Combine images in a Drive folder into one PDF

import io
from datetime import date
from google.oauth2.credentials import Credentials
from googleapiclient.discovery import build
from googleapiclient.http import MediaIoBaseUpload
from clickruntime import on_trigger, credentials, http, state, report_fetched

FOLDER = "to-pdf-folder-id"

@on_trigger
def run(event):
    drive, done = build("drive", "v3", credentials=Credentials(credentials.connection("google", "work")), cache_discovery=False), set(state.get("done") or [])
    images = [f for f in drive.files().list(q=f"'{FOLDER}' in parents and mimeType contains 'image/' and trashed=false", orderBy="name",
              fields="files(id,name)").execute()["files"] if f["id"] not in done]
    report_fetched(len(images))
    if not images:
        return {"summary": "Nothing new"}
    slides = build("slides", "v1", credentials=Credentials(credentials.connection("google", "work")), cache_discovery=False).presentations()
    deck = slides.create(body={"title": f"Images {date.today()}"}).execute()["presentationId"]
    reqs = []
    for i, img in enumerate(images):
        drive.permissions().create(fileId=img["id"], body={"type": "anyone", "role": "reader"}).execute()
        reqs += [{"createSlide": {"objectId": f"s{i}", "insertionIndex": i}},
                 {"createImage": {"url": f"https://drive.google.com/uc?id={img['id']}", "elementProperties": {"pageObjectId": f"s{i}"}}}]
    slides.batchUpdate(presentationId=deck, body={"requests": reqs}).execute()
    pdf = drive.files().export(fileId=deck, mimeType="application/pdf").execute()
    drive.files().create(body={"name": f"Images {date.today()}.pdf", "parents": [FOLDER]}, media_body=MediaIoBaseUpload(io.BytesIO(pdf), mimetype="application/pdf")).execute()
    for img in images:
        drive.permissions().delete(fileId=img["id"], permissionId="anyoneWithLink").execute()
    state.set("done", list(done | {i["id"] for i in images})[-2000:])
    return {"images": len(images)}