//-----------------------------------------------------------------------------------------
//  Function:   read_fov_file (string fovfile)
//
//  Reads the FOV data file.
//
//  Input:
//    file.....the complete path + name of the FOV data file
//
//  Notes:
//     The FOV file format is 5 header lines, then a matrix (# of bands+1, # elevation angles),
//     where each row is: elevation angle, then FOV response for bands 1-nband
//
//  Source: Mark Hervig, GATS
//-----------------------------------------------------------------------------------------

#include "sofiefov.h"
#include "fortranfunctions.h"

#include <fstream>
#include <iostream>
#include <cassert>
#include <algorithm>


void sofiefov::read_fov_file (const std::string& fovfile, int* reverse) 
{
	fov_response.resize(16);
/* 
THis function is expecting to read a file with the following convention.
+ elevations values mean towards the ground    - elevation angles are toward space
*/

   char   header[512];   // for header lines in the file         

   std::ifstream inputFile;   //the input file

   inputFile.open(fovfile.c_str(), std::ios_base::in);  // open the file

   inputFile.getline(header,511);  // read a header line
   inputFile.getline(header,511);
   inputFile >> nel;               // read the number of elevation angles
   inputFile.getline(header,511);
   inputFile >> nband;             // read the number of bands
   inputFile.getline(header,511);
   inputFile.getline(header,511);

   std::cout << nel << " elevation angles and " << nband << " bands" << std::endl;


   double temp_sc;

   for (int i = 0; i < nel; i++) {  // loop over elevation

 //    temp_ar.clear();

//       if (j == 0) {  // the elevation
         inputFile >> temp_sc; 
         elevation.push_back(temp_sc);
   //      std::cout << temp_sc;
 //      }
     for (int j = 0; j < nband; j++) {  // loop over bands
 
//       if (j > 0) {  // the FOV response data
         inputFile >> temp_sc;
         fov_response[j].push_back(temp_sc);
    //     std::cout << " " << temp_sc;
 //      }

     }

 //    fov_response.push_back(temp_ar);
   //  std::cout << std::endl;
   }

   inputFile.close();


/* file sofie_fov_elevation_V1.3.txt has + angles toward space - toward ground
   we reverse that here so positive is toward ground and - is toward space */


   if(*reverse != 0) { 
      std::reverse(elevation.begin(),elevation.end() );
      std::transform(elevation.begin(), elevation.end(), 
	   	elevation.begin(),std::negate<double>() );
      for (int j = 0; j < nband; j++) {  // loop over bands
        std::reverse(fov_response[j].begin(), fov_response[j].end()) ;
      }
      std::cout << " reversed FOV arrays " << std::endl;
   }
 
}

std::vector<double>  sofiefov::get_fov_elev(const int band) 
{
	assert(band > 0 && band <= 16);
	return elevation;
}

std::vector<double>  sofiefov::get_fov_response(const int band) 
{
	assert(band > 0 && band <= 16);
	return fov_response.at(band-1);
}