Notifications on event update

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

lib/mobilizon/cldr.ex

@@ -0,0 +1,9 @@
+defmodule Mobilizon.Cldr do
+  @moduledoc """
+  Module to define supported locales
+  """
+
+  use Cldr,
+    locales: ["cs", "de", "en", "es", "fr", "it", "ja", "nl", "pl", "pt", "ru"],
+    providers: [Cldr.Number, Cldr.Calendar, Cldr.DateTime]
+end

lib/mobilizon/events/events.ex

@@ -262,11 +262,19 @@ defmodule Mobilizon.Events do
   Updates an event.
   """
   @spec update_event(Event.t(), map) :: {:ok, Event.t()} | {:error, Ecto.Changeset.t()}
-  def update_event(%Event{} = event, attrs) do
-    event
-    |> Repo.preload(:tags)
-    |> Event.update_changeset(attrs)
-    |> Repo.update()
+  def update_event(%Event{} = old_event, attrs) do
+    with %Ecto.Changeset{changes: changes} = changeset <-
+           old_event |> Repo.preload(:tags) |> Event.update_changeset(attrs) do
+      with {:ok, %Event{} = new_event} <- Repo.update(changeset) do
+        Mobilizon.Service.Events.Tool.calculate_event_diff_and_send_notifications(
+          old_event,
+          new_event,
+          changes
+        )
+
+        {:ok, new_event}
+      end
+    end
   end
 
   @doc """
@@ -1301,6 +1309,15 @@ defmodule Mobilizon.Events do
     )
   end
 
+  @spec list_participants_for_event_query(String.t()) :: Ecto.Query.t()
+  def list_local_emails_user_participants_for_event_query(event_id) do
+    Participant
+    |> join(:inner, [p], a in Actor, on: p.actor_id == a.id and is_nil(a.domain))
+    |> join(:left, [_p, a], u in User, on: a.user_id == u.id)
+    |> where([p], p.event_id == ^event_id)
+    |> select([_p, a, u], {a, u})
+  end
+
   @spec list_participations_for_user_query(integer()) :: Ecto.Query.t()
   defp list_participations_for_user_query(user_id) do
     from(

lib/mobilizon_web/email/email.ex

@@ -11,7 +11,8 @@ defmodule MobilizonWeb.Email do
   def base_email(args) do
     instance = Config.instance_config()
 
-    new_email(args)
+    args
+    |> new_email()
     |> from(Config.instance_email_from())
     |> put_header("Reply-To", Config.instance_email_reply_to())
     |> assign(:instance, instance)

lib/mobilizon_web/email/event.ex

@@ -0,0 +1,43 @@
+defmodule MobilizonWeb.Email.Event do
+  @moduledoc """
+  Handles emails sent about events.
+  """
+
+  use Bamboo.Phoenix, view: MobilizonWeb.EmailView
+
+  import Bamboo.Phoenix
+
+  import MobilizonWeb.Gettext
+
+  alias Mobilizon.Events.Event
+  alias Mobilizon.Actors.Actor
+  alias Mobilizon.Users.User
+  alias MobilizonWeb.Email
+
+  @spec event_updated(User.t(), Actor.t(), Event.t(), Event.t(), list(), String.t()) ::
+          Bamboo.Email.t()
+  def event_updated(
+        %User{} = user,
+        %Actor{} = actor,
+        %Event{} = old_event,
+        %Event{} = event,
+        changes,
+        locale \\ "en"
+      ) do
+    Gettext.put_locale(locale)
+
+    subject =
+      gettext(
+        "Event %{title} has been updated",
+        title: old_event.title
+      )
+
+    Email.base_email(to: {Actor.display_name(actor), user.email}, subject: subject)
+    |> assign(:locale, locale)
+    |> assign(:event, event)
+    |> assign(:old_event, old_event)
+    |> assign(:changes, changes)
+    |> assign(:subject, subject)
+    |> render(:event_updated)
+  end
+end

lib/mobilizon_web/templates/email/event_participation_rejected.html.eex

@@ -35,7 +35,7 @@
               <tr>
                 <td bgcolor="#ffffff" align="left" style="padding: 20px 30px 0px 30px; color: #666666; font-family: 'Lato', Helvetica, Arial, sans-serif; font-size: 18px; font-weight: 400; line-height: 25px;" >
                   <p style="margin: 0;">
-                    <%= gettext "You requested to participate in event %{title}", title: @event.title %>
+                    <%= gettext "You requested to participate in event %{title}.", title: @event.title %>
                   </p>
                 </td>
               </tr>

lib/mobilizon_web/templates/email/event_updated.html.eex

@@ -0,0 +1,110 @@
+<!-- HERO -->
+    <tr>
+        <td bgcolor="#424056" align="center" style="padding: 0px 10px 0px 10px;">
+            <!--[if (gte mso 9)|(IE)]>
+            <table align="center" border="0" cellspacing="0" cellpadding="0" width="600">
+            <tr>
+            <td align="center" valign="top" width="600">
+            <![endif]-->
+            <table border="0" cellpadding="0" cellspacing="0" width="100%" style="max-width: 600px;" >
+                <tr>
+                    <td bgcolor="#ffffff" align="center" valign="top" style="padding: 40px 20px 20px 20px; border-radius: 4px 4px 0px 0px; color: #111111; font-family: 'Lato', Helvetica, Arial, sans-serif; font-size: 48px; font-weight: 400; letter-spacing: 4px; line-height: 48px;">
+                      <h1 style="font-size: 48px; font-weight: 400; margin: 0;">
+                      <%= gettext "Event updated!" %>
+                      </h1>
+                    </td>
+                </tr>
+            </table>
+            <!--[if (gte mso 9)|(IE)]>
+            </td>
+            </tr>
+            </table>
+            <![endif]-->
+        </td>
+    </tr>
+    <!-- COPY BLOCK -->
+    <tr>
+        <td bgcolor="#f4f4f4" align="center" style="padding: 0px 10px 0px 10px;">
+            <!--[if (gte mso 9)|(IE)]>
+            <table align="center" border="0" cellspacing="0" cellpadding="0" width="600">
+            <tr>
+            <td align="center" valign="top" width="600">
+            <![endif]-->
+            <table border="0" cellpadding="0" cellspacing="0" width="100%" style="max-width: 600px;" >
+              <!-- COPY -->
+              <tr>
+                <td bgcolor="#ffffff" align="left" style="padding: 20px 30px 0px 30px; color: #666666; font-family: 'Lato', Helvetica, Arial, sans-serif; font-size: 18px; font-weight: 400; line-height: 25px;" >
+                  <p style="margin: 0;">
+                    <%= gettext "The event %{title} was updated", title: @old_event.title %>
+                  </p>
+                </td>
+              </tr>
+              <tr>
+                <td bgcolor="#ffffff" align="left" style="padding: 20px 30px 40px 30px; color: #777777; font-family: 'Lato', Helvetica, Arial, sans-serif; font-size: 18px; font-weight: 400; line-height: 25px;" >
+                  <table width="100%">
+                    <%= if MapSet.member?(@changes, :title) do %>
+                      <tr>
+                        <td bgcolor="#ffffff" align="left">
+                          <%= gettext "Title" %>
+                        </td>
+                        <td bgcolor="#ffffff" align="left">
+                          <%= @event.title %>
+                        </td>
+                      </tr>
+                    <% end %>
+                    <%= if MapSet.member?(@changes, :begins_on) do %>
+                      <tr>
+                        <td bgcolor="#ffffff" align="left">
+                          <%= gettext "Start of event" %>
+                        </td>
+                        <td bgcolor="#ffffff" align="left">
+                          <%= datetime_to_string(@event.begins_on) %>
+                        </td>
+                      </tr>
+                    <% end %>
+                    <%= if MapSet.member?(@changes, :ends_on) do %>
+                      <tr>
+                        <td bgcolor="#ffffff" align="left">
+                          <%= gettext "Ending of event" %>
+                        </td>
+                        <td bgcolor="#ffffff" align="left">
+                          <%= datetime_to_string(@event.ends_on) %>
+                        </td>
+                      </tr>
+                    <% end %>
+                </table>
+                </td>
+              </tr>
+              <!-- BULLETPROOF BUTTON -->
+              <tr>
+                <td bgcolor="#ffffff" align="left">
+                  <table width="100%" border="0" cellspacing="0" cellpadding="0">
+                    <tr>
+                      <td bgcolor="#ffffff" align="center" style="padding: 20px 30px 60px 30px;">
+                        <table border="0" cellspacing="0" cellpadding="0">
+                          <tr>
+                              <td align="center" style="border-radius: 3px;" bgcolor="#424056"><a href="<%= page_url(MobilizonWeb.Endpoint, :event, @event.id) %>" target="_blank" style="font-size: 20px; font-family: Helvetica, Arial, sans-serif; color: #ffffff; text-decoration: none; color: #ffffff; text-decoration: none; padding: 15px 25px; border-radius: 2px; border: 1px solid #424056; display: inline-block;">
+                              <%= gettext "Go to event page" %>
+                              </a></td>
+                          </tr>
+                        </table>
+                      </td>
+                    </tr>
+                  </table>
+                </td>
+              </tr>
+              <tr>
+                <td bgcolor="#ffffff" align="left" style="padding: 20px 30px 40px 30px; color: #777777; font-family: 'Lato', Helvetica, Arial, sans-serif; font-size: 14px; font-weight: 400; line-height: 20px;" >
+                  <p style="margin: 0">
+                    <%= gettext "If you need to cancel your participation, just access the event page through link above and click on the participation button." %>
+                  </p>
+                </td>
+              </tr>
+            </table>
+            <!--[if (gte mso 9)|(IE)]>
+            </td>
+            </tr>
+            </table>
+            <![endif]-->
+        </td>
+    </tr>

lib/mobilizon_web/templates/email/event_updated.text.eex

@@ -0,0 +1,21 @@
+<%= gettext "Event updated!" %>
+
+==
+
+<%= gettext "The event %{title} was just updated", title: @old_event.title %>
+
+<%= if MapSet.member?(@changes, :title) do %>
+    <%= gettext "New title: %{title}", title: @event.title %>
+<% end %>
+
+<%= if MapSet.member?(@changes, :begins_on) do %>
+    <%= gettext "New date and time for start of event: %{begins_on}", begins_on: datetime_to_string(@event.begins_on) %>
+<% end %>
+
+<%= if MapSet.member?(@changes, :ends_on) do %>
+    <%= gettext "New date and time for ending of event: %{ends_on}", ends_on: datetime_to_string(@event.ends_on) %>
+<% end %>
+
+<%= gettext "View the updated event on: %{link}", link: page_url(MobilizonWeb.Endpoint, :event, @event.id) %>
+
+<%= gettext "If you need to cancel your participation, just access the event page through link above and click on the participation button." %>

lib/mobilizon_web/views/email_view.ex

@@ -1,3 +1,10 @@
 defmodule MobilizonWeb.EmailView do
   use MobilizonWeb, :view
+
+  def datetime_to_string(%DateTime{} = datetime, locale \\ "en") do
+    with {:ok, string} <-
+           Cldr.DateTime.to_string(datetime, Mobilizon.Cldr, format: :medium, locale: locale) do
+      string
+    end
+  end
 end

lib/service/events/tools.ex

@@ -0,0 +1,50 @@
+defmodule Mobilizon.Service.Events.Tool do
+  @moduledoc """
+  Event-related tools
+  """
+  alias Mobilizon.Events
+  alias Mobilizon.Events.Event
+  alias Mobilizon.Actors.Actor
+  alias Mobilizon.Users.User
+  alias MobilizonWeb.Email
+  alias Mobilizon.Storage.Repo
+
+  @important_changes [:title, :begins_on, :ends_on]
+
+  def calculate_event_diff_and_send_notifications(
+        %Event{} = old_event,
+        %Event{id: event_id} = event,
+        changes
+      ) do
+    important = MapSet.new(@important_changes)
+
+    diff =
+      changes
+      |> Map.keys()
+      |> MapSet.new()
+      |> MapSet.intersection(important)
+
+    if MapSet.size(diff) > 0 do
+      Repo.transaction(fn ->
+        event_id
+        |> Events.list_local_emails_user_participants_for_event_query()
+        |> Repo.stream()
+        |> Enum.to_list()
+        |> Enum.each(
+          &send_notification_for_event_update_to_participant(&1, old_event, event, diff)
+        )
+      end)
+    end
+  end
+
+  defp send_notification_for_event_update_to_participant(
+         {%Actor{} = actor, %User{} = user},
+         %Event{} = old_event,
+         %Event{} = event,
+         diff
+       ) do
+    user
+    |> Email.Event.event_updated(actor, old_event, event, diff)
+    |> Email.Mailer.deliver_later()
+  end
+end