/*  File name: platy_bt.c
 *  Purpose:This is the main program for Assignment #1, CST8152, Winter 17
 *  Version: 1.17.1
 *  Author: S^R
 *  Date: 9 January 2017
 */   

/* The #define _CRT_SECURE_NO_WARNINGS should be used in MS Visual Studio projects
 * to suppress the warnings about using "unsafe" functions like fopen()
 * and standard sting library functions defined in string.h.
 * The define directive does not have any effect on other compiler projects (gcc, Borland).
 */
#define _CRT_SECURE_NO_WARNINGS

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>

#include "buffer.h"

/* constant definitions */
#define INIT_CAPACITY 200 /* initial buffer capacity */
#define INC_FACTOR 15      /* increment factor */

/*check for ANSI C compliancy */
#define ANSI_C 0
#if defined(__STDC__)
#undef ANSI_C
#define ANSI_C 1
#endif

/*  Declaration of an error printing function with
 *  variable number of arguments
 */
void err_printf(char *fmt, ...);
/*  Declaration of a buffer contents display function */
void display (Buffer *ptr_Buffer); 
long get_filesize(char *fname);

int main(int argc, char **argv){
	
   pBuffer ptr_Buffer;   /* pointer to Buffer structure */
   FILE *fi;             /* input file handle */
   int loadsize = 0;     /*the size of the file loaded in the buffer */
   int ansi_c = !ANSI_C; /* ANSI C compliancy flag */
    
/* Check if the compiler option is set to compile ANSI C */
/* __DATE__, __TIME__, __LINE__, __FILE__, __STDC__ are predefined preprocessor macros*/
  if(ansi_c){
    err_printf("Date: %s  Time: %s",__DATE__, __TIME__);
    err_printf("ERROR: Compiler is not ANSI C compliant!\n");
    exit(1);
  }

/* missing file name or/and mode parameter */
  if (argc <= 2){

     err_printf("\nDate: %s  Time: %s",__DATE__, __TIME__);
     err_printf("\nRuntime error at line %d in file %s\n", __LINE__, __FILE__);
	  err_printf("%s\b\b\b\b%s%s",argv[0],": ","Missing parameters.");
	  err_printf("Usage: platybt source_file_name mode");
	  exit(1);
	}
	
/* create a source code input buffer */		
	switch(*argv[2]){
	 case 'f': case 'a': case 'm': break;
	 default:
	  err_printf("%s%s%s",argv[0],": ","Wrong mode parameter.");
	  exit(1);
	}
/*create the input buffer */
    ptr_Buffer = b_create(INIT_CAPACITY,INC_FACTOR,*argv[2]);
	if (ptr_Buffer == NULL){
		err_printf("%s%s%s",argv[0],": ","Could not create buffer.");
		exit(1);
	}

/* open the source file */
	if ((fi = fopen(argv[1],"r")) == NULL){
		err_printf("%s%s%s%s",argv[0],": ", "Cannot open file: ",argv[1]);
		exit (1);
	}

/* load a source file into the input buffer  */
     printf("Reading file %s ....Please wait\n",argv[1]);
     loadsize = b_load (fi,ptr_Buffer);
     if(loadsize == R_FAIL1)
       err_printf("%s%s%s",argv[0],": ","Error in loading buffer.");

/* close the source file */	
 	fclose(fi);
/*find the size of the file  */
    if (loadsize == LOAD_FAIL){
     printf("The input file %s %s\n", argv[1],"is not completely loaded.");
     printf("Input file size: %ld\n", get_filesize(argv[1]));
    } 
/* set a mark at the last char in the buffer*/
  b_setmark(ptr_Buffer,b_size(ptr_Buffer));

/* display the contents of the input buffer */	  
   display(ptr_Buffer);

/* pack the buffer 
 * if possible, add end-of-file character (EOF) to the buffer
 * display again
 */
  if(b_pack(ptr_Buffer)){         
    if(!b_addc(ptr_Buffer, EOF))
      err_printf("%s%s%s",argv[0],": ","Error in writing to buffer.");
    display(ptr_Buffer);
  }  


/* free the dynamic memory used by the buffer */  
  b_free(ptr_Buffer);
/* make the buffer invalid
   It is not necessary here because the function terminates anyway,
   but will prevent run-time errors and crashes in future expansions
*/
  ptr_Buffer = NULL;
/*return success */
  return (0);
}

/* error printing function with variable number of arguments*/
void err_printf( char *fmt, ... ){
/*Initialize variable list */   
  va_list ap;
  va_start(ap, fmt);
     
  (void)vfprintf(stderr, fmt, ap);
   va_end(ap);

  /* Move to new line */
  if( strchr(fmt,'\n') == NULL )
     fprintf(stderr,"\n");
}

void display (Buffer *ptr_Buffer){
  printf("\nPrinting buffer parameters:\n\n");
  printf("The capacity of the buffer is:  %d\n",b_capacity(ptr_Buffer));
  printf("The current size of the buffer is:  %d\n",b_size(ptr_Buffer));
  printf("The operational mode of the buffer is:   %d\n",b_mode(ptr_Buffer));
  printf("The increment factor of the buffer is:  %u\n",b_incfactor(ptr_Buffer));
  printf("The current mark of the buffer is:  %d\n",b_mark(ptr_Buffer));
/*printf("The reallocation flag is:   %d\n",b_rflag(ptr_Buffer));*/
  printf("\nPrinting buffer contents:\n\n");
  b_print(ptr_Buffer);
}

long get_filesize(char  *fname){
   FILE *input;
   long flength;
   input = fopen(fname, "r");
   if(input == NULL){
      err_printf("%s%s","Cannot open file: ",fname);  
	  return 0;
   }
   fseek(input, 0L, SEEK_END);
   flength = ftell(input);   
   fclose(input);
   return flength;
}