Inefficiently fetch email from LDAP directory

lib/recycledcloud/accounts.ex

@@ -23,7 +23,7 @@ defmodule RecycledCloud.Accounts do
 
   """
   def get_user_by_username(username) when is_binary(username) do
-    User.get_by_username(username)
+    User.get_by_username(username) |> User.maybe_populate_email()
   end
 
   @doc """
@@ -58,7 +58,9 @@ defmodule RecycledCloud.Accounts do
       ** (Ecto.NoResultsError)
 
   """
-  def get_user!(id), do: Repo.get!(User, id)
+  def get_user!(id) do
+    Repo.get!(User, id) |> User.maybe_populate_email()
+  end
 
   ## User registration
 
@@ -149,8 +151,9 @@ defmodule RecycledCloud.Accounts do
   defp user_email_multi(user, email, context) do
     changeset = user |> User.email_changeset(%{email: email}) |> User.confirm_changeset()
 
+    # TODO: change email in LDAP here.
+
     Ecto.Multi.new()
-    |> Ecto.Multi.update(:user, changeset)
     |> Ecto.Multi.delete_all(:tokens, UserToken.user_and_contexts_query(user, [context]))
   end
 
@@ -233,7 +236,7 @@ defmodule RecycledCloud.Accounts do
   """
   def get_user_by_session_token(token) do
     {:ok, query} = UserToken.verify_session_token_query(token)
-    Repo.one(query)
+    Repo.one(query) |> User.maybe_populate_email()
   end
 
   @doc """

lib/recycledcloud/accounts/user.ex

@@ -4,7 +4,7 @@ defmodule RecycledCloud.Accounts.User do
   require Logger
   require Exldap
   alias RecycledCloud.{LDAP,Accounts}
-  alias RecycledCloud.Accounts.{User, UserToken, UserNotifier}
+  alias RecycledCloud.Accounts.User
   alias RecycledCloud.Repo
 
   @derive {Inspect, except: [:password]}
@@ -22,10 +22,29 @@ defmodule RecycledCloud.Accounts.User do
     "uid=#{uid},ou=users,dc=recycled,dc=cloud"
   end
 
+  def maybe_populate_email(user) do
+    query = fn ldap_conn -> Exldap.search_field(ldap_conn, :uid, user.username) end
+    case query |> LDAP.execute do
+      {:ok, []} ->
+        user
+      {:ok, result} ->
+        {:ok, entry} = result |> Enum.fetch(0)
+        attributes = entry |> Map.get(:attributes) |> Enum.into(%{})
+        email = attributes
+                |> Map.get('mail')
+                |> Enum.at(0)
+                |> List.to_string
+
+        user |> Map.put(:email, email)
+      {:error, _} ->
+        user
+    end
+  end
+
   def get_by_username(username) when is_binary(username) do
     local_user = Repo.get_by(User, username: username)
     if local_user do
-      Map.put(local_user, :email, "unknown@domain.tld")
+      local_user
     else
       query = fn ldap_conn -> Exldap.search_field(ldap_conn, :uid, username) end
       case query |> LDAP.execute do
@@ -42,12 +61,7 @@ defmodule RecycledCloud.Accounts.User do
                      |> Enum.at(0)
                      |> List.to_string
 
-          email = attributes
+          case Accounts.register_user(%{username: username}) do
-                     |> Map.get('email')
-                     |> Enum.at(0)
-                     |> List.to_string
-
-          case Accounts.register_user(%{username: username, email: email}) do
             {:ok, user} -> user
             {:error, _} -> nil
           end

lib/recycledcloud_web/templates/user_settings/edit.html.eex

@@ -1,7 +1,7 @@
 <h1>Account settings</h1>
 
 <p>
-You are currently logged in as <i><%= @current_user.username %></i>, using <%
+You are currently logged in as <i><%= @current_user.username %></i>, using <%=
 @current_user.email %> as primary contact method.
 </p>