#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
 
enum {
    MAXLEN=255
};
 
typedef struct list {
    char name[MAXLEN];
    char address[MAXLEN];
    char phone[MAXLEN];
    struct list *next;
} ADDRESS;
 
void add_to_list (void);
void delete_from_list (void);
void search_name (void);
void list_names (void);
void quit_program (void);
void edit(void);
ADDRESS *hol= NULL;
 
int main()
{
    char input[MAXLEN];
 
 
    while (1) {
        printf ("What you want to do?\n");
        printf("a.Search\n");
        printf("b.Add\n");
        printf("c.Delete\n");
        printf("d.Edit\n");
        printf("e.Display Option\n");
        printf("f.Exit\n");
 
 
        fgets (input, MAXLEN,stdin);
        switch (input[0]) {
            case ('a'):
            case ('A'):
                search_name();
                break;
            case ('b'):
            case ('B'):
                add_to_list();
                break;
            case ('c'):
            case ('C'):
                delete_from_list();
                break;
            case ('d'):
            case ('D'):
                edit();
                break;
            case ('e'):
            case ('E'):
                quit_program();
                return (0);
            default:
                printf ("Unknown command\n");
        }
 
    }
    return 0;
}
 
void add_to_list (void)
 
{
    ADDRESS *new_name;
 
    new_name= (ADDRESS *)malloc (sizeof (ADDRESS));
    if (new_name == NULL) {
        printf ("Out of memory!\n");
        exit (-1);
    }
 
    printf ("Name> ");
    fgets (new_name->name, MAXLEN, stdin);
    printf ("Address> ");
    fgets (new_name->address, MAXLEN, stdin);
    printf ("Tel> ");
    fgets (new_name->phone, MAXLEN, stdin);
    /* Chain the new item into the list */
    new_name->next= hol;
    hol= new_name;
}
 
void delete_from_list (void)
 
{
    ADDRESS *del_ptr;   /* Pointer to find name to delete */
    ADDRESS *prev_ptr;  /* Pointer to name BEFORE this name */
    char del_name[MAXLEN]; /* Name to delete */
 
    printf ("Name> ");
    fgets (del_name, MAXLEN, stdin);
 
    if (hol == NULL) {
        printf ("No list to delete from\n");
        return;
    }
    if (strcmp(hol->name, del_name) == 0) {
        del_ptr= hol;
        hol= hol->next;
        free(del_ptr);
        return;
    }
 
    prev_ptr= hol;
    while (prev_ptr->next != NULL) {
 
        if (strcmp(prev_ptr->next->name,del_name) == 0) {
            del_ptr= prev_ptr->next;
            prev_ptr->next= del_ptr->next;
            free(del_ptr);
            return;
        }
        prev_ptr= prev_ptr->next;
    }
    printf ("Name not found!\n");
}
 
void search_name (void)
 
 
{
    char name[MAXLEN];  /* Name to look for */
    ADDRESS *search_ptr;
    printf ("Name> ");
    fgets (name, MAXLEN, stdin);
    search_ptr= hol;
    while (search_ptr != NULL) {
        if (strcmp (search_ptr->name, name) == 0) {
            printf ("Address: %s", search_ptr->address);
            printf ("Tel: %s", search_ptr->phone);
            return;
        }
        search_ptr= search_ptr->next;
    }
    printf ("No such name\n");
}
 
void list_names (void)
 
{
    ADDRESS *tmp_ptr; /* Traverses list */
    printf ("All names in address book:\n");
    tmp_ptr= hol;
    while (tmp_ptr != NULL) {
        printf ("%s",tmp_ptr->name);
        tmp_ptr= tmp_ptr->next;
    }
}
 
void quit_program (void)
{
    ADDRESS *del_ptr;
 
    while (hol != NULL) {
       del_ptr= hol;
       hol= hol->next;
       free(del_ptr);
    }
}
 
 
void edit (void)
 
{
    ADDRESS *edi_ptr;   /* Pointer to find name to edit */
    ADDRESS *prev_ptr;  /* Pointer to name BEFORE this name */
    char edi_name[MAXLEN]; /* Name to edit */
 
    printf ("Name> ");
    fgets (edi_name, MAXLEN, stdin);
 
    if (hol == NULL) {
        printf ("No list to edit from\n");
        return;
    }
    if (strcmp(hol->name, edi_name) == 0) {
        edi_ptr= hol;
        hol= hol->next;
        free(edi_ptr);
        return;
    }
 
    prev_ptr= hol;
    while (prev_ptr->next != NULL) {
 
        if (strcmp(prev_ptr->next->name,edi_name) == 0) {
            edi_ptr= prev_ptr->next;
            prev_ptr->next= edi_ptr->next;
            free(edi_ptr);
            return;
        }
        prev_ptr= prev_ptr->next;
    }
    printf ("Name not found!\n");
}

void delete_from_list (void)

{
    ADDRESS *del_ptr;   /* Pointer to find name to delete */
    ADDRESS *prev_ptr;  /* Pointer to name BEFORE this name */
    char del_name[MAXLEN]; /* Name to delete */

    printf ("Name> ");
    fgets (del_name, MAXLEN, stdin);

    if (hol == NULL) {
        printf ("No list to delete from\n");
        return;
    }
    if (strcmp(hol->name, del_name) == 0) {
        del_ptr= hol;
        hol= hol->next;
        free(del_ptr);
        return;
    }

    prev_ptr= hol;
    while (prev_ptr->next != NULL) {

        if (strcmp(prev_ptr->next->name,del_name) == 0) {
            del_ptr= prev_ptr->next;
            prev_ptr->next= del_ptr->next;
            free(del_ptr);
            return;
        }
        prev_ptr= prev_ptr->next;
    }
    printf ("Name not found!\n");
}