1 files changed, 59 insertions, 7 deletions
diff --git a/src/main/java/moe/nea/libautoupdate/CurrentVersion.java b/src/main/java/moe/nea/libautoupdate/CurrentVersion.java
index 8c0837e..e6e4ff8 100644
--- a/src/main/java/moe/nea/libautoupdate/CurrentVersion.java
+++ b/src/main/java/moe/nea/libautoupdate/CurrentVersion.java
@@ -1,21 +1,73 @@
 package moe.nea.libautoupdate;
 
+import com.google.gson.JsonElement;
+import com.google.gson.JsonPrimitive;
+
 /**
  * Provider interface for getting the current version of this jar.
  */
 public interface CurrentVersion {
+
     /**
-     * @return the version number
+     * Create a {@link CurrentVersion} that compares only numbers. (Other version types will be assumed to be newer.)
+     *
+     * @param number the current version number
      */
-    int getCurrentVersionNumber();
+    static CurrentVersion of(int number) {
+        return new CurrentVersion() {
+            @Override
+            public String display() {
+                return String.valueOf(number);
+            }
+
+            @Override
+            public boolean isOlderThan(JsonElement element) {
+                if (!element.isJsonPrimitive()) return true;
+                JsonPrimitive prim = element.getAsJsonPrimitive();
+                if (!prim.isNumber()) return true;
+                return prim.getAsInt() > number;
+            }
+
+            @Override
+            public String toString() {
+                return "VersionNumber (" + number + ")";
+            }
+        };
+    }
 
     /**
-     * Create a constant {@link CurrentVersion}
+     * Create a {@link CurrentVersion} that uses git tag names. Any difference in tag name will be treated as newer.
      *
-     * @param number the constant version number
-     * @return
+     * @param tagName the current tag name
      */
-    static CurrentVersion of(int number) {
-        return () -> number;
+    static CurrentVersion ofTag(String tagName) {
+       return new CurrentVersion() {
+           @Override
+           public String display() {
+               return tagName;
+           }
+
+           @Override
+           public boolean isOlderThan(JsonElement element) {
+               return !new JsonPrimitive(tagName).equals(element);
+           }
+
+           @Override
+           public String toString() {
+               return "VersionTag (" + tagName + ")";
+           }
+       };
     }
+
+    /**
+     * @return a user-friendly representation of this version
+     */
+    String display();
+
+    /**
+     * Compare to another version, represented as JSON.
+     *
+     * @return true, if this version is older than the other version and an update to that version should occur.
+     */
+    boolean isOlderThan(JsonElement element);
 }