"""Combine multiple PDFs into one, optionally rotating them

Requires "pypdf" library, tested with v5.2.0 at time of writing

MIT No Attribution

Copyright (c) 2025 Joe Kerhin

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
"""

# /// script
# requires-python = ">=3.9"
# dependencies = [
#   "pypdf>5.0",
# ]
# ///
import argparse
from pathlib import Path
from typing import List

from pypdf import PdfReader, PdfWriter


def combine_and_rotate(filenames: List[str], rot_deg_cw: int) -> PdfWriter:
    writer = PdfWriter()
    for fname in filenames:
        with PdfReader(fname) as reader:
            for page in reader.pages:
                writer.add_page(page.rotate(rot_deg_cw))
    return writer


def main():
    parser = argparse.ArgumentParser(description="Combine and rotate PDFs")
    parser.add_argument(
        "-r",
        "--rotation-deg-cw",
        default=0,
        type=int,
        help="Degrees (clockwise) to rotate each page of input PDFs",
    )
    parser.add_argument(
        "-o",
        "--output-name",
        type=str,
        help="Output file name. If not provided, combine input filenames",
    )
    parser.add_argument("filenames", nargs="+")
    args = parser.parse_args()

    out_name = args.output_name
    if out_name is None:
        out_name = "_".join(Path(f).stem for f in args.filenames)
        out_name += ".pdf"

    writer = combine_and_rotate(args.filenames, args.rotation_deg_cw)
    with open(out_name, "wb") as hdl:
        writer.write(hdl)


if __name__ == "__main__":
    main()