# sales/views/receipts.py import logging import json import csv import string import base64 from datetime import datetime, timedelta from decimal import Decimal from io import BytesIO from django.shortcuts import render, redirect, get_object_or_404 from django.contrib import messages from django.contrib.auth.decorators import login_required from django.http import JsonResponse, HttpResponse from django.views.decorators.csrf import csrf_exempt from django.utils import timezone from django.db import transaction from django.db.models import Sum, Count, Q, F from django.core.exceptions import PermissionDenied from inventory.models import Product from core.models import Branch from core.utils import check_limit_or_block, filter_orders_by_user_branch from accounts.decorators import role_required from sales.models import ( POSOrder, POSOrderItem, PaymentTransaction, DailySalesSummary, UnusualTransaction, Customer, Refund, ) from sales.forms import POSOrderForm, POSOrderItemForm logger = logging.getLogger(__name__) BASE36_ALPHABET = "0123456789abcdefghijklmnopqrstuvwxyz" def _to_base36(num: int) -> str: """Convert positive int to base36 (same as JS toString(36)).""" if num == 0: return "0" result = "" while num > 0: num, rem = divmod(num, 36) result = BASE36_ALPHABET[rem] + result return result def _get_company_settings(request): """Helper: return CompanySettings for request.company, or None.""" company = getattr(request, 'company', None) return getattr(company, 'settings', None) def generate_verification_code(order: POSOrder, business_name: str = "") -> str: """ Generate the same verification code as the JS on the receipt template. Raw string: order_number | created_at(YmdHis) | business_name Hash: 32-bit int, multiplied by 31 each step, base36, padded to 8, SP-XXXX-XXXX. """ created_str = order.created_at.strftime("%Y%m%d%H%M%S") raw = f"{order.order_number}|{created_str}|{business_name}" h = 0 for ch in raw: h = (h * 31 + ord(ch)) & 0xFFFFFFFF # 32-bit code = _to_base36(h).upper() code = code.rjust(8, "0")[-8:] return f"SP-{code[:4]}-{code[4:]}" def verify_order(request): """ Public verification page for QR scans. URL: /sales/verify-order/?order= """ order_number = request.GET.get("order", "").strip() company = getattr(request, 'company', None) cs = getattr(company, 'settings', None) business_name = cs.business_name if cs else "" order = None verification_code = None is_valid = False if order_number and company: order = POSOrder.objects.filter(order_number=order_number, company=company).first() if order: verification_code = generate_verification_code(order, business_name) is_valid = True context = { "order_number": order_number, "order": order, "verification_code": verification_code, "is_valid": is_valid, "company_settings": cs, } return render(request, "sales/verify_order.html", context) from rest_framework.authtoken.models import Token from django.conf import settings def print_receipt(request, order_id): """Print HTML receipt (with QR) for completed order""" if not request.user.is_authenticated: token_key = request.GET.get('token') if token_key: try: token = Token.objects.get(key=token_key) # Verify token owner belongs to this company token_user_company = getattr(token.user, 'company', None) if token_user_company is None or token_user_company != request.company: return redirect(f"{settings.LOGIN_URL}?next={request.path}") request.user = token.user except Token.DoesNotExist: return redirect(f"{settings.LOGIN_URL}?next={request.path}") else: return redirect(f"{settings.LOGIN_URL}?next={request.path}") order = get_object_or_404(POSOrder, id=order_id, company=request.company) order_items = POSOrderItem.objects.filter(order=order).select_related('product') company = getattr(request, 'company', None) cs = getattr(company, 'settings', None) # --- Ensure cs is at least populated with company details if it's generic --- if company and cs: if not cs.business_name or cs.business_name in ["My Business", "Modern POS Business", "MODERN POS BUSINESS", "MODERN POS business"]: cs.business_name = company.name if not cs.business_address and company.address: cs.business_address = company.address if not cs.business_phone and company.phone: cs.business_phone = company.phone currency_symbol = cs.currency_symbol if cs else '₦' # --- Generate QR code for HTML receipt --- qr_code_b64 = None try: import qrcode from django.urls import reverse qr_url = reverse("sales:verify_order") + f"?order={order.order_number}" qr_data = request.build_absolute_uri(qr_url) qr = qrcode.QRCode(version=1, box_size=4, border=1) qr.add_data(qr_data) qr.make(fit=True) img = qr.make_image(fill_color="black", back_color="white") buffer = BytesIO() img.save(buffer, format="PNG") qr_code_b64 = base64.b64encode(buffer.getvalue()).decode("ascii") except Exception as e: logger.warning(f"QR generation error: {e}") context = { 'order': order, 'order_items': order_items, 'system_settings': cs, 'qr_code': qr_code_b64, 'currency_symbol': currency_symbol, 'user_role': request.user.role, 'user_name': request.user.get_full_name() or request.user.username, 'split_payments': order.split_payments if order.is_split_payment else None, } return render(request, 'sales/receipt.html', context) @login_required def repeat_sale(request, order_id): """ Repeat a previous order: creates a new draft POS order pre-loaded with the same products (at their CURRENT prices) and deducts stock. Respects unlimited_stock setting. """ import random, string as _string company = getattr(request, 'company', None) original_order = get_object_or_404(POSOrder, id=order_id, company=company) cs = getattr(company, 'settings', None) unlimited_stock = getattr(cs, 'enable_unlimited_stock', False) if cs else False pos_mode = getattr(cs, 'pos_interface_mode', 'classic') if cs else 'classic' if pos_mode == 'grid': cart_items = [] for item in original_order.items.select_related('product').all(): product = item.product if not product: continue cart_items.append({ 'id': product.id, 'productId': product.id, 'name': product.name, 'price': float(product.price), 'quantity': float(item.quantity), 'stockQuantity': float(product.stock_quantity) if not unlimited_stock else 999999.0, 'wholesalePrice': float(product.wholesale_price) if product.wholesale_price else None, 'wholesaleMinQty': float(product.wholesale_min_quantity) if product.wholesale_min_quantity else 0.0, 'basePrice': float(product.price) }) request.session['grid_preload_cart'] = cart_items messages.success(request, f'Repeat order loaded {len(cart_items)} item(s) into cart.') return redirect('sales:pos_grid') suffix = ''.join(random.choices(_string.ascii_uppercase + _string.digits, k=5)) new_order = POSOrder.objects.create( company=company, order_number=f"RPT-{timezone.now().strftime('%m%d%H%M')}-{suffix}", total_amount=0, final_amount=0, cashier=request.user.username, payment_method='cash', branch=original_order.branch, ) items_added = 0 for item in original_order.items.select_related('product').all(): product = item.product if product is None: messages.warning(request, f'A product could not be found (it may have been deleted).') continue qty = item.quantity if not unlimited_stock and product.stock_quantity < qty: messages.warning( request, f'Insufficient stock for "{product.name}" (available: {product.stock_quantity}). Skipped.' ) continue # Use CURRENT price, not original order price current_price = product.price # Apply wholesale if applicable if (product.wholesale_price and product.wholesale_min_quantity and product.wholesale_min_quantity > 0 and qty >= product.wholesale_min_quantity): current_price = product.wholesale_price POSOrderItem.objects.create( order=new_order, product=product, product_name=product.name, quantity=qty, unit_price=current_price, total_price=current_price * qty, ) if not unlimited_stock: product.stock_quantity -= qty product.save() items_added += 1 # Recalculate totals order_items = POSOrderItem.objects.filter(order=new_order) subtotal = sum(item.total_price for item in order_items) new_order.total_amount = subtotal new_order.tax_amount = Decimal('0') new_order.final_amount = subtotal new_order.save() request.session['current_order_id'] = new_order.id if items_added: messages.success(request, f'Repeat order created with {items_added} item(s). Review & complete the order below.') else: messages.warning(request, 'No items could be added to repeat order (insufficient stock or deleted products).') return redirect('sales:pos') @login_required @role_required(['admin', 'manager']) def reverse_order(request, order_id): """ Reverse / Refund a completed order: 1. Restore all product stock quantities. 2. If customer had credit balance on this order, clear it. 3. Change order status → 'cancelled'. 4. Create a Refund record for audit trail. 5. Log action in AuditLog. """ company = getattr(request, 'company', None) order = get_object_or_404(POSOrder, id=order_id, company=company) cs = getattr(company, 'settings', None) unlimited_stock = getattr(cs, 'enable_unlimited_stock', False) if cs else False if order.status == 'cancelled': messages.warning(request, f'Order #{order.order_number} is already cancelled.') return redirect('sales:transaction_history') # Check if already refunded from sales.models import Refund if hasattr(order, 'refund'): messages.warning(request, f'Order #{order.order_number} has already been reversed.') return redirect('sales:transaction_history') reason = request.POST.get('reason', 'Reversed by staff') if request.method == 'POST' else '' if request.method == 'POST': with transaction.atomic(): # 1. Restore stock stock_restored = False if not unlimited_stock: for item in order.items.select_related('product').all(): if item.product: item.product.stock_quantity += item.quantity item.product.save() stock_restored = True # 2. Clear customer credit balance if this was a credit order credit_adjusted = False if order.balance_amount > Decimal('0') and order.customer: order.amount_paid = order.final_amount order.balance_amount = Decimal('0') order.payment_status = 'full' credit_adjusted = True # 3. Cancel the order order.status = 'cancelled' order.save() # 4. Create Refund record Refund.objects.create( company=company, original_order=order, refunded_by=request.user.username, reason=reason or 'No reason provided', refund_amount=order.final_amount, stock_restored=stock_restored, credit_adjusted=credit_adjusted, ) # 5. Audit log try: from accounts.audit import log_action log_action(request, 'reverse_order', target=order.order_number, extra=f'Refund amount: {order.final_amount}') except Exception: pass messages.success( request, f'Order #{order.order_number} has been reversed. ' f'Stock restored: {"Yes" if not unlimited_stock else "N/A (unlimited)"}. ' f'Customer credit adjusted: {"Yes" if credit_adjusted else "No"}.' ) return redirect('sales:transaction_history') # GET: show confirmation page context = { 'order': order, 'order_items': order.items.select_related('product').all(), 'user_role': request.user.role, 'user_name': request.user.get_full_name() or request.user.username, } return render(request, 'sales/reverse_order_confirm.html', context) @login_required @role_required(['admin', 'manager']) def generate_receipt_with_qr(request, order_id): """Generate receipt PDF with QR code for verification""" try: import qrcode from reportlab.pdfgen import canvas from reportlab.lib.pagesizes import A4 from reportlab.lib.colors import Color except ImportError: return HttpResponse("PDF generation libraries not installed.", status=500) order = get_object_or_404(POSOrder, id=order_id, company=request.company) order_items = POSOrderItem.objects.filter(order=order).select_related('product') company = getattr(request, 'company', None) cs = getattr(company, 'settings', None) biz_name = cs.business_name if cs else "MODERN POS" biz_address = cs.business_address if cs else "" receipt_footer = cs.receipt_footer if cs else "Thank you for your patronage!" from django.urls import reverse qr_url = reverse("sales:verify_order") + f"?order={order.order_number}" qr_data = request.build_absolute_uri(qr_url) qr = qrcode.QRCode(version=1, box_size=10, border=5) qr.add_data(qr_data) qr.make(fit=True) img = qr.make_image(fill_color="black", back_color="white") buf = BytesIO() img.save(buf, format='PNG') qr_image = buf.getvalue() buffer = BytesIO() p = canvas.Canvas(buffer, pagesize=A4) width, height = A4 p.saveState() texture_color = Color(0.85, 0.85, 0.85, alpha=0.15) p.setFillColor(texture_color) p.setFont("Helvetica", 22) for y in range(0, int(height), 120): for x in range(0, int(width), 250): p.drawString(x, y, str(order.order_number)) p.restoreState() p.setFont("Helvetica-Bold", 20) p.drawString(40, height - 60, biz_name) p.setFont("Helvetica", 11) p.drawString(40, height - 82, biz_address) p.setFont("Helvetica-Bold", 12) p.drawString(40, height - 110, f"ORDER RECEIPT - #{order.order_number}") p.setFont("Helvetica", 10) p.drawString(40, height - 130, f"Date: {order.created_at.strftime('%Y-%m-%d %H:%M')}") p.drawString(250, height - 130, f"Cashier: {order.cashier}") p.setFont("Helvetica-Bold", 12) y_position = height - 170 p.drawString(40, y_position, "ITEMS PURCHASED") p.setFont("Helvetica", 10) y_position -= 20 for item in order_items: p.drawString(40, y_position, f"{item.quantity} x {item.product.name}") p.drawRightString(400, y_position, f"₦{item.total_price}") y_position -= 16 y_position -= 10 p.line(40, y_position, 400, y_position) y_position -= 20 p.setFont("Helvetica-Bold", 11) p.drawString(40, y_position, "Subtotal:") p.drawRightString(400, y_position, f"₦{order.total_amount}") y_position -= 18 p.drawString(40, y_position, "Total Amount:") p.drawRightString(400, y_position, f"₦{order.final_amount}") y_position -= 18 p.drawString(40, y_position, "Payment Method:") p.drawRightString(400, y_position, order.get_payment_method_display()) if qr_image: p.setFont("Helvetica", 10) p.drawString(40, y_position - 40, "Scan to verify order:") p.drawImage(BytesIO(qr_image), 40, y_position - 140, width=110, height=110) p.setFont("Helvetica-Oblique", 10) p.drawString(40, 40, receipt_footer) p.showPage() p.save() buffer.seek(0) return HttpResponse(buffer.getvalue(), content_type='application/pdf')