/*
Program 4 - password program with more requirements
 -build a database of names and passwords (3 of them)
 -password must
   1) have length >= 6
   2) >= 1 uppercase character
   3) >= 1 lowercase character
   4) >= 1 digit
   5) >= 1 special character (punctuation)
   6) no spaces
   7) start with an alphabetical character
   
 -give user three chances to input name and password correctly
*/

#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define N 50
#define NUM 3

int isValidPassword(char password[])
{
    int i;
    int upper=0, lower=0, digit=0, punct=0, space=0;
    
    if(strlen(password)<6) return 0;
    if(!isalpha(password[0])) return 0;
    
    for(i=0; i<strlen(password); i++)
    {
         if(isspace(password[i])) return 0;
         if(isupper(password[i])) upper++;
         if(islower(password[i])) lower++;
         if(isdigit(password[i])) digit++;
         if(ispunct(password[i])) punct++;
    }
    
    if(upper >0 && lower > 0 && punct > 0 && digit > 0) return 1;
    
    return 0;
}

void main()
{
     char names[NUM][N];
     char pws[NUM][N];
     char pwguess[50];
     char nameguess[50];
     int i, j;
     
     printf("Enter %d names in the format\tname password\n", NUM);
     for(i=0; i<NUM; i++)
     {
         printf("enter name and password %d: ", i);
         scanf("%s%s", names[i], pws[i]);
         
         while(!isValidPassword(pws[i]))
         {
              printf("password does not meet requirements!\n");
              printf("enter name and password %d: ", i);
              scanf("%s%s", names[i], pws[i]);
         }
         
     }   
     
     printf("\nDatabase of usernames and passwords built!\n\n\n");
     
     
     for(j=0; j<3; j++)
     {
         printf("Enter your name and password: ", nameguess);
         scanf("%s%s", nameguess, pwguess);
         
         for(i=0; i<NUM; i++)
          {
           if(strcmp(names[i], nameguess)==0 && strcmp(pws[i], pwguess)==0)
               {
                   printf("successfully logged in\n"); 
                   system("pause");
                   return; 
               }
          }
          printf("incorrect name and password\n");
     }
     
     printf("Too many login attemps were made. This computer is now locked...\n");
     
     system("pause");
}