Update email login cases - only 422 email exist case can success now

lib/recognizer/accounts.ex

@@ -652,8 +652,16 @@ defmodule Recognizer.Accounts do
   settings.
   """
   def check_two_factor_notification_time(user) do
-    {:ok, attrs} = get_new_two_factor_settings(user)
-    check_two_factor_notification_time(attrs, 100)
+    case get_new_two_factor_settings(user) do
+      {:ok, attrs} when not is_nil(attrs) ->
+        check_two_factor_notification_time(attrs, 100)
+
+      {:ok, nil} ->
+        {:error, :no_two_factor_settings}
+
+      {:error, reason} ->
+        {:error, reason}
+    end
   end
 
   def check_two_factor_notification_time(attrs, two_factor_issue_time) do

lib/recognizer/bigcommerce.ex

@@ -16,16 +16,70 @@ defmodule Recognizer.BigCommerce do
 
   def create_customer(user) do
     case Client.create_customer(user) do
-      {:ok, bc_id} ->
-        Repo.insert(%Customer{user_id: user.id, bc_id: bc_id})
-        {:ok, user}
+      {:ok, :email_already_exists} ->
+        handle_email_already_exists(user)
+
+      {:ok, bc_id} when is_integer(bc_id) ->
+        handle_new_customer_created(user, bc_id)
 
       {:error, e} ->
-        Logger.error("error creating bigcommerce customer: #{inspect(e)}")
-        {:error, e}
+        handle_customer_creation_error(user, e)
+    end
+  end
+
+  defp handle_email_already_exists(user) do
+    Logger.info("BigCommerce customer email already exists for user #{user.id}, attempting to link existing customer")
+
+    case Client.get_customers(emails: [user.email]) do
+      {:ok, [customer_id | _]} ->
+        link_existing_customer(user, customer_id)
+
+      {:ok, []} ->
+        handle_customer_not_found_error(user)
+
+      {:error, e} ->
+        handle_get_customers_error(user, e)
     end
   end
 
+  defp link_existing_customer(user, customer_id) do
+    case Repo.insert(%Customer{user_id: user.id, bc_id: customer_id}) do
+      {:ok, _} ->
+        Logger.info("Successfully linked existing BigCommerce customer #{customer_id} to user #{user.id}")
+        {:ok, user}
+
+      {:error, changeset} ->
+        Logger.error("Failed to link BigCommerce customer to user: #{inspect(changeset)}")
+        {:error, {:bigcommerce_link_failed, changeset}}
+    end
+  end
+
+  defp handle_customer_not_found_error(user) do
+    Logger.error("BigCommerce reported email exists but customer not found via API for user #{user.id}")
+    {:error, {:bigcommerce_customer_not_found, "Email exists but customer not found"}}
+  end
+
+  defp handle_get_customers_error(user, e) do
+    Logger.error("Failed to get existing BigCommerce customer for user #{user.id}: #{inspect(e)}")
+    {:error, {:bigcommerce_api_error, e}}
+  end
+
+  defp handle_new_customer_created(user, bc_id) do
+    case Repo.insert(%Customer{user_id: user.id, bc_id: bc_id}) do
+      {:ok, _} ->
+        {:ok, user}
+
+      {:error, changeset} ->
+        Logger.error("Failed to save BigCommerce customer ID to database: #{inspect(changeset)}")
+        {:ok, user}
+    end
+  end
+
+  defp handle_customer_creation_error(user, e) do
+    Logger.error("BigCommerce customer creation failed for user #{user.id}: #{inspect(e)}")
+    {:error, e}
+  end
+
   def get_or_create_customer(%{email: email, id: id} = user) do
     Logger.info("Starting BigCommerce get_or_create_customer for user #{id} with email #{email}")
 
@@ -54,17 +108,13 @@ defmodule Recognizer.BigCommerce do
 
       {:error, e} ->
         Logger.error("Error while getting BigCommerce customer: #{inspect(e)}")
-        # Don't fail account creation due to BigCommerce API errors
-        # This ensures verification emails are still sent
-        Logger.info("Continuing account creation process despite BigCommerce error")
-        {:ok, user}
+        # Apply strict approach: fail account creation for BigCommerce API errors
+        {:error, e}
 
       e ->
         Logger.error("Unexpected error while getting or creating BigCommerce customer: #{inspect(e)}")
-        # Don't fail account creation due to BigCommerce errors
-        # This ensures verification emails are still sent
-        Logger.info("Continuing account creation process despite unexpected BigCommerce error")
-        {:ok, user}
+        # Apply strict approach: fail account creation for unexpected errors
+        {:error, "Unexpected BigCommerce error"}
     end
   end
 
@@ -75,11 +125,16 @@ defmodule Recognizer.BigCommerce do
 
   def update_customer(user) do
     case Client.update_customer(Repo.preload(user, :bigcommerce_user)) do
+      {:ok, :email_already_exists} ->
+        # When updating, email already exists is actually a success condition
+        Logger.info("BigCommerce customer update: email already exists for user #{user.id}, treating as success")
+        {:ok, user}
+
       {:ok, _} ->
         {:ok, user}
 
       {:error, e} ->
-        Logger.error("error creating bigcommerce customer: #{inspect(e)}")
+        Logger.error("BigCommerce customer update failed: #{inspect(e)}")
         {:error, e}
     end
   end

lib/recognizer/bigcommerce/client.ex

@@ -48,6 +48,9 @@ defmodule Recognizer.BigCommerce.Client do
       {:ok, %Response{body: response, status_code: 200}} ->
         {:ok, response}
 
+      {:ok, %Response{status_code: 422, body: body}} ->
+        handle_422_error(body, "create")
+
       {:ok, %Response{status_code: 429, headers: headers}} ->
         sleep_for_rate_limit(headers)
         post_customer(customer_json)
@@ -65,6 +68,9 @@ defmodule Recognizer.BigCommerce.Client do
       {:ok, %Response{body: response, status_code: 200}} ->
         {:ok, response}
 
+      {:ok, %Response{status_code: 422, body: body}} ->
+        handle_422_error(body, "update")
+
       {:ok, %Response{status_code: 429, headers: headers}} ->
         sleep_for_rate_limit(headers)
         put_customer(customer_json)
@@ -77,6 +83,36 @@ defmodule Recognizer.BigCommerce.Client do
     end
   end
 
+  # Precisely analyze 422 errors to determine if it's email duplication
+  defp handle_422_error(body, operation) do
+    case Jason.decode(body) do
+      {:ok, %{"errors" => %{".customer_update" => error}}} when is_binary(error) ->
+        if String.contains?(String.downcase(error), "email") and
+             String.contains?(String.downcase(error), "already in use") do
+          Logger.info("BigCommerce customer #{operation}: email already exists, treating as success - #{error}")
+          {:ok, :email_already_exists}
+        else
+          Logger.error("BigCommerce customer #{operation} failed with validation error: #{error}")
+          {:error, {:validation_error, error}}
+        end
+
+      {:ok, %{"errors" => errors}} ->
+        Logger.error("BigCommerce customer #{operation} failed with errors: #{inspect(errors)}")
+        {:error, {:validation_errors, errors}}
+
+      {:ok, decoded} ->
+        Logger.error("BigCommerce customer #{operation} failed with unexpected 422 response: #{inspect(decoded)}")
+        {:error, {:unexpected_422, decoded}}
+
+      {:error, json_error} ->
+        Logger.error(
+          "BigCommerce customer #{operation} failed with unparseable 422 response: #{body}, JSON error: #{inspect(json_error)}"
+        )
+
+        {:error, {:unparseable_422, body}}
+    end
+  end
+
   def get_customers(queries \\ []) do
     with params <- customer_queries_as_params(queries),
          full_uri <- customers_uri(),
@@ -125,10 +161,17 @@ defmodule Recognizer.BigCommerce.Client do
   end
 
   defp get_id(response) do
-    case Jason.decode(response) do
-      {:ok, %{"data" => [%{"id" => id}]}} -> {:ok, id}
-      {:error, e} -> {:error, e}
-      e -> {:error, e}
+    case response do
+      :email_already_exists ->
+        # If email already exists, return special response for upper level handling
+        {:ok, :email_already_exists}
+
+      _ ->
+        case Jason.decode(response) do
+          {:ok, %{"data" => [%{"id" => id}]}} -> {:ok, id}
+          {:error, e} -> {:error, e}
+          e -> {:error, e}
+        end
     end
   end
 

lib/recognizer_web/controllers/accounts/prompt/two_factor_controller.ex

@@ -25,12 +25,24 @@ defmodule RecognizerWeb.Accounts.Prompt.TwoFactorController do
 
   def edit(conn, _params) do
     user = conn.assigns.user
-    {:ok, %{two_factor_seed: seed}} = Accounts.get_new_two_factor_settings(user)
 
-    render(conn, "confirm.html",
-      barcode: Authentication.generate_totp_barcode(user, seed),
-      totp_app_url: Authentication.get_totp_app_url(user, seed)
-    )
+    case Accounts.get_new_two_factor_settings(user) do
+      {:ok, %{two_factor_seed: seed}} ->
+        render(conn, "confirm.html",
+          barcode: Authentication.generate_totp_barcode(user, seed),
+          totp_app_url: Authentication.get_totp_app_url(user, seed)
+        )
+
+      {:ok, nil} ->
+        conn
+        |> put_flash(:error, "Two factor setup not found. Please set up two factor authentication first.")
+        |> redirect(to: Routes.prompt_two_factor_path(conn, :new))
+
+      {:error, _reason} ->
+        conn
+        |> put_flash(:error, "Error retrieving two factor settings. Please try again.")
+        |> redirect(to: Routes.prompt_two_factor_path(conn, :new))
+    end
   end
 
   def update(conn, params) do