Merge and rotate PDF files from the command line

pdf_utils.py

"""
Usage:
    python3 main.py --res <resources_folder> --out <output_folder>
    Merge and rotate PDF files from the command line

Options:
    --res <resources_folder>   Path to the folder containing resource directories with PDF files.
    --out <output_folder>      Path to the output folder where merged and rotated PDFs will be saved.

Requirements:
    PyPDF2
"""

import os
import argparse
import PyPDF2

## Helper Functions ##
def merge_pdfs(pdf_path_list, output_path):
    pdf_merger = PyPDF2.PdfMerger()
    pdf_path_list.sort()
    for pdf in pdf_path_list:
        if not check_file_extension(pdf, ".pdf"):
            print(f"Found invalid file: {pdf}. Skipping...")
            continue

        try:
            with open(pdf, 'rb') as file:
                pdf_merger.append(file)
        except Exception as e:
            print(f"Failed to merge {pdf}: {e}")

    with open(f"{output_path}.pdf", 'wb') as output_file:
        pdf_merger.write(output_file)

def rotate_pdf(input_path, output_path):
    try:
        with open(input_path, 'rb') as file:
            reader = PyPDF2.PdfReader(file)
            writer = PyPDF2.PdfWriter()

            for index, page in enumerate(reader.pages):
                rotated_page = page.rotate(90) if index % 2 == 0 else page.rotate(270)
                writer.add_page(rotated_page)

        with open(output_path, 'wb') as output_file:
            writer.write(output_file)
    except Exception as e:
        print(f"Failed to rotate {input_path}: {e}")

def get_all_dirs(path) -> list:
    return [d for d in os.listdir(path) if os.path.isdir(os.path.join(path, d))]

def get_all_files(folder_path) -> list:
    return [os.path.join(folder_path, f) for f in os.listdir(folder_path)]

def check_file_extension(file_path, extension):
    _, file_ext = os.path.splitext(file_path)
    return file_ext.lower() == extension.lower()

def main(res_folder_path, output_folder_path):
    # read res dir and folders
    folders = get_all_dirs(res_folder_path)

    # create output folder if it doesn't exist
    os.makedirs(output_folder_path, exist_ok=True)

    for folder_name in folders:
        folder_path = os.path.join(res_folder_path, folder_name)
        pdf_files = get_all_files(folder_path)

        # Merge PDFs from the folder
        merge_pdfs(pdf_files, os.path.join(output_folder_path, folder_name))

        # Rotate the merged PDF
        rotate_pdf(input_path=os.path.join(output_folder_path, f"{folder_name}.pdf"),
                    output_path=os.path.join(output_folder_path, f"{folder_name}.pdf"))

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="Merge and rotate PDF files from the command line")
    parser.add_argument('--res', type=str, required=True, help="Path to the resources folder.")
    parser.add_argument('--out', type=str, required=True, help="Path to the output folder.")

    args = parser.parse_args()

    main(args.res, args.out)