#include <stdio.h>
#include <math.h>
#include <iostream>
#include <iomanip>
#include <stdlib.h>

struct Node
{
	struct data
	{
		int ID;
		float ms;
	}number;

	Node * Next;
	Node * Previous;
};


Node * Start;

void AddToFront();
void DeleteBeginning();
void PrintListForward();
void PrintListBackward();

void main()
{
	Start = 0;
	int Choice;
	Choice = 0;

	printf("************** MAIN MENU ****************\n");
	printf("Please Enter one of the following Choices\n");
	printf("************** MAIN MENU ****************\n\n");

	do
	{
		printf("======================================================\n");
		printf("1.	Add a node to the front of the list.\n");
		printf("2.	Delete a node from the beginning of the list.\n");
		printf("3.	Print a list Forward.\n");
		printf("4.	Print a list Backward.\n");
		printf("======================================================\n");
		printf("5: Exit the program.\n");

		scanf_s("%d", &Choice);

		switch (Choice)
		{
		case 1:
			AddToFront();
			break;
		case 2:
			DeleteBeginning();
			break;
		case 3:
			PrintListForward();
			break;
		case 4:
			PrintListBackward();
			break;
		default:
			break;
		}

	} while (Choice != 5); //when the choice is == 5, the program returns
}

void AddToFront()
{
	Node * NewNode;
	NewNode = (Node *)malloc(sizeof(Node));
	printf("\n");
	printf("Enter ID: ");
	scanf("%d", &NewNode->number.ID);
	printf("Enter milliseconds: ");
	scanf("%f", &NewNode->number.ms);

	if (Start == 0)
	{
		NewNode->Previous = 0;
		NewNode->Next = 0;
		Start = NewNode;
	}
	else
	{
		Node *temp = Start;

		while (temp->Next != 0)
		{
			temp = temp->Next;
		}

		NewNode->Previous = temp;
		temp->Next = NewNode;
		NewNode->Next = 0;
	}
}

void PrintListBackward()
{
	if (Start == 0)
	{
		printf("Nothing to print, insert some elements first.\n\n");
		return;
	}
	Node *temp = Start;
	//Go to the first element
	while (temp->Next != 0)
	{
		temp = temp->Next;
	}

	//Print from first to last
	while (temp != 0)
	{
		/*printf("%d", temp->data);
		printf("->");
		temp = temp->Next;*/

		printf("%d", temp->number.ID);
		printf(" -> ");
		printf("ms: %0.1f", temp->number.ms);
		printf(" -> ");
		temp = temp->Previous;
	}
	printf("NULL\n");
}

void PrintListForward()
{

	if (Start == 0)
	{
		printf("Nothing to print, insert some elements first.\n\n");
		return;
	}
	Node *temp = Start;
	//Go till the last element
	while (temp->Previous != 0)
	{
		temp = temp->Previous;
	}

	//Print from last to first
	while (temp != 0)
	{
		printf("%d", temp->number.ID);
		printf("->");
		printf("ms: %0.1f", temp->number.ms);
		printf(" -> ");
		temp = temp->Next;
	}
	printf("NULL\n");
}

void DeleteBeginning()
{
	if (Start == 0)
	{
		printf("Nothing to delete, insert some elements first.\n\n");
	}
	else if (Start->Next == 0 && Start->Previous == 0) { //There is only one element and it should be removed.
		Start = 0; //this removes the only element
	}
	else
	{
		Node *temp = Start;
		//Go to the LAST element of the list
		while (temp->Next != 0)
		{
			temp = temp->Next;
		}

		//Loop till first element that has a Previous element
		while (temp->Previous != 0)
		{
			//Verify if the element after the current one is the first
			//We want the one before the first to remove its Previous
			if (temp->Previous->Previous == 0) {
				break;
			}
			temp = temp->Previous;
		}
		Node *PreviousOfTemp = temp->Previous;
		Node * NewStart = temp;

		temp->Previous = 0;
		free(PreviousOfTemp);
		Start = NewStart;

		PrintListForward();
	}
}