Library Management System Class Diagram

classDiagram
  class Book {
    +String isbn
    +String title
    +List~String~ authors
    +availableCopies() int
  }
  class BookCopy {
    +int copyId
    +String status
    +markIssued() void
    +markReturned() void
  }
  class Member {
    <<abstract>>
    +int memberId
    +String name
    +String email
    +borrowLimit() int
  }
  class StudentMember {
    +String rollNumber
    +borrowLimit() int
  }
  class FacultyMember {
    +String department
    +borrowLimit() int
  }
  class Loan {
    +Date issueDate
    +Date dueDate
    +Date returnDate
    +calculateFine() decimal
  }
  class Librarian {
    +int staffId
    +issueBook(Member, BookCopy) Loan
    +returnBook(Loan) void
  }
  class Catalogue {
    +search(String query) List~Book~
  }
  Book "1" *-- "many" BookCopy
  Member <|-- StudentMember
  Member <|-- FacultyMember
  Member "1" --> "many" Loan
  Loan --> BookCopy
  Librarian ..> Loan : creates
  Catalogue o-- Book