1#!/usr/bin/env python3
2"""
3This script creates a 400×400 thumbnail of a specific page of a PDF file.
4
5It uses similar thumbnailing logic to docstore [1], but it allows me to
6pick a particular page rather than the first page.
7
8This is helpful because sometimes I download PDF cross-stitch patterns
9where the first page contains text which isn't a good thumbnail, but
10later pages do show the whole pattern.
11
12[1]: https://github.com/alexwlchan/docstore/blob/main/src/docstore/thumbnails.py
13
14"""
15
16import argparse
17import os
18import sys
19import subprocess
20import tempfile
21
22from pypdf import PdfReader, PdfWriter
23
24
25def parse_args(argv):
26    parser = argparse.ArgumentParser(
27        prog=os.path.basename(__file__),
28        description="Get thumbnails from a specific page of a PDF file.",
29    )
30
31    parser.add_argument("PATH")
32    parser.add_argument(
33        "--page",
34        type=int,
35        metavar="PAGE_NUMBER",
36        help="which page of the PDF to get",
37        required=True,
38    )
39    parser.add_argument(
40        "--width", type=int, help="pixel width of the generated thumbnail", default=400
41    )
42
43    return parser.parse_args(argv)
44
45
46if __name__ == "__main__":
47    args = parse_args(sys.argv[1:])
48
49    reader = PdfReader(args.PATH)
50
51    # Remember that pages are 0-indexed
52    try:
53        page = reader.pages[args.page - 1]
54    except IndexError:
55        sys.exit(f"Unrecognised page: {args.page}, expected 1...{len(reader.pages)}")
56
57    writer = PdfWriter()
58    writer.add_page(page)
59
60    with tempfile.TemporaryDirectory(suffix=".pdf") as temp_dir:
61        out_path = os.path.join(temp_dir, os.path.basename(args.PATH))
62
63        with open(out_path, "wb") as out_file:
64            writer.write(out_file)
65
66        subprocess.check_call(
67            ["qlmanage", "-t", out_path, "-s", f"{args.width}x{args.width}", "-o", "."]
68        )