/*
 * Sample C code with linked list.
 */

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

#define ADD_EMPLOYEE 1
#define REMOVE_EMPLOYEE 2
#define FIND_EMPLOYEE_NAME 3
#define FIND_EMPLOYEE_AGE 4
#define LIST_ALL_EMPLOYEES 5

struct e_node {
   char name[50];
   int age;
   struct e_node *next;
};

typedef struct e_node node;

node *head;

void insert_to_list(int e_age, char *e_name) {

  node *new_employee;
  new_employee->age = e_age;
  strcpy(new_employee->name,e_name);
  new_employee->next = NULL;
  
  //add the node to the front
  if (head != NULL) {
    new_employee->next = head;
  }
  head = new_employee;

}

void print_employee_info() {

   node *cur = head;

   while(cur != NULL) {
      printf("Employee Name : %s, Age : %d \n",cur->name, cur->age);
      cur = cur->next;
   }
}

void cleanup() {

  node *cur = head;
  node *pre;
   
  while(cur != NULL) {
     pre = cur;
     cur = cur->next;
     free(pre);
  }
}

void add_employee_info() {
   char employee_name[50];
   int employee_age;

   printf("\n Enter employee age : ");
   scanf("%d", &employee_age);
   printf("\n Enter employee name : ");
   scanf("%s", &employee_name);

   //put it into linked list
   insert_to_list(employee_age, employee_name);

}
   
int remove_employee_info() {

   char e_name[50];

   printf("\n Employee name : ");
   scanf("%s",e_name);

   node *cur = head;
   node *prev = NULL;
   while (cur != NULL) {
      if (!strcmp(cur->name,e_name)) {
          printf("Found employee record...deleting...\n");
          if (cur == head) {
             head = cur->next;
          } else {
             prev->next = cur->next;
          }
          free(cur);
          return 1;
      }else {
         prev = cur;
         cur = cur->next;
      }
   }

   return 0;
}



int main(int argc, char *argv[]) {

  int operation_code;

  head = NULL;

  while (1) {

      printf("\n Specify Operation (Insert(1), Delete(2), List(5)) : ");
      scanf("%d", &operation_code);

      if (operation_code == ADD_EMPLOYEE) add_employee_info();
      else if (operation_code == REMOVE_EMPLOYEE) {
          if (!remove_employee_info()) printf("Cant find employee record\n");
      }
      else if (operation_code == LIST_ALL_EMPLOYEES) print_employee_info();
      else break;

  }

  cleanup();

  return 0;

}