bill.js

document.addEventListener('DOMContentLoaded', function() {
    // Try to get data from both localStorage and URL
    let billData;
    
    // Method 1: Check for message data
    window.addEventListener('message', function(event) {
        if (event.data.type === 'billData') {
            billData = event.data.data;
            displayBill(billData);
        }
    });
    
    // Method 2: Check localStorage
    const storedBill = localStorage.getItem('currentBill');
    if (storedBill) {
        try {
            billData = JSON.parse(storedBill);
            displayBill(billData);
            return;
        } catch (e) {
            console.error('Error parsing stored bill data', e);
        }
    }
    
    // Method 3: Check URL parameters
    const urlParams = new URLSearchParams(window.location.search);
    const encodedData = urlParams.get('data');
    if (encodedData) {
        try {
            billData = JSON.parse(decodeURIComponent(encodedData));
            displayBill(billData);
            return;
        } catch (e) {
            console.error('Error parsing URL bill data', e);
        }
    }
    
    // If no data found
    if (!billData) {
        document.body.innerHTML = '<div class="container"><h2>No bill data found</h2><p>Please scan the QR code again or ask the shopkeeper to resend the bill.</p></div>';
        return;
    }
    
    function displayBill(billData) {
        // Set shop and bill info
        document.getElementById('shopName').textContent = billData.shop;
        document.getElementById('billDate').textContent = billData.date;
        document.getElementById('billNumber').textContent = billData.billNumber;
        
        // Set customer info
        document.getElementById('customerName').textContent = billData.customer.name;
        document.getElementById('customerPhone').textContent = billData.customer.phone;
        
        // Add items to table
        const billItemsTable = document.getElementById('billItems');
        billItemsTable.innerHTML = '';
        
        billData.items.forEach(item => {
            const row = document.createElement('tr');
            row.innerHTML = `
                <td>${item.name}</td>
                <td>${item.quantity}</td>
                <td>$${parseFloat(item.price).toFixed(2)}</td>
                <td>$${item.total}</td>
            `;
            billItemsTable.appendChild(row);
        });
        
        // Set totals
        document.getElementById('subtotal').textContent = '$' + billData.subtotal.toFixed(2);
        document.getElementById('tax').textContent = '$' + billData.tax.toFixed(2);
        document.getElementById('total').textContent = '$' + billData.total.toFixed(2);
        
        // Generate payment QR code (example)
        new QRCode(document.getElementById('paymentQR'), {
            text: `upi://pay?pa=shop@upi&am=${billData.total}&tn=Bill ${billData.billNumber}`,
            width: 150,
            height: 150
        });
        
        // Add print button
        const printBtn = document.createElement('button');
        printBtn.id = 'printBtn';
        printBtn.textContent = 'Print Bill';
        printBtn.onclick = window.print;
        document.querySelector('.bill-view').appendChild(printBtn);
    }
});