check if tag can really be created locally and remote

release.sh

@@ -28,9 +28,28 @@ fi
 
 CURRENT_MAJOR=${CURRENT_VERSION#v}
 
+if ! [[ "$CURRENT_VERSION" =~ ^v[0-9]+$ ]]; then
+    echo "Error: Invalid version format in $VERSION_FILE. Expected v0, v1, v2, etc."
+    exit 1
+fi
+
 NEXT_VERSION=$((CURRENT_MAJOR + 1))
 NEXT_VERSION_STR="v$NEXT_VERSION"
 
+if git rev-parse "refs/tags/$NEXT_VERSION_STR" >/dev/null 2>&1; then
+    echo "Error: Tag $NEXT_VERSION_STR already exists locally."
+    exit 1
+fi
+
+if git remote get-url origin >/dev/null 2>&1; then
+    if git ls-remote --tags origin "$NEXT_VERSION_STR" 2>/dev/null | grep -q "$NEXT_VERSION_STR"; then
+        echo "Error: Tag $NEXT_VERSION_STR already exists on remote."
+        exit 1
+    fi
+else
+    echo "Warning: No remote configured. You can still create the release locally."
+fi
+
 echo "Current version: $CURRENT_VERSION"
 echo "Proposed version: $NEXT_VERSION_STR"
 echo ""