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



struct Node
{
	int data;
	Node * Next;
	Node * Prev;
};

Node * Start;
//Declaring Functions

void AddToFront();
void AddToBack();
void AddToMiddle();
void AddBeforeNode();

void DeleteFirstNode();
void DeleteLastNode();
void DeleteAfterNode();
void DeleteBeforeNode();

void PrintListForward();
void PrintListBack();

void saveSeqFile();
void loadSeqFile();
void saveRdmFile();
void loadRdmFile();

void createNewLinkList(int);
void main() {

	Start = 0;
	int Choice;
	int MaxChoices;


	// set up your Maximum Choice here
	MaxChoices = 15;
	// It creates a menu with 10 items
	Choice = 0;

	while (Choice < MaxChoices)
	{
		printf("\n\n");
		printf("--------------------------------- MAIN MENU ---------------------------------\n\n");
		printf("                  Please Enter one of the following Choices\n\n");
		printf("--------------------------- Linked List Processing --------------------------\n\n\n");
		printf("%s\n", "1: Add a Node to the Front of the List");
		printf("%s\n", "2: Add a node to the back of the list ");
		printf("%s\n", "3: Add a node to the middle of the list after a specific node");
		printf("%s\n", "4: Add a node to the middle of the list before a specific node");
		printf("%s\n", "5: Delete a node from the front of the list");
		printf("%s\n", "6: Delete a node from the back of the list");
		printf("%s\n", "7: Delete a node from the middle of the list after a specific node");
		printf("%s\n", "8: Delete a node from the middle of the list before a specific node");
		printf("%s\n", "9: Print a list forward");
		printf("%s\n", "10: Print a list backward");
		printf("%s\n", "11: Save in Sequential file");
		printf("%s\n", "12: Load from Sequential file");
		printf("%s\n", "13: Save in Ramdom file");
		printf("%s\n", "14: Load from Ramdom file");
		printf("%s\n", "15: Exit The Program");
		printf("-----------------------------------------------------------------------------");
		printf("\n\n");

		// Print Your choices here
		scanf("%d", &Choice);

		switch (Choice)
		{
		case 1:
			AddToFront();
			break;

		case 2:
			AddToBack();
			break;

		case 3:
			AddToMiddle();
			break;

		case 4:
			AddBeforeNode();
			break;

		case 5:
			DeleteFirstNode();
			PrintListForward();
			break;

		case 6:
			DeleteLastNode();
			break;

		case 7:
			DeleteAfterNode();
			break;

		case 8:
			DeleteBeforeNode();
			break;

		case 9:
			PrintListForward();
			break;

		case 10:
			PrintListBack();
			break;

		case 11:
			saveSeqFile();
			break;

		case 12:
			loadSeqFile();
			break;

		case 13:
			saveRdmFile();
			break;

		case 14:
			loadRdmFile();
			break;

		case 15:
			break;
		}
	}
	return;
}
// ***********************************************************
// ************************ FUNCTIONS ************************
// ***********************************************************


//CASE 1 -------------> Add note to the begining of the list
void AddToFront() {

	Node * NewNode;

	if (Start == 0)
	{
		//This list is empty. Create the first node

		NewNode = (Node *)malloc(sizeof(Node));
		printf("\n");
		printf("Enter data for the node: ");
		scanf("%d", &NewNode->data);
		NewNode->Next = 0;
		NewNode->Prev = 0;
		Start = NewNode;

		//Print list
		printf("\n");
		printf("Addition of First Node done!\n\n");
		PrintListForward();
	}
	else
	{
		//If the list is not Empty then create new node
		NewNode = (Node *)malloc(sizeof(Node));
		printf("\n");
		printf("Enter data for the node: ");
		scanf("%d", &NewNode->data);
		printf("\n");

		//NewNode 2nd layer (Next) points to the start of a Next Node
		NewNode->Next = Start;
		//NewNode 3rd layer (Prev) point to nothing
		NewNode->Prev = 0;
		//The previous Node 3rd layer (Prev) points to the Node that is been added
		Start->Prev = NewNode;
		//Start variable is now the Current Node, the one that's been added
		Start = NewNode;

		//Print list
		printf("New node added at the begining of the list!\n\n");
		PrintListForward();
	}
	return;
}
//CASE 2 -------------> Add Node to Last part of the list
void AddToBack() {

	Node * NewNode;

	if (Start == 0)
	{
		//This list is empty. Create the first node

		NewNode = (Node *)malloc(sizeof(Node));
		printf("\n");
		printf("Enter data for the node: ");
		scanf("%d", &NewNode->data);
		NewNode->Next = 0;
		NewNode->Prev = 0;
		Start = NewNode;

		//Print list
		printf("\n");
		printf("Addition of First Node done!\n\n");
		PrintListForward();
	}
	else
	{
		//when the list is not empty we have to check every node until we find the last one

		Node * Current;
		Current = Start;

		while (Current->Next != 0)
		{
			Current = Current->Next;
		}
		//After finding the last node of the list we can create a new node
		NewNode = (Node *)malloc(sizeof(Node));
		printf("\n");
		printf("Enter data for the node: ");
		scanf("%d", &NewNode->data);
		printf("\n");
		//NewNode 2nd layer (Next) points to nothing
		NewNode->Next = 0;
		//NewNode 3rd layer (Prev) point to the start of the Current Node
		NewNode->Prev = Current;
		//The actual Node 2nd layer (Next) points to the Node that is been added
		Current->Next = NewNode;
		//Print list
		printf("New node added at the end of the list!\n\n");
		PrintListForward();
	}
	return;
}
//CASE 3 -------------> Add to middle after
void AddToMiddle() {

	if (Start == 0)
	{
		printf("\n");
		printf("List is empty! Please add nodes to list");
		printf("\n");

		return;
	}

	int findData, findIt;
	Node * Current;
	Node * NextOfCurrent;

	findIt = 0;
	Current = Start;
	NextOfCurrent = Current->Next;


	printf("\n");
	printf("Please insert data of node you want to add: ");
	scanf("%d", &findData);
	printf("\n");

	while (Current != 0)
	{
		if (Current->data == findData)
		{
			findIt = 1;
			break;
		}

		Current = Current->Next;
		if (Current == 0) // If Current is 0 (is the end of the list) the finish the while
		{
			break;
		}
		NextOfCurrent = Current->Next;

	}if (findIt == 0)
	{
		printf("We can't find the node!");
		return;
	}
	//If data is found we can add a new node next to it
	Node * NewNode;
	NewNode = (Node*)malloc(sizeof(Node));
	printf("\n");
	printf("Enter data for the new node: ");
	scanf("%d", &NewNode->data);
	printf("\n");

	if (NextOfCurrent == 0)
	{
		Current->Next = NewNode;
		NewNode->Prev = Current;
		NewNode->Next = 0;
		printf("The node is succesfully added after ");
		printf("%d\n", findData);
		PrintListForward();
		return;
	}

	Current->Next = NewNode;
	NewNode->Prev = Current;
	NextOfCurrent->Prev = NewNode;
	NewNode->Next = NextOfCurrent;
	printf("The new node was added after: ");
	printf("%d", findData);
	printf("\n");

	PrintListForward();
}
//CASE 4 ------------->
void AddBeforeNode() {

	if (Start == 0)
	{
		printf("\n");
		printf("List is empty! Please add nodes to list");
		printf("\n");

		return;
	}

	int findData, findIt;
	Node * Current;
	Node * PrevOfCurrent;

	findIt = 0;
	Current = Start;
	PrevOfCurrent = Current->Prev;

	printf("\n");
	printf("Please insert data of node you want to add: ");
	scanf("%d", &findData);
	printf("\n");

	while (Current != 0)
	{
		if (Current->data == findData)
		{
			findIt = 1;
			break;
		}

		Current = Current->Next;
		if (Current == 0) // If Current is 0 (is the end of the list) the finish the while
		{
			break;
		}
		PrevOfCurrent = Current->Prev;

	}if (findIt == 0)
	{
		printf("We can't find the node!");
		return;
	}
	//If data is found we can add a new node next to it
	Node * NewNode;
	NewNode = (Node*)malloc(sizeof(Node));
	printf("\n");
	printf("Enter data for the new node: ");
	scanf("%d", &NewNode->data);
	printf("\n");


	if (PrevOfCurrent != 0)
	{
		Current->Prev = NewNode;
		NewNode->Next = Current;
		PrevOfCurrent->Next = NewNode;
		printf("\n");
		printf("The node is succesfully added after ");
		printf("%d\n", findData);
		printf("The new node was added before: ");
		printf("%d", findData);
		printf("\n");
		PrintListForward();
		return;
	}
	if (PrevOfCurrent == 0)
	{
		printf("The node can't be add before the first node, use option 1 in menu\n\n");
		PrintListForward();
	}
}
//CASE 5 -------------> Delete first Node of the list
void DeleteFirstNode() {

	if (Start == 0)
	{
		printf("\n");
		printf("List is empty! Please add nodes to list");
		printf("\n");

		return;
	}

	Node * Current;
	Node * NextOfCurrent;

	Current = Start;
	NextOfCurrent = Current->Next;

	//When there's only one we empty the list again
	if (NextOfCurrent == 0)
	{
		Start = 0;
	}
	//If there are more nodes in the list
	else
	{
		NextOfCurrent->Prev = 0;
		Start = NextOfCurrent;
	}
	free(Current);
}
//CASE 6 -------------> Delete last Node of the list
void DeleteLastNode() {

	if (Start == 0)
	{
		printf("\n");
		printf("List is empty! Please add nodes to list");
		printf("\n");

		return;
	}

	Node * NextOfCurrent;
	Node * Current;

	Current = Start;
	NextOfCurrent = Current->Next;

	if (NextOfCurrent == 0 && Current->Prev == 0)
	{
		Start = 0;
		free(Current);
		//Print list
		printf("\n");
		printf("The list is now empty, you delete the only node!\n\n");
		PrintListForward();

		return;
	}
	//when the list is not empty we have to check every node until we find the last one

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

	//After finding the last node of the list we can delete node

	//Current is now the last one and we can delete Next of current
	Current->Next = 0;
	free(NextOfCurrent);

	//Print list
	printf("\n");
	printf("Last Node is been delete!\n\n");
	PrintListForward();

	return;
}
//CASE 7 -------------> Delete After Node
void DeleteAfterNode() {
	//Case 1 Empty list, return to menu
	if (Start == 0)
	{
		printf("\n");
		printf("List is empty! Please add nodes to list");
		printf("\n");

		return;
	}

	int findData, findIt;
	Node * Current;
	Node * NextOfCurrent;

	findIt = 0;
	Current = Start;

	NextOfCurrent = Current->Next;

	printf("\n");
	printf("Please insert data of node you want to delete after: ");
	scanf("%d", &findData);
	printf("\n");

	//Find the node enter by user
	while (Current != 0)
	{
		if (Current->data == findData)
		{
			//You found the node
			findIt = 1;
			break;
		}
		Current = Current->Next;
		if (Current == 0) // If Current is 0 (is the end of the list) the finish the while
		{
			break;
		}
		NextOfCurrent = Current->Next;
	}
	if (findIt == 0) //Case 5 Node enter by user can't be found
	{
		printf("We can't find the node!");
		return;
	}

	//when the user wants to delete the node after the last.
	if (Current->Next == 0)
	{
		printf("You can't delete this one, because there is no node next to delete");
		return;
	}
	//when you want to delete the last node
	if (NextOfCurrent->Next == 0)
	{
		printf("You just delete the last node!\n");
		Current->Next = 0;
		free(NextOfCurrent);
		PrintListForward();
		return;
	}


	Current->Next = NextOfCurrent->Next;
	NextOfCurrent->Prev = Current;
	free(NextOfCurrent);
	printf("The node after %d was delete.", findData);
	printf("\n");

	PrintListForward();

	return;
}
//CASE 8 -------------> Delete Before Node
void DeleteBeforeNode() {

	//Case 1 Empty list, return to menu
	if (Start == 0)
	{
		printf("\n");
		printf("List is empty! Please add nodes to list");
		printf("\n");

		return;
	}

	int findData, findIt;
	Node * Current;
	Node * PrevOfCurrent;

	findIt = 0;
	Current = Start;

	PrevOfCurrent = Current->Prev;

	printf("\n");
	printf("Please insert data of node you want to delete before: ");
	scanf("%d", &findData);
	printf("\n");

	//Find the node enter by user
	while (Current != 0)
	{
		if (Current->data == findData)
		{
			//You found the node
			findIt = 1;
			break;
		}
		Current = Current->Next;
		if (Current == 0) // If Current is 0 (is the end of the list) the finish the while
		{
			break;
		}
		PrevOfCurrent = Current->Prev;
	}
	if (findIt == 0) //Case 5 Node enter by user can't be found
	{
		printf("We can't find the node!");
		return;
	}
	//when the user wants to delete the node before the first.
	if (Current->Prev == 0)
	{
		printf("You can't delete this one, because there is no node before to delete");
		PrintListForward();
		return;
	}
	//when you want to delete the first node
	if (PrevOfCurrent->Prev == 0)
	{
		printf("The node can't be delete!, use option 5 in menu to delete first node\n\n");
		PrintListForward();
		return;
	}

	Current->Prev = PrevOfCurrent->Prev;
	PrevOfCurrent->Prev->Next = Current;

	printf("\n");
	printf("The node before %d was delete.", findData);
	printf("\n");
	PrintListForward();

	return;
}
//CASE 9 ------------->Print List Forward
void PrintListForward() {

	if (Start == 0)
	{
		printf("\n");
		printf("List is empty! Please add nodes to list");
		printf("\n");

		return;
	}

	Node * Current;

	// The Current Node (NewNode) created is using the variable Start
	Current = Start;

	printf("\n");
	printf("This is the list:");
	printf("\n\n");

	while (Current != 0)
	{
		printf("%d", Current->data);
		printf("->");
		Current = Current->Next;
	}
	printf("NULL\n");

	return;
}
//CASE 10 -------------> Print List Backward
void PrintListBack() {
	if (Start == 0)
	{
		printf("\n");
		printf("List is empty! Please add nodes to list");
		printf("\n");

		return;
	}

	Node * Current;

	// The Current Node (NewNode) created is using the variable Start
	Current = Start;

	printf("\n");
	printf("This is the list backwards:");
	printf("\n\n");

	while (Current->Next != 0)
	{
		Current = Current->Next;
	}
	while (Current != 0)
	{
		printf("%d", Current->data);
		printf("->");
		Current = Current->Prev;
	}
	printf("NULL\n");
}
//CASE 11 -------------> Save Sequential file
void saveSeqFile()
{
	Node * Current;
	Current = Start;

	FILE * CfPtr;

	if (Current == NULL)
	{
		printf("it is a empty list");
		return;
	}
	if ((CfPtr = fopen("SequenceFile.dat", "w")) == NULL)
	{
		printf("there is no file\n");
	}
	else
	{
		CfPtr = fopen("SequenceFile.dat", "w");

		while (Current != 0)
		{
			fprintf(CfPtr, "%d", Current->data);
			if (Current->Next != 0) //
			{
				fprintf(CfPtr, "%s", "\n");
			}
			Current = Current->Next;
		}
	}

	printf("saved succesfully!\n");
	fclose(CfPtr);

}
//CASE 12 -------------> Load Sequential file
void loadSeqFile()
{
	Node * current;
	current = Start;
	FILE * CfPtr;
	int tempInteger;

	while (current != NULL)
	{
		current = current->Next;
		DeleteFirstNode();
	}
	//the list is empty

	if ((CfPtr = fopen("SequenceFile.dat", "r")) == NULL)
	{
		printf("there is no file\n");
	}
	else
	{
		while (!feof(CfPtr)) //Not the end of file
		{
			fscanf(CfPtr, "%d", &tempInteger);
			createNewLinkList(tempInteger);
		}
	}
	fclose(CfPtr);
	PrintListForward();
}
//FUNCTION NOT IN MENU -------------> Using a argument to create a linked list
void createNewLinkList(int aIntegerValue)
{
	Node * NewNode;
	if (Start == 0)
	{
		//This list is empty. Create the first node
		NewNode = (Node *)malloc(sizeof(Node));
		NewNode->data = aIntegerValue;
		NewNode->Next = 0;
		NewNode->Prev = 0;
		Start = NewNode;
	}
	else
	{
		//when the list is not empty we have to check every node until we find the last one
		Node * Current;
		Current = Start;
		while (Current->Next != 0)
		{
			Current = Current->Next;
		}

		NewNode = (Node *)malloc(sizeof(Node));
		NewNode->data = aIntegerValue;
		NewNode->Next = 0;
		NewNode->Prev = Current;
		Current->Next = NewNode;
	}
	return;
}
//CASE 13 -------------> Save Ramdom File
void saveRdmFile(){

	BlankRdmFile();

	//add list is empty



	Node * Current;
	Current = Start;

	FILE *cfPtr;

	//r+ read and write, read and more.
	if ((cfPtr = fopen("credit.dat", "r+")) == NULL)
		printf("File could not be opened.\n");
	else {

		while (Current->data != 0) {
			printf("Enter number: \n");
			scanf("%d", Current->data);

			//fseek will go to the file and skip some records before getting to the destination
			//SEEK_SET is to start from the begining of the file
			//&client.acctNum - 1 is the number of elements to skip, if the user wants to go to the begining of element 10, the program needs to skip 9 elements.
			fseek(cfPtr, (Current->data - 1) *
				sizeof(int), SEEK_SET);

			//write the info one time in the document.
			fwrite(&Current->data, sizeof(struct Node), 1, cfPtr);
			printf("Enter account number\n? ");
			scanf("%d", &Current->data);
		}
	}

	fclose(cfPtr);
}



//Create blank Ramdom file
void BlankRdmFile(){
	int i;

	//Use interger not struct because in this case it only has one data as int
	struct Node NodeData = { 0 };

	FILE * cfPtr;

	if ((cfPtr = fopen("NodeList.dat", "w")) == NULL)
		printf("File could not be opened.\n");
	else {
		//Write one blank client the same size of the struct, 1 time inside Document.
		//This loop will go for 100 times, it would create a file with 100 blank clients.
		for (i = 1; i <= 100; i++)
			fwrite(&NodeData,
			sizeof(struct Node), 1, cfPtr);

		fclose(cfPtr);
	}

	return;
}