void bye(void)/*Bye to user*/
{
  printf("Thank you for using your addressbook.  Bye!");
}

void welcome(void)/*welcome message to user*/
{
   printf("Welcome to your address book!\n");
}

    void menu(void)/*prints menu to the screen*/
   {
      printf(" Please choose an option from the menu below:\n");
      printf("1. Add a new contact\n");
      printf("2. Delete an old contact\n");
      printf("3. Edit an existing contact\n");
      printf("4. Search for an existing contact\n");
   }

    void displayBook(book book1[], int conts)/*displays current address book to screen*/
   {
      stream file1 = fopen( "People.txt", "r");
      printf("\tAddress Book\n");
      printf("First name\tLast name\tAddress\tCity\tState\tPhone number\n");
      printf("-------------------------------------------------------------------\n");
      int x;
      for(x = 0; x<conts; x++)/*loops to display all contacts*/
      {
         printf("%s\t", book1[x].first);
         printf("%s\t", book1[x].last);
         printf("%80c\t", book1[x].address);
         printf("%s\t", book1[x].city);
         printf("%s\t", book1[x].state);
         printf("%s\n", book1[x].phone);
      }
      fclose(file1);
   }

    void addContact(book book1[], int *conts)
   {
      stream file1 = fopen( "People.txt", "a");
      int counter = *conts;
      char ans = 'y';
  
      while(ans == 'y')/*loops while user wants to add contacts to address book*/
      {
         printf("Enter the first name of the new contact:\n");
         scanf("%s", &book1[counter].first);
         printf("Enter the last name of the new contact:\n");
         scanf("%s", &book1[counter].last);
         printf("Enter the address of the new contact:\n");
         scanf("%80c", &book1[counter].address);
         printf("Enter the city of the new contact:\n");
         scanf("%s", &book1[counter].city);
         printf("Enter the state of the new contact(2 letter abbreviation):\n");
         scanf("%s", &book1[counter].state);
         printf("Enter the new contact phone number:\n");
         scanf("%s", &book1[counter].phone);
      
         counter++;
      
         fprintf(file1, "%s,", &book1[counter].first);/*prints new input to file*/
         fprintf(file1, "%s,", &book1[counter].last);
         fprintf(file1, "%80c,", &book1[counter].address);
         fprintf(file1, "%s,", &book1[counter].city);
         fprintf(file1, "%s,", &book1[counter].state);
         fprintf(file1, "%s\n", &book1[counter].phone);
      
         puts(" ");
         printf("Add another contact?\n");
         scanf("%c", ans);/*loop answer*/
         ans = tolower(ans);
      }
      *conts = counter;
      fclose(file1);
   }

    void deleteContact(book book1[], int conts)/*function to delete a contact*/
   {
      stream file1 = fopen( "People.txt", "a");
      int x;
      char ln[50];
      printf("Enter the last name of the contact you would like to delete:\n");
      scanf("%s", &ln);
      for(x = 0; x<conts; x++)/*loops to replace "deleted" content with following contact*/
      {
         if(strcmp(book1[x].last, ln) == 0)
         {    
            while(x<conts)
            {
               book1[x] = book1[x+1];
               x++;
            }
        
            conts--;
            break;
         }
      }
      for(x = 0; x<conts; x++)/*prints new output to file*/
      {
         fprintf(file1, "%s, ", &book1[x].first);
         fprintf(file1, "%s, ", &book1[x].last);
         fprintf(file1, "%80c, ", &book1[x].address);
         fprintf(file1, "%s, ", &book1[x].city);
         fprintf(file1, "%s, ", &book1[x].state);
         fprintf(file1, "%s, ", &book1[x].phone);
      }
      fclose(file1);
   }

    void editContact(book book1[], int conts)/*function to edit one contact out of the file*/
   {
      stream file1 = fopen( "People.txt", "a");
      int x, an;
      char ln[50];
      printf("Enter the last name of the contact you would like to edit:\n");
      scanf("%s", &ln);
      for(x = 0; x<conts; x++)/*loops through entire address book*/
      {
         if(strcmp(book1[x].last, ln) == 0)/*compares last name entered to contacts to find one to edit*/
         {
            printf("%s\t%s\t%80c\t%s\t%s\t%s\n", book1[x].first, book1[x].last, book1[x].address, book1[x].city, book1[x].state, book1[x].phone);
            printf("What would you like to edit?\n1. First name\n2. Last name\n3. Address\n4. City\n5. State\n6. Phone Number\n");
            printf("Enter the number of the option you choose:\n");
            scanf("%i", &an);
            switch(an)/*user enters choice of what they want to edit in the contact*/
            {
               case 1:
                  printf("Enter the new first name:\n");
                  scanf("%s", book1[x].first);
                  break;
               case 2:
                  printf("Enter the new last name:\n");
                  scanf("%s", book1[x].last);
                  break;
               case 3:
                  printf("Enter the new address:\n");
                  scanf("%80c", book1[x].address);
                  break;
               case 4:
                  printf("Enter the new city:\n");
                  scanf("%s", book1[x].city);
                  break;
               case 5:
                  printf("Enter the new state (two letter abbreviation):\n");
                  scanf("%s", book1[x].state);
                  break;
               case 6:
                  printf("Enter the new phone number (area code first):\n");
                  scanf("%s", book1[x].phone);
                  break;
               default:
                  printf("Error: not a valid option\n");
                  break;
            }
            for(x = 0; x < conts; x ++)
            {
               fprintf(file1, "%s,", book1[x].first);
               fprintf(file1, "%s,", book1[x].last);
               fprintf(file1, "%80c,", book1[x].address);
               fprintf(file1, "%s,", book1[x].city);
               fprintf(file1, "%s,", book1[x].state);
               fprintf(file1, "%s\n", book1[x].phone);
            }
         }
      }
      fclose(file1);
   }

    void search(book book1[], int conts)/*function to search and display one contact in address book*/
   {
      stream file1 = fopen( "People.txt", "r");
      int x;
      char ln[50];
      printf("Enter the last name of the contact you are searching for\n");
      scanf("%s", &ln);
      for(x = 0; x<conts; x++)/*searches through entire contact list by last name*/
      {
         if(strcmp(book1[x].last, ln) == 0)/*compares every name to find the right one to display*/
         {
            printf("First name\tLast name\tAddress\tCity\tState\tPhone number\n");
            printf("--------------------------------------------\n");
            printf("%s\t%s\t%80c\t%s\t%s\t%s\n", book1[x].first, book1[x].last, book1[x].address, book1[x].city, book1[x].state, book1[x].phone);
            break;
         }
      }
      fclose(file1);
   }