#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>

int split_s(char *argv[], FILE *file_ptr){
    FILE *file_ptr_new;
    char name[100], buffer[100], c;
    int number_of_items_transferred_f, kol = 0;
    number_of_items_transferred_f = atoi(argv[3]) / sizeof(char);   //Определение размера нового

    struct stat buf;                                                     //Определение размера исходного файла
    stat(argv[1], &buf);
    long size, number_of_items_transferred = 0;
    size = buf.st_size;
    printf("Source file size: %lu\n", size);

    for (int i = 0; ; i++){
        kol = 0;
        strcpy(name, argv[5]);                                  //Создание новых
        itoa(i, buffer, 10);
        strcat(name, buffer);
        strcat(name, ".txt");

        file_ptr_new = fopen(name, "wb");

        while (number_of_items_transferred < size) {
            if (kol < number_of_items_transferred_f) {
                c = getc(file_ptr);
                fputc(c, file_ptr_new);
                number_of_items_transferred++;
                kol++;
            }

            if (kol == number_of_items_transferred_f) {
                fclose(file_ptr_new);
                break;
            }
        }

        if (number_of_items_transferred >= size){
            fclose(file_ptr_new);
            return 0;
        }
    }
}

int split_n(char *argv[], FILE *file_ptr){
    FILE *file_ptr_new;
    char name[100], buffer[100], c;
    int kol = 0;

    struct stat buf;                                             //Определение размера исходного файла
    stat(argv[1], &buf);
    long size, number_of_items_transferred = 0;
    size = buf.st_size;
    printf("Source file size: %lu\n", size);

    long new_size = size / atoi(argv[3]);              //Размер новых файлов
    printf("New file size: %lu\n", new_size);

    for (int i = 0; ; i++){
        kol = 0;

        strcpy(name, argv[5]);                          //Создание нового файла
        itoa(i, buffer, 10);
        strcat(name, buffer);
        strcat(name, ".txt");
        file_ptr_new = fopen(name, "wb");

        while (number_of_items_transferred < size) {

            if (kol < new_size) {
                c = getc(file_ptr);
                fputc(c, file_ptr_new);
                number_of_items_transferred++;
                kol++;
            }

            if (kol == new_size) {
                fclose(file_ptr_new);
                break;
            }
        }
        if (number_of_items_transferred >= size){
            fclose(file_ptr_new);
            return 0;
        }
   }

}

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

    FILE *file_ptr = fopen(argv[1], "rb");

    if (file_ptr == NULL){
        printf("\nError: file error.");
        return 1;
    }

    if (argc < 6){
        printf("\nError: Not all arguments received.");
        fclose(file_ptr);
        return  1;
    }

    if ((strcmp(argv[2], "-s") != 0 && strcmp(argv[2], "-n") != 0) || (strcmp(argv[4], "-b") != 0) || atoi(argv[3]) < 0){
        printf("\nError: parameter error.");
        fclose(file_ptr);
        return 1;
    }

    if (strcmp (argv[2], "-s")==0)
        split_s(argv, file_ptr);
    if (strcmp (argv[2], "-n")==0)
        split_n(argv, file_ptr);

    fclose(file_ptr);

    return 0;

}