Use the Snap versioning automation of ubuntu/desktop-snaps (#28)

Remove the versioning automation scripting from snapcraft.yaml and add the needed changes so that the GitHub action of ubuntu/desktop-snaps does the versioning automation.

- Hard-code "version" and "grade" metadata fields in snapcraft.yaml. The GitHub action modifies this file to bumb the version. This also improves readability, having the current version number visible near the top of the file.

- Remove "override-pull:" in the "foomatic-db" part. We use the versioning automation in the GitHub action and do not need our own script any more.

- Remove the "jq" from the "build-packages:" in the "foomatic-db" part. This was only needed for our own versioning automation script.

- In the workflow file, .github/workflows/auto-update.yml, we add the parameter "version-schema: '^(\d{8})'" to the call of the GitHub action. This tell to the action to also perform versioning automation and it also tells the format of the upstream version numbers.

- We do not remove the "adopt-info: foomatic-db" even with all metadata fields in snapcraft.yaml being hard-coded and no "craftctl set ..." calls in the "foomatic-db" part. It only tells the GitHub action which part is the supplier of the upstream version number.

- A leftover comment which is not correct any more got removed now.

.github/workflows/auto-update.yml

@@ -17,4 +17,4 @@ jobs:
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           repo: ${{ github.repository }}
-
+          version-schema: '^(\d{8})'

snap/snapcraft.yaml

@@ -1,5 +1,7 @@
 name: ps-printer-app
 base: core22
+version: 20240202-2
+grade: stable
 summary: PostScript Printer Application
 description: |
   The PostScript Printer Application is a PAPPL (Printer Application Framework) based Printer Application
@@ -540,79 +542,6 @@ parts:
 #   version-format:
 #     format: '%V'
     plugin: nil
-    override-pull: |
-      set -eux
-      # Do the actual pull task
-      craftctl default
-      # Settings:
-      # Force channel: auto/devel/edge/stable
-      CHANNEL=stable
-      # Force package release number (integer) or "auto"
-      PACKAGERELEASE=auto
-      # As foomatic-db is simply a collection of printer data and not
-      # some software which is under continuous development and
-      # milestones of the development turn into releases, it is simply
-      # versioned by the date (a cron job on OpenPrinting "releases"
-      # it every day.
-      #
-      # As we want to download it from GIT and not grab a daily
-      # tarball for sake of Snap automation we simply take the date of
-      # the day after the day of the execution of the pull task of
-      # this part as the version number (this is the version in which
-      # the current GIT state would land).
-      # Time stamp of Snap build in Snap Store
-      snapbuilddatehuman=`curl -s -H 'Snap-Device-Series: 16' https://api.snapcraft.io/v2/snaps/info/ps-printer-app | jq -r '."channel-map" | .[] | select(.channel.name == "edge") | select(.channel.architecture == "amd64") | ."created-at"'`
-      snapbuilddate=`date +%s --date=$snapbuilddatehuman`
-      if [ -z "$snapbuilddate" ]; then
-          snapbuilddate=0
-      fi
-      # Time stamp of the last GIT commit of the snapping repository
-      pushd $CRAFT_PROJECT_DIR
-      gitcommitdate=`git log -1 --date=unix | grep Date: | perl -p -e 's/Date:\s*//'`
-      popd
-      if [ -z "$gitcommitdate" ]; then
-          gitcommitdate=0
-      fi
-      # Previous stable and development version
-      prevstable="$(curl -s -H 'Snap-Device-Series: 16' https://api.snapcraft.io/v2/snaps/info/ps-printer-app | jq -r '."channel-map" | .[] | select(.channel.name == "stable") | select(.channel.architecture == "'$CRAFT_TARGET_ARCH'") | .version')"
-      if [ -z "$prevstable" ]; then
-          prevstable=0
-      fi
-      prevdevel="$(curl -s -H 'Snap-Device-Series: 16' https://api.snapcraft.io/v2/snaps/info/ps-printer-app | jq -r '."channel-map" | .[] | select(.channel.name == "edge") | select(.channel.architecture == "'$CRAFT_TARGET_ARCH'") | .version')"
-      if [ -z "$prevdevel" ]; then
-          prevdevel=0
-      fi
-      # Previous version in general
-      dpkg --compare-versions "$prevdevel" lt "$prevstable" && prevversion=$prevstable || prevversion=$prevdevel
-      # Current upstream version of foomatic-db
-      # Assuming release tags are in the format YYYYMMDD
-      upstreamversion="$(git describe --tags --always | sed -e 's/^v//;s/-/+git/;s/\([0-9]\{4\}\)\([0-9]\{2\}\)\([0-9]\{2\}\)/\1\2\3/')"
-      # Determine package release number
-      if test "x$PACKAGERELEASE" = "xauto"; then
-          packagerelease=`echo "$prevversion" | perl -p -e 's/^('"$upstreamversion"'\-(\d+)|.*)$/\2/'`
-          if [ -z "$packagerelease" ]; then
-              packagerelease=1
-          else
-              if test "$gitcommitdate" -gt "$snapbuilddate"; then
-                  packagerelease=$(( $packagerelease + 1 ))
-              fi
-          fi
-      else
-          packagerelease=$PACKAGERELEASE
-      fi
-      # Compose version string
-      version="$upstreamversion-$packagerelease"
-      # Select channel
-      if test "x$CHANNEL" = "xedge" -o "x$CHANNEL" = "xdevel"; then
-          grade=devel
-      elif test "x$CHANNEL" = "xstable"; then
-          grade=stable
-      else
-          [ -n "$(echo $version | grep "+git")" ] && grade=devel || grade=stable
-      fi
-      # Set version and grade
-      craftctl set version="$version"
-      craftctl set grade="$grade"
     override-build: |
       set -eux
       # Remove non-PostScript manufacturer PPD files
@@ -633,7 +562,6 @@ parts:
       - perl-base
       - python3
       - xz-utils
-      - jq
       - curl
     stage-packages:
       - python3
@@ -669,9 +597,7 @@ parts:
     source: https://salsa.debian.org/printing-team/hplip.v2.git
     source-type: git
     source-tag: 'debian/3.22.10+dfsg0-4'
-    source-depth: 1 
-    # Excluding hplip from the update automation process because the UpdateSnap script is
-    # unable to retrieve the source-tag or source-branch for this repository.
+    source-depth: 1
 # ext:updatesnap
 #   version-format:
 #     format: 'debian/%V'