fetch viewer so user id can be passed to segment

android/Omnivore/app/src/main/graphql/Viewer.graphql

@@ -0,0 +1,13 @@
+query Viewer {
+  me {
+    id
+    name
+    isFullUser
+    profile {
+      id
+      username
+      pictureUrl
+      bio
+    }
+  }
+}

android/Omnivore/app/src/main/java/app/omnivore/omnivore/models/Viewer.kt

@@ -0,0 +1,9 @@
+package app.omnivore.omnivore.models
+
+data class Viewer(
+  val id: String,
+  val name: String,
+  val username: String,
+  val pictureUrl: String?,
+)
+

android/Omnivore/app/src/main/java/app/omnivore/omnivore/networking/ViewerQuery.kt

@@ -0,0 +1,20 @@
+package app.omnivore.omnivore.networking
+
+import app.omnivore.omnivore.graphql.generated.ViewerQuery
+import app.omnivore.omnivore.models.Viewer
+
+suspend fun Networker.viewer(): Viewer? {
+  val result = authenticatedApolloClient().query(ViewerQuery()).execute()
+  val me = result.data?.me
+
+  return if (me != null) {
+    Viewer(
+      id = me.id,
+      name = me.name,
+      username = me.profile.username,
+      pictureUrl = me.profile.pictureUrl
+    )
+  } else {
+    null
+  }
+}

android/Omnivore/app/src/main/java/app/omnivore/omnivore/ui/auth/LoginViewModel.kt

@@ -8,6 +8,8 @@ import androidx.lifecycle.viewmodel.compose.viewModel
 import app.omnivore.omnivore.*
 import app.omnivore.omnivore.graphql.generated.SearchQuery
 import app.omnivore.omnivore.graphql.generated.ValidateUsernameQuery
+import app.omnivore.omnivore.networking.Networker
+import app.omnivore.omnivore.networking.viewer
 import com.apollographql.apollo3.ApolloClient
 import com.apollographql.apollo3.api.Optional
 import com.google.android.gms.auth.api.signin.GoogleSignInAccount
@@ -37,7 +39,8 @@ data class PendingEmailUserCreds(
 @HiltViewModel
 class LoginViewModel @Inject constructor(
   private val datastoreRepo: DatastoreRepository,
-  private val eventTracker: EventTracker
+  private val eventTracker: EventTracker,
+  private val networker: Networker
 ): ViewModel() {
   private var validateUsernameJob: Job? = null
 
@@ -92,7 +95,12 @@ class LoginViewModel @Inject constructor(
   }
 
   fun registerUser() {
-    // TODO: eventTracker.registerUser()
+    viewModelScope.launch {
+      val viewer = networker.viewer()
+      viewer?.let {
+        eventTracker.registerUser(viewer.id)
+      }
+    }
   }
 
   private fun resetState() {