We need a library book management software for a school/college library that works fully offline on local computers using Python + Tkinter + SQLite, while automatically taking online backups (e.g., to a cloud server like Google Drive or a simple web API) so that data is safe and can be restored if the system crashes. The system should manage books, members, and book issue/return, with proper user logins, license-based restrictions, and comprehensive reports for daily library work. Key objectives Computerize book entry, book issue, and book return processes. Maintain complete records of books, members, and which books are issued to whom. Work offline on library computers, but sync/backup data to an online server automatically at set intervals. Provide secure user login so only authorized staff can change data. Include license-based restrictions to limit features/users based on purchased license keys. Core features (functional requirements) User roles and login Admin login with username and password. Admin can manage users, books, and all settings. Librarian/staff login with limited rights (issue/return books, view records, basic edits). Optional member login (students/teachers) to view their own issued books and due dates. Ability to create, edit, deactivate user accounts. Member (student/teacher) management Add, edit, delete member records (name, ID, class/department, contact, status). Search members by ID, name, class, or other fields. View member history: books issued, returned, overdue, fines (if we add fine feature later). Book management Add new books with details: title, author, publisher, subject/category, ISBN, price, rack/shelf, quantity, etc. Edit and delete book records (only for admin or authorized staff). Track total copies and available copies. Search books by title, author, subject, ISBN, or availability. Issue and return of books Issue book: select member and book, save issue date and due date, and update available copies automatically. Return book: mark book as returned, update stock, and record return date. Show which books are currently issued to which member, with due dates and status (issued/returned/overdue). Prevent issuing if no copy is available, or if member has reached maximum issued books (configurable limit). Reports and search List of all books with filters (subject, author, availability). List of all issued books, overdue books, and returned books within a date range. Member-wise report: all books ever issued to a specific member. Expanded reports: Daily/weekly/monthly issue/return summaries, overdue books with fines calculation, most popular books/authors/subjects, inventory/stock reports (total books, low stock alerts), borrowing statistics by member type/class/department, and export to Excel/PDF/CSV. Backup and sync (offline + online) The primary system runs offline on local machine(s) using SQLite database. Automatic scheduled backup to an online server (e.g., daily or hourly), without user needing to do manual export. Option to manually trigger backup and restore from backup when required. Backups must be secure and only accessible to admin. License-based restrictions Software activation via license key (one-time or subscription-based). Limit features/users based on license type: e.g., basic license (up to 100 books/members, no reports), pro license (unlimited data, full reports, multi-user), enterprise (multi-computer install, custom reports). Grace period (e.g., 30 days trial), then lock features until valid key entered. Check license on startup and periodically. Non-functional requirements Technology stack: Python 3.x with Tkinter for GUI (desktop app, easy to install and run offline), SQLite for local database. Online backup via simple API or file upload (e.g., to cloud storage). No web server needed for core use. Simple, user-friendly interface suitable for library staff with basic computer knowledge. Fast search and data entry even for a large number of books and members. Secure storage of user passwords (encrypted) and proper access control. Reliable backups so that no data is lost even if local system is damaged. Expected deliverables Fully working executable/software (Python app, with installer for Windows) that can be installed on library computers. Database setup (SQLite + online backup configuration) with basic instructions. User guide/manual for admin and librarian (how to login, add books, add members, issue/return books, generate reports, manage licenses, take/restore backup). Sample license keys and code for handling license validation. Add one more window in this whenever user want to delete the book check that whether it is not issued to the client(student, teacher) and add delete_book table/window. option of deleting/write-off is destroyed/ lost/ torn/ and other.