Improve TagDeserializer logic

nostr-java-event/src/main/java/nostr/event/json/deserializer/TagDeserializer.java

@@ -25,41 +25,46 @@
 import nostr.event.tag.VoteTag;
 
 import java.io.IOException;
+import java.util.Map;
+import java.util.function.Function;
 
 public class TagDeserializer<T extends BaseTag> extends JsonDeserializer<T> {
 
+    private static final Map<String, Function<JsonNode, ? extends BaseTag>> TAG_DECODERS = Map.ofEntries(
+            Map.entry("a", AddressTag::deserialize),
+            Map.entry("d", IdentifierTag::deserialize),
+            Map.entry("e", EventTag::deserialize),
+            Map.entry("g", GeohashTag::deserialize),
+            Map.entry("l", LabelTag::deserialize),
+            Map.entry("L", LabelNamespaceTag::deserialize),
+            Map.entry("p", PubKeyTag::deserialize),
+            Map.entry("r", ReferenceTag::deserialize),
+            Map.entry("t", HashtagTag::deserialize),
+            Map.entry("u", UrlTag::deserialize),
+            Map.entry("v", VoteTag::deserialize),
+            Map.entry("emoji", EmojiTag::deserialize),
+            Map.entry("expiration", ExpirationTag::deserialize),
+            Map.entry("nonce", NonceTag::deserialize),
+            Map.entry("price", PriceTag::deserialize),
+            Map.entry("relays", RelaysTag::deserialize),
+            Map.entry("subject", SubjectTag::deserialize)
+    );
+
     @Override
     public T deserialize(JsonParser jsonParser, DeserializationContext deserializationContext) throws IOException {
 
         JsonNode node = jsonParser.getCodec().readTree(jsonParser);
-        // Extract relevant data from the JSON node
-        var code = node.get(0);
-
-        if (code == null) {
-            throw new IOException("Unknown tag code: " + null);
+        if (!node.isArray() || node.size() == 0 || node.get(0) == null) {
+            throw new IOException("Malformed JSON: Expected a non-empty array.");
         }
+        String code = node.get(0).asText();
+
+        Function<JsonNode, ? extends BaseTag> decoder = TAG_DECODERS.get(code);
+        BaseTag tag = decoder != null
+                ? decoder.apply(node)
+                : new GenericTagDecoder<>().decode(node.toString());
 
-        // Perform custom deserialization logic based on the concrete class
-        return switch (code.asText()) {
-            case "a" -> AddressTag.deserialize(node);
-            case "d" -> IdentifierTag.deserialize(node);
-            case "e" -> EventTag.deserialize(node);
-            case "g" -> GeohashTag.deserialize(node);
-            case "l" -> LabelTag.deserialize(node);
-            case "L" -> LabelNamespaceTag.deserialize(node);
-            case "p" -> PubKeyTag.deserialize(node);
-            case "r" -> ReferenceTag.deserialize(node);
-            case "t" -> HashtagTag.deserialize(node);
-            case "u" -> UrlTag.deserialize(node);
-            case "v" -> VoteTag.deserialize(node);
-            case "emoji" -> EmojiTag.deserialize(node);
-            case "expiration" -> ExpirationTag.deserialize(node);
-            case "nonce" -> NonceTag.deserialize(node);
-            case "price" -> PriceTag.deserialize(node);
-            case "relays" -> RelaysTag.deserialize(node);
-            case "subject" -> SubjectTag.deserialize(node);
-            default -> (T) new GenericTagDecoder<>().decode(node.toString());
-        };
+        return (T) tag;
 
     }
 }

nostr-java-event/src/test/java/nostr/event/unit/TagDeserializerTest.java

@@ -0,0 +1,71 @@
+package nostr.event.unit;
+
+import nostr.event.BaseTag;
+import nostr.event.tag.AddressTag;
+import nostr.event.tag.EventTag;
+import nostr.event.tag.PriceTag;
+import nostr.event.tag.UrlTag;
+import nostr.event.tag.GenericTag;
+import org.junit.jupiter.api.Test;
+
+import java.math.BigDecimal;
+
+import static nostr.base.IEvent.MAPPER_AFTERBURNER;
+import static org.junit.jupiter.api.Assertions.*;
+
+class TagDeserializerTest {
+
+    @Test
+    void testAddressTagDeserialization() throws Exception {
+        String pubKey = "bbbd79f81439ff794cf5ac5f7bff9121e257f399829e472c7a14d3e86fe76984";
+        String json = "[\"a\",\"1:" + pubKey + ":test\",\"ws://localhost:8080\"]";
+        BaseTag tag = MAPPER_AFTERBURNER.readValue(json, BaseTag.class);
+        assertInstanceOf(AddressTag.class, tag);
+        AddressTag aTag = (AddressTag) tag;
+        assertEquals(1, aTag.getKind());
+        assertEquals(pubKey, aTag.getPublicKey().toString());
+        assertEquals("test", aTag.getIdentifierTag().getUuid());
+        assertEquals("ws://localhost:8080", aTag.getRelay().getUri());
+    }
+
+    @Test
+    void testEventTagDeserialization() throws Exception {
+        String id = "494001ac0c8af2a10f60f23538e5b35d3cdacb8e1cc956fe7a16dfa5cbfc4346";
+        String json = "[\"e\",\"" + id + "\",\"wss://relay.example.com\",\"root\"]";
+        BaseTag tag = MAPPER_AFTERBURNER.readValue(json, BaseTag.class);
+        assertInstanceOf(EventTag.class, tag);
+        EventTag eTag = (EventTag) tag;
+        assertEquals(id, eTag.getIdEvent());
+        assertEquals("wss://relay.example.com", eTag.getRecommendedRelayUrl());
+        assertEquals("root", eTag.getMarker().getValue());
+    }
+
+    @Test
+    void testPriceTagDeserialization() throws Exception {
+        String json = "[\"price\",\"10.99\",\"USD\"]";
+        BaseTag tag = MAPPER_AFTERBURNER.readValue(json, BaseTag.class);
+        assertInstanceOf(PriceTag.class, tag);
+        PriceTag pTag = (PriceTag) tag;
+        assertEquals(new BigDecimal("10.99"), pTag.getNumber());
+        assertEquals("USD", pTag.getCurrency());
+    }
+
+    @Test
+    void testUrlTagDeserialization() throws Exception {
+        String json = "[\"u\",\"http://example.com\"]";
+        BaseTag tag = MAPPER_AFTERBURNER.readValue(json, BaseTag.class);
+        assertInstanceOf(UrlTag.class, tag);
+        UrlTag uTag = (UrlTag) tag;
+        assertEquals("http://example.com", uTag.getUrl());
+    }
+
+    @Test
+    void testGenericFallback() throws Exception {
+        String json = "[\"unknown\",\"value\"]";
+        BaseTag tag = MAPPER_AFTERBURNER.readValue(json, BaseTag.class);
+        assertInstanceOf(GenericTag.class, tag);
+        GenericTag gTag = (GenericTag) tag;
+        assertEquals("unknown", gTag.getCode());
+        assertEquals("value", gTag.getAttributes().get(0).getValue());
+    }
+}