#include "header.h"

int menu()
{
	int value = 0;
	char c = '\0';
	int running = 0;
	char temp[16];
	NodePtr list = NULL;

	while (running == 0)
	{
		c = '\0';

		printf("\n/**** Welcome ****\\\n");
		printf("| 1. Insert\t  |\n");
		printf("| 2. Delete\t  |\n");
		printf("| 3. Print\t  |\n");
		printf("| 4. Exit\t  |\n");
		printf("|*****************|\n");
		printf("Enter a Command Val: ");
		c = getchar();
		getchar();
		switch (c)
		{
		case('1') :		//insert

			printf("Please enter an integer value: ");
			gets(temp);
			value = atoi(temp);

			insert(&list, value);
			printf("\n");
			break;
		case('2') :		//delete

			printf("Please enter an integer value: ");
			gets(temp);
			value = atoi(temp);
			printf("\n");
			delete(&list, value);
			break;
		case('3') :		//print
			print(list);
			break;
		case('4') :		//exit
			printf("4\n");
			running = 1;
			break;
		}
	}
	return 0;
}

int insert(NodePtr *list, int value)
{
	//Nodes used to insert into list
	NodePtr newNode;
	NodePtr prevNode;
	NodePtr currNode;

	//allocate memory for node
	newNode = malloc(sizeof(Node));

	//no space available
	if (newNode == NULL)
	{
		printf("Error node creation failed!\n");
		return -1;
	}

	//assign variables to temp node
	newNode->value = value;

	prevNode = NULL;
	currNode = *list;

	//loop to current location
	while ((currNode != NULL) && (value > currNode->value))
	{
		prevNode = currNode;
		currNode = currNode->next;
	}

	//front of list
	if (prevNode == NULL)
	{
		newNode->next = *list;
		*list = newNode;
	}
	//middle or end of list
	else
	{
		//insert new node between prevNode and currNode
		prevNode->next = newNode;
		newNode->next = currNode;
	}
	return 0;
}

//delete node of the value 
int delete(NodePtr *list, int value)
{
	//Nodes used to insert into list
	NodePtr temp;
	NodePtr prevNode;
	NodePtr currNode;

	if (*list == NULL)
	{
		printf("List is empty.\n");
		return -1;

	}

	if (value == (*list)->value)
	{
		temp = *list;

		*list = (*list)->next;

		free(temp);

		return value;
	}
	else
	{
		prevNode = *list;
		currNode = (*list)->next;

		while ((currNode != NULL) && (currNode->value != value))
		{
			prevNode = currNode;
			currNode = currNode->next;
		}

		if (currNode != NULL)
		{
			temp = currNode;
			prevNode->next = currNode->next;

			free(temp);
			return value;
		}
	}
}

//This will print the contents of the list
int print(NodePtr list)
{
	if (list == NULL)
	{
		printf("\nList is empty.\n\n");
		return 0;
	}
	else
	{
		printf("\nContents of the list:\n");
		while (list != NULL)
		{
			printf(" Node %d -->", list->value);
			list = list->next;

		}

		printf(" NULL\n");
	}

}