/// <summary>
/// Deletes given book from database.
/// </summary>
/// <param name="book">Book to be deleted</param>
public void DeleteBook(Book book)
{
var db = new LibraryDBEntities();
var query = db.Book.Where(p => p.BookId.Equals(book.BookId)).FirstOrDefault();
db.Book.Remove(query);
db.SaveChanges();
}
/// <summary>
/// Assignes user to given book.
/// </summary>
/// <param name="user">user who loans a book</param>
/// <param name="book">book to be loaned</param>
public void setBookHolder(User user, Book book)
{
var db = new LibraryDBEntities();
var query = db.Book.Where(p => p.BookId.Equals(book.BookId)).First();
query.User = user;
db.SaveChanges();
}
/// <summary>
/// Makes a query to database to update given book's User and DueDate. Meaning that book is loaned out to given user by username for given timespan.
/// </summary>
/// <param name="book">Book to be updated</param>
/// <param name="username">User's username who will loan given book</param>
/// <param name="loanTime">Due date is calculated by DateTime.Now + loanTime</param>
public void LoanBook(Book book, string username, TimeSpan loanTime)
{
var db = new LibraryDBEntities();
var query = db.Book.Where(p => p.BookId.Equals(book.BookId)).First();
query.User = db.User.Where(p => p.Username.Equals(username)).First();
query.DueDate = DateTime.Now + loanTime;
db.SaveChanges();
}
/// <summary>
/// Updates given book's User(holder) to null and DueDate to null. Meaning that User has returned that book.
/// </summary>
/// <param name="book">Book whose user is to be assigned to null</param>
public void ReturnBook(Book book)
{
var db = new LibraryDBEntities();
var query = db.Book.Where(p => p.BookId.Equals(book.BookId)).First();
query.BookHolderId = null;
query.DueDate = null;
db.SaveChanges();
}
/// <summary>
/// Makes a query to database to update book's title. All books that have same title and author are updated.
/// </summary>
/// <param name="title">New title</param>
/// <param name="book">Book to be updated</param>
public void setBookTitle(string title, Book book)
{
var db = new LibraryDBEntities();
var query = db.Book.Where(p => p.BookTitle.Equals(book.BookTitle) && p.BookAuthorId.Equals(book.BookAuthorId)).Select(p => (Book)p);
foreach (var _book in query)
{
_book.BookTitle = title;
}
db.SaveChanges();
}
/// <summary>
/// Adds author to database.
/// </summary>
/// <param name="author">Author to be added to database</param>
public void setAuthor(Author author)
{
var db = new LibraryDBEntities();
using (db)
{
var query = db.Author.Where(p => p.AuthorId.Equals(author.AuthorId)).FirstOrDefault();
query.AuthorId = author.AuthorId;
query.AuthorFirstName = author.AuthorFirstName;
query.AuthorLastName = author.AuthorLastName;
db.SaveChanges();
}
}
/// <summary>
/// Makes a query to database to check if given book is over due.
/// </summary>
/// <param name="book">Book to be checked</param>
/// <returns>True if book is over due</returns>
public bool IsDue(Book book)
{
if (book != null)
{
var db = new LibraryDBEntities();
var query = db.Book.Where(p => p.BookId.Equals(book.BookId)).First();
if (query.DueDate < DateTime.Now)
{
return(true);
}
else
{
return(false);
}
}
else
{
return(false);
}
}
/// <summary>
/// Adds given book to database. If book.Author's first name and last name are not found in database then new author is created.
/// </summary>
/// <param name="book">Book to be added to database</param>
public void AddBook(Book book)
{
var db = new LibraryDBEntities();
Book newBook = new Book()
{
BookTitle = book.BookTitle,
};
var author = db.Author.Where(p => p.AuthorFirstName.Equals(book.Author.AuthorFirstName) && p.AuthorLastName.Equals(book.Author.AuthorLastName)).FirstOrDefault();
if (author == null)
{
newBook.Author = book.Author;
db.Book.Add(newBook);
}
else
{
newBook.Author = author;
db.Book.Add(newBook);
}
db.SaveChanges();
}
/// <summary>
/// Makes a query to database. Retrives FirstOrDefault() instance of book based on id.
/// </summary>
/// <param name="id">Id used to search a book</param>
/// <returns>Book if found, otherwise null</returns>
public Book getBookById(int id)
{
var query = new LibraryDBEntities().Book.Where(p => p.BookId.Equals(id)).FirstOrDefault();
return(query);
}
/// <summary>
/// Checks if username is unique.
/// </summary>
/// <param name="username">username to be checked</param>
/// <returns>True if username is unique</returns>
public bool ValidateUsername(string username)
{
var query = new LibraryDBEntities().User.Where(p => p.Username.Equals(username)).FirstOrDefault();
return(query == null ? true : false);
}
/// <summary>
/// Validates username and password for authentication.
/// </summary>
/// <param name="username">Username is used to search user from database</param>
/// <param name="hashedPassword">HashedPassword is used to compare password from database</param>
/// <returns>True if passwords match</returns>
public bool ValidatePassword(string username, string hashedPassword)
{
var query = new LibraryDBEntities().User.Where(p => p.Username.Equals(username)).FirstOrDefault();
return(query == null ? false : query.Password.Equals(hashedPassword) ? true : false);
}
/// <summary>
/// Makes a query to database to retrive all books in database.
/// </summary>
/// <returns>ICollection of Books</returns>
public ICollection <Book> getBooks()
{
var query = new LibraryDBEntities().Book.Select(p => p as Book);
return(query.ToList());
}
