multiviewer-for-f1: add update script (#336246)

* Added update script for multiviewer-for-f1

* Fix update script to perform check

Checks if the version pulled from our metadata API is the same as the current version, preventing a pull of the package if an update is not necessary.

* nixfmt

* nixfmt fix

pkgs/by-name/mu/multiviewer-for-f1/package.nix

@@ -22,6 +22,7 @@
   nss,
   pango,
   xorg,
+  writeScript,
 }:
 let
   id = "232635194";
@@ -93,6 +94,30 @@ stdenvNoCC.mkDerivation rec {
     runHook postInstall
   '';
 
+  passthru.updateScript = writeScript "update-multiviewer-for-f1" ''
+    #!/usr/bin/env nix-shell
+    #!nix-shell -i bash -p curl common-updater-scripts
+    set -eu -o pipefail
+
+    # Get latest API for packages, store so we only make one request
+    latest=$(curl -s "https://api.multiviewer.app/api/v1/releases/latest/")
+
+    # From the downloaded JSON extract the url, version and id
+    link=$(echo $latest | jq -r '.downloads[] | select(.platform=="linux_deb").url')
+    id=$(echo $latest | jq -r '.downloads[] | select(.platform=="linux_deb").id')
+    version=$(echo $latest | jq -r '.version')
+
+    if [ "$version" != "${version}" ]
+    then
+      # Pre-calculate package hash
+      hash=$(nix-prefetch-url --type sha256 $link)
+
+      # Update ID and version in source
+      update-source-version ${pname} "$id" --version-key=id
+      update-source-version ${pname} "$version" "$hash" --system=x86_64-linux
+    fi
+  '';
+
   meta = with lib; {
     description = "Unofficial desktop client for F1 TV®";
     homepage = "https://multiviewer.app";