add simple create identity flow

shared/src/commonMain/kotlin/su/reya/coop/Nostr.kt

@@ -3,13 +3,22 @@ package su.reya.coop
 import rust.nostr.sdk.Client
 import rust.nostr.sdk.ClientBuilder
 import rust.nostr.sdk.ClientOptions
+import rust.nostr.sdk.EventBuilder
+import rust.nostr.sdk.Keys
+import rust.nostr.sdk.Metadata
+import rust.nostr.sdk.MetadataRecord
 import rust.nostr.sdk.NostrDatabase
 import rust.nostr.sdk.NostrGossip
+import rust.nostr.sdk.NostrSigner
 import rust.nostr.sdk.RelayUrl
 
 class Nostr {
     var client: Client? = null
         private set
+    var signer: NostrSigner? = null
+        private set
+    var deviceSigner: NostrSigner? = null
+        private set
 
     fun init(dbPath: String) {
         val lmdb = NostrDatabase.lmdb(dbPath)
@@ -29,4 +38,25 @@ class Nostr {
     suspend fun disconnect() {
         this.client?.shutdown()
     }
+
+    suspend fun createIdentity(keys: Keys, name: String, bio: String, picture: String?) {
+        signer = NostrSigner.keys(keys)
+
+        // Construct metadata
+        val metadata = Metadata.fromRecord(
+            MetadataRecord(
+                name = name,
+                displayName = name,
+                about = bio,
+                picture = picture
+            )
+        )
+
+        // Construct event and sign it
+        val builder = EventBuilder.metadata(metadata).build(keys.publicKey())
+        val event = this.signer?.signEvent(builder) ?: return
+
+        // Send event to relays
+        this.client?.sendEvent(event)
+    }
 }