Library Management System

from datetime import datetime, timedelta
import json

class Book:
    def __init__(self, isbn, title, author, copies=1):
        self.isbn = isbn
        self.title = title
        self.author = author
        self.copies = copies
        self.available = copies

    def __str__(self):
        return f"[{self.isbn}] {self.title} by {self.author} ({self.available}/{self.copies} available)"

class Member:
    def __init__(self, member_id, name):
        self.member_id = member_id
        self.name = name
        self.borrowed_books = []  # list of {"isbn": ..., "date": ...}

    def __str__(self):
        return f"[{self.member_id}] {self.name} - {len(self.borrowed_books)} books borrowed"

class Library:
    def __init__(self):
        self.books = {}
        self.members = {}

    def add_book(self):
        isbn = input("ISBN: ")
        title = input("Title: ")
        author = input("Author: ")
        copies = int(input("Copies: "))
        self.books[isbn] = Book(isbn, title, author, copies)
        print(f"✅ Book '{title}' added!")

    def register_member(self):
        mid = input("Member ID: ")
        name = input("Name: ")
        self.members[mid] = Member(mid, name)
        print(f"✅ Member '{name}' registered!")

    def borrow_book(self):
        mid = input("Member ID: ")
        isbn = input("Book ISBN: ")
        if mid not in self.members:
            print("Member not found!")
            return
        if isbn not in self.books or self.books[isbn].available <= 0:
            print("Book not available!")
            return
        self.books[isbn].available -= 1
        self.members[mid].borrowed_books.append({
            "isbn": isbn, "date": datetime.now().strftime("%Y-%m-%d")
        })
        print(f"✅ Book borrowed successfully!")

    def return_book(self):
        mid = input("Member ID: ")
        isbn = input("Book ISBN: ")
        member = self.members.get(mid)
        if not member:
            print("Member not found!")
            return
        for b in member.borrowed_books:
            if b["isbn"] == isbn:
                member.borrowed_books.remove(b)
                self.books[isbn].available += 1
                borrow_date = datetime.strptime(b["date"], "%Y-%m-%d")
                days = (datetime.now() - borrow_date).days
                fine = max(0, (days - 14)) * 5  # ₹5/day after 14 days
                print(f"✅ Book returned! Days: {days}" + (f", Fine: ₹{fine}" if fine > 0 else ""))
                return
        print("Book not found in member's borrowed list!")

    def search(self):
        query = input("Search: ").lower()
        results = [b for b in self.books.values() if query in b.title.lower() or query in b.author.lower()]
        for b in results:
            print(f"  {b}")
        if not results:
            print("No books found!")

    def list_books(self):
        for b in self.books.values():
            print(f"  {b}")

def main():
    lib = Library()
    while True:
        print("\n1.Add Book 2.Register Member 3.Borrow 4.Return 5.Search 6.List Books 7.Exit")
        ch = input("Choice: ")
        if ch == "1": lib.add_book()
        elif ch == "2": lib.register_member()
        elif ch == "3": lib.borrow_book()
        elif ch == "4": lib.return_book()
        elif ch == "5": lib.search()
        elif ch == "6": lib.list_books()
        elif ch == "7": break

main()