/*
 *  =========================================================================
 *  filetest.c -- basic file I/O example.
 *  
 *  Open a specified input file (from command line, or request it) and read
 *  first two lines.  The first line is a comment line specifying what is in
 *  the file (or what the data represents).  The second line is the count of
 *  the number of remaining lines of data.  For this example, the data in the
 *  file will be regarded as real and imaginary part of a complex number and
 *  converted to magnitude and angle. The converted data will be output to
 *  a new file.
 *  
 *  Written By : D. Mazzoni and M. Austin                        January 1994  
 *  =========================================================================
 */

#include <stdio.h>
#include <stdlib.h>          /* for calloc declaration               */
#include <string.h>          /* for strcpy                           */
#include "miscellaneous.h"   /* miscellaneous prototypes and enums   */
#include "convertcomplex.h"  /* type definitions and prototype to process data */

int main( int argc, char ** argv ) {
FILE * FpIn, * FpOut;        /* File handles                                  */
char caInFile[MaxFile];      /* input filename                                */
char caOutFile[MaxFile];     /* output filename                               */
char caErrorMessage[MaxFile];/* buffer for error message                      */
char caComment[MaxChar];     /* comment line storage                          */
int iNumLines;               /* number of input lines                         */
int iCnt;                    /* line counter                                  */
COMPLEX * cxpInData;         /* dynamically allocated after file size known   */
EULER   * eupOutData;        /* dynamically allocated after file size known   */
const char * const kcpkReadFile  = "r";   /* file read/write constants         */
const char * const kcpkWriteFile = "w";
const char * const kcpkIndicator = "converted";  /* indicate change in output
                                                  * file comment line         */

/* 
 * [a] : Check if input and output files have been included on the command
 *       line. If yes, open files entered from the command line, copy names
 *       if from argv. If not, then prompt the user for the file names.
 */

   if( argc != 3 ) {

       do {
          printf( "\n\nEnter the input filename -->" );
          gets( caInFile );
          FpIn = fopen( caInFile, kcpkReadFile );
          CheckFile( FpIn );
       } while( NULL == FpIn );

       do {
          printf( "Enter output filename -->" );
          gets( caOutFile );
          FpOut = fopen( caOutFile, kcpkWriteFile );
          CheckFile( FpOut );
       } while( NULL == FpOut );

   } else {
       FpIn  = fopen( strcpy( caInFile, argv[1] ),  kcpkReadFile  );
       FpOut = fopen( strcpy( caOutFile, argv[2] ), kcpkWriteFile );
       if( NULL == FpIn || NULL == FpOut ) {
          sprintf( caErrorMessage, "Fatal Error: %s in %s on line %3i.",
                   __FILE__, __LINE__ );
          fatalError( caErrorMessage, NULL);
       }
   }

/* [b] : Now that files are open, we can process data.  First read and printf
 *       the comment line to distinguish this data set.                      
 */

   fgets( caComment, MaxChar, FpIn );
   printf( "File \"%s\" contains: %s", caInFile, caComment );

/* [c] : Get the number of lines in the input file: */

   if( 1 != fscanf( FpIn, "%i%*c", &iNumLines ) ) 
       fatalError( "Bad or missing number of data points in input file", NULL );

/* [d] : Allocate memory for data */

   cxpInData  = (COMPLEX *) safeCalloc( iNumLines, sizeof( COMPLEX ),
                                        __FILE__, __LINE__ );

   eupOutData = (EULER *)   safeCalloc( iNumLines, sizeof( EULER ),
                                        __FILE__, __LINE__ );

/* [e] : Read the data into the array */

   printf( "Reading %d lines of input data ...", iNumLines );
   for( iCnt = 0; iCnt < iNumLines; ++iCnt )
     if( EOF == fscanf( FpIn, "%f%f", &(cxpInData[iCnt].fReal) ,
                                      &(cxpInData[iCnt].fImag) ) ) {
         sprintf( caErrorMessage, "Premature end of data in %s on line %3d",
                  __FILE__, __LINE__ );
         fatalError( caErrorMessage, NULL);
     }

   printf( " done.\n");

/* [f] : Process the data, convert complex numbers */

   printf( "Converting data to Euler's form ...");
   for( iCnt = 0; iCnt < iNumLines; ++iCnt )  
        eupOutData[iCnt] = complexToEuler( cxpInData[iCnt] );

   printf( " done.\n");

/* [g] : Output normalized data */

   printf( "Writing converted data to file \"%s\" ...", caOutFile );
   fprintf( FpOut, "%s %s", kcpkIndicator, caComment );
   fprintf( FpOut, "%d\n", iNumLines );
   for( iCnt = 0; iCnt < iNumLines; ++iCnt )
      fprintf(FpOut, "%-f \t %-f\n", eupOutData[iCnt].fMagn, eupOutData[iCnt].fAngle);

   printf( " done.\n" );

/* [h] : cleanup and close files  */

   free( cxpInData );
   free( eupOutData );
   fclose( FpIn );
   fclose( FpOut );
   printf( "Done.  Exiting program.\n" );
}