koreader: ship RSS feeds

hosts/common/programs/koreader/default.nix

@@ -1,6 +1,26 @@
-{ ... }:
+{ config, lib, sane-lib, ... }:
 
-{
+let
+  feeds = sane-lib.feeds;
+  allFeeds = config.sane.feeds;
+  wantedFeeds = feeds.filterByFormat [ "image" "text" ] allFeeds;
+  koreaderRssEntries = builtins.map (feed:
+    # format:
+    # { "<rss/atom url>", limit = <int>, download_full_article=<bool>, include_images=<bool>, enable_filter=<bool>, filter_element = "<css selector>"},
+    # limit = 0                    => download and keep *all* articles
+    # download_full_article = true => populate feed by downloading the webpage -- not just what's encoded in the RSS <article> tags
+    # - use this for articles where the RSS only encodes content previews
+    # enable_filter         = true => only render content that matches the filter_element css selector.
+    let fields = [
+      (lib.escapeShellArg feed.url)
+      "limit = 5"
+      "download_full_article = false"
+      "include_images = true"
+      "enable_filter = false"
+      "filter_element = \"\""
+    ]; in "{ ${lib.concatStringsSep ", " fields } }"
+  ) wantedFeeds;
+in {
   sane.programs.koreader = {
     # koreader applies these lua "patches" at boot:
     # - <https://github.com/koreader/koreader/wiki/User-patches>
@@ -8,6 +28,14 @@
     # fs.".config/koreader/patches".symlink.target = "${./.}";
     fs.".config/koreader/patches/2-colin-NetworkManager-isConnected.lua".symlink.target = "${./2-colin-NetworkManager-isConnected.lua}";
 
+    # koreader news plugin, enabled by default. file format described here:
+    # - <repo:koreader/koreader:plugins/newsdownloader.koplugin/feed_config.lua>
+    fs.".config/koreader/news/feed_config.lua".symlink.text = ''
+      return {--do NOT change this line
+        ${lib.concatStringsSep ",\n  " koreaderRssEntries}
+      }--do NOT change this line
+    '';
+
     # koreader on aarch64 errors if there's no fonts directory (sandboxing thing, i guess)
     fs.".local/share/fonts".dir = {};