#!/usr/bin/env python3

import argparse
from pathlib import Path

import img2pdf


SUPPORTED_EXTENSIONS = {".jpg", ".jpeg", ".png"}


def images_to_pdf(images: list[Path], output: Path) -> None:
    # A4 page dimensions in PDF points (1 point = 1/72 inch).
    a4_size = (img2pdf.mm_to_pt(210), img2pdf.mm_to_pt(297))

    # Scale images proportionally to fit within A4 pages.
    layout = img2pdf.get_layout_fun(
        pagesize=a4_size,
        fit=img2pdf.FitMode.into,
        auto_orient=True,
    )

    with output.open("wb") as pdf_file:
        pdf_file.write(
            img2pdf.convert(
                [str(image) for image in images], #type: ignore
                layout_fun=layout,
            )
        )

def main() -> None:
    parser = argparse.ArgumentParser(
        description="Convert JPEG/PNG images into a PDF, one image per page."
    )

    parser.add_argument(
        "images",
        nargs="+",
        type=Path,
        help="Input JPEG/PNG images in page order",
    )

    parser.add_argument(
        "-o",
        "--output",
        type=Path,
        default=Path("output.pdf"),
        help="Output PDF file (default: output.pdf)",
    )

    args = parser.parse_args()

    images_to_pdf(args.images, args.output)

    print(f"Created: {args.output}")


if __name__ == "__main__":
    main()