FEATURE: Chat notification emails

app/jobs/scheduled/email_chat_notifications.rb

@@ -0,0 +1,13 @@
+# frozen_string_literal: true
+
+module Jobs
+  class EmailChatNotifications < ::Jobs::Scheduled
+    every 5.minutes
+
+    def execute(args = {})
+      return unless SiteSetting.chat_enabled
+
+      DiscourseChat::ChatMailer.send_unread_mentions_summary
+    end
+  end
+end

app/models/chat_message.rb

@@ -68,7 +68,11 @@ def excerpt
     return uploads.first.original_filename if cooked.blank? && uploads.present?
 
     # this may return blank for some complex things like quotes, that is acceptable
-    PrettyText.excerpt(cooked, 50)
+    PrettyText.excerpt(cooked, 50, {})
+  end
+
+  def cooked_for_excerpt
+    (cooked.blank? && uploads.present?) ? "<p>#{uploads.first.original_filename}</p>" : cooked
   end
 
   def push_notification_excerpt

app/models/direct_message_channel.rb

@@ -17,7 +17,7 @@ def chat_channel_title_for_user(chat_channel, acting_user)
     # all users deleted
     return chat_channel.id if !users.first
 
-    usernames_formatted = users.map { |u| "@#{u.username}" }
+    usernames_formatted = users.sort_by(&:username).map { |u| "@#{u.username}" }
     if usernames_formatted.size > 5
       return I18n.t(
         "chat.channel.dm_title.multi_user_truncated",

app/models/user_chat_channel_membership.rb

@@ -38,16 +38,17 @@ def changes_for_direct_message_channels
 #
 # Table name: user_chat_channel_memberships
 #
-#  id                         :bigint           not null, primary key
-#  user_id                    :integer          not null
-#  chat_channel_id            :integer          not null
-#  last_read_message_id       :integer
-#  following                  :boolean          default(FALSE), not null
-#  muted                      :boolean          default(FALSE), not null
-#  desktop_notification_level :integer          default("mention"), not null
-#  mobile_notification_level  :integer          default("mention"), not null
-#  created_at                 :datetime         not null
-#  updated_at                 :datetime         not null
+#  id                                :bigint           not null, primary key
+#  user_id                           :integer          not null
+#  chat_channel_id                   :integer          not null
+#  last_read_message_id              :integer
+#  following                         :boolean          default(FALSE), not null
+#  muted                             :boolean          default(FALSE), not null
+#  desktop_notification_level        :integer          default("mention"), not null
+#  mobile_notification_level         :integer          default("mention"), not null
+#  created_at                        :datetime         not null
+#  updated_at                        :datetime         not null
+#  last_read_message_when_emailed_id :integer
 #
 # Indexes
 #

app/views/user_notifications/chat_summary.html.erb

@@ -0,0 +1,76 @@
+<div class="summary-email">
+  <table class="chat-summary-header text-header with-dir" style="background-color:#<%= @header_bgcolor -%>;width:100%;min-width:100%;">
+    <tr>
+      <td align="center" style="text-align: center;padding: 20px 0; font-family:Arial,sans-serif;">
+
+        <a href="<%= Discourse.base_url %>" style="color:#<%= @header_color -%>;font-size:22px;text-decoration:none;">
+          <%- if logo_url.blank? %>
+            <%= SiteSetting.title %>
+          <%- else %>
+            <img src="<%= logo_url %>" height="40" style="clear:both;display:block;height:40px;margin:auto;max-width:100%;outline:0;text-decoration:none;" alt="<%= SiteSetting.title %>">
+          <%- end %>
+        </a>
+
+      </td>
+    </tr>
+    <tr>
+      <td align="center" style="font-weight:bold;font-size:22px;color:#0a0a0a">
+        <%= I18n.t("user_notifications.chat_summary.description", count: @messages.size) %>
+      </td>
+    </tr>
+  </table>
+
+  <%- @grouped_mentions.each do |chat_channel, messages| %>
+    <%- other_messages_count = messages.size - 2 %>
+    <table class="chat-summary-content" style="padding:1em;margin-top:20px;width:100%;min-width:100%;background-color:#f7f7f7;">
+      <tbody>
+        <tr>
+          <td colspan="100%">
+            <h5 style="margin:0.5em 0 0.5em 0;font-size:0.9em;"><%= chat_channel.title(@user) %></h5>
+          </td>
+        </tr>
+        <%- messages.take(2).each do |chat_message| %>
+          <%- sender = chat_message.user %>
+          <%- sender_name = @display_usernames ? sender.username : sender.name %>
+
+          <tr class="message-row">
+            <td style="white-space:nowrap;vertical-align:top;padding:<%= rtl? ? '1em 2em 0 0' : '1em 0 0 2em' %>">
+              <img src="<%= sender.small_avatar_url -%>" style="height:20px;width:20px;margin:<%= rtl? ? '0 0 5px 0' : '0 5px 0 0' %>;border-radius:50%;clear:both;display:inline-block;outline:0;text-decoration:none;vertical-align:top;" alt="<%= sender_name -%>">
+              <span style="display:inline-block;color:#0a0a0a;vertical-align:top;font-weight:bold;">
+                <%= sender_name -%>
+              </span>
+              <span style="display:inline-block;color:#0a0a0a;font-size:0.8em;">
+                <%= I18n.l(@user_tz.to_local(chat_message.created_at), format: :long) -%>
+              </span>
+            </td>
+            <td style="width:99%;margin:0;padding:<%= rtl? ? '0 2em 0 0' : '0 0 0 2em' %>;vertical-align:top;">
+              <%= email_excerpt(chat_message.cooked_for_excerpt) %>
+            </td>
+          </tr>
+        <%- end %>
+        <tr>
+          <td colspan="100%" style="padding:<%= rtl? ? '2em 2em 0 0' : '2em 0 0 2em' %>">
+            <a class="more-messages-link" href="<%= messages.first.url %>">
+              <%- if other_messages_count <= 0 %>
+                <%= I18n.t("user_notifications.chat_summary.view_messages", count: messages.size)%>
+              <%- else %>
+                <%= I18n.t("user_notifications.chat_summary.view_more", count: other_messages_count)%>
+              <%- end %>
+            </a>
+          </td>
+        </tr>
+      </tbody>
+    </table>
+  <%- end %>
+</div>
+
+<table class='summary-footer with-dir' style="margin-top:2em;width:100%">
+  <tr>
+    <td align="center">
+      <%= raw(t 'user_notifications.chat_summary.unsubscribe',
+              site_link: html_site_link,
+              email_preferences_link: link_to(t('user_notifications.chat_summary.your_chat_settings'), Discourse.base_url + '/my/preferences/chat'))  
+      %>
+    </td>
+  </tr>
+</table>

app/views/user_notifications/chat_summary.text.erb

@@ -0,0 +1,8 @@
+<%- site_link = raw(@markdown_linker.create(@site_name, '/')) %>
+<%= t('user_notifications.chat_summary.description', count: @messages.size,) %>
+<%= raw(@markdown_linker.create(t("user_notifications.chat_summary.view_messages", count: @messages.size), "/chat")) %>
+<%= raw(t :'user_notifications.chat_summary.unsubscribe',
+       site_link: site_link,
+       email_preferences_link: @markdown_linker.create(t('user_notifications.chat_summary.your_chat_settings'), Discourse.base_url + '/my/preferences/chat'))
+%>
+<%= raw(@markdown_linker.references) %>

assets/javascripts/discourse/controllers/preferences-chat.js

@@ -6,15 +6,26 @@ import { action } from "@ember/object";
 import { popupAjaxError } from "discourse/lib/ajax-error";
 import { CHAT_SOUNDS } from "discourse/plugins/discourse-chat/discourse/initializers/chat-notification-sounds";
 
-const chatAttrs = [
+const CHAT_ATTRS = [
   "chat_enabled",
   "chat_isolated",
   "only_chat_push_notifications",
   "ignore_channel_wide_mention",
   "chat_sound",
+  "chat_email_frequency",
+];
+
+const EMAIL_FREQUENCY_OPTIONS = [
+  { name: I18n.t(`chat.email_frequency.never`), value: "never" },
+  { name: I18n.t(`chat.email_frequency.when_away`), value: "when_away" },
 ];
 
 export default Controller.extend({
+  init() {
+    this._super(...arguments);
+    this.set("emailFrequencyOptions", EMAIL_FREQUENCY_OPTIONS);
+  },
+
   @discourseComputed
   chatSounds() {
     return Object.keys(CHAT_SOUNDS).map((value) => {
@@ -35,7 +46,7 @@ export default Controller.extend({
   save() {
     this.set("saved", false);
     return this.model
-      .save(chatAttrs)
+      .save(CHAT_ATTRS)
       .then(() => {
         this.set("saved", true);
         if (!isTesting()) {

assets/javascripts/discourse/initializers/chat-user-options.js

@@ -5,6 +5,7 @@ const CHAT_ISOLATED_FIELD = "chat_isolated";
 const ONLY_CHAT_PUSH_NOTI_FIELD = "only_chat_push_notifications";
 const IGNORE_CHANNEL_WIDE_MENTION = "ignore_channel_wide_mention";
 const CHAT_SOUND = "chat_sound";
+const CHAT_EMAIL_FREQUENCY = "chat_email_frequency";
 
 export default {
   name: "chat-user-options",
@@ -18,6 +19,7 @@ export default {
         api.addSaveableUserOptionField(ONLY_CHAT_PUSH_NOTI_FIELD);
         api.addSaveableUserOptionField(IGNORE_CHANNEL_WIDE_MENTION);
         api.addSaveableUserOptionField(CHAT_SOUND);
+        api.addSaveableUserOptionField(CHAT_EMAIL_FREQUENCY);
       }
     });
   },

assets/javascripts/discourse/templates/preferences/chat.hbs

@@ -59,4 +59,18 @@
   }}
 </div>
 
+<div class="control-group chat-setting controls-dropdown">
+  <label for="user_chat_email_frequency">{{i18n "chat.email_frequency.title"}}</label>
+  {{combo-box
+    valueProperty="value"
+    content=emailFrequencyOptions
+    value=model.user_option.chat_email_frequency
+    id="user_chat_email_frequency"
+    onChange=(action (mut model.user_option.chat_email_frequency))
+  }}
+  {{#if (eq model.user_option.chat_email_frequency "when_away")}}
+    <div class="control-instructions">{{i18n "chat.email_frequency.description"}}</div>
+  {{/if}}
+</div>
+
 {{save-controls id="user_chat_preference_save" model=model action=(action "save") saved=saved}}

config/locales/client.en.yml

@@ -70,6 +70,11 @@ en:
         public_available: "There are public channels available for you to follow."
         start_direct_message: "You can also start a personal chat with one or more users."
         title: "Get started by joining a channel"
+      email_frequency:
+        description: "We'll only email you if we haven't seen you in the last 15 minutes."
+        never: "Never"
+        title: "Email Notifications"
+        when_away: "Only when away"
       enable: "Enable chat"
       flag: "Flag"
       flagged: "This message has been flagged for review"

config/locales/server.en.yml

@@ -116,3 +116,22 @@ en:
   reviewable_score_types:
     needs_review:
       title: "Needs Review"
+
+  user_notifications:
+    chat_summary:
+      deleted_user: "Deleted user"
+      description:
+        one: "You have a new chat message"
+        other: "You have new chat messages"
+      from: "%{site_name}"
+      subject:
+        one: "[%{email_prefix}] New chat message"
+        other: "[%{email_prefix}] New chat messages"
+      unsubscribe: "This chat summary is sent from %{site_link} when you are away. Change your %{email_preferences_link}."
+      view_messages:
+        one: "View message"
+        other: "View %{count} messages"
+      view_more:
+        one: "View %{count} more message"
+        other: "View %{count} more messages"
+      your_chat_settings: "chat email frequency preference"

db/migrate/20220518140004_track_last_unread_mention_when_emailed.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class TrackLastUnreadMentionWhenEmailed < ActiveRecord::Migration[7.0]
+  def change
+    add_column :user_chat_channel_memberships, :last_unread_mention_when_emailed_id, :integer
+  end
+end

db/post_migrate/20220516142658_remove_email_statuses_table.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+class RemoveEmailStatusesTable < ActiveRecord::Migration[7.0]
+  def up
+    remove_index :chat_message_email_statuses, :status
+    remove_index :chat_message_email_statuses, [:user_id, :chat_message_id]
+
+    Migration::TableDropper.execute_drop("chat_message_email_statuses")
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end

db/post_migrate/20220518180642_remove_user_option_last_emailed_at.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class RemoveUserOptionLastEmailedAt < ActiveRecord::Migration[7.0]
+  def change
+    remove_column :user_options, :last_emailed_for_chat, :datetime
+  end
+end

lib/chat_mailer.rb

@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+class DiscourseChat::ChatMailer
+  def send_unread_mentions_summary
+    return unless SiteSetting.chat_enabled
+
+    users_with_unprocessed_unread_mentions.find_each do |user|
+      # user#memberships_with_unread_messages is a nested array that looks like [[membership_id, unread_message_id]]
+      # Find the max unread id per membership.
+      membership_and_max_unread_mention_ids = user.memberships_with_unread_messages
+        .group_by { |memberships| memberships[0] }
+        .transform_values do |membership_and_msg_ids|
+          membership_and_msg_ids.max_by { |membership, msg| msg }
+        end.values
+
+      Jobs.enqueue(:user_email,
+        type: "chat_summary",
+        user_id: user.id,
+        force_respect_seen_recently: true,
+        memberships_to_update_data: membership_and_max_unread_mention_ids
+      )
+    end
+  end
+
+  private
+
+  def users_with_unprocessed_unread_mentions
+    when_away_frequency = UserOption.chat_email_frequencies[:when_away]
+    allowed_group_ids = DiscourseChat.allowed_group_ids
+
+    User
+      .select('users.id', 'ARRAY_AGG(ARRAY[uccm.id, c_msg.id]) AS memberships_with_unread_messages')
+      .joins(:user_option)
+      .where(user_options: { chat_enabled: true, chat_email_frequency: when_away_frequency })
+      .where('users.last_seen_at < ?', 15.minutes.ago)
+      .joins(:groups)
+      .where(groups: { id: allowed_group_ids })
+      .joins('INNER JOIN user_chat_channel_memberships uccm ON uccm.user_id = users.id')
+      .joins('INNER JOIN chat_channels cc ON cc.id = uccm.chat_channel_id')
+      .joins('INNER JOIN chat_messages c_msg ON c_msg.chat_channel_id = uccm.chat_channel_id')
+      .joins('LEFT OUTER JOIN chat_mentions c_mentions ON c_mentions.chat_message_id = c_msg.id')
+      .where(uccm: { following: true })
+      .where('c_msg.deleted_at IS NULL AND c_msg.user_id <> users.id')
+      .where(
+        <<~SQL
+          (c_mentions.user_id = uccm.user_id OR cc.chatable_type = 'DirectMessageChannel') AND
+          (uccm.last_read_message_id IS NULL OR c_msg.id > uccm.last_read_message_id) AND
+          (uccm.last_unread_mention_when_emailed_id IS NULL OR c_msg.id > uccm.last_unread_mention_when_emailed_id)
+        SQL
+      )
+      .group('users.id, uccm.user_id')
+  end
+end

lib/chat_message_creator.rb

@@ -39,7 +39,10 @@ def create
       ChatDraft.where(user_id: @user.id, chat_channel_id: @chat_channel.id).destroy_all
       ChatPublisher.publish_new!(@chat_channel, @chat_message, @staged_id)
       Jobs.enqueue(:process_chat_message, { chat_message_id: @chat_message.id })
-      DiscourseChat::ChatNotifier.notify_new(chat_message: @chat_message, timestamp: @chat_message.created_at)
+      DiscourseChat::ChatNotifier.notify_new(
+        chat_message: @chat_message,
+        timestamp: @chat_message.created_at
+      )
     rescue => error
       @error = error
     end
@@ -53,13 +56,15 @@ def failed?
 
   def validate_user_permissions!
     return if @guardian.can_create_chat_message!
+
     raise StandardError.new(
       I18n.t("chat.errors.user_cannot_send_message")
     )
   end
 
   def validate_channel_status!
     return if @guardian.can_create_channel_message?(@chat_channel)
+
     raise StandardError.new(
       I18n.t("chat.errors.channel_new_message_disallowed", status: @chat_channel.status_name)
     )

lib/chat_message_updater.rb

@@ -31,7 +31,10 @@ def update
       revision = save_revision!
       ChatPublisher.publish_edit!(@chat_channel, @chat_message)
       Jobs.enqueue(:process_chat_message, { chat_message_id: @chat_message.id })
-      DiscourseChat::ChatNotifier.notify_edit(chat_message: @chat_message, timestamp: revision.created_at)
+      DiscourseChat::ChatNotifier.notify_edit(
+        chat_message: @chat_message,
+        timestamp: revision.created_at
+      )
     rescue => error
       @error = error
     end