from io import BytesIO
from typing import BinaryIO

from fpdf import FPDF
import pdfrw
from pdfrw import PdfReader
from pdfrw.objects.pdfdict import PdfDict


class PdfMaker:
    def __init__(self, size: tuple):
        self.size = size

        self.writer = pdfrw.PdfWriter()

    def clear(self):
        del self.writer
        self.writer = pdfrw.PdfWriter()

    def add_image(self, image_data):
        size = self.size

        fpdf = FPDF(format=size, unit="pt")
        width, height = self.size
        fpdf.add_page()
        fpdf.image(image_data, 0, 0, width, height)
        fpdf_reader: pdfrw.PdfReader = pdfrw.PdfReader(fdata=bytes(fpdf.output()))
        self.writer.addpage(fpdf_reader.getPage(0))

    def add_pdf(self, pdf_data: BytesIO):
        pdf_reader = pdfrw.PdfReader(fdata=bytes(pdf_data.read()))
        self.writer.addpage(pdf_reader.getPage(0))

    def add_pdfs(self, pdf_data: BytesIO):
        pdf_reader = pdfrw.PdfReader(fdata=bytes(pdf_data.read()))
        self.writer.addpages(pdf_reader.readpages(pdf_reader.Root))

    def get_bytes(self):
        result_io = BytesIO()
        self.writer.write(result_io)
        result_io.seek(0)
        return result_io

    @staticmethod
    def check_is_correct_aspects_ratio(file: BinaryIO):
        pdf = PdfReader(file)
        allowed_aspects_ratio = 1.45
        page: PdfDict

        try:
            page: PdfDict = pdf.getPage(0)
        except IndexError:
            raise Exception("Ошибка. В документе нет страниц.")

        try:
            pdf.getPage(1)
            raise Exception("Ошибка. В документе должна быть только одна страница.")
        except IndexError:
            pass

        media_box = page.MediaBox
        width = float(media_box[2]) - float(media_box[0])
        height = float(media_box[3]) - float(media_box[1])

        aspect_ratio = width / height
        if abs(aspect_ratio - allowed_aspects_ratio) > 0.01:
            raise Exception("Ошибка. Страница документа должна быть размером 58х40.")
        file.seek(0)