pdf.py

import io

from PyPDF2 import PdfReader, PdfWriter
from reportlab.lib.pagesizes import A4
from reportlab.pdfbase import pdfmetrics
from reportlab.pdfbase.ttfonts import TTFont
from reportlab.pdfgen.canvas import Canvas
from server.models.contract import Contract


class LoanDocumentHandler:
    def get_watermark(self, contract: Contract) -> io.BytesIO:
        packet = io.BytesIO()
        canvas = Canvas(packet, pagesize=A4)
        # set font, because default fonts don't support utf-8
        pdfmetrics.registerFont(
            TTFont('GothamProMedium', 'GothamProMedium.ttf'))
        canvas.setFont("GothamProMedium", 10)
        canvas.drawString(350, 709, str(contract.amount))
        canvas.showPage()
        canvas.save()
        return packet

    def generate_doc_pdf(self, contract: Contract) -> io.BytesIO:
        buffer = io.BytesIO()
        output = PdfWriter()
        watermark = self.get_watermark(contract)
        existing_pdf = PdfReader('p2pcontract.pdf')
        watermark_obj = PdfReader(watermark)  # read your existing PDF
        for page_number in range(len(existing_pdf.pages)):
            watermark_page = watermark_obj.pages[page_number]
            existing_pdf_page = existing_pdf.pages[page_number]
            existing_pdf_page.merge_page(watermark_page)
            output.add_page(existing_pdf_page)
        output.write(buffer)
        return buffer


pdf_service = LoanDocumentHandler()