/*
*Progamer's Name: Dillon Bong Zi Hang
*Program Description: Library Management System Login Menu
*Last Updated: 7 - February - 2016
*/

// Header File
#include"LMS_Header.h"
#include"Functions.h"


/* Library Management System Login Menu  */
int main()
{
	// Get username and password and ignore whitespace
	printf("***********************************************\n");
	printf("*           Library Management System         *\n");
	printf("***********************************************\n\n");
	printf("Username: ");
	scanf("%s", &u);
	fflush(stdin);
	printf("\nPassword: ");
	scanf("%s", &p);
	fflush(stdin);
	// Entered username and password is equal to Admin
	if ((strcmp(username, u)) == 0 && (strcmp(password, p)) == 0)
	{
		// Login success from login menu. Go to Main Menu
		{
			printf("\nLogin Successful\n\n");
			system("pause");
			system("cls");
			Main_Menu();
		}
	}
	else
	{
		// Login failed from login menu. Re-enter username and password
		printf("\nLogin Failed\n\n");
		system("pause");
		system("cls");
		main();
	}
	system("pause>nul");
	return 0;
	getch();
}

/* Library Management System Main Menu */
int Main_Menu()
{
	printf("***********************************************\n");
	printf("*           Main Menu                         *\n");
	printf("***********************************************\n\n");
	printf("1. Add New Book\n");
	printf("2. Modify Book Details\n");
	printf("3. Remove Book\n");
	printf("4. View Book List\n");
	printf("5. Book Check In\n");
	printf("6. Book Check Out\n");
	printf("7. Search Menu\n");
	printf("8. View Logs\n");
	printf("9. Exit\n\n");
	printf("Please select an option: ");
	{
		// Gets user's option
		gets(main_menu_option);
		// if user confirmation's string length is equal to 1
		if (strlen(main_menu_option) == 1)
		{
			switch (main_menu_option[0])
			{
				// Goto Add New Book Menu
			case '1':
				fflush(stdin);
				system("cls");
				Books = Add_New_Book(file_pointer);
				break;
				// Goto Modify Book Details
			case '2':
				fflush(stdin);
				system("cls");
				Modify_Book_Details_1();
				break;
			case '3':
				fflush(stdin);
				system("cls");
				Remove_Book(file_pointer, Books);
				break;
			case '4':
				printf("");
				break;
			case '5':
				printf("");
				break;
			case '6':
				printf("");
				break;
			case '7':
				printf("");
				break;
			case '8':
				printf("");
				break;
			case '9':
				// Terminating the Program
				printf("\nProgram will now terminate. Press any key to continue");
				system("pause>nul");
				exit(0);
				break;
			default:
				// Invalid Input from the user
				printf("\nInvalid input please re-enter an option");
				system("pause>nul");
				system("cls");
				Main_Menu();
				break;
			}
		}
		else
		{
			printf("\nInvalid input please re-enter an option");
			system("pause>nul");
			system("cls");
			Main_Menu();
			fflush(stdin);
		}

	}
	system("pause>nul");
	return 0;
	getch();
}


/* Add New Book Menu */
int Add_New_Book(FILE *file_pointer)
{
	// Open Books Data Text File in append or create binary mode
	file_pointer = fopen(filename, "ab+");
	// If file is unable to open, then display error
	if (file_pointer == NULL)
	{
		printf("File cannot be opened.");
		system("pause>nul");
		system("cls");
		Main_Menu();
	}
	else
	{
		printf("***********************************************\n");
		printf("*               Add New Book                  *\n");
		printf("***********************************************\n\n");

		memset(&t, 0, sizeof(t));
		// Accept Book ID as input
		printf("1. Book ID: ");
		scanf("%99[^\n]s", &t.Book_ID);
		fflush(stdin);

		// Accept Book Title as input
		printf("\n2. Book Title: ");
		scanf("%199[^\n]s", &t.Book_Title);
		fflush(stdin);

		// Accept Book Edition as input
		printf("\n3. Book Edition: ");
		scanf("%49[^\n]s", &t.Book_Edition);
		fflush(stdin);

		// Accept Year of Publication as input
		printf("\n4. Year of Publication: ");
		scanf("%49[^\n]s", &t.Year_of_Publication);
		fflush(stdin);

		// Accept Shelf Location as input
		printf("\n5. Shelf Location: ");
		scanf("%49[^\n]s", &t.Shelf_Location);
		fflush(stdin);

		// Accept Price as input
		printf("\n5. Price(RM): ");
		scanf("%19[^\n]s", &t.Price);
		fflush(stdin);

		printf("\nConfirm (y/n)? Type -1 to return to Main Menu: ");
		// Indefinite While Loop to Confirm Data
		while (1)
		{
			gets(add_new_book_confirm);
			fflush(stdin);
			// Compare user input to escape
			if (stricmp(add_new_book_confirm, "-1") != 0)
			{
				// if user confirmation's string length is equal to 1
				if (strlen(add_new_book_confirm) == 1)
				{
					switch (add_new_book_confirm[0])
					{
						// Save all data into file
					case 'y':
					{
						Add_Record_function(file_pointer);
						fclose(file_pointer);
						fflush(stdin);
						printf("\nRecord Successfully Added. Add new book (y/n): ");
						// Indefinite While Loop to get add new book input
						while (1)
						{
							gets(add_more_book_confirm);
							fflush(stdin);
							if (strlen(add_more_book_confirm) == 1)
							{
								switch (add_more_book_confirm[0])
								{
								case 'y':
									system("cls");
									Add_New_Book(file_pointer);
									break;
								case 'n':
									system("cls");
									Main_Menu();
									break;
								default:
									fflush(stdin);
									printf("\nInvalid input. Please Re-Enter Confirmation to Add New Book: ");
								}
							}
							else
							{
								fflush(stdin);
								printf("\nInvalid input. Please Re-Enter Confirmation to Add New Book: ");
							}
						}
						break;
					}
					// Return to Add New Book Menu
					case 'n':
					{
						fflush(stdin);
						fclose(file_pointer);
						system("cls");
						Add_New_Book(file_pointer);
						break;
					}
					// Invalid Input. Re-enter user confirmation
					default:
					{
						fflush(stdin);
						printf("\nInvalid input. Please Re-Enter Confirmation: ");
						break;
					}
					}
				}
				else
				{
					// Invalid Input. Re-enter user confirmation
					printf("\nInvalid input. Please Re-Enter Confirmation: ");
				}

			}
			// User input equals to esc then return to main menu
			else if (stricmp(add_new_book_confirm, "-1") == 0)
			{
				fclose(file_pointer);
				printf("\nThe program will now return to Main Menu");
				system("pause>nul");
				system("cls");
				Main_Menu();
			}
		}
	}
	system("pause>nul");
	return 0;
	getch();
}

/* Modify Book Details 1 Menu */
int Modify_Book_Details_1()
{
	// Open Books Data Text File in read mode
	file_pointer = fopen(filename, "r");
	// If file is unable to open, then display error
	if (file_pointer == NULL)
	{
		printf("The file cannot be opened.");
		system("pause>nul");
		system("cls");
		Main_Menu();
	}
	else{
		printf("***********************************************\n");
		printf("*              Modify Book Details            *\n");
		printf("***********************************************\n\n");
		printf("No.  Book ID    Book Title\n");
		// while loop to display file data until end of file
		num2 = 1;
		// Displaying Book ID and Book Title
		while (fread(&t, sizeof(struct Books_Data), 1, file_pointer))
		{
			// Aligning Text
			printf(" %d.  %-10s %s\n", num2, t.Book_ID, t.Book_Title);
			num2++;
		}
		printf("\nType -1 to return to Main Menu.\nEnter the Book Number to update the book details: ");
		// while loop to get user option
		while (1)
		{
			//gets user option
			scanf("%d", &Books);
			Books -= 1;
			fflush(stdin);
			if (Books == -2) // Return to Main Menu
			{
				printf("\nThe program will now return to Main Menu");
				system("pause>nul");
				system("cls");
				Main_Menu();
			}
			else if (Books < -1) // Invalid Input
			{
				printf("\nInvalid Option. Please Re-Enter: ");
			}
			else if (Books >= 0)
			{
				// Check for Valid Book Number
				if (!View_Book_List_function(file_pointer, Books))
				{
					printf("\nError. Book Number Not Found.\n");
					fclose(file_pointer);
					system("pause>nul");
					system("cls");
					Modify_Book_Details_1();
				}
				else
				{
					system("cls");
					fclose(file_pointer);
					Modify_Book_Details_2(file_pointer, Books);
				}
			}
			else
			{
				printf("\nInvalid Input. Please Re-Enter: ");
			}
		}
	}
	system("pause>nul");
	return 0;
	getch();
}

/* Modify Book Details 2 Menu */
int Modify_Book_Details_2(FILE *file_pointer, int BooksNum)
{
	// Open file in read and binary mode
	file_pointer = fopen(filename, "rb+");
	// If file is unable to open, then display error
	if (file_pointer == NULL)
	{
		printf("The file cannot be opened.");
		system("pause>nul");
		system("cls");
		Main_Menu();
	}
	else{
		// Display Book Details
		printf("***********************************************\n");
		printf("*              Modify Book Details            *\n");
		printf("***********************************************\n\n");
		printf("Book Number           : %d\n\n", BooksNum + 1);
		printf("1. Book ID            : %s\n", t.Book_ID);
		printf("2. Book Title         : %s\n", t.Book_Title);
		printf("3. Book Edition       : %s\n", t.Book_Edition);
		printf("4. Year of Publication: %s\n", t.Year_of_Publication);
		printf("5. Shelf Location     : %s\n", t.Shelf_Location);
		printf("6. Price(RM)          : %s\n", t.Price);
		printf("7. Save Book Details.\n\n");
		printf("8. Please select an option. Type -1 to return to previous menu: ");
		// indefinite while loop to get user option
		while (1)
		{
			scanf("%d", &option);
			fflush(stdin);
			switch (option)
			{
				// Modify Book ID
			case 1:
			{
				system("cls");
				printf("1. Current Book ID: %s\n\n", t.Book_ID);
				printf("2. New Book ID: ");
				scanf("%99[^\n]s", t.Book_ID);
				fflush(stdin);
				system("cls");
				Modify_Book_Details_2(file_pointer, BooksNum);
				break;
			}
			// Modify Book Title
			case 2:
			{
				system("cls");
				printf("1. Current Book Title: %s\n\n", t.Book_Title);
				printf("2. New Book Title: ");
				scanf("%199[^\n]s", t.Book_Title);
				fflush(stdin);
				system("cls");
				Modify_Book_Details_2(file_pointer, BooksNum);
				break;
			}
			// Modify Book Edition
			case 3:
			{
				system("cls");
				printf("1. Current Book Edition: %s\n\n", t.Book_Edition);
				printf("2. New Book Edition: ");
				scanf("%49[^\n]s", t.Book_Edition);
				fflush(stdin);
				system("cls");
				Modify_Book_Details_2(file_pointer, BooksNum);
				break;
			}
			// Modify Year of Publication
			case 4:
			{
				system("cls");
				printf("1. Current Year of Publication: %s\n\n", t.Year_of_Publication);
				printf("2. New Year of Publication: ");
				scanf("%49[^\n]s", t.Year_of_Publication);
				fflush(stdin);
				system("cls");
				Modify_Book_Details_2(file_pointer, BooksNum);
				break;
			}
			// Modify Shelf Location
			case 5:
			{
				system("cls");
				printf("1. Current Shelf Locatin: %s\n\n", t.Shelf_Location);
				printf("2. New Shelf Location: ");
				scanf("%49[^\n]s", t.Shelf_Location);
				fflush(stdin);
				system("cls");
				Modify_Book_Details_2(file_pointer, BooksNum);
				break;
			}
			// Modify Price
			case 6:
			{
				system("cls");
				printf("1. Current Price(RM): %s\n\n", t.Price);
				printf("2. New Price(RM): ");
				scanf("%49[^\n]s", t.Price);
				fflush(stdin);
				system("cls");
				Modify_Book_Details_2(file_pointer, BooksNum);
				break;
			}
			// Save all details into file
			case 7:
			{
				if (Add_New_Book_function(file_pointer, BooksNum))
				{
					printf("\nBook Details Updated.\n");
				}
				fclose(file_pointer);
				system("pause>nul");
				system("cls");
				Modify_Book_Details_1();
				break;
			}
			// Return to Previous Menu
			case -1:
			{
				printf("\nThe program will now return to Main Menu");
				system("pause>nul");
				system("cls");
				Modify_Book_Details_1();
				break;
			}
			// User option is invalid
			default:
			{
				printf("\nInvalid Input. Please Re-Enter: ");
				break;
			}
			}
		}
	}
	system("pause>nul");
	return 0;
	getch();
}

int Remove_Book(FILE *file_pointer, int BooksNum)
{
	// Open Books Data Text File in read and binary mode
	file_pointer = fopen(filename, "rb");
	// If file canont be opened then display error
	if (!file_pointer) {
		printf("The file cannot be opened.");
		system("pause>nul");
		system("cls");
		Main_Menu();
	}
	// Open Temp Books Data in write and binary mode
	file_pointer_temp = fopen("temp.dat", "a");

	// If file cannot be opened then display error
	if (!file_pointer_temp) {
		printf("The temp file cannot be opened.");
		system("pause>nul");
		system("cls");
		Main_Menu();
	}
	else
	{
		printf("***********************************************\n");
		printf("*                Remove Book                  *\n");
		printf("***********************************************\n\n");
		printf("No.  Book ID    Book Title\n");
		num2 = 1;
		// Displaying Book ID and Book Title
		while (fread(&t, sizeof(struct Books_Data), 1, file_pointer))
		{
			// Aligning Text
			printf(" %d.  %-10s %s\n", num2, t.Book_ID, t.Book_Title);
			num2++;
		}
		printf("\nType -1 to return to Main Menu.\nEnter the booknumber to be removed: ");
		// while loop to get user option
		while (1)
		{
			//gets user option
			scanf("%d", &Books);
			Books -= 1;
			fflush(stdin);
			if (Books == -2) // Return to Main Menu
			{
				printf("\nThe program will now return to Main Menu");
				system("pause>nul");
				system("cls");
				Main_Menu();
			}
			else if (Books < -1) // Invalid Input
			{
				printf("\nInvalid Option. Please Re-Enter: ");
			}
			else if (Books >= 0)
			{
				// Check for Valid Book Number
				if (!View_Book_List_function(file_pointer, Books))
				{
					printf("\nError. Book Number Not Found.\n");
					fclose(file_pointer);
					fclose(file_pointer_temp);
					system("pause>nul");
					system("cls");
					Remove_Book(file_pointer, BooksNum);
				}
				else
				{
					// Search the file for book number
					while (fread(&t, sizeof(struct Books_Data), 1, file_pointer) != NULL) {
						if (BooksNum == Books) {
							printf("\nThe Book Number was found and deleted.\n\n");
							found = 1;
						}
						// Write the unmatched book number into the temporary file
						else {
							fwrite(&t, sizeof(struct Books_Data), 1, file_pointer_temp);
						}
					}
					// No Book Number found
					if (!found) {
						printf("\nNo Book Number found");
						system("pause>nul");
						system("cls");
						Remove_Book(file_pointer, BooksNum);
					}
					else
					{
						// Close the file pointers
						fclose(file_pointer);
						fclose(file_pointer_temp);
						// Remove the current file and rename the temporary file
						remove("Books Data.dat");
						rename("temp.dat", "Books Data.dat");
						system("pause>nul");
						system("cls");
						Main_Menu();
					}
				}
			}
			else
			{
				printf("\nInvalid Input. Please Re-Enter: ");
			}
		}
	}
	system("pause>nul");
	return 0;
	getch();
}