1 files changed, 45 insertions, 0 deletions
diff --git a/pkgs/applications/office/libreoffice/darwin/update-utils.nix b/pkgs/applications/office/libreoffice/darwin/update-utils.nix
new file mode 100644
index 00000000000..fb4a7b0e7b2
--- /dev/null
+++ b/pkgs/applications/office/libreoffice/darwin/update-utils.nix
@@ -0,0 +1,45 @@
+{ lib }:
+let
+# extractLatestVersionFromHtml :: String -> String
+  extractLatestVersionFromHtml = htmlString:
+    let
+      majorMinorPatchGroup = "([0-9]+\\.[0-9]+\\.[0-9]+)";
+      splittedVersions = builtins.split "href=\"${majorMinorPatchGroup}" htmlString;
+      stableVersions = builtins.concatLists (builtins.filter (e: builtins.isList e) splittedVersions);
+    in
+      if stableVersions == []
+        then abort "Failed to extract versions from html."
+        else lib.last (builtins.sort builtins.lessThan stableVersions);
+
+# getHtml :: String -> String
+  getHtml = url:
+    builtins.readFile (builtins.fetchurl url);
+
+# getLatestStableVersion :: String
+  getLatestStableVersion =
+    extractLatestVersionFromHtml (getHtml "https://download.documentfoundation.org/libreoffice/stable/");
+
+# extractSha256FromHtml :: String -> String
+  extractSha256FromHtml = htmlString:
+    let
+      sha256 = (builtins.match ".*([0-9a-fA-F]{64}).*" htmlString);
+    in
+      if sha256 == []
+        then abort "Failed to extract sha256 from html."
+        else builtins.head sha256;
+
+# getSha256 :: String -> String
+  getSha256 = dmgUrl: oldVersion: newVersion:
+    extractSha256FromHtml (getHtml (getSha256Url dmgUrl oldVersion newVersion));
+
+# getSha256Url :: String -> String -> String -> String
+  getSha256Url = dmgUrl: oldVersion: newVersion:
+    (builtins.replaceStrings [ oldVersion ] [ newVersion ] dmgUrl) + ".sha256";
+
+# nullHash :: String
+  nullHash = "0000000000000000000000000000000000000000000000000000000000000000";
+in
+{
+  inherit extractLatestVersionFromHtml getHtml getLatestStableVersion
+    extractSha256FromHtml getSha256 getSha256Url nullHash;
+}