ScriptType: add ID string, deprecate numeric ID

core/src/main/java/org/bitcoinj/base/ScriptType.java

@@ -16,20 +16,85 @@
 
 package org.bitcoinj.base;
 
+import java.util.Arrays;
+import java.util.Optional;
+
 /**
- * Enumeration of Bitcoin script types.
+ * Supported Bitcoin script types and their <i>script identifier strings</i>. The <i>script identifier string</i> for a {@code ScriptType}
+ * is the "human-readable identifier string" of a <i>Script Expression</i> as defined in
+ * <a href="https://github.com/bitcoin/bips/blob/master/bip-0380.mediawiki">BIP 380</a>.
+ * Only the subset of identifier strings defined in
+ * <a href="https://github.com/bitcoin/bips/blob/master/bip-0381.mediawiki">BIP 381</a> and
+ * <a href="https://github.com/bitcoin/bips/blob/master/bip-0382.mediawiki">BIP 382</a> map to valid {@code ScriptType} instances.
+ * @see <a href="https://github.com/bitcoin/bips/blob/master/bip-0380.mediawiki">BIP 380: Output Script Descriptors General Operation</a>
+ * @see <a href="https://github.com/bitcoin/bips/blob/master/bip-0381.mediawiki">BIP 381: Non-Segwit Output Script Descriptors</a>
+ * @see <a href="https://github.com/bitcoin/bips/blob/master/bip-0382.mediawiki">BIP 382: Segwit Output Script Descriptors</a>
  */
 public enum ScriptType {
-    P2PKH(1), // pay to pubkey hash (aka pay to address)
-    P2PK(2), // pay to pubkey
-    P2SH(3), // pay to script hash
-    P2WPKH(4), // pay to witness pubkey hash
-    P2WSH(5), // pay to witness script hash
-    P2TR(6); // pay to taproot
+    P2PKH("pkh", 1),    // pay to pubkey hash (aka pay to address)
+    P2PK("pk", 2),      // pay to pubkey
+    P2SH("sh", 3),      // pay to script hash
+    P2WPKH("wpkh", 4),  // pay to witness pubkey hash
+    P2WSH("wsh", 5),    // pay to witness script hash
+    P2TR("tr", 6);      // pay to taproot
 
+    private final String scriptIdentifierString;
+
+    /**
+     * @deprecated Use {@link #numericId()} or better yet use {@link #id()} to get a script identifier string
+     */
+    @Deprecated
     public final int id;
 
-    ScriptType(int id) {
-        this.id = id;
+    /**
+     * @param id script identifier string
+     * @param numericId numeric id for (temporary?) backward-compatibility
+     */
+    ScriptType(String id, int numericId) {
+        this.scriptIdentifierString = id;
+        this.id = numericId;
+    }
+
+    /**
+     * Use this method to create a {@code ScriptType} from a known good <i>script identifier string</i>.
+     * @param id A script identifier string
+     * @return the script type
+     * @throws IllegalArgumentException if unknown/invalid script identifier string
+     */
+    public static ScriptType of(String id) {
+        return find(id)
+                .orElseThrow(() -> new IllegalArgumentException("Unknown ScriptType ID"));
+    }
+
+    /**
+     * Use this method to create a {@code ScriptType} from a <i>script identifier string</i> that should be
+     * validated.
+     * @param id A script identifier string
+     * @return A {@code ScriptType}-containing {@code Optional} or {@link Optional#empty()}
+     */
+    public static Optional<ScriptType> find(String id) {
+        return Arrays.stream(values())
+                .filter(v -> v.id().equals(id))
+                .findFirst();
+    }
+
+    /**
+     * Return the <i>script identifier string</i> for this {@code ScriptType}.
+     * <p>
+     * Be careful: the {@link #id()} method returns a different type and value than what is in the {@code deprecated} {@link #id} field.
+     * @return A <i>script identifier string</i>
+     */
+    public String id() {
+        return scriptIdentifierString;
+    }
+
+    /**
+     * This is deprecated. But less deprecated than accessing the {@link #id} field directly.
+     * @return A numeric ID
+     * @deprecated Using {@link #id()} to get a script identifier string is preferred.
+     */
+    @Deprecated
+    public int numericId() {
+        return id;
     }
 }

core/src/main/java/org/bitcoinj/store/DatabaseFullPrunedBlockStore.java

@@ -959,7 +959,7 @@ public abstract class DatabaseFullPrunedBlockStore implements FullPrunedBlockSto
             s.setBytes(5, out.getScript().getProgram());
             s.setString(6, out.getAddress());
             ScriptType scriptType = out.getScript().getScriptType();
-            s.setInt(7, scriptType != null ? scriptType.id : 0);
+            s.setInt(7, scriptType != null ? scriptType.numericId() : 0);
             s.setBoolean(8, out.isCoinbase());
             s.executeUpdate();
             s.close();