বইয়ের স্টক ফিচার বানাই

// Book Schema
const bookSchema = new mongoose.Schema({
  quantity: { type: Number, default: 0 }, // Inventory quantity field
});

const stockbookSchema = new mongoose.Schema({
    book: {
      type: mongoose.Schema.Types.ObjectId,
      ref: 'Book',
      required: true,
    },
    quantity: { type: Number, required: true },
    dateAdded: { type: Date, default: Date.now },
  });
  
  const Stockbook = mongoose.model('Stockbook', stockbookSchema);

module.exports = { Author, Book ,Member,Loan,Stockbook};

const { Author, Book,Member,Loan,Stockbook } = require('./models');
// Save a stockbook entry
router.post('/add-stockbook', async (req, res) => {
    try {
      const { book, quantity } = req.body;
  
      // Create a stockbook entry
      const stockbookEntry = new Stockbook({ book: book, quantity });
      await stockbookEntry.save();
  
      // Update the book's quantity
      await Book.findByIdAndUpdate(book, { $inc: { quantity } });
  
      res.json(stockbookEntry);
    } catch (err) {
      console.error(err);
      res.status(500).json({ error: 'Failed to save stockbook entry' });
    }
  });
  

router.post('/loans', async (req, res) => {
    try {
      const { bookId, memberId, dueDate } = req.body;
  
      // Decrement the book's quantity in the inventory
      await Book.findByIdAndUpdate(bookId, { $inc: { quantity: -1 } });
  
      // Create a loan record
      const loan = new Loan({ book: bookId, member: memberId, dueDate });
      await loan.save();
  
      res.json(loan);
    } catch (err) {
      console.error(err);
      res.status(500).json({ error: 'Failed to loan the book' });
    }
  });

  // Receive a returned book
router.put('/receive-book/:loanId', async (req, res) => {
    try {
      const loanId = req.params.loanId;
  
      // Increment the book's quantity in the inventory
      const loan = await Loan.findById(loanId);
      await Book.findByIdAndUpdate(loan.book, { $inc: { quantity: 1 } });
  
      // Update the loan record with the return date
      const returnDate = new Date();
      await Loan.findByIdAndUpdate(loanId, { returnDate });
  
      res.json({ message: 'Book received and loan record updated' });
    } catch (err) {
      console.error(err);
      res.status(500).json({ error: 'Failed to receive the book' });
    }
  });