feat: prevent join requests with equal mail

docs/onboarding-join-concept.md

@@ -196,7 +196,7 @@ Implementation spec for Subtask 5.
 - **Pre-confirmation store:** **DB only.** Same JoinRequest resource; no ETS, no stateless token. Confirmation token stored as **hash** in DB; raw token only in email link. **24h** retention for `pending_confirmation`; **hard-delete** of expired records via scheduled job (e.g. Oban cron).
 - **Confirmation route:** **`/confirm_join/:token`** so existing `starts_with?(path, "/confirm")` covers it.
 - **Public path for `/join`:** **Add `/join` explicitly** to the page-permission plug’s `public_path?/1` (e.g. in `CheckPagePermission`) so unauthenticated users can reach the join page.
-- **JoinRequest schema:** Status `pending_confirmation` | `submitted` | `approved` | `rejected`. Typed: **email** (required), **first_name**, **last_name** (optional). **form_data** (jsonb) + **schema_version** for remaining form fields. **confirmation_token_hash**, **confirmation_token_expires_at**; **submitted_at**, **approved_at**, **rejected_at**, **reviewed_by_user_id** for audit. Idempotent confirm (unique constraint on token hash or update only when status is `pending_confirmation`).
+- **JoinRequest schema:** Status `pending_confirmation` | `submitted` | `approved` | `rejected`. Typed: **email** (required), **first_name**, **last_name** (optional). **form_data** (jsonb) + **schema_version** for remaining form fields. **confirmation_token_hash**, **confirmation_token_expires_at**; **submitted_at**, **approved_at**, **rejected_at**, **reviewed_by_user_id**, **reviewed_by_display** (denormalized reviewer email for "Geprüft von" without loading User) for audit. Idempotent confirm (unique constraint on token hash or update only when status is `pending_confirmation`).
 - **Approval outcome:** Admin-configurable. Default: approval creates Member only (no User). Optional "create User on approval" is **left for later**.
 - **Rate limiting:** Honeypot + rate limiting from the start (e.g. Hammer.Plug).
 - **Settings:** Own section "Onboarding / Join" in global settings; `join_form_enabled` plus field selection; display as list/badges; detailed UX in a **separate subtask**.

lib/membership/join_request.ex

@@ -77,6 +77,17 @@ defmodule Mv.Membership.JoinRequest do
 
       change Mv.Membership.JoinRequest.Changes.RejectRequest
     end
+
+    # Internal: resend confirmation (new token) when user submits form again with same email.
+    # Called from domain with authorize?: false; not exposed to public.
+    update :regenerate_confirmation_token do
+      description "Set new confirmation token and expiry (resend flow)"
+      require_atomic? false
+
+      argument :confirmation_token, :string, allow_nil?: false
+
+      change Mv.Membership.JoinRequest.Changes.RegenerateConfirmationToken
+    end
   end
 
   policies do
@@ -175,6 +186,11 @@ defmodule Mv.Membership.JoinRequest do
     attribute :approved_at, :utc_datetime_usec
     attribute :rejected_at, :utc_datetime_usec
     attribute :reviewed_by_user_id, :uuid
+
+    attribute :reviewed_by_display, :string do
+      description "Denormalized reviewer display (e.g. email) for UI without loading User"
+    end
+
     attribute :source, :string
 
     create_timestamp :inserted_at

lib/membership/join_request/changes/approve_request.ex

@@ -16,11 +16,13 @@ defmodule Mv.Membership.JoinRequest.Changes.ApproveRequest do
 
     if current_status == :submitted do
       reviewed_by_id = Helpers.actor_id(context.actor)
+      reviewed_by_display = Helpers.actor_email(context.actor)
 
       changeset
       |> Ash.Changeset.force_change_attribute(:status, :approved)
       |> Ash.Changeset.force_change_attribute(:approved_at, DateTime.utc_now())
       |> Ash.Changeset.force_change_attribute(:reviewed_by_user_id, reviewed_by_id)
+      |> Ash.Changeset.force_change_attribute(:reviewed_by_display, reviewed_by_display)
     else
       Ash.Changeset.add_error(changeset,
         field: :status,

lib/membership/join_request/changes/helpers.ex

@@ -16,4 +16,24 @@ defmodule Mv.Membership.JoinRequest.Changes.Helpers do
   end
 
   def actor_id(_), do: nil
+
+  @doc """
+  Extracts the actor's email for display (e.g. reviewed_by_display).
+
+  Supports both atom and string keys for compatibility with different actor representations.
+  """
+  @spec actor_email(term()) :: String.t() | nil
+  def actor_email(nil), do: nil
+
+  def actor_email(actor) when is_map(actor) do
+    raw = Map.get(actor, :email) || Map.get(actor, "email")
+    if is_nil(raw), do: nil, else: actor_email_string(raw)
+  end
+
+  def actor_email(_), do: nil
+
+  defp actor_email_string(raw) do
+    s = raw |> to_string() |> String.trim()
+    if s == "", do: nil, else: s
+  end
 end

lib/membership/join_request/changes/regenerate_confirmation_token.ex

@@ -0,0 +1,30 @@
+defmodule Mv.Membership.JoinRequest.Changes.RegenerateConfirmationToken do
+  @moduledoc """
+  Sets a new confirmation token hash and expiry on an existing join request (resend flow).
+
+  Used when the user submits the join form again with the same email while a request
+  is still pending_confirmation. Internal use only (domain calls with authorize?: false).
+  """
+  use Ash.Resource.Change
+
+  alias Mv.Membership.JoinRequest
+
+  @confirmation_validity_hours 24
+
+  @spec change(Ash.Changeset.t(), keyword(), Ash.Resource.Change.context()) :: Ash.Changeset.t()
+  def change(changeset, _opts, _context) do
+    token = Ash.Changeset.get_argument(changeset, :confirmation_token)
+
+    if is_binary(token) and token != "" do
+      hash = JoinRequest.hash_confirmation_token(token)
+      expires_at = DateTime.utc_now() |> DateTime.add(@confirmation_validity_hours, :hour)
+
+      changeset
+      |> Ash.Changeset.force_change_attribute(:confirmation_token_hash, hash)
+      |> Ash.Changeset.force_change_attribute(:confirmation_token_expires_at, expires_at)
+      |> Ash.Changeset.force_change_attribute(:confirmation_sent_at, DateTime.utc_now())
+    else
+      changeset
+    end
+  end
+end

lib/membership/join_request/changes/reject_request.ex

@@ -15,11 +15,13 @@ defmodule Mv.Membership.JoinRequest.Changes.RejectRequest do
 
     if current_status == :submitted do
       reviewed_by_id = Helpers.actor_id(context.actor)
+      reviewed_by_display = Helpers.actor_email(context.actor)
 
       changeset
       |> Ash.Changeset.force_change_attribute(:status, :rejected)
       |> Ash.Changeset.force_change_attribute(:rejected_at, DateTime.utc_now())
       |> Ash.Changeset.force_change_attribute(:reviewed_by_user_id, reviewed_by_id)
+      |> Ash.Changeset.force_change_attribute(:reviewed_by_display, reviewed_by_display)
     else
       Ash.Changeset.add_error(changeset,
         field: :status,

lib/membership/membership.ex

@@ -29,7 +29,11 @@ defmodule Mv.Membership do
   require Ash.Query
   import Ash.Expr
   alias Ash.Error.Query.NotFound, as: NotFoundError
+  alias Mv.Helpers.SystemActor
   alias Mv.Membership.JoinRequest
+  alias Mv.Membership.Member
+  alias MvWeb.Emails.JoinAlreadyMemberEmail
+  alias MvWeb.Emails.JoinAlreadyPendingEmail
   alias MvWeb.Emails.JoinConfirmationEmail
   require Logger
 
@@ -365,15 +369,130 @@ defmodule Mv.Membership do
 
   ## Returns
     - `{:ok, request}` - Created JoinRequest in status pending_confirmation, email sent
+    - `{:ok, :notified_already_member}` - Email already a member; notice sent by email only (no request created)
+    - `{:ok, :notified_already_pending}` - Email already has pending/submitted request; notice or resend sent by email only
     - `{:error, :email_delivery_failed}` - Request created but confirmation email could not be sent (logged)
     - `{:error, error}` - Validation or authorization error
   """
   def submit_join_request(attrs, opts \\ []) do
     actor = Keyword.get(opts, :actor)
-    token = Map.get(attrs, :confirmation_token) || generate_confirmation_token()
+    email = normalize_submit_email(attrs)
 
-    # Raw token is passed to the submit action; JoinRequest.Changes.SetConfirmationToken
-    # hashes it before persist. Only the hash is stored; the raw token is sent in the email link.
+    pending =
+      if email != nil and email != "", do: pending_join_request_with_email(email), else: nil
+
+    cond do
+      email != nil and email != "" and member_exists_with_email?(email) ->
+        send_already_member_and_return(email)
+
+      pending != nil ->
+        handle_already_pending(email, pending)
+
+      true ->
+        do_create_join_request(attrs, actor)
+    end
+  end
+
+  defp normalize_submit_email(attrs) do
+    raw = attrs["email"] || attrs[:email]
+    if is_binary(raw), do: String.trim(raw), else: nil
+  end
+
+  defp member_exists_with_email?(email) when is_binary(email) do
+    system_actor = SystemActor.get_system_actor()
+    opts = [actor: system_actor, domain: __MODULE__]
+
+    case Ash.get(Member, %{email: email}, opts) do
+      {:ok, _member} -> true
+      _ -> false
+    end
+  end
+
+  defp member_exists_with_email?(_), do: false
+
+  defp pending_join_request_with_email(email) when is_binary(email) do
+    system_actor = SystemActor.get_system_actor()
+
+    query =
+      JoinRequest
+      |> Ash.Query.filter(expr(email == ^email and status in [:pending_confirmation, :submitted]))
+      |> Ash.Query.sort(inserted_at: :desc)
+      |> Ash.Query.limit(1)
+
+    case Ash.read_one(query, actor: system_actor, domain: __MODULE__) do
+      {:ok, request} -> request
+      _ -> nil
+    end
+  end
+
+  defp pending_join_request_with_email(_), do: nil
+
+  defp apply_anti_enumeration_delay do
+    Process.sleep(100 + :rand.uniform(200))
+  end
+
+  defp send_already_member_and_return(email) do
+    case JoinAlreadyMemberEmail.send(email) do
+      {:ok, _} ->
+        :ok
+
+      {:error, reason} ->
+        Logger.error("Join already-member email failed for #{email}: #{inspect(reason)}")
+    end
+
+    apply_anti_enumeration_delay()
+    {:ok, :notified_already_member}
+  end
+
+  defp handle_already_pending(email, existing) do
+    if existing.status == :pending_confirmation do
+      resend_confirmation_to_pending(email, existing)
+    else
+      send_already_pending_and_return(email)
+    end
+  end
+
+  defp resend_confirmation_to_pending(email, request) do
+    new_token = generate_confirmation_token()
+
+    case request
+         |> Ash.Changeset.for_update(:regenerate_confirmation_token, %{
+           confirmation_token: new_token
+         })
+         |> Ash.update(domain: __MODULE__, authorize?: false) do
+      {:ok, _updated} ->
+        case JoinConfirmationEmail.send(email, new_token, resend: true) do
+          {:ok, _} ->
+            :ok
+
+          {:error, reason} ->
+            Logger.error("Join resend confirmation email failed for #{email}: #{inspect(reason)}")
+        end
+
+        apply_anti_enumeration_delay()
+        {:ok, :notified_already_pending}
+
+      {:error, _} ->
+        # Fallback: do not create duplicate; send generic pending email
+        send_already_pending_and_return(email)
+    end
+  end
+
+  defp send_already_pending_and_return(email) do
+    case JoinAlreadyPendingEmail.send(email) do
+      {:ok, _} ->
+        :ok
+
+      {:error, reason} ->
+        Logger.error("Join already-pending email failed for #{email}: #{inspect(reason)}")
+    end
+
+    apply_anti_enumeration_delay()
+    {:ok, :notified_already_pending}
+  end
+
+  defp do_create_join_request(attrs, actor) do
+    token = Map.get(attrs, :confirmation_token) || generate_confirmation_token()
     attrs_with_token = Map.put(attrs, :confirmation_token, token)
 
     case Ash.create(JoinRequest, attrs_with_token,
@@ -384,6 +503,7 @@ defmodule Mv.Membership do
       {:ok, request} ->
         case JoinConfirmationEmail.send(request.email, token) do
           {:ok, _email} ->
+            apply_anti_enumeration_delay()
             {:ok, request}
 
           {:error, reason} ->

lib/mv_web/emails/join_already_member_email.ex

@@ -0,0 +1,42 @@
+defmodule MvWeb.Emails.JoinAlreadyMemberEmail do
+  @moduledoc """
+  Sends an email when someone submits the join form with an address that is already a member.
+
+  Used for anti-enumeration: the UI shows the same success message; only the email
+  informs the recipient. Uses the unified email layout.
+  """
+  use Phoenix.Swoosh,
+    view: MvWeb.EmailsView,
+    layout: {MvWeb.EmailLayoutView, "layout.html"}
+
+  use MvWeb, :verified_routes
+  import Swoosh.Email
+  use Gettext, backend: MvWeb.Gettext, otp_app: :mv
+
+  alias Mv.Mailer
+
+  @doc """
+  Sends the "already a member" notice to the given address.
+
+  Returns `{:ok, email}` on success, `{:error, reason}` on delivery failure.
+  """
+  def send(email_address) when is_binary(email_address) do
+    subject = gettext("Membership application – already a member")
+
+    assigns = %{
+      subject: subject,
+      app_name: Mailer.mail_from() |> elem(0),
+      locale: Gettext.get_locale(MvWeb.Gettext)
+    }
+
+    email =
+      new()
+      |> from(Mailer.mail_from())
+      |> to(email_address)
+      |> subject(subject)
+      |> put_view(MvWeb.EmailsView)
+      |> render_body("join_already_member.html", assigns)
+
+    Mailer.deliver(email, Mailer.smtp_config())
+  end
+end

lib/mv_web/emails/join_already_pending_email.ex

@@ -0,0 +1,43 @@
+defmodule MvWeb.Emails.JoinAlreadyPendingEmail do
+  @moduledoc """
+  Sends an email when someone submits the join form with an address that already
+  has a submitted (confirmed) application under review.
+
+  Used for anti-enumeration: the UI shows the same success message; only the email
+  informs the recipient. Uses the unified email layout.
+  """
+  use Phoenix.Swoosh,
+    view: MvWeb.EmailsView,
+    layout: {MvWeb.EmailLayoutView, "layout.html"}
+
+  use MvWeb, :verified_routes
+  import Swoosh.Email
+  use Gettext, backend: MvWeb.Gettext, otp_app: :mv
+
+  alias Mv.Mailer
+
+  @doc """
+  Sends the "application already under review" notice to the given address.
+
+  Returns `{:ok, email}` on success, `{:error, reason}` on delivery failure.
+  """
+  def send(email_address) when is_binary(email_address) do
+    subject = gettext("Membership application – already under review")
+
+    assigns = %{
+      subject: subject,
+      app_name: Mailer.mail_from() |> elem(0),
+      locale: Gettext.get_locale(MvWeb.Gettext)
+    }
+
+    email =
+      new()
+      |> from(Mailer.mail_from())
+      |> to(email_address)
+      |> subject(subject)
+      |> put_view(MvWeb.EmailsView)
+      |> render_body("join_already_pending.html", assigns)
+
+    Mailer.deliver(email, Mailer.smtp_config())
+  end
+end

lib/mv_web/emails/join_confirmation_email.ex

@@ -18,10 +18,16 @@ defmodule MvWeb.Emails.JoinConfirmationEmail do
   Uses the same SMTP configuration as the test mail (Settings or boot ENV) via
   `Mailer.deliver/2` with `Mailer.smtp_config/0` for consistency.
 
-  Called from the domain after a JoinRequest is created (submit flow).
+  Called from the domain after a JoinRequest is created (submit flow) or when
+  resending to an existing pending request.
+
+  ## Options
+    - `:resend` - If true, adds a short note that the link is being sent again for an existing request.
+
   Returns `{:ok, email}` on success, `{:error, reason}` on delivery failure.
   """
-  def send(email_address, token) when is_binary(email_address) and is_binary(token) do
+  def send(email_address, token, opts \\ [])
+      when is_binary(email_address) and is_binary(token) do
     confirm_url = url(~p"/confirm_join/#{token}")
     subject = gettext("Confirm your membership request")
 
@@ -29,7 +35,8 @@ defmodule MvWeb.Emails.JoinConfirmationEmail do
       confirm_url: confirm_url,
       subject: subject,
       app_name: Mailer.mail_from() |> elem(0),
-      locale: Gettext.get_locale(MvWeb.Gettext)
+      locale: Gettext.get_locale(MvWeb.Gettext),
+      resend: Keyword.get(opts, :resend, false)
     }
 
     email =

lib/mv_web/live/join_request_live/helpers.ex

@@ -21,9 +21,24 @@ defmodule MvWeb.JoinRequestLive.Helpers do
   @doc """
   Returns the reviewer display string (e.g. email) for a join request, or nil if none.
 
-  Accepts a join request struct or map with optional :reviewed_by_user (loaded User struct).
+  Prefers the denormalized :reviewed_by_display (set on approve/reject) so the UI
+  works for all roles without loading the User resource. Falls back to
+  :reviewed_by_user when loaded (e.g. admin or legacy data before backfill).
   """
   def reviewer_display(req) when is_map(req) do
+    case Map.get(req, :reviewed_by_display) do
+      s when is_binary(s) ->
+        trimmed = String.trim(s)
+        if trimmed == "", do: reviewer_display_from_user(req), else: trimmed
+
+      _ ->
+        reviewer_display_from_user(req)
+    end
+  end
+
+  def reviewer_display(_), do: nil
+
+  defp reviewer_display_from_user(req) do
     user = Map.get(req, :reviewed_by_user)
 
     case user do
@@ -42,6 +57,4 @@ defmodule MvWeb.JoinRequestLive.Helpers do
         nil
     end
   end
-
-  def reviewer_display(_), do: nil
 end

lib/mv_web/live/join_request_live/show.ex

@@ -264,11 +264,16 @@ defmodule MvWeb.JoinRequestLive.Show do
   defp format_applicant_value(nil), do: nil
   defp format_applicant_value(""), do: nil
   defp format_applicant_value(%Date{} = date), do: DateFormatter.format_date(date)
-  defp format_applicant_value(value) when is_map(value), do: format_applicant_value_from_map(value)
+
+  defp format_applicant_value(value) when is_map(value),
+    do: format_applicant_value_from_map(value)
+
   defp format_applicant_value(value) when is_boolean(value),
     do: if(value, do: gettext("Yes"), else: gettext("No"))
+
   defp format_applicant_value(value) when is_binary(value) or is_number(value),
     do: to_string(value)
+
   defp format_applicant_value(value), do: to_string(value)
 
   defp format_applicant_value_from_map(value) do
@@ -283,8 +288,10 @@ defmodule MvWeb.JoinRequestLive.Show do
   end
 
   defp format_applicant_value_simple(raw, _value) when is_binary(raw), do: raw
+
   defp format_applicant_value_simple(raw, _value) when is_boolean(raw),
     do: if(raw, do: gettext("Yes"), else: gettext("No"))
+
   defp format_applicant_value_simple(raw, _value) when is_integer(raw), do: to_string(raw)
   defp format_applicant_value_simple(_raw, value), do: to_string(value)
 

lib/mv_web/templates/emails/join_already_member.html.heex

@@ -0,0 +1,10 @@
+<div style="color: #111827;">
+  <p style="margin: 0 0 16px; font-size: 16px; line-height: 1.5;">
+    {gettext(
+      "We have received your request. The email address you entered is already registered as a member."
+    )}
+  </p>
+  <p style="margin: 0; font-size: 14px; color: #6b7280;">
+    {gettext("If you have any questions, please contact us.")}
+  </p>
+</div>

lib/mv_web/templates/emails/join_already_pending.html.heex

@@ -0,0 +1,10 @@
+<div style="color: #111827;">
+  <p style="margin: 0 0 16px; font-size: 16px; line-height: 1.5;">
+    {gettext(
+      "We have received your request. You already have a membership application that is being reviewed."
+    )}
+  </p>
+  <p style="margin: 0; font-size: 14px; color: #6b7280;">
+    {gettext("If you have any questions, please contact us.")}
+  </p>
+</div>

lib/mv_web/templates/emails/join_confirmation.html.heex

@@ -1,4 +1,9 @@
 <div style="color: #111827;">
+  <%= if @resend do %>
+    <p style="margin: 0 0 16px; font-size: 16px; line-height: 1.5;">
+      {gettext("You already had a pending request. Here is a new confirmation link.")}
+    </p>
+  <% end %>
   <p style="margin: 0 0 16px; font-size: 16px; line-height: 1.5;">
     {gettext(
       "We have received your membership request. To complete it, please click the link below."

priv/gettext/de/LC_MESSAGES/default.po

@@ -3800,3 +3800,34 @@ msgstr "Status und Prüfung"
 #, elixir-autogen, elixir-format
 msgid "We could not send the confirmation email. Please try again later or contact support."
 msgstr "Die Bestätigungs-E-Mail konnte nicht versendet werden. Bitte versuche es später erneut oder wende dich an den Support."
+
+#: lib/mv_web/templates/emails/join_already_member.html.heex
+#: lib/mv_web/templates/emails/join_already_pending.html.heex
+#, elixir-autogen, elixir-format
+msgid "If you have any questions, please contact us."
+msgstr "Bei Fragen kannst du dich gerne an uns wenden."
+
+#: lib/mv_web/emails/join_already_member_email.ex
+#, elixir-autogen, elixir-format
+msgid "Membership application – already a member"
+msgstr "Mitgliedsantrag – bereits Mitglied"
+
+#: lib/mv_web/emails/join_already_pending_email.ex
+#, elixir-autogen, elixir-format
+msgid "Membership application – already under review"
+msgstr "Mitgliedsantrag – wird bereits geprüft"
+
+#: lib/mv_web/templates/emails/join_already_member.html.heex
+#, elixir-autogen, elixir-format
+msgid "We have received your request. The email address you entered is already registered as a member."
+msgstr "Wir haben deine Anfrage erhalten. Die angegebene E-Mail-Adresse ist bereits als Mitglied registriert."
+
+#: lib/mv_web/templates/emails/join_already_pending.html.heex
+#, elixir-autogen, elixir-format
+msgid "We have received your request. You already have a membership application that is being reviewed."
+msgstr "Wir haben deine Anfrage erhalten. Du hast bereits einen Mitgliedsantrag, der geprüft wird."
+
+#: lib/mv_web/templates/emails/join_confirmation.html.heex
+#, elixir-autogen, elixir-format
+msgid "You already had a pending request. Here is a new confirmation link."
+msgstr "Du hattest bereits einen offenen Antrag. Hier ist ein neuer Bestätigungslink."

priv/gettext/default.pot

@@ -3800,3 +3800,34 @@ msgstr ""
 #, elixir-autogen, elixir-format
 msgid "We could not send the confirmation email. Please try again later or contact support."
 msgstr ""
+
+#: lib/mv_web/templates/emails/join_already_member.html.heex
+#: lib/mv_web/templates/emails/join_already_pending.html.heex
+#, elixir-autogen, elixir-format
+msgid "If you have any questions, please contact us."
+msgstr ""
+
+#: lib/mv_web/emails/join_already_member_email.ex
+#, elixir-autogen, elixir-format
+msgid "Membership application – already a member"
+msgstr ""
+
+#: lib/mv_web/emails/join_already_pending_email.ex
+#, elixir-autogen, elixir-format
+msgid "Membership application – already under review"
+msgstr ""
+
+#: lib/mv_web/templates/emails/join_already_member.html.heex
+#, elixir-autogen, elixir-format
+msgid "We have received your request. The email address you entered is already registered as a member."
+msgstr ""
+
+#: lib/mv_web/templates/emails/join_already_pending.html.heex
+#, elixir-autogen, elixir-format
+msgid "We have received your request. You already have a membership application that is being reviewed."
+msgstr ""
+
+#: lib/mv_web/templates/emails/join_confirmation.html.heex
+#, elixir-autogen, elixir-format
+msgid "You already had a pending request. Here is a new confirmation link."
+msgstr ""

priv/gettext/en/LC_MESSAGES/default.po

@@ -3800,3 +3800,34 @@ msgstr "Status and review"
 #, elixir-autogen, elixir-format
 msgid "We could not send the confirmation email. Please try again later or contact support."
 msgstr ""
+
+#: lib/mv_web/templates/emails/join_already_member.html.heex
+#: lib/mv_web/templates/emails/join_already_pending.html.heex
+#, elixir-autogen, elixir-format
+msgid "If you have any questions, please contact us."
+msgstr "If you have any questions, please contact us."
+
+#: lib/mv_web/emails/join_already_member_email.ex
+#, elixir-autogen, elixir-format
+msgid "Membership application – already a member"
+msgstr "Membership application – already a member"
+
+#: lib/mv_web/emails/join_already_pending_email.ex
+#, elixir-autogen, elixir-format
+msgid "Membership application – already under review"
+msgstr "Membership application – already under review"
+
+#: lib/mv_web/templates/emails/join_already_member.html.heex
+#, elixir-autogen, elixir-format
+msgid "We have received your request. The email address you entered is already registered as a member."
+msgstr "We have received your request. The email address you entered is already registered as a member."
+
+#: lib/mv_web/templates/emails/join_already_pending.html.heex
+#, elixir-autogen, elixir-format
+msgid "We have received your request. You already have a membership application that is being reviewed."
+msgstr "We have received your request. You already have a membership application that is being reviewed."
+
+#: lib/mv_web/templates/emails/join_confirmation.html.heex
+#, elixir-autogen, elixir-format
+msgid "You already had a pending request. Here is a new confirmation link."
+msgstr "You already had a pending request. Here is a new confirmation link."

priv/repo/migrations/20260313120000_add_reviewed_by_display_to_join_requests.exs

@@ -0,0 +1,30 @@
+defmodule Mv.Repo.Migrations.AddReviewedByDisplayToJoinRequests do
+  @moduledoc """
+  Adds reviewed_by_display to join_requests for showing reviewer in UI without loading User.
+
+  Backfills existing rows from users.email where reviewed_by_user_id is set.
+  """
+
+  use Ecto.Migration
+
+  def up do
+    alter table(:join_requests) do
+      add :reviewed_by_display, :text
+    end
+
+    # Backfill from users.email for rows that have reviewed_by_user_id
+    execute """
+    UPDATE join_requests j
+    SET reviewed_by_display = u.email
+    FROM users u
+    WHERE j.reviewed_by_user_id = u.id
+      AND j.reviewed_by_user_id IS NOT NULL
+    """
+  end
+
+  def down do
+    alter table(:join_requests) do
+      remove :reviewed_by_display
+    end
+  end
+end

test/membership/join_request_approval_domain_test.exs

@@ -67,6 +67,18 @@ defmodule Mv.Membership.JoinRequestApprovalDomainTest do
     end
   end
 
+  describe "reviewed_by_display" do
+    test "get_join_request returns reviewed_by_display so UI can show reviewer without loading User" do
+      request = Fixtures.submitted_join_request_fixture()
+      reviewer = Fixtures.user_with_role_fixture("normal_user")
+
+      assert {:ok, _} = Membership.approve_join_request(request.id, actor: reviewer)
+
+      assert {:ok, loaded} = Membership.get_join_request(request.id, actor: reviewer)
+      assert loaded.reviewed_by_display == to_string(reviewer.email)
+    end
+  end
+
   describe "reject_join_request/2" do
     test "reject does not create a member" do
       request = Fixtures.submitted_join_request_fixture()

test/membership/join_request_approval_policy_test.exs

@@ -49,6 +49,7 @@ defmodule Mv.Membership.JoinRequestApprovalPolicyTest do
       assert approved.status == :approved
       assert approved.approved_at != nil
       assert approved.reviewed_by_user_id == user.id
+      assert approved.reviewed_by_display == to_string(user.email)
     end
 
     test "admin can approve a submitted join request", %{request: request} do
@@ -89,6 +90,7 @@ defmodule Mv.Membership.JoinRequestApprovalPolicyTest do
       assert rejected.status == :rejected
       assert rejected.rejected_at != nil
       assert rejected.reviewed_by_user_id == user.id
+      assert rejected.reviewed_by_display == to_string(user.email)
     end
 
     test "admin can reject a submitted join request", %{request: request} do

test/membership/join_request_test.exs

@@ -12,7 +12,12 @@ defmodule Mv.Membership.JoinRequestTest do
   """
   use Mv.DataCase, async: true
 
+  require Ash.Query
+  import Ash.Expr
+
+  alias Mv.Fixtures
   alias Mv.Membership
+  alias Mv.Membership.JoinRequest
 
   # Valid minimal attributes for submit (email required; confirmation_token optional for tests)
   @valid_submit_attrs %{
@@ -136,6 +141,60 @@ defmodule Mv.Membership.JoinRequestTest do
     end
   end
 
+  describe "submit_join_request/2 anti-enumeration (already member / already pending)" do
+    test "returns {:ok, :notified_already_member} and creates no JoinRequest when email is already a member" do
+      member =
+        Fixtures.member_fixture(%{
+          email: "already_member#{System.unique_integer([:positive])}@example.com"
+        })
+
+      attrs = %{
+        email: member.email,
+        confirmation_token: "token-#{System.unique_integer([:positive])}"
+      }
+
+      assert {:ok, :notified_already_member} = Membership.submit_join_request(attrs, actor: nil)
+
+      system_actor = Mv.Helpers.SystemActor.get_system_actor()
+
+      {:ok, requests} =
+        JoinRequest
+        |> Ash.Query.filter(expr(email == ^member.email))
+        |> Ash.read(actor: system_actor, domain: Mv.Membership)
+
+      assert requests == []
+    end
+
+    test "returns {:ok, :notified_already_pending} and does not create duplicate when same email submits again (resend)" do
+      email = "resend#{System.unique_integer([:positive])}@example.com"
+      token1 = "first-token-#{System.unique_integer([:positive])}"
+      attrs1 = %{email: email, confirmation_token: token1}
+
+      assert {:ok, request1} = Membership.submit_join_request(attrs1, actor: nil)
+      assert request1.status == :pending_confirmation
+
+      attrs2 = %{
+        email: email,
+        confirmation_token: "second-token-#{System.unique_integer([:positive])}"
+      }
+
+      assert {:ok, :notified_already_pending} = Membership.submit_join_request(attrs2, actor: nil)
+
+      system_actor = Mv.Helpers.SystemActor.get_system_actor()
+
+      {:ok, requests} =
+        JoinRequest
+        |> Ash.Query.filter(expr(email == ^email))
+        |> Ash.read(actor: system_actor, domain: Mv.Membership)
+
+      assert length(requests) == 1
+      assert hd(requests).id == request1.id
+
+      # Resend path updates the request (new token stored); confirmation_sent_at will have been set/updated
+      assert hd(requests).confirmation_sent_at != nil
+    end
+  end
+
   describe "allowlist (server-side field filter)" do
     test "submit with non-allowlisted form_data keys does not persist those keys" do
       # Allowlist restricts which fields are accepted; extra keys must not be stored.