/* This is part of the netCDF package.
   Copyright 2006 University Corporation for Atmospheric Research/Unidata.
   See COPYRIGHT file for conditions of use.

   This is an example which reads some surface pressure and
   temperatures. The data file read by this program is produced
   companion program sfc_pres_temp_wr.cxx. It is intended to
   illustrate the use of the netCDF C++ API.

   This program is part of the netCDF tutorial:
   http://www.unidata.ucar.edu/software/netcdf/docs/netcdf-tutorial

   Full documentation of the netCDF C++ API can be found at:
   http://www.unidata.ucar.edu/software/netcdf/docs/netcdf-cxx

   $Id: sfc_pres_temp_rd.cpp,v 1.3 2007/07/30 00:18:22 forbes Exp $
*/

#include <iostream>
#include <netcdfcpp4.h>

using namespace std;
using namespace netCDF;

// We are reading 2D data, a 6 x 12 lat-lon grid.
static const int NLAT = 6;
static const int NLON = 12;

// These are used to calculate the values we expect to find. 
static const float SAMPLE_PRESSURE = 900;
static const float SAMPLE_TEMP = 9.0;
static const float START_LAT = 25.0;
static const float START_LON = -125.0;

// Return this code to the OS in case of failure.
static const int NC_ERR = 2;

int main(void)
{
   // These will hold our pressure and temperature data.
   float presIn[NLAT][NLON];
   float tempIn[NLAT][NLON];

   // These will hold our latitudes and longitudes.
   float latsIn[NLAT];
   float lonsIn[NLON];
  
  try
  {
   // Open the file and check to make sure it's valid.
   NcFile dataFile("sfc_pres_temp.nc", NcFile::ReadOnly);

   // There are a number of inquiry functions in netCDF which can be
   // used to learn about an unknown netCDF file. In this case we know
   // that there are 2 netCDF dimensions, 4 netCDF variables, no
   // global attributes, and no unlimited dimension.

//fix these later
	cout<<"there are "<<dataFile.getNumVars()<<" variables"<<endl;
	cout<<"there are "<<dataFile.getNumAtts()<<" attributes"<<endl;
	//cout<<"there is "<<dataFile.isUnlimited()<< " unlimited dimensions"<<endl;
 //  if ( dataFile.getNumVars() != 4)
	//return NC_ERR;
// || dataFile.getNumAtts() != 4 // right now it returns 0 b/c the file doesn't see variable attributes 
//dataFile.isUnlimDim() != 0// check to see if an unlimited dim is present, not sure this is currently implemented in the interface
     
   // We get back a pointer to each NcVar we request. Get the
   // latitude and longitude coordinate variables.
   NcVar *latVar, *lonVar;
   if (!(latVar = dataFile.getVar("latitude")))
      return NC_ERR;

   if (!(lonVar = dataFile.getVar("longitude")))
      return NC_ERR;
 
   // Read the latitude and longitude coordinate variables into arrays
   // latsIn and lonsIn.
   if (!latVar->get(latsIn, NLAT))
      return NC_ERR;

   if (!lonVar->get(lonsIn, NLON))
      return NC_ERR;

   // Check the coordinate variable data. 
   for(int lat = 0; lat < NLAT; lat++)
      if (latsIn[lat] != START_LAT + 5. * lat)
	 return NC_ERR;
   
   // Check longitude values.
   for (int lon = 0; lon < NLON; lon++)
      if (lonsIn[lon] != START_LON + 5. * lon)
	 return NC_ERR;

   // We get back a pointer to each NcVar we request. 
   NcVar *presVar, *tempVar;
   if (!(presVar = dataFile.getVar("pressure")))
      return NC_ERR;

   if (!(tempVar = dataFile.getVar("temperature")))
      return NC_ERR;
       
   // Read the data. Since we know the contents of the file we know
   // that the data arrays in this program are the correct size to
   // hold all the data.
   if (!presVar->get(&presIn[0][0], NLAT, NLON))
      return NC_ERR;
   if (!tempVar->get(&tempIn[0][0], NLAT, NLON))
      return NC_ERR;
       
   // Check the data. 
   for (int lat = 0; lat < NLAT; lat++)
      for (int lon = 0; lon < NLON; lon++)
	 if (presIn[lat][lon] != SAMPLE_PRESSURE + (lon * NLAT + lat)
	     || tempIn[lat][lon] != SAMPLE_TEMP + .25 * (lon * NLAT + lat))
	    return NC_ERR;
   
   // Each of the netCDF variables has a "units" attribute. Let's read
   // them and check them.
   NcAtt *att;
   string units;
   
   if (!(att = latVar->getAtt("units")))
      return NC_ERR;

   /*units = att->getValue();
   if (units != "degrees_north")
{
	cout<<"getValue returned "<<units<<endl;
      return NC_ERR;
}*/
   // Attributes and attribute values should be deleted by the caller
   // when no longer needed, to prevent memory leaks.
   

   if (!(att = lonVar->getAtt("units")))
      return NC_ERR;
  /*units = att->getValue();
  if (units != "degrees_east")
     return NC_ERR;
  */
   
   if (!(att = presVar->getAtt("units")))
      return NC_ERR;
//   units = att->getValue();
  // if (units != "hPa")
    //  return NC_ERR;
  
   
   if (!(att = tempVar->getAtt("units")))
      return NC_ERR;
   /*units = att->getValue();
   if (units != "celsius")
      return NC_ERR;*/

   // The file will be automatically closed by the destructor. This
   // frees up any internal netCDF resources associated with the file,
   // and flushes any buffers.
   cout << "*** SUCCESS reading example file sfc_pres_temp.nc!" << endl;
   return 0;
  }
  catch(NcException e)
  {
     e.what();
     cout<<"FAILURE********************************8"<<endl;
     return 1;
  }
}