/* standard stuff */
#include <stdio.h>
#include <stdlib.h>

/* malloc */
#include <malloc.h>

/* memset */
#include <string.h>

/* error handling */
#include <errno.h>

/* rate */
#include <time.h>

/* explicitly compile with -D_OFFSET_FILE_BITS=64 if it fails at 2G */
#define _FILE_OFFSET_BITS 64

#define TUI
#define BARLEN 80

#define NAME "filefiller"
#define VERSION "0.1"
#define ME "cancer"


/* #define DEBUG */
#define BLOCKSIZE (unsigned long long)4096
#define REFRESHINTERVAL 1024
#define FILLCHAR 0x00

void usage(char *binname) {
    printf("%s v%s\n\n Usage:\n %s filename blocks\n\n This executable uses:\n  BLOCKSIZE = %llu\n  REFRESHINTERVAL = %d\n  FILLCHAR = 0x%X\n\n~%s\n", NAME, VERSION, binname, BLOCKSIZE, REFRESHINTERVAL, FILLCHAR, ME);
    exit(0);
}

int main(int argc, char **argv) {

    if(argc < 3) usage(argv[0]);
    FILE *fd;

    fd = fopen(argv[1], "r");
    if(fd != NULL) {
        #ifdef DEBUG
          printf("File exists, removing.");
        #endif
        fclose(fd);
        remove(argv[1]);
    }

    fd = fopen(argv[1], "wb");

    size_t x = 0;
    char *b = malloc(sizeof(char)*BLOCKSIZE);

    #ifdef DEBUG
      printf("Allocated %llu bytes.\n", BLOCKSIZE);
    #endif

    unsigned long long c = atoll(argv[2]);
    memset(b, FILLCHAR, BLOCKSIZE);

    #ifdef DEBUG
      printf("Zeroed %llu bytes.\n", BLOCKSIZE);
    #endif

    #ifdef TUI
      puts("FILENAME PERCENT BLOCKS_DONE BLOCKS_LEFT BLOCKS_TOT FILESIZE");
    #endif


    time_t starttime = time(0);
    time_t endtime = time(0);
    unsigned long long blocksintime = 0;
    unsigned long long totalblocks  = 0;

    for(unsigned long long i = 1; i <= c; i++) {


        if((x = fwrite(b, sizeof(char), BLOCKSIZE, fd)) < BLOCKSIZE) {

            #ifdef DEBUG
              if(ferror(fd)) {
                  printf("ferror\n");
                  printf("%d %s \n", errno, strerror(errno));

              }

              else if(feof(fd)) {
                  printf("\reof\n");
              }

              else {
                  printf("\r%d %s \n", errno, strerror(errno));
              }

              printf("Wrote %llu bytes instead of %llu.\n", (unsigned long long)x, BLOCKSIZE);
            #endif

            puts("\n");
            fclose(fd);
            remove(argv[1]);
            return EXIT_FAILURE;
        }


        blocksintime++;
        endtime = time(0);
        if(endtime > starttime) {
            totalblocks = blocksintime;
            blocksintime = 0;
            starttime = endtime;
        }


        if(i % REFRESHINTERVAL == 0 || i == c) {
            #ifdef TUI
              printf("\r%-8s %-7.2lf %-11llu %-11llu %-11llu", argv[1], ((double)i/(double)c*100), i, c-i, c);

              unsigned long long X = i*BLOCKSIZE;
              char *sizes = " KMGTPEZY";

              while(X >= 1024) {
                  X >>= 10;
                  sizes++;
              }

              printf("%llu%-4c ", X, *sizes);

              X = totalblocks*BLOCKSIZE;
              sizes = " KMGTPEZY";

              while(X >= 1024) {
                  X >>= 10;
                  sizes++;
              }

              printf("%lldblk/s %lld%cbits/s\033[K\n[\033[7m\033[2G", totalblocks, X*8, *sizes);


              for(unsigned int j = 2; j < (unsigned int)((double)i/(double)c*BARLEN); j++) {
                  printf(" ");
              }

              printf("\033[0m\033[%dG]\033[1A\r", BARLEN);
            #endif
        }
    }
    puts("\n");

    #if defined(DEBUG) || !defined(TUI)
      printf("Wrote %llu blocks of %llu (=%llu bytes) to file %s.\n", c, BLOCKSIZE, c*BLOCKSIZE, argv[1]);
    #endif

    free(b);
    fclose(fd);
}