update the updater

scripts/bash/update.sh

@@ -1,14 +1,34 @@
 #!/bin/bash
 log="logger -t update.sh -s "
 
-${log} "Updating the main repository"
-cd /home/pi/PlanktonScope
+function update(){
+    sudo killall -15 raspimjpeg
+    sudo killall -15 python3
+    git stash
+    git merge
+    git checkout stash@'{0}' -- config.json hardware.json
+    # TODO we need to change this to drop stash@{1} if changes made to the flow are to be restored by the user
+    git stash drop
+    sudo systemctl restart nodered.service
+}
 
-sudo killall -15 raspimjpeg
-sudo killall -15 python3
-git stash
-git pull
-git checkout stash@{0} -- config.json hardware.json
-git stash drop
-sudo systemctl restart nodered.service
-${log} "Done!"
+${log} "Updating the main repository"
+cd /home/pi/PlanktonScope || { echo "/home/pi/PlanktonScope does not exist"; exit 1; }
+
+# TODO We need to add here a way to load the latest version of this script and execute it again
+remote=$(git ls-remote -h origin master | awk '{print $1}')
+local=$(git rev-parse HEAD)
+${log} "Local : $local - Remote: $remote"
+if [[ "$local" == "$remote" ]]; then
+    ${log} "nothing to do!"
+else
+    git fetch
+    UPDATE=$(git diff --numstat origin/master scripts/bash/update.sh | awk '/update.sh/ {print $NF}')
+    if [[ -n "${UPDATE}" ]]; then
+        # Update the file and restart the script
+        git checkout origin/master scripts/bash/update.sh
+        exec scripts/bash/update.sh
+    fi
+    update
+    ${log} "Done!"
+fi