add update for did

dids/src/main/kotlin/web5/sdk/dids/did/BearerDid.kt

@@ -61,6 +61,20 @@ public class BearerDid(
     return Pair(signer, verificationMethod)
   }
 
+  /**
+   * Return a copy of the bearer did with any changes provided
+   * If no arguments are provided just returns an immutable copy.
+   *
+   * @return an immutable copy of the BearerDid with any changes applied
+   */
+  @JvmOverloads
+  public fun copy(
+    uri: String = this.uri,
+    did: Did = this.did,
+    keyManager: KeyManager = this.keyManager,
+    document: DidDocument = this.document
+  ) = BearerDid(uri, did, keyManager, document)
+
   /**
    * Converts a `BearerDid` object to a portable format containing the URI and verification methods
    * associated with the DID.

dids/src/main/kotlin/web5/sdk/dids/didcore/DidDocument.kt

@@ -102,6 +102,39 @@ public class DidDocument(
     return if (id.startsWith("#")) "${this.id}$id" else id
   }
 
+  /**
+   * Return a copy of the document with any changes provided.
+   * If no arguments are provided just returns an immutable copy of the DidDocument.
+   *
+   * @return an immutable copy of the DidDocument with any changes applied
+   */
+  @JvmOverloads
+  fun copy(
+    id: String = this.id,
+    context: List<String>? = this.context,
+    alsoKnownAs: List<String>? = this.alsoKnownAs,
+    controller: List<String>? = this.controller,
+    verificationMethod: List<VerificationMethod>? = this.verificationMethod,
+    service: List<Service>? = this.service,
+    assertionMethod: List<String>? = this.assertionMethod,
+    authentication: List<String>? = this.authentication,
+    keyAgreement: List<String>? = this.keyAgreement,
+    capabilityDelegation: List<String>? = this.capabilityDelegation,
+    capabilityInvocation: List<String>? = this.capabilityInvocation
+  ) = DidDocument(
+    id,
+    context,
+    alsoKnownAs,
+    controller,
+    verificationMethod,
+    service,
+    assertionMethod,
+    authentication,
+    keyAgreement,
+    capabilityDelegation,
+    capabilityInvocation
+  )
+
   /**
    * Finds the first available assertion method from the [DidDocument]. When [assertionMethodId]
    * is null, the function will return the first available assertion method.

dids/src/main/kotlin/web5/sdk/dids/methods/dht/DidDht.kt

@@ -97,6 +97,19 @@ public class CreateDidDhtOptions(
   public val alsoKnownAses: Iterable<String>? = null,
 ) : CreateDidOptions
 
+/**
+ * Specifies options for updating a "did:dht" Decentralized Identifier (DID).
+ * Any options not specified will retain the value from the DID being updated.
+ *
+ * @property verificationMethods A list of [Jwk]s to add to the DID Document mapped to their purposes
+ * as verification methods, and an optional controller for the verification method.
+ * @property services A list of [Service]s to add to the DID Document.
+ * @property publish Whether to publish the DID Document to the DHT after creation.
+ * @property controllers A list of controller DIDs to add to the DID Document.
+ * @property alsoKnownAses A list of also known as identifiers to add to the DID Document.
+ */
+public typealias UpdateDidDhtOptions = CreateDidDhtOptions
+
 private const val PROPERTY_SEPARATOR = ";"
 private const val ARRAY_SEPARATOR = ","
 private val logger = KotlinLogging.logger {}
@@ -202,6 +215,47 @@ public sealed class DidDhtApi(configuration: DidDhtConfiguration) {
     return BearerDid(didUri, did, keyManager, didDocument)
   }
 
+  /**
+   * Updates an existing "did:dht" DID by applying the provided changes to the DID Document.
+   *
+   * @param bearerDid The existing "did:dht" DID to update.
+   * @param options Optional parameters ([UpdateDidDhtOptions]) to specify additional keys, services, and optional
+   * publishing during the update.
+   * @return The updated [BearerDid] instance.
+   */
+  public fun update(bearerDid: BearerDid, options: UpdateDidDhtOptions): BearerDid {
+    val existingDidDocument = bearerDid.document
+
+    val updatedServices = options.services ?: existingDidDocument.service
+    val updatedControllers = options.controllers ?: existingDidDocument.controller
+    val updatedAlsoKnownAses = options.alsoKnownAses ?: existingDidDocument.alsoKnownAs
+
+    val updatedVerificationMethods = existingDidDocument.verificationMethod?.toMutableList() ?: mutableListOf()
+    options.verificationMethods?.forEach { (publicKey, purposes, controller) ->
+      val verificationMethod = VerificationMethod.Builder()
+        .id("${existingDidDocument.id}#${publicKey.kid ?: publicKey.computeThumbprint()}")
+        .type("JsonWebKey")
+        .controller(controller ?: existingDidDocument.id)
+        .publicKeyJwk(publicKey)
+        .build()
+      updatedVerificationMethods.add(verificationMethod)
+    }
+
+    val updatedDidDocument = existingDidDocument.copy(
+      service = updatedServices?.toList(),
+      controller = updatedControllers?.toList(),
+      alsoKnownAs = updatedAlsoKnownAses?.toList(),
+      verificationMethod = updatedVerificationMethods
+    )
+
+    val updatedBearerDid = bearerDid.copy(document = updatedDidDocument)
+
+    if (options.publish) {
+      publish(bearerDid.keyManager, updatedDidDocument)
+    }
+
+    return updatedBearerDid
+  }
   /**
    * Resolves a "did:dht" DID into a [DidResolutionResult], which contains the DID Document and possible related
    * metadata.

dids/src/test/kotlin/web5/sdk/dids/did/BearerDidTest.kt

@@ -8,13 +8,41 @@ import org.mockito.kotlin.spy
 import org.mockito.kotlin.verify
 import org.mockito.kotlin.whenever
 import web5.sdk.crypto.InMemoryKeyManager
+import web5.sdk.dids.didcore.DidDocument
+import web5.sdk.dids.didcore.Service
+import web5.sdk.dids.methods.dht.CreateDidDhtOptions
+import web5.sdk.dids.methods.dht.DidDht
+import web5.sdk.dids.methods.dht.UpdateDidDhtOptions
 import web5.sdk.dids.methods.jwk.DidJwk
 import kotlin.test.Test
+import kotlin.test.assertContains
 import kotlin.test.assertEquals
 import kotlin.test.assertNotNull
 
 class BearerDidTest {
 
+  @Test
+  fun `update service endpoint of existing did`() {
+    val keyManager = InMemoryKeyManager()
+    var myBearerDid = DidDht.create(keyManager, CreateDidDhtOptions(publish = true))
+
+    val existingBearerDid: BearerDid = myBearerDid
+
+    val serviceToUpdate = Service.Builder()
+      .id("pfi")
+      .type("PFI")
+      .serviceEndpoint(listOf("https://example.com/"))
+      .build()
+
+    val updatedBearerDid = DidDht.update(existingBearerDid,
+      UpdateDidDhtOptions(services = listOf(serviceToUpdate)))
+
+    DidDht.publish(updatedBearerDid.keyManager, updatedBearerDid.document)
+
+    assertEquals(1, updatedBearerDid.document.service?.size)
+    assertEquals(serviceToUpdate, updatedBearerDid.document.service?.first())
+  }
+
   @Test
   fun `getSigner should return a signer and verification method`() {
     val keyManager = spy(InMemoryKeyManager())