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

struct Employee{
    char firstName[256];
    char lastName[256];
    int age;
    int sinNumber;
    char status;
};

struct Node{
    struct Employee *employee;
    struct Node *next;
};

void initilizeList(struct Node* _head){
    _head = (struct Node*) malloc(sizeof(struct Node));
    _head = NULL;
    //_head->employee = initEmployee
}

//given a list and the data of the new employee it adds it to the end of the list
int addEmployeeEnd(struct Node** _head, char _firstName[256], char _lastName[256], int _age, int _sinNum, char _status){
    struct Node *newNode;
    newNode = (struct Node*)malloc (sizeof(struct Node));

    //initialize employee
    struct Employee *employee = (struct Employee*)malloc(sizeof(struct Employee));

    strcpy(employee->firstName, _firstName);
    strcpy(employee->lastName, _lastName);
    employee->age = _age;
    employee->sinNumber = _sinNum;
    employee->status = _status;

    //link the node with the new employee struct
    newNode->employee = employee;

    //if the list is empty make it the first element
    if (*_head == NULL){
        *_head = newNode;
        return 1;
    }

    //navigate to the end of the list
    struct Node* current;
    for(current = *_head;current->next!=NULL;current=current->next);

    //add newNode to the end of the list
    current->next = newNode;
    newNode->next = NULL;

    return 1;
}

//given a list and the data of the new employee it adds it to the front of the list
int addEmployeeFront(struct Node** _head, char _firstName[256], char _lastName[256], int _age, int _sinNum, char _status){
    struct Node *newNode;
    newNode = (struct Node*)malloc (sizeof(struct Node));

    //initialize employee
    struct Employee *employee = (struct Employee*)malloc(sizeof(struct Employee));

    strcpy(employee->firstName, _firstName);
    strcpy(employee->lastName, _lastName);
    employee->age = _age;
    employee->sinNumber = _sinNum;
    employee->status = _status;

    //link the node with the new employee struct
    newNode->employee = employee;

    //if the list is empty make it the first element
    if (*_head == NULL){
        *_head = newNode;
        return 1;
    }

    //add it to the front of the list
    newNode->next = *_head;
    *_head = newNode;

    return 1;
}

/*
int getnode(){


}*/

//removes an (single?) employee of the given lastName or SIN number
void removeEmployee(struct Node** _head, char _firstName [256], int _sinNum){
    struct Node* current = *_head;
    struct Node* temp;
    while(current!=NULL){
        if (strcmp(current->next->employee->firstName, _firstName) == 0 || current->next->employee->sinNumber == _sinNum){
            temp = current->next;
            current->next = current->next->next;
            free(temp);
        }
        else{
            current = current ->next;
        }
    }
}

//duplicates each nodes so that there is _times amount of each node
int Reapeated(struct Node* _head, int _times){
    struct Node* current = _head;
    struct Node* result = (struct Node*) malloc (sizeof(struct Node));
    result = NULL;
    //int count = 0;
    while(current!=NULL){
        int i;
        for (i = 1;i<_times;i++){
            //adds the current->employee to the end of the list _times-1 times
            //since there is already one already in the list
            addEmployeeEnd(&result, current->employee->firstName, current->employee->lastName, current->employee->age, current->employee->sinNumber, current->employee->status);
        }
        current=current->next;
        //count++;
    }
    _head = result;
    return 1;
}

//deletes every elements except the one(s) with the given last name
void deleteExpt(struct Node** _head, char _lastName[256]){
    struct Node *newHead;
    newHead = (struct Node*) malloc (sizeof(struct Node));

    struct Node *current;
    current = (struct Node*) malloc (sizeof(struct Node));

    int count = 0;

    while((*_head)->next!=NULL){
        if (strcmp((*_head)->employee->lastName, _lastName)==0 && count ==0){
            newHead = *_head;
            newHead->next = current;
            count++;
        }
        else if (strcmp((*_head)->employee->lastName, _lastName)==0){
            //struct Node *temp;
            //temp = (struct Node*) malloc (sizeof(struct Node));
            current->next = *_head;
            current = current ->next;
        }
    }

    *_head = newHead;
}

//deletes the entire list by free each element and settign head to NULL
void deleteList(struct Node** _head){
    struct Node* current = *_head;
    struct Node* temp;
    while(current!=NULL){
        temp = current;
        current = current->next;
        //free(temp->employee);
        free(temp);
        //temp=NULL;
    }
    *_head = NULL;
}

//splits a single linked list into two linked lists with even elements with the extra going in the first section
void divideList (struct Node *source, struct Node** first, struct Node** second){
    struct Node* current;

    //length function?
    int length = 0;
    for (current = source;current!=NULL;current=current->next){
        length++;
    }

    if(length<2){
        *first = source;
        *second = NULL;
    }
    else{
        //changes length so the first list has the extra element if needed
        length = (length -1)/2;
        current = source;
        int i;
        for(i = 0;i<length;i++){
            current = current->next;
        }

        *first = source;
        *second = current->next;
        current->next = NULL;
    }
}

//displays all of the employess in the list
void displayList(struct Node *_head){
    struct Node* current;
    for(current = _head;current!=NULL;current=current->next)
        //printf("%s, %s\n%d\n%d\n%c\n", current->employee.lastName, current->employee.firstName, current->employee.age, current->employee.sinNumber, current->employee.status);
        printf("%s, %s\n%d\n%d\n%c\n", current->employee->lastName ? current->employee->lastName : "NULL", current->employee->firstName ? current->employee->firstName : "NULL", current->employee->age, current->employee->sinNumber, current->employee->status);
    printf("\n");
}

//displays all of the employees in the list that are older than _age
void displayList1(struct Node* _head, int _age){
    struct Node* current;
    for (current = _head;current !=NULL; current= current->next){
        if (current->employee->age > _age)
            //displayEmployee
            printf("%s, %s\n%d\n%d\n%c\n", current->employee->lastName, current->employee->firstName, current->employee->age, current->employee->sinNumber, current->employee->status);
    }
    printf("\n");
}

//displays all of the employees in the list that have the same status as _status
void displayList2(struct Node* _head, char _status){
    struct Node* current = _head;
    while(current !=NULL){
        if (current->employee->status == _status)
            //displayEmployee
            printf("First Name: %s\nLast Name: %s\nAge: %d\nSIN Number: %d\nStatus: %s\n", current->employee->lastName, current->employee->firstName, current->employee->age, current->employee->sinNumber, current->employee->status=='a'?"Active":(current->employee->status=='s'?"Suspended":"Retired"));
        current = current->next;
    }
    printf("\n");
}


int main (){
    struct Node *head;

    head = (struct Node*) malloc (sizeof(struct Node));
    head = NULL;
    //initilizeList(head);

    int age;
    int sinNum;
    char firstName [256];
    char lastName [256];
    char status;

    char temp;

    int i;
    for (i =1;;i++){
        printf("Enter the first name of Employee #%d. Enter 'q' to stop entering employees.\n", i);
        scanf("%s%c", firstName, &temp);

        if (strcmp(firstName,"q")==0)
            break;

        printf("Enter his/her last name.\n");
        scanf("%s%c", lastName, &temp);

        printf("Enter his/her age\n");
        scanf("%d%c", &age, &temp);

        printf("Enter his/her SIN number\n");
        scanf("%d%c", &sinNum, &temp);

        printf("Enter the status of the employee 'a' active, 's' suspended, 't' terminated.\n");
        scanf("%c%c", &status, &temp);

        addEmployeeFront(&head, firstName, lastName, age, sinNum, status);
        //displayList(head);
    }

    displayList(head);

    //displayList1(head, 50);
    //displayList2(head, 'a');

    return 0;
}