#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
#include "func.h"

int split_files( char *filename , unsigned long int _s)
{
    FILE            *fp_orig,
                    *fp_split;

    unsigned
        long int    orig_pos, orig_size,
                    split_pos, split_size,
                    i, n,
                    bytes_left;

    int             filenr,
                    pieces,
					bytes_read,
					allow_read;

    struct stat     *buf;
    char            *c_byte,
                    *split_fname,
                    *orig_fname,
					*split_sfname;


    i = n = 0;
    orig_pos = orig_size = 0;
    split_pos = split_size = 0;
    filenr = 1;


    buf = (struct stat*)malloc(sizeof(struct stat*));
    c_byte = (char*)malloc(sizeof(char*)*4096);
    split_fname = (char*)malloc(sizeof(char*) * 200);
    orig_fname = (char*)malloc(sizeof(char*) * 200);

    strcpy(orig_fname,filename);

    stat(orig_fname,buf);
    orig_size = buf->st_size;

	if (_s >= orig_size)
	{
		printf("Splitted filesize is same as size of the filename!\n"
			"Try using cp(1) instead...\n");
		exit(0);
	}

	fp_orig = fopen(orig_fname,"r");

	if (fp_orig == NULL)
    {
        perror("error opening input file");
        return -1;
    }

    split_size = _s;


    bytes_left = orig_size;

	orig_fname = strip_path( orig_fname );

    pieces = orig_size / split_size;
    if ((orig_size % split_size) > 0) pieces++;

	if (pieces > 999)
	{
		printf("You will be ending up with over %d files, while i"
			"rather wouldn't go over the 999... Perhaps you"
			"could choose a bigger output size?\n");
		exit(0);
	}

    printf("Splitting %s into %d pieces.\n",orig_fname, pieces);

    while (orig_pos < orig_size)
    {
        if (filenr < 10)
            sprintf(split_fname,"%s.00%d",orig_fname,filenr);
        else if (filenr < 100)
            sprintf(split_fname,"%s.0%d",orig_fname,filenr);
        else if (filenr < 1000)
            sprintf(split_fname,"%s.%d",orig_fname,filenr);

        fp_split = fopen(split_fname,"w");
        if (fp_split == NULL)
        {
            perror("error opening output file");
            return -1;
        }


        split_pos = 0;

		split_sfname = shorten_path(split_fname);

        printf("%s\t\t\t%d bytes\n",split_sfname,split_size);
		bytes_read = 0;
		allow_read = 4096;

        while (split_pos < split_size)
        {
			if ((split_pos+allow_read)-1 - split_size < 4096)
				allow_read = split_size % 4096;

            bytes_read = fread(c_byte, 1, allow_read, fp_orig);
            fwrite(c_byte, 1, bytes_read, fp_split);

            orig_pos+=bytes_read;
            split_pos+=bytes_read;
#ifdef DEBUG
            printf("split pos:\t%d\n",split_pos);
            printf("split size:\t%d\n",split_size);
			printf("allow_read:\t%d\n",allow_read);
			sleep(1);
#endif

        }

        bytes_left -= split_size;

        if (bytes_left < split_size)
            split_size = bytes_left;

        filenr++;

        fclose(fp_split);
    }

    fclose(fp_orig);

    return 0;

}