#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <sys/types.h>
#include <string.h>
#include <crypt.h>

#define max_pass_size 3
#define students_pass_file "passwords.txt"
#define max_forks 4

typedef struct{
        char username[35];
        char password[15];
}       User;

typedef struct{
        char username[35];
        char password[15];
}       New_User;

static char *Alfabeth = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
int nsucessos=0,ntentativas=0;

void worker();
void master();
int n_pass();
void carrega_tabela();
int BruteForce();
int CheckCrypt();

// File descriptors for the pipe channel
int channel[2];

int main() {
        int size,i=0;
        New_User new_tabela;
    // Create a pipe
    pipe(channel);
    char word[max_pass_size+1] = "";
        size=n_pass();
        User tabela[size];
        carrega_tabela(tabela,size);
        //for (i=0;i<size;i++) printf("%s %s\n",tabela[i].username,tabela[i].password);
    // Create the processes
    pid_t id;
    while(i<max_forks){
                id = fork();
        if (id == 0) {
            close(channel[0]);
                        //sleep(1);
                        //worker(tabela, size, i);
                        BruteForce(word, 0, size/max_forks, tabela, i);
            i=max_forks;
            //exit(0);
        }
        i++;
        }
        if (id > 0)
        {
                        while(1){
                read(channel[0], &new_tabela, sizeof(New_User));
                printf("username:%s_password:%s\n", new_tabela.username, new_tabela.password);
                        //master(tabela);
                    }
                }
    return 0;
}

int n_pass(){
        int size=0;
        char temp[50];
        FILE *ficheiro=fopen(students_pass_file,"r");
        while ((fscanf(ficheiro,"%s",temp) != -1 ))             size++;
        fclose(ficheiro);
        return size;
}

void carrega_tabela(User *tabela, int size){

    int i=0;
    char temp[50];
        char *result;

        FILE *ficheiro=fopen(students_pass_file,"r");

        while ((fscanf(ficheiro,"%s",temp) != -1 )){
                result=strtok(temp,":");
                strcpy(tabela[i].username,result);
                result=strtok(NULL,"\n");
                strcpy(tabela[i].password,result);
                i++;
        }
        fclose(ficheiro);
}

/*void worker(User *tabela, int size, int proc_n) {

    int i, test;
    test=size/max_forks;
    char word[10];

    close(channel[0]);

    while (1) {
        for (i = 1; i < max_pass_size+1; i++){
            BruteForce(word, 0, i, test, tabela, proc_n);
        }
    }
    return;
}*/

void master(User *tabela) {
        New_User new_tabela;

    close(channel[1]);
    fd_set read_set;

        FD_ZERO(&read_set);
        FD_SET(channel[0], &read_set);
        if ( select(channel[0]+1, &read_set, NULL, NULL, NULL) > 0 ) {
            if (FD_ISSET(channel[0], &read_set))
                read(channel[0], &new_tabela, sizeof(New_User));
                printf("username:%s_password:%s\n", new_tabela.username, new_tabela.password);
                return;
        }
        //sleep(1);
}

int BruteForce(char *word, int counter, int size, User *tabela, int check){
        New_User new_tabela;
    int i,j,result;
    char aux[15];
    if (counter >= max_pass_size) return 0;
    for (i = 0; i < strlen(Alfabeth); i++)
    {
        word[counter] = Alfabeth[i];
        word[counter+1] = '\0';
        strcpy(aux,crypt(word,"10"));
        for (j=0;j<size;j++){
                        ntentativas++;
                        result = strcmp(aux, tabela[j+(check*size)].password);
                                if (result == 0)
                                {
                                        strcpy(new_tabela.password,word);
                                        strcpy(new_tabela.username,tabela[i+(check*size)].username);
                                        nsucessos++;
                                        //printf("[%d][%d][%3d][%3d]username:%s_password:%s\n",check,getpid(),j+(check*size),nsucessos,tabela[j+(check*size)].username,word);
                                        write(channel[1], &new_tabela, sizeof(New_User));
                                }
                }
                //CheckCrypt (word, size, tabela, check);
                //if (nsucessos == size)                kill(getpid(), SIGKILL);
                BruteForce(word, counter+1, size, tabela, check);
    }
    return 0;
}

/*int CheckCrypt(char *word, int size, User *tabela, int check)
{
        New_User new_tabela;
        int x=0;
        int result,i;
        char password[10];
        strcpy(password,word);
        word = crypt(word,"10");

        for (i=0;i<size;i++){
                ntentativas++;
                result = strcmp(word, tabela[i+(check*size)].password);

                if (result == 0){
                    strcpy(new_tabela.password,password);
                    strcpy(new_tabela.username,tabela[i+(check*size)].username);
                        nsucessos++;

                        printf("[%d][%d][%3d][%3d]username:%s_password:%s\n",check,getpid(),i+(check*size),nsucessos,tabela[i+(check*size)].username,password);

                        write(channel[1], &new_tabela, sizeof(New_User));
//                      check++;
                }
        }
//      check++;
        return 0;
}*/