Fixes version comparison for balloted versions

Fixes #168

matchbox-server/src/main/java/ca/uhn/fhir/jpa/packages/PackageVersionComparator.java

@@ -0,0 +1,82 @@
+/*-
+ * #%L
+ * HAPI FHIR JPA Server
+ * %%
+ * Copyright (C) 2014 - 2023 Smile CDR, Inc.
+ * %%
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * #L%
+ */
+package ca.uhn.fhir.jpa.packages;
+
+import java.math.BigDecimal;
+import java.util.Comparator;
+
+import static org.apache.commons.lang3.StringUtils.isNumeric;
+
+public class PackageVersionComparator implements Comparator<String> {
+	public static final PackageVersionComparator INSTANCE = new PackageVersionComparator();
+
+	@Override
+	public int compare(String o1, String o2) {
+
+		String[] o1parts = o1.split("\\.");
+		String[] o2parts = o2.split("\\.");
+
+		for (int i = 0; i < o1parts.length && i < o2parts.length; i++) {
+			String i1part = o1parts[i];
+			String i2part = o2parts[i];
+
+			if (isNumeric(i1part)) {
+				if (isNumeric(i2part)) {
+					int cmp = new BigDecimal(i1part).compareTo(new BigDecimal(i2part));
+					if (cmp != 0) {
+						return cmp;
+					}
+				}
+			}
+
+			// MATCHBOX FIX for https://github.com/ahdis/matchbox/issues/168
+			if (i == o1parts.length - 1 || i == o2parts.length - 1) {
+				if (o1.endsWith("-ballot")) {
+					return -1;
+				} else if (o2.endsWith("-ballot")) {
+					return 1;
+				}
+			}
+
+			int cmp = i1part.compareTo(i2part);
+			if (cmp != 0) {
+				return cmp;
+			}
+		}
+
+
+		return o1parts.length - o2parts.length;
+	}
+
+	public static boolean isEquivalent(String theSpec, String thePackageVersion) {
+		String[] o1parts = theSpec.split("\\.");
+		String[] o2parts = thePackageVersion.split("\\.");
+
+		for (int i = 0; i < o1parts.length; i++) {
+			if (!o1parts[i].equals("x")) {
+				if (!o1parts[i].equals(o2parts[i])) {
+					return false;
+				}
+			}
+		}
+
+		return true;
+	}
+}