# requirements.txt
diff-pdf-visually==1.7.0
PyPDF2==2.10.6
pytest==7.1.3

# test_same_pdf.py
import io
import shutil
import tempfile
from PyPDF2 import PdfMerger, PdfReader
from diff_pdf_visually import pdf_similar
import os
import pytest
import logging


logger = logging.getLogger(__name__)

FILE_INPUT_URI = "arret_maladie.pdf"
FILE_OUTPUT_URI = "output.pdf"


def file_as_bytesio(filepath: str):
    """Open a file as BytesIO, read only."""
    with open(filepath, "rb") as f:
        return io.BytesIO(f.read())


def test_pdf_merger():

    # Open document and merge it into a temporary file
    merger = PdfMerger()

    merger.append(PdfReader(file_as_bytesio(FILE_INPUT_URI)))

    # Write the final merged document
    temp_file = tempfile.NamedTemporaryFile()
    merger.write(temp_file.name)

    temp_file_path = temp_file.name

    # Compare VISUALLY the content of the newly generated file with the expected content
    if not pdf_similar(temp_file_path, FILE_INPUT_URI):
        # If files don't match visually, the test fails.
        # Copy the newly generated file to the current directory to manually check what is wrong
        current_dir = os.path.dirname(__file__)
        new_file_path = os.path.join(current_dir, FILE_OUTPUT_URI)
        shutil.copy2(temp_file.name, new_file_path)
        logger.error(f"The newly merged file does not match with the intput file.")
        # Fail the test on purpose
        assert False