break;
    case CCTK_VARIABLE_COMPLEX16: retval = myGH->HDF5_COMPLEX16; break;
#endif
#ifdef CCTK_REAL16
    case CCTK_VARIABLE_REAL16:    retval = H5T_NATIVE_LDOUBLE; break;
    case CCTK_VARIABLE_COMPLEX32: retval = myGH->HDF5_COMPLEX32; break;
#endif

    default: CCTK_VWarn (0, __LINE__, __FILE__, CCTK_THORNSTRING,
                         "Unsupported CCTK variable datatype %d", cctk_type);
             retval = -1;
  }*/

  return (retval);
}




//////////////////////////////////////////////////////////////////////////////
// private routines
//////////////////////////////////////////////////////////////////////////////
static void* SetupGH (tFleshConfig* const fleshconfig,
                      const int convLevel, cGH* const cctkGH)
{
  DECLARE_CCTK_PARAMETERS;

  int error_count = 0;

  // register CarpetIONirvana's routines as a new I/O method
  const int IOMethod = CCTK_RegisterIOMethod ("IONirvana");
  CCTK_RegisterIOMethodOutputGH (IOMethod, OutputGH);
  CCTK_RegisterIOMethodOutputVarAs (IOMethod, OutputVarAs);
  CCTK_RegisterIOMethodTimeToOutput (IOMethod, TimeToOutput);
  CCTK_RegisterIOMethodTriggerOutput (IOMethod, TriggerOutput);

  if (not CCTK_Equals (verbose, "none")) {
    CCTK_INFO ("I/O Method 'Nirvana': Sending data to Nirvana ");
  }

  const int numvars = CCTK_NumVars ();

  // allocate a new GH extension structure
  CarpetIONirvanaGH* myGH = new CarpetIONirvanaGH;

  myGH->requests.resize(numvars);
  myGH->out_vars = strdup ("");
  myGH->out_every_default = out_every - 1;

  // initial I/O parameter check
  myGH->out_dir = 0;
  myGH->stop_on_parse_errors = strict_io_parameter_check;
  CheckSteerableParameters (cctkGH, myGH);
  myGH->stop_on_parse_errors = 0;


  return (myGH);
}


static void CheckSteerableParameters (const cGH *const cctkGH,
                                      CarpetIONirvanaGH *myGH)
{
  DECLARE_CCTK_PARAMETERS;

  // re-parse the 'IOHDF5::out_dir' parameter if it has changed
  const char *my_out_dir = *out_dir ? out_dir : io_out_dir;
  char *the_out_dir;
  if (strcmp (my_out_dir, ".")) {
    int i = strlen (my_out_dir);
    if (not strstr (my_out_dir, "%u")) {
      the_out_dir = (char*) malloc (i + 2);
      strcpy (the_out_dir, my_out_dir);
      the_out_dir[i] = '/';
      the_out_dir[i+1] = 0;
    } else {
      // TODO: ensure that there is exactly one "%u" and no other "%"
      // substrings, except possibly "%%".
      the_out_dir = (char*) malloc (i + 20);
      snprintf (the_out_dir, i+19, my_out_dir, dist::rank());
      strcat (the_out_dir, "/");
    }
  } else {
    the_out_dir = strdup ("");
  }

  if (not myGH->out_dir or strcmp (the_out_dir, myGH->out_dir)) {
    free (myGH->out_dir);
    myGH->out_dir = the_out_dir;

    // create the output directory
    int result = IOUtil_CreateDirectory (cctkGH, myGH->out_dir,
                                         true,
                                         dist::rank());
    if (result < 0) {
      CCTK_VWarn (1, __LINE__, __FILE__, CCTK_THORNSTRING,
                  "Problem creating HDF5 output directory '%s'", myGH->out_dir);
    } else if (result > 0 and CCTK_Equals (verbose, "full")) {
      CCTK_VInfo (CCTK_THORNSTRING,
                  "HDF5 output directory '%s' already exists", myGH->out_dir);
    }
  } else {
    free (the_out_dir);
  }

  // re-parse the 'IONirvana::out_vars' parameter if it has changed
  if (strcmp (out_vars, myGH->out_vars)) {
#ifdef IOUTIL_PARSER_HAS_OUT_DT
    IOUtil_ParseVarsForOutput (cctkGH, CCTK_THORNSTRING, "IONirvana::out_vars",
                               myGH->stop_on_parse_errors, out_vars,
                               -1, -1.0, &myGH->requests[0]);
#else
    IOUtil_ParseVarsForOutput (cctkGH, CCTK_THORNSTRING, "IONirvana::out_vars",
                               myGH->stop_on_parse_errors, out_vars,
                               -1, &myGH->requests[0]);
#endif

    // notify the user about the new setting
    if (not CCTK_Equals (verbose, "none")) {
      int count = 0;
      ostringstream msg;
      msg << "Periodic scalar output requested for:";
      for (int vi=0; vi<CCTK_NumVars(); ++vi) {
        if (myGH->requests[vi]) {
          ++count;
          char* const fullname = CCTK_FullName(vi);
          msg << eol << "   " << fullname;
          free (fullname);
        }
      }
      if (count > 0) {
        CCTK_INFO (msg.str().c_str());
      }
    }

    // save the last setting of 'IOHDF5::out_vars' parameter
    free (myGH->out_vars);
    myGH->out_vars = strdup (out_vars);
  }
}


static int OutputGH (const cGH* const cctkGH)
{
  static Carpet::Timer timer ("CarpetIONirvana::OutputGH");
  timer.start();
  for (int vindex = CCTK_NumVars () - 1; vindex >= 0; vindex--) {
    if (TimeToOutput (cctkGH, vindex)) {
      TriggerOutput (cctkGH, vindex);
    }
  }
  timer.stop();

  return (0);
}


static int TimeToOutput (const cGH* const cctkGH, const int vindex)
{
  DECLARE_CCTK_ARGUMENTS;
  DECLARE_CCTK_PARAMETERS;

  const int numvars = CCTK_NumVars();
  assert (vindex>=0 and vindex<numvars);

  if (CCTK_GroupTypeFromVarI (vindex) != CCTK_GF and not do_global_mode) {
    return 0;
  }

  CarpetIONirvanaGH *myGH =
    (CarpetIONirvanaGH *) CCTK_GHExtension (cctkGH, CCTK_THORNSTRING);
  CheckSteerableParameters (cctkGH, myGH);

  // check if output for this variable was requested
  if (not myGH->requests[vindex]) {
    return (0);
  }

  // check whether this refinement level should be output
  if (not (myGH->requests[vindex]->refinement_levels & (1 << reflevel))) {
    return (0);
  }

  // check if output for this variable was requested individually
  // by a "<varname>{ out_every = <number> }" option string
  // this will overwrite the output criterion setting
  const char *myoutcriterion = CCTK_EQUALS (out_criterion, "default") ?
                               io_out_criterion : out_criterion;
  if (myGH->requests[vindex]->out_every >= 0) {
    myoutcriterion = "divisor";
  }

  if (CCTK_EQUALS (myoutcriterion, "never")) {
    return (0);
  }

  // check whether to output at this iteration
  bool output_this_iteration = false;

  if (CCTK_EQUALS (myoutcriterion, "iteration")) {
    int myoutevery = out_every == -2 ? io_out_every : out_every;
    if (myoutevery > 0) {
      if (*this_iteration == cctk_iteration) {
        // we already decided to output this iteration
        output_this_iteration = true;
      } else if (cctk_iteration >= *next_output_iteration) {
        // it is time for the next output
        output_this_iteration = true;
        *this_iteration = cctk_iteration;
        *next_output_iteration = cctk_iteration + myoutevery;
      }
    }
  } else if (CCTK_EQUALS (myoutcriterion, "divisor")) {
    int myoutevery = out_every == -2 ? io_out_every : out_every;
    if (myGH->requests[vindex]->out_every >= 0) {
      myoutevery = myGH->requests[vindex]->out_every;
    }
    if (myoutevery > 0 and (cctk_iteration % myoutevery) == 0) {
      // we already decided to output this iteration
      output_this_iteration = true;
    }
  } else if (CCTK_EQUALS (myoutcriterion, "time")) {
    CCTK_REAL myoutdt = out_dt == -2 ? io_out_dt : out_dt;
    if (myoutdt == 0 or *this_iteration == cctk_iteration) {
      output_this_iteration = true;
    } else if (myoutdt > 0) {
      int do_output =
        (cctk_time / cctk_delta_time >=
         *next_output_time / cctk_delta_time - 1.0e-12);
      MPI_Bcast (&do_output, 1, MPI_INT, 0, dist::comm());
      if (do_output) {
        // it is time for the next output
        output_this_iteration = true;
        *this_iteration = cctk_iteration;
        *next_output_time = cctk_time + myoutdt;
      }
    }
  }

  return output_this_iteration ? 1 : 0;
}


static int TriggerOutput (const cGH* const cctkGH, const int vindex)
{
  DECLARE_CCTK_PARAMETERS;
  int retval;

  char* const fullname = CCTK_FullName(vindex);
  
  const int gindex = CCTK_GroupIndexFromVarI(vindex);
  char* const groupname = CCTK_GroupName(gindex);
  for (char* p=groupname; *p; ++p) *p=tolower(*p);
  retval = OutputVarAs (cctkGH, fullname, groupname);
  free (groupname);
  
  free (fullname);

  return (retval);
}


static void GetVarIndex (int vindex, const char* optstring, void* arg)
{
  if (optstring) {
    char *fullname = CCTK_FullName (vindex);
    CCTK_VWarn (2, __LINE__, __FILE__, CCTK_THORNSTRING,
                "Option string '%s' will be ignored for Nirvana output of "
                "variable '%s'", optstring, fullname);
    free (fullname);
  }

  *((int *) arg) = vindex;
}


static int OutputVarAs (const cGH* const cctkGH, const char* const fullname,
                        const char* const alias)
{
  DECLARE_CCTK_ARGUMENTS;
  DECLARE_CCTK_PARAMETERS;

  int error_count = 0;
  int vindex = -1;

  if (CCTK_TraverseString (fullname, GetVarIndex, &vindex, CCTK_VAR) < 0) {
    CCTK_VWarn (1, __LINE__, __FILE__, CCTK_THORNSTRING,
                "error while parsing variable name '%s' (alias name '%s')",
                fullname, alias);
    return (-1);
  }

  if (vindex < 0) {
    return (-1);
  }

  const int group = CCTK_GroupIndexFromVarI (vindex);
  assert (group >= 0);
  cGroup groupdata;
  CCTK_GroupData (group, &groupdata);
  if (groupdata.grouptype == CCTK_SCALAR or groupdata.grouptype == CCTK_ARRAY) {
    assert (do_global_mode);
  }

  // get the default I/O request for this variable
  const CarpetIONirvanaGH *myGH =
    (CarpetIONirvanaGH *) CCTK_GHExtension (cctkGH, CCTK_THORNSTRING);
  ioRequest* request = myGH->requests[vindex];
  if (not request) {
#ifdef IOUTIL_PARSER_HAS_OUT_DT
    request = IOUtil_DefaultIORequest (cctkGH, vindex, 1, -1.0);
#else
    request = IOUtil_DefaultIORequest (cctkGH, vindex, 1);
#endif
  }

  // Get grid hierarchy extentsion from IOUtil
  const ioGH * const iogh = (const ioGH *) CCTK_GHExtension (cctkGH, "IO");
  assert (iogh);


  // Invent a base file name
  int ioproc = 0, nfiles = 1;
  string filename;
  filename.append (myGH->out_dir);
  //filename.append (alias);
  filename.append("cactus-simulation-output");
  if (not (groupdata.disttype == CCTK_DISTRIB_CONSTANT or
           dist::size() == 1)) {
    ioproc = dist::rank();
    nfiles = dist::size();
  }

  // check if the file has been created already
  typedef std::map<string, vector<vector<vector<int> > > > filelist;
  static filelist created_files;
  filelist::iterator thisfile = created_files.find (filename);
  bool is_new_file = thisfile == created_files.end();
  if (is_new_file) {
    int const numvars = CCTK_NumVars ();
    vector<vector<vector<int> > > last_outputs;   // [ml][rl][var]
    last_outputs.resize (mglevels);
    for (int ml = 0; ml < mglevels; ++ml) {
      last_outputs[ml].resize (maxreflevels);
      for (int rl = 0; rl < maxreflevels; ++rl) {
        last_outputs[ml][rl].resize (numvars, cctk_iteration - 1);
      }
    }
    thisfile = created_files.insert (thisfile,
                                     filelist::value_type (filename,
                                                           last_outputs));
    assert (thisfile != created_files.end());
  }

  const int firstvar = CCTK_FirstVarIndexI(group);
  const int numvars  = CCTK_NumVarsInGroupI(group);

  // check if this variable has been output already during this iteration
  int& last_output = thisfile->second.at(mglevel).at(reflevel).at(vindex);
  if (last_output == cctk_iteration) {
    // Has already been output during this iteration
    if (vindex == firstvar + numvars - 1) {
      char* varname = CCTK_FullName(vindex);
      CCTK_VWarn (5, __LINE__, __FILE__, CCTK_THORNSTRING,
                  "Skipping output for variable \"%s\", because this variable "
                  "has already been output during the current iteration -- "
                  "probably via a trigger during the analysis stage",
                  varname);
      free (varname);
    }
    return (0);
  }
  assert (last_output < cctk_iteration);
  last_output = cctk_iteration;

  // Check for storage
  if (not CCTK_QueryGroupStorageI (cctkGH, group)) {
    CCTK_VWarn (1, __LINE__, __FILE__, CCTK_THORNSTRING,
                "Cannot output variable '%s' because it has no storage",
                fullname);
    return (0);
  }

  // Open the output file if this is a designated I/O processor
  CCTK_REAL io_files = 0;
  CCTK_REAL io_bytes = 0;
  BeginTimingIO (cctkGH);

  if (CCTK_Equals (verbose, "full")) {
    CCTK_VInfo (CCTK_THORNSTRING,
                "Writing variable '%s' on mglevel %d reflevel %d",
                fullname, mglevel, reflevel);
  }
  for (int var = firstvar; var < firstvar + numvars; var++) {
    ioRequest* r = myGH->requests[var];
    if (not r) {
#ifdef IOUTIL_PARSER_HAS_OUT_DT
      r = IOUtil_DefaultIORequest (cctkGH, var, 1, -1.0);
#else
      r = IOUtil_DefaultIORequest (cctkGH, var, 1);
#endif
    }
    if (groupdata.disttype == CCTK_DISTRIB_CONSTANT) {
      error_count += WriteVar(cctkGH, filename, ioproc, io_bytes, r);
    }
    else
       error_count += WriteVar(cctkGH, filename, ioproc, io_bytes, r);
    
    if (r != myGH->requests[var]) IOUtil_FreeIORequest (&r);

    // mark this variable to have been output at this iteration
    thisfile->second.at(mglevel).at(reflevel).at(var) = cctk_iteration;
  }

  // free I/O request structure
  if (request != myGH->requests[vindex]) {
    IOUtil_FreeIORequest (&request);
  }

  // Close the file
  
  EndTimingIO (cctkGH, io_files, io_bytes, true);

  if (error_count > 0 and abort_on_io_errors) {
    CCTK_WARN (0, "Aborting simulation due to previous I/O errors");
  }

  return (0);
}






} // namespace CarpetIONirvana