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

typedef struct text text;
struct text{
    char info[105];
};

int comp(const void* a, const void* b){
    text* aa = (text*)a;
    text* bb = (text*) b;
    if(strcmp(aa->info, bb->info) > 0) return 1;
    if(strcmp(aa->info, bb->info) < 0) return -1;
    return 0;

}


int find(char *path, FILE *output, int number){
    char buf;
    int index;
    int j;
    char new_path[255];
    DIR *dir = opendir(path);
    DIR *try_dir = NULL;
    if (dir){
        struct dirent *de = readdir(dir);
        while(de){
            for (j=0; j < 255;j++)
                new_path[j] = '\0';
            if (strcmp(de->d_name, ".") != 0 && strcmp(de->d_name, "..") != 0){
                strcpy(new_path, path);
                strcat(new_path, "/");
                strcat(new_path, de->d_name);
                if (opendir(new_path)){
                    number = find(new_path, output, number);
                }
                else{
                    if (strcmp(de->d_name, ".") != 0 && strcmp(de->d_name, "..") != 0 && strstr(de->d_name, ".txt") && !strstr(de->d_name, "result")){
                        FILE *file = fopen(new_path, "r");
                        char temp[100];
                        while(fgets(temp, 100, file)){
                            fprintf(output, " %s", temp);
                            number++;
                        }
                        fclose(file);
                    }
                }
            }
            de = readdir(dir);
        }
        closedir(dir);
        return number;
    }
    return -1;
}

void sort(FILE *input, text **file, int number){
    char buf;
    int i;
    for (i =0; i< number; i++){
        fscanf(input, "%c", &buf);
        fgets((*file)[i].info, 100, input);
    }
    qsort(*file, number, sizeof(text), comp);
}


int main(){
    int number =0;
    int i;
    FILE *answer;
    answer = fopen("./a.txt", "w+");
    number = find(".", answer, number);
    text *file = calloc(number + 5, sizeof(text));
    fclose(answer);
    answer = fopen("./a.txt", "r");
    sort(answer, &file, number);
    fclose(answer);
    answer = fopen("./a.txt", "w");
    for (i=0; i<number;i++){
        printf("%s", file[i].info);
    }
    for (i=0; i<number;i++){
        fprintf(answer, "%s", file[i].info);
    }
    fclose(answer);
    free(file);
}