newsboat: add git-to-rss script

home/newsboat.nix

@@ -2,6 +2,7 @@
 {
   programs.newsboat.enable = true;
   xdg.configFile."newsboat/config".source = ../newsboat/config;
+  xdg.configFile."newsboat/git-rss.py".source = ../newsboat/git-rss.py;
   # newsboat considers this config, I consider it state
   xdg.configFile."newsboat/urls".source = ~/state/rss-urls;
 }

newsboat/git-rss.py

@@ -0,0 +1,80 @@
+#! /usr/bin/env nix-shell
+#! nix-shell -i python3 -p "python3.withPackages(ps: with ps; [GitPython])"
+
+# Quick an ugly script to generate a rss feed from a git repo
+import re
+import sys
+import email.utils
+import xml.etree.ElementTree as ET
+from git import Repo
+from git import NoSuchPathError
+
+
+def str_to_remote_name(string):
+    # The format is not entirely clear, so let's just go with something simple.
+    return re.sub(r'[^a-zA-Z0-9]', '-', string)
+
+def get_updates(url, branch, web_url_template):
+    name = str_to_remote_name(url)
+
+    repo_path = "~/.cache/newsboat/git-tracker"
+    try:
+        repo = Repo(repo_path)
+    except NoSuchPathError:
+        repo = Repo.init(repo_path, mkdir=True)
+
+    try:
+        remote = repo.remote(name)
+        assert list(remote.urls) == [url]
+    except ValueError:
+        remote = repo.create_remote(name, url)
+        assert remote.exists()
+    # Parallelism
+    # https://github.com/gitpython-developers/GitPython/issues/584#issuecomment-282474005
+    remote.fetch()
+
+    history = repo.iter_commits(remote.refs[branch])
+
+    for commit in history:
+        yield generate_rss_item(
+            title=commit.summary,
+            content="\n".join(commit.message.splitlines()[2:]),
+            link=web_url_template.format(commit.hexsha),
+            author=commit.author,
+            date=email.utils.format_datetime(commit.committed_datetime),
+        )
+
+
+def generate_rss_item(title, content, link, author, date):
+    item = ET.Element("item")
+    ET.SubElement(item, "title").text = title
+    ET.SubElement(item, "description").text = content
+    ET.SubElement(item, "link").text = link
+    ET.SubElement(item, "author").text = author
+    ET.SubElement(item, "guid").text = link
+    ET.SubElement(item, "pubDate").text = date
+    return item
+
+
+def format_rss(posts):
+    rss_root = ET.Element("rss", {"version": "2.0"})
+    channel = ET.SubElement(rss_root, "channel")
+    description = ET.SubElement(channel, "description", text="Channel desccription") # TODO data
+    link = ET.SubElement(channel, "link", text="something")
+    title = ET.SubElement(channel, "title", text="Some patreon feed")
+    for post in posts:
+        channel.append(post)
+    return rss_root
+
+
+def _main():
+    url = sys.argv[1]
+    branch = sys.argv[2] if len(sys.argv) > 2 else "master"
+    web_url_template = sys.argv[3] if len(sys.argv) > 3 else url + "/{}"
+    posts = get_updates(url, branch, web_url_template)
+    xml = format_rss(posts)
+    print(ET.tostring(xml, encoding="unicode", short_empty_elements=False))
+
+
+if __name__ == "__main__":
+    _main()