Expose SOP revision info more fine-grained

external-sop/src/main/java/sop/external/operation/VersionExternal.java

@@ -100,6 +100,42 @@ public class VersionExternal implements Version {
         }
     }
 
+    @Override
+    public int getSopSpecVersionNumber() {
+        String revision = getSopSpecVersion();
+        String firstLine;
+        if (revision.contains("\n")) {
+            firstLine = revision.substring(0, revision.indexOf("\n"));
+        } else {
+            firstLine = revision;
+        }
+
+        if (!firstLine.contains("-")) {
+            return -1;
+        }
+
+        return Integer.parseInt(firstLine.substring(firstLine.lastIndexOf("-") + 1));
+    }
+
+    @Override
+    public boolean isSopSpecImplementationIncomplete() {
+        String revision = getSopSpecVersion();
+        return revision.startsWith("~");
+    }
+
+    @Override
+    public String getSopSpecImplementationIncompletenessRemarks() {
+        String revision = getSopSpecVersion();
+        if (revision.contains("\n")) {
+            String tail = revision.substring(revision.indexOf("\n") + 1).trim();
+
+            if (!tail.isEmpty()) {
+                return tail;
+            }
+        }
+        return null;
+    }
+
     @Override
     public String getSopSpecVersion() {
         String[] command = new String[] {binary, "version", "--sop-spec"};

sop-java/src/main/java/sop/operation/Version.java

@@ -47,13 +47,62 @@ public interface Version {
      */
     String getExtendedVersion();
 
+    /**
+     * Return the version number of the latest targeted SOP spec revision.
+     *
+     * @return SOP spec revision number
+     */
+    int getSopSpecVersionNumber();
+
+    /**
+     * Return the latest targeted revision of the SOP spec.
+     *
+     * @return SOP spec revision string
+     */
+    default String getSopSpecRevisionString() {
+        return "draft-dkg-openpgp-stateless-cli-" + String.format("%02d", getSopSpecVersionNumber());
+    }
+
+    /**
+     * Return <pre>true</pre>, if this implementation of the SOP spec is known to be incomplete or defective.
+     *
+     * @return true if incomplete, false otherwise
+     */
+    boolean isSopSpecImplementationIncomplete();
+
+    /**
+     * Return free-form text containing remarks about the completeness of the SOP implementation.
+     * If no remarks are known, this method returns <pre>null</pre>.
+     *
+     * @return remarks or null
+     */
+    String getSopSpecImplementationIncompletenessRemarks();
+
     /**
      * Return the revision of the SOP specification that this implementation is implementing, for example,
      * <pre>draft-dkg-openpgp-stateless-cli-06</pre>.
      * If the implementation targets a specific draft but the implementer knows the implementation is incomplete,
-     * it should prefix the draft title with a "~" (TILDE, U+007E), for example: <pre>~draft-dkg-openpgp-stateless-cli-06</pre>.
+     * it should prefix the draft title with a "~" (TILDE, U+007E), for example:
+     * <pre>~draft-dkg-openpgp-stateless-cli-06</pre>.
+     * The implementation MAY emit additional text about its relationship to the targeted draft on the lines following
+     * the versioned title.
      *
      * @return implemented SOP spec version
      */
-    String getSopSpecVersion();
+    default String getSopSpecVersion() {
+        StringBuilder sb = new StringBuilder();
+        if (isSopSpecImplementationIncomplete()) {
+            sb.append('~');
+        }
+
+        sb.append(getSopSpecRevisionString());
+
+        if (getSopSpecImplementationIncompletenessRemarks() != null) {
+            sb.append('\n')
+                    .append('\n')
+                    .append(getSopSpecImplementationIncompletenessRemarks());
+        }
+
+        return sb.toString();
+    }
 }

sop-java/src/testFixtures/java/sop/testsuite/operation/VersionTest.java

@@ -14,6 +14,7 @@ import java.util.stream.Stream;
 
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 
 @EnabledIf("sop.testsuite.operation.AbstractSOPTest#hasBackends")
@@ -56,7 +57,13 @@ public class VersionTest extends AbstractSOPTest {
     @MethodSource("provideInstances")
     public void sopSpecVersionTest(SOP sop) {
         String sopSpec = sop.version().getSopSpecVersion();
-        assertTrue(sopSpec.startsWith("draft-dkg-openpgp-stateless-cli-") ||
-                sopSpec.startsWith("~draft-dkg-openpgp-stateless-cli-"));
+        if (sop.version().isSopSpecImplementationIncomplete()) {
+            assertTrue(sopSpec.startsWith("~draft-dkg-openpgp-stateless-cli-"));
+        } else {
+            assertTrue(sopSpec.startsWith("draft-dkg-openpgp-stateless-cli-"));
+        }
+
+        int sopRevision = sop.version().getSopSpecVersionNumber();
+        assertTrue(sop.version().getSopSpecRevisionString().endsWith("" + sopRevision));
     }
 }