mendeley: Add update-checker script, add myself as maintainer

Doesn't actually edit the file,
but reports when an update is available
and provides useful information.

pkgs/applications/office/mendeley/default.nix

@@ -31,6 +31,8 @@
 # will leave entries on your system after uninstalling mendeley.
 # (they can be removed by running '$out/bin/install-mendeley-link-handler.sh -u')
 , autorunLinkHandler ? true
+# Update script
+, writeScript
 }:
 
 assert stdenv.system == "i686-linux" || stdenv.system == "x86_64-linux";
@@ -133,11 +135,14 @@ stdenv.mkDerivation {
   dontStrip = true;
   dontPatchElf = true;
 
-  meta = {
+  updateScript = import ./update.nix { inherit writeScript; };
+
+  meta = with stdenv.lib; {
     homepage = http://www.mendeley.com;
     description = "A reference manager and academic social network";
-    license = stdenv.lib.licenses.unfree;
-    platforms = stdenv.lib.platforms.linux;
+    license = licenses.unfree;
+    platforms = platforms.linux;
+    maintainers  = with maintainers; [ dtzWill ];
   };
 
 }

pkgs/applications/office/mendeley/update.nix

@@ -0,0 +1,60 @@
+{ writeScript }:
+
+writeScript "update-mendeley" ''
+  function follow() {
+    local URL=$1
+    while true; do
+      NEWURL=$(curl -m20 -sI "$URL" -o /dev/null -w '%{redirect_url}')
+      [ -z "$NEWURL" ] && break
+      [[ $NEWURL = $URL ]] && (echo "redirect loop?!"; exit 1)
+      echo "Following $URL -> $NEWURL ..." >&2
+      URL=$NEWURL
+    done
+
+    echo $URL
+  }
+
+  amd64URL=$(follow https://www.mendeley.com/repositories/ubuntu/stable/amd64/mendeleydesktop-latest)
+  amd64V=$(basename $amd64URL|grep -m1 -o "[0-9]\+\.[0-9]\+\.[0-9]\+")
+  i386URL=$(follow https://www.mendeley.com/repositories/ubuntu/stable/i386/mendeleydesktop-latest)
+  i386V=$(basename $i386URL|grep -m1 -o "[0-9]\+\.[0-9]\+\.[0-9]\+")
+
+  echo "amd64 version: $amd64V"
+  echo "i386 version:  $i386V"
+  if [[ $amd64V != $i386V ]]; then
+    echo "Versions not the same!"
+    exit 1
+  fi
+
+  if grep -q -F "$amd64V" ${./default.nix}; then
+    echo "No new version yet, nothing to do."
+    echo "Have a nice day!"
+    exit 0
+  fi
+
+  amd64OldHash=$(nix-instantiate --eval --strict -A "mendeley.src.drvAttrs.outputHash" --argstr system "x86_64-linux"| tr -d '"')
+  i386OldHash=$(nix-instantiate --eval --strict -A "mendeley.src.drvAttrs.outputHash" --argstr system "i686-linux"| tr -d '"')
+
+  echo "Prefetching amd64..."
+  amd64NewHash=$(nix-prefetch-url $amd64URL)
+  echo "Prefetching i386..."
+  i386NewHash=$(nix-prefetch-url $i386URL)
+
+  # Don't actually update, just report that an update is available
+  cat <<EOF
+
+
+  Time to update to $amd64V !
+
+  32bit (i386):
+    Old: $i386OldHash
+    New: $i386NewHash
+  64bit (amd64):
+    Old: $amd64OldHash
+    New: $amd64NewHash
+
+  Exiting so this information is seen...
+  (no update is actually performed here)
+  EOF
+  exit 1
+''