add action changes for email sync

lib/mv/email_sync/helpers.ex

@@ -0,0 +1,93 @@
+defmodule Mv.EmailSync.Helpers do
+  @moduledoc """
+  Shared helper functions for email synchronization between User and Member.
+
+  Handles the complexity of `around_transaction` callback results and 
+  provides clean abstractions for email updates within transactions.
+  """
+
+  require Logger
+  import Ecto.Changeset
+
+  @doc """
+  Extracts the record from an Ash action result.
+
+  Handles both 2-tuple `{:ok, record}` and 4-tuple 
+  `{:ok, record, changeset, notifications}` patterns.
+  """
+  def extract_record({:ok, record, _changeset, _notifications}), do: {:ok, record}
+  def extract_record({:ok, record}), do: {:ok, record}
+  def extract_record({:error, _} = error), do: error
+
+  @doc """
+  Updates the result with a new record while preserving the original structure.
+
+  If the original result was a 4-tuple, returns a 4-tuple with the updated record.
+  If it was a 2-tuple, returns a 2-tuple with the updated record.
+  """
+  def update_result_record({:ok, _old_record, changeset, notifications}, new_record) do
+    {:ok, new_record, changeset, notifications}
+  end
+
+  def update_result_record({:ok, _old_record}, new_record) do
+    {:ok, new_record}
+  end
+
+  @doc """
+  Updates an email field directly via Ecto within the current transaction.
+
+  This bypasses Ash's action system to ensure the update happens in the
+  same database transaction as the parent action.
+  """
+  def update_email_via_ecto(record, new_email) do
+    record
+    |> cast(%{email: to_string(new_email)}, [:email])
+    |> Mv.Repo.update()
+  end
+
+  @doc """
+  Synchronizes email to a linked record if it exists.
+
+  Returns the original result unchanged, or an error if sync fails.
+  """
+  def sync_email_to_linked_record(result, linked_record, new_email) do
+    with {:ok, _source} <- extract_record(result),
+         record when not is_nil(record) <- linked_record,
+         {:ok, _updated} <- update_email_via_ecto(record, new_email) do
+      # Successfully synced - return original result unchanged
+      result
+    else
+      nil ->
+        # No linked record - return original result
+        result
+
+      {:error, error} ->
+        # Sync failed - log and propagate error to rollback transaction
+        Logger.error("Email sync failed: #{inspect(error)}")
+        {:error, error}
+    end
+  end
+
+  @doc """
+  Overrides the record's email with the linked email if emails differ.
+
+  Returns updated result with new record, or original result if no update needed.
+  """
+  def override_with_linked_email(result, linked_email) do
+    with {:ok, record} <- extract_record(result),
+         true <- record.email != to_string(linked_email),
+         {:ok, updated_record} <- update_email_via_ecto(record, linked_email) do
+      # Email was different - return result with updated record
+      update_result_record(result, updated_record)
+    else
+      false ->
+        # Emails already match - no update needed
+        result
+
+      {:error, error} ->
+        # Override failed - log and propagate error
+        Logger.error("Email override failed: #{inspect(error)}")
+        {:error, error}
+    end
+  end
+end