""" thermal_receipt.py ================== Drop-in replacement for _generate_thermal_receipt_pdf(). Uses fpdf2 only — no WeasyPrint, no heavy deps. Design decisions ---------------- - 80mm thermal width → 2mm left margin, 4mm right margin → 74mm usable - Content is left-shifted: MARGIN_L=2, MARGIN_R=4 gives more room on the left - Courier for all numeric/tabular content (monospace = aligned columns) - Helvetica for headings, labels, branding (proportional = compact) - Column layout: ITEM 40mm | QTY 11mm | PRICE 23mm = 74mm total - Dashed dividers via set_dash_pattern() - Branded top stripe via filled rect in forest green (#417A52) - Serial numbers as indented sub-line under item name - QR code bottom-right, footer text bottom-left Readability rules ----------------- - Minimum font size for any readable content: 9pt - Secondary/meta content (serial, ref, timestamp): 8.5pt + GREY_DARK - Decorative chrome only (tear-off dashes): 7pt + GREY_LIGHT - Grey text never used for primary information — BLACK or GREY_DARK only - Row heights scale with font size throughout Margin layout ------------- MARGIN_L = 2mm (left — shifted in to gain space) MARGIN_R = 4mm (right) USABLE_W = 80 - 2 - 4 = 74mm Columns: 40 + 11 + 23 = 74mm exactly """ from fpdf import FPDF from datetime import datetime import tempfile import os # ── Constants ───────────────────────────────────────────────────────────────── PAGE_W = 80 # mm — standard 80mm thermal roll MARGIN_L = 2 # mm — left margin (shifted in for extra space) MARGIN_R = 4 # mm — right margin USABLE_W = PAGE_W - MARGIN_L - MARGIN_R # 74mm # Column widths — must sum exactly to USABLE_W (74mm) COL_ITEM = 40 # wider item column; gains 4mm vs old layout COL_QTY = 11 COL_PRICE = 23 # Brand colours (RGB) FOREST = (65, 122, 82) # #417A52 FOREST_DARK = (44, 87, 57) # #2C5739 WHITE = (255, 255, 255) BLACK = (0, 0, 0) GREY_DARK = (60, 60, 60) # served-by, serial, ref, timestamp GREY_MID = (90, 90, 90) # dividers and structural lines only GREY_LIGHT = (140, 140, 140) # decorative chrome only (tear-off dashes) # ── ThermalPDF ──────────────────────────────────────────────────────────────── class ThermalPDF(FPDF): """80mm thermal receipt canvas with left-shifted margins.""" def __init__(self): super().__init__(unit='mm', format=(PAGE_W, 400)) self.set_margins(MARGIN_L, 0, MARGIN_R) self.set_auto_page_break(auto=False) self.add_page() # ── Drawing helpers ──────────────────────────────────────────────────────── def solid_line(self, lw=0.25): self.set_line_width(lw) self.set_draw_color(*GREY_DARK) self.line(MARGIN_L, self.get_y(), PAGE_W - MARGIN_R, self.get_y()) def dashed_line(self): self.set_line_width(0.15) self.set_draw_color(*GREY_MID) self.set_dash_pattern(dash=0.8, gap=0.8) self.line(MARGIN_L, self.get_y() + 1, PAGE_W - MARGIN_R, self.get_y() + 1) self.set_dash_pattern(dash=0, gap=0) self.ln(2) def vspace(self, h=2): self.ln(h) # ── Branding ─────────────────────────────────────────────────────────────── def stripe(self): """3mm forest-green bar across the full page top.""" self.set_fill_color(*FOREST) self.rect(0, 0, PAGE_W, 3, style='F') self.set_y(3) self.vspace(2) def section_label(self, text): """Spaced-caps section divider label — left-aligned, dark grey.""" self.vspace(2) self.set_font('Helvetica', 'B', 8.5) self.set_text_color(*GREY_DARK) self.cell(0, 3.5, text.upper(), ln=True, align='L') self.set_text_color(*BLACK) self.vspace(1) # ── Main receipt function ───────────────────────────────────────────────────── def _generate_thermal_receipt_pdf(sale): """ Generate a professional 80mm thermal receipt PDF. Args ---- sale : Sale model instance (Django ORM object) Returns ------- bytes -- raw PDF bytes ready to serve or write to disk. """ pdf = ThermalPDF() # ── STRIPE ──────────────────────────────────────────────────────────────── pdf.stripe() # ── BUSINESS HEADER ─────────────────────────────────────────────────────── pdf.set_font('Helvetica', 'B', 13) pdf.set_text_color(*BLACK) pdf.cell(0, 5, sale.business.name.upper(), ln=True, align='C') biz = sale.business pdf.set_font('Helvetica', '', 9) pdf.set_text_color(*GREY_DARK) if getattr(biz, 'email', None): pdf.cell(0, 4, biz.email, ln=True, align='C') if getattr(biz, 'address_line1', None): for line in biz.address_line1.split('\n')[:2]: pdf.cell(0, 4, line.strip(), ln=True, align='C') if getattr(biz, 'phone_number', None): pdf.cell(0, 4, f"Tel: {biz.phone_number}", ln=True, align='C') if getattr(biz, 'tax_id', None): pdf.cell(0, 4, f"PIN: {biz.tax_id}", ln=True, align='C') pdf.set_text_color(*BLACK) pdf.vspace(2) pdf.solid_line() pdf.vspace(2) # ── RECEIPT META ────────────────────────────────────────────────────────── pdf.set_font('Helvetica', '', 9) pdf.cell(USABLE_W * 0.5, 4, sale.sale_date.strftime('%d/%m/%Y'), align='L') pdf.cell(USABLE_W * 0.5, 4, 'SALES RECEIPT', align='R', ln=True) pdf.set_font('Helvetica', '', 9) pdf.cell(USABLE_W * 0.5, 4, sale.sale_date.strftime('%I:%M %p').upper(), align='L') pdf.set_font('Helvetica', 'B', 9) pdf.cell(USABLE_W * 0.5, 4, f"#{sale.sale_number}", align='R', ln=True) pdf.vspace(2) # ── CUSTOMER ────────────────────────────────────────────────────────────── if sale.customer: pdf.set_font('Helvetica', 'B', 9.5) pdf.set_text_color(*BLACK) name_line = sale.customer.name.upper() if getattr(sale.customer, 'phone', None): name_line += f" {sale.customer.phone}" pdf.cell(0, 4.5, name_line, ln=True) # ── SERVED BY ───────────────────────────────────────────────────────────── if getattr(sale, 'salesperson', None): pdf.vspace(1) pdf.set_font('Helvetica', '', 9) pdf.set_text_color(*GREY_DARK) pdf.cell(0, 4, f"Served by: {sale.salesperson.get_full_name()}", ln=True, align='L') pdf.set_text_color(*BLACK) pdf.vspace(2) pdf.dashed_line() pdf.vspace(2) # ── ITEMS TABLE HEADER ──────────────────────────────────────────────────── pdf.set_font('Helvetica', 'B', 9) pdf.set_text_color(*GREY_DARK) pdf.cell(COL_ITEM, 4, 'ITEM', align='L') pdf.cell(COL_QTY, 4, 'QTY', align='C') pdf.cell(COL_PRICE, 4, 'AMOUNT', align='R', ln=True) pdf.set_text_color(*BLACK) pdf.vspace(1) pdf.dashed_line() pdf.vspace(2) # ── ITEMS ───────────────────────────────────────────────────────────────── for sale_item in sale.items.all(): # Resolve the underlying inventory/accessory object for serial number actual = None if sale_item.item_type == 'inventory_item' and sale_item.inventory_item: actual = sale_item.inventory_item elif sale_item.item_type == 'accessory_item' and sale_item.accessory_item: actual = sale_item.accessory_item item_name = sale_item.item_name.upper() serial = ( actual.serial_number if actual and getattr(actual, 'serial_number', None) else None ) # ── Word-wrap item name into COL_ITEM width ──────────────────────── # Font must match the render font below for accurate measurement pdf.set_font('Helvetica', 'B', 9) words = item_name.split() lines = [] current = '' for word in words: test = (current + ' ' + word).strip() if pdf.get_string_width(test) <= COL_ITEM - 0.5: current = test else: if current: lines.append(current) current = word if current: lines.append(current) # First line: name | qty | unit price pdf.set_font('Helvetica', 'B', 9) pdf.cell(COL_ITEM, 4.5, lines[0], align='L') pdf.set_font('Courier', '', 9) pdf.cell(COL_QTY, 4.5, str(sale_item.quantity), align='C') pdf.cell(COL_PRICE, 4.5, f"KES {float(sale_item.unit_price):,.2f}", align='R', ln=True) # Overflow name lines (rare for short names) if len(lines) > 1: pdf.set_font('Helvetica', '', 9) pdf.set_text_color(*BLACK) for extra in lines[1:]: pdf.cell(COL_ITEM, 4, extra, align='L', ln=True) # Serial number sub-line if serial: pdf.set_font('Helvetica', '', 8.5) pdf.set_text_color(*GREY_DARK) pdf.cell(0, 3.5, f" S/N: {serial}", align='L', ln=True) pdf.set_text_color(*BLACK) pdf.vspace(1.5) # ── TOTALS ──────────────────────────────────────────────────────────────── pdf.vspace(1) pdf.dashed_line() pdf.vspace(2) def total_row(label, value, bold=False, large=False): size = 11 if large else 9 style = 'B' if bold else '' gutter = 3 row_h = size * 0.45 + 1.5 pdf.set_font('Helvetica', style, size) pdf.cell(COL_ITEM + COL_QTY - gutter, row_h, label, align='R') pdf.cell(gutter, row_h, '') pdf.set_font('Courier', style, size) pdf.cell(COL_PRICE, row_h, value, align='R', ln=True) total_row('Subtotal ', f"KES {float(sale.subtotal):,.2f}") if sale.discount_amount > 0: total_row('Discount', f"-KES {float(sale.discount_amount):,.2f}") if sale.tax_amount > 0: total_row('VAT (16%)', f"KES {float(sale.tax_amount):,.2f}") # Short rule above grand total (totals column only) pdf.vspace(1) pdf.set_line_width(0.2) pdf.set_draw_color(*GREY_DARK) line_x = MARGIN_L + COL_ITEM + COL_QTY pdf.line(line_x, pdf.get_y(), PAGE_W - MARGIN_R, pdf.get_y()) pdf.vspace(1) total_row('TOTAL ', f"KES {float(sale.total_amount):,.2f}", bold=True, large=True) pdf.vspace(2) pdf.solid_line() pdf.vspace(3) # ── PAYMENT DETAILS ─────────────────────────────────────────────────────── if sale.payments.exists(): gutter = 3 for payment in sale.payments.all(): method = payment.payment_mode.get_name_display().upper() pdf.set_font('Helvetica', '', 9) pdf.cell(COL_ITEM + COL_QTY - gutter, 4.5, method, align='R') pdf.cell(gutter, 4.5, '') pdf.set_font('Courier', '', 9) pdf.cell(COL_PRICE, 4.5, f"KES {float(payment.amount):,.2f}", align='R', ln=True) if payment.reference_number: pdf.set_font('Helvetica', '', 8.5) pdf.set_text_color(*GREY_DARK) pdf.cell(0, 3.5, f"Ref: {payment.reference_number}", align='R', ln=True) pdf.set_text_color(*BLACK) total_paid = sum(float(p.amount) for p in sale.payments.all()) change = total_paid - float(sale.total_amount) if change > 0.005: pdf.vspace(1) pdf.set_font('Helvetica', 'B', 9) pdf.cell(COL_ITEM + COL_QTY - gutter, 4.5, 'CHANGE', align='R') pdf.cell(gutter, 4.5, '') pdf.set_font('Courier', 'B', 9) pdf.cell(COL_PRICE, 4.5, f"KES {change:,.2f}", align='R', ln=True) pdf.vspace(2) pdf.dashed_line() pdf.vspace(2) # ── WARRANTY & POLICY ───────────────────────────────────────────────────── pdf.set_font('Helvetica', 'B', 9) pdf.set_text_color(*BLACK) pdf.cell(0, 4, 'WARRANTY & POLICY', ln=True) pdf.vspace(1) pdf.set_font('Helvetica', '', 9) pdf.set_text_color(*BLACK) notes = [ "I. New equipment - 12 months warranty", "II. EX-UK/Refurbished - 6 months warranty", "III. Adapters, RAM, storage & software excluded", "IV. Exchanges for defective items within warranty only", "V. Returns accepted within 7 business days", ] for note in notes: pdf.cell(0, 4, note, ln=True) pdf.set_text_color(*BLACK) pdf.vspace(2) pdf.solid_line() pdf.vspace(3) # ── FOOTER: branding left | QR right ───────────────────────────────────── footer_y = pdf.get_y() qr_size = 16 # mm text_w = USABLE_W - qr_size - 2 qr_path = None # Generate QR code try: import qrcode qr = qrcode.QRCode( version=1, error_correction=qrcode.constants.ERROR_CORRECT_M, box_size=4, border=1, ) qr.add_data('https://www.trato.binbyte.co.ke') qr.make(fit=True) qr_img = qr.make_image(fill_color='black', back_color='white') with tempfile.NamedTemporaryFile(delete=False, suffix='.png') as tmp: qr_img.save(tmp.name, format='PNG') qr_path = tmp.name except Exception: pass # QR is non-critical; continue without it # Branding text (left column) pdf.set_font('Helvetica', 'B', 9) pdf.set_text_color(*BLACK) pdf.cell(text_w, 4, sale.business.name.upper(), ln=True) pdf.set_font('Helvetica', 'B', 8.5) pdf.set_text_color(*FOREST) pdf.cell(text_w, 4, 'Powered by Trato - BinByte', ln=True) pdf.set_font('Helvetica', '', 8.5) pdf.set_text_color(*GREY_DARK) pdf.cell(text_w, 4, 'trato.binbyte.co.ke', ln=True) pdf.cell(text_w, 4, '+254 798 969 800', ln=True) pdf.set_text_color(*BLACK) # QR code (right column, anchored to footer_y) if qr_path: qr_x = PAGE_W - MARGIN_R - qr_size try: pdf.image(qr_path, x=qr_x, y=footer_y, w=qr_size, h=qr_size) except Exception: pass finally: try: os.unlink(qr_path) except Exception: pass # Advance cursor past whichever column is taller footer_end_y = max(pdf.get_y(), footer_y + qr_size) pdf.set_y(footer_end_y) pdf.vspace(3) # ── THANK YOU ───────────────────────────────────────────────────────────── pdf.solid_line(lw=0.3) pdf.vspace(3) pdf.set_font('Helvetica', 'B', 9.5) pdf.set_text_color(*BLACK) pdf.cell(0, 4.5, 'THANK YOU FOR YOUR PURCHASE!', ln=True, align='C') pdf.vspace(1) pdf.set_font('Helvetica', '', 8.5) pdf.set_text_color(*GREY_DARK) pdf.cell(0, 4, f"Printed: {datetime.now().strftime('%d/%m/%Y %I:%M %p')}", ln=True, align='C') pdf.set_text_color(*BLACK) pdf.vspace(3) # ── TEAR-OFF DASHES ─────────────────────────────────────────────────────── # Decorative only — GREY_LIGHT + 7pt intentional pdf.set_font('Helvetica', '', 7) pdf.set_text_color(*GREY_LIGHT) pdf.cell(0, 3, '- ' * 19, ln=True, align='C') pdf.set_text_color(*BLACK) pdf.vspace(2) # ── OUTPUT ──────────────────────────────────────────────────────────────── pdf_output = pdf.output(dest='S') if isinstance(pdf_output, (bytes, bytearray)): return bytes(pdf_output) return pdf_output.encode('latin-1')