From 7d10944055ff2673da4eee3c233897cba5c10691 Mon Sep 17 00:00:00 2001
From: Joffrey JAFFEUX <j.jaffeux@gmail.com>
Date: Thu, 3 Mar 2022 12:03:21 +0100
Subject: [PATCH] FEATURE: adds support for timezone (recurring and non
 recurring) (#237)

---
 app/models/discourse_post_event/event.rb      | 10 ++++++++--
 .../discourse_post_event/event_serializer.rb  |  1 +
 .../models/discourse-post-event-event.js      | 15 ++++++++-------
 .../modal/discourse-post-event-builder.hbs    |  9 +++++++++
 .../discourse-post-event-decorator.js         |  5 +++--
 assets/javascripts/lib/raw-event-helper.js    |  4 ++++
 config/locales/client.en.yml                  |  3 +++
 ..._timezone_to_discourse_post_event_event.rb |  7 +++++++
 lib/discourse_post_event/event_parser.rb      |  3 ++-
 lib/discourse_post_event/event_validator.rb   |  6 ++++++
 lib/discourse_post_event/rrule_generator.rb   |  4 ++--
 plugin.rb                                     |  4 ++--
 spec/acceptance/recurrence_spec.rb            | 18 +++++++++++++++++-
 .../discourse_post_event/pretty_text_spec.rb  | 15 +++++++++++++++
 .../rrule_generator_spec.rb                   | 19 +++++++++++++++++++
 15 files changed, 106 insertions(+), 17 deletions(-)
 create mode 100644 db/migrate/20220228163400_adds_timezone_to_discourse_post_event_event.rb

diff --git a/app/models/discourse_post_event/event.rb b/app/models/discourse_post_event/event.rb
index 44484a08..4b838da1 100644
--- a/app/models/discourse_post_event/event.rb
+++ b/app/models/discourse_post_event/event.rb
@@ -282,6 +282,7 @@ module DiscoursePostEvent
           original_ends_at: event_params[:end],
           url: event_params[:url],
           recurrence: event_params[:recurrence],
+          timezone: event_params[:timezone],
           status: event_params[:status].present? ? Event.statuses[event_params[:status].to_sym] : event.status,
           reminders: event_params[:reminders],
           raw_invitees: event_params[:"allowed-groups"] ? event_params[:"allowed-groups"].split(',') : nil
@@ -329,7 +330,12 @@ module DiscoursePostEvent
     end
 
     def calculate_next_date
-      return { starts_at: original_starts_at, ends_at: original_ends_at } if !original_ends_at || self.recurrence.blank? || original_starts_at > Time.current
+      if !original_ends_at || self.recurrence.blank? || original_starts_at > Time.current
+        return {
+          starts_at: original_starts_at,
+          ends_at: original_ends_at
+        }
+      end
 
       recurrence = nil
 
@@ -357,7 +363,7 @@ module DiscoursePostEvent
         recurrence = "FREQ=WEEKLY;BYDAY=#{byday}"
       end
 
-      next_starts_at = RRuleGenerator.generate(recurrence, original_starts_at)
+      next_starts_at = RRuleGenerator.generate(recurrence, original_starts_at, tzid: self.timezone)
       difference = original_ends_at - original_starts_at
       next_ends_at = next_starts_at + difference.seconds
 
diff --git a/app/serializers/discourse_post_event/event_serializer.rb b/app/serializers/discourse_post_event/event_serializer.rb
index 37b1cc16..2734017a 100644
--- a/app/serializers/discourse_post_event/event_serializer.rb
+++ b/app/serializers/discourse_post_event/event_serializer.rb
@@ -8,6 +8,7 @@ module DiscoursePostEvent
     attributes :watching_invitee
     attributes :starts_at
     attributes :ends_at
+    attributes :timezone
     attributes :stats
     attributes :status
     attributes :raw_invitees
diff --git a/assets/javascripts/discourse/models/discourse-post-event-event.js b/assets/javascripts/discourse/models/discourse-post-event-event.js
index f86e33c1..8f273952 100644
--- a/assets/javascripts/discourse/models/discourse-post-event-event.js
+++ b/assets/javascripts/discourse/models/discourse-post-event-event.js
@@ -2,12 +2,13 @@ import RestModel from "discourse/models/rest";
 import { ajax } from "discourse/lib/ajax";
 
 const ATTRIBUTES = {
-  id: {},
-  name: {},
-  starts_at: {},
-  ends_at: {},
-  raw_invitees: {},
-  url: {},
+  id: null,
+  name: null,
+  starts_at: null,
+  ends_at: null,
+  raw_invitees: null,
+  url: null,
+  timezone: null,
   status: {
     transform(value) {
       return STATUSES[value];
@@ -51,7 +52,7 @@ const Event = RestModel.extend({
     const attributesKeys = Object.keys(ATTRIBUTES);
     attributesKeys.forEach((key) => {
       const attribute = ATTRIBUTES[key];
-      if (attribute.transform) {
+      if (attribute?.transform) {
         props[key] = attribute.transform(props[key]);
       }
     });
diff --git a/assets/javascripts/discourse/templates/modal/discourse-post-event-builder.hbs b/assets/javascripts/discourse/templates/modal/discourse-post-event-builder.hbs
index c8ccfb9b..7c5f2826 100644
--- a/assets/javascripts/discourse/templates/modal/discourse-post-event-builder.hbs
+++ b/assets/javascripts/discourse/templates/modal/discourse-post-event-builder.hbs
@@ -28,6 +28,15 @@
         }}
       {{/event-field}}
 
+      {{#event-field class="timezone" label="discourse_post_event.builder_modal.timezone.label"}}
+        {{timezone-input
+          value=model.eventModel.timezone
+          onChange=(action (mut model.eventModel.timezone))
+          class="input-xxlarge"
+          none="discourse_post_event.builder_modal.timezone.remove_timezone"
+        }}
+      {{/event-field}}
+
       {{#event-field label="discourse_post_event.builder_modal.status.label"}}
         <label class="radio-label">
           {{radio-button
diff --git a/assets/javascripts/initializers/discourse-post-event-decorator.js b/assets/javascripts/initializers/discourse-post-event-decorator.js
index dd477a9f..7613c3e7 100644
--- a/assets/javascripts/initializers/discourse-post-event-decorator.js
+++ b/assets/javascripts/initializers/discourse-post-event-decorator.js
@@ -115,6 +115,7 @@ function _attachWidget(api, cooked, eventModel) {
     eventContainer.appendChild(glueContainer);
 
     const startsAt = moment(eventModel.starts_at);
+    const timezone = eventModel.timezone || "UTC";
     const format = guessDateFormat(
       startsAt,
       eventModel.ends_at && moment(eventModel.ends_at)
@@ -129,7 +130,7 @@ function _attachWidget(api, cooked, eventModel) {
           .utc(eventModel.starts_at)
           .format("YYYY-MM-DD")} time=${moment
           .utc(eventModel.starts_at)
-          .format("HH:mm")} format=${format}]`
+          .format("HH:mm")} format=${format} timezone=${timezone}]`
       );
 
       if (eventModel.ends_at) {
@@ -137,7 +138,7 @@ function _attachWidget(api, cooked, eventModel) {
         dates.push(
           `[date=${endsAt.format("YYYY-MM-DD")} time=${endsAt.format(
             "HH:mm"
-          )} format=${format}]`
+          )} format=${format} timezone=${timezone}]`
         );
       }
 
diff --git a/assets/javascripts/lib/raw-event-helper.js b/assets/javascripts/lib/raw-event-helper.js
index c29c570a..165097af 100644
--- a/assets/javascripts/lib/raw-event-helper.js
+++ b/assets/javascripts/lib/raw-event-helper.js
@@ -19,6 +19,10 @@ export function buildParams(startsAt, endsAt, eventModel, siteSettings) {
     params.url = eventModel.url;
   }
 
+  if (eventModel.timezone) {
+    params.timezone = eventModel.timezone;
+  }
+
   if (eventModel.recurrence) {
     params.recurrence = eventModel.recurrence;
   }
diff --git a/config/locales/client.en.yml b/config/locales/client.en.yml
index a484592e..060d05f4 100644
--- a/config/locales/client.en.yml
+++ b/config/locales/client.en.yml
@@ -359,6 +359,9 @@ en:
         update: "Save"
         attach: "Create event"
         add_reminder: "Add reminder"
+        timezone:
+          label: Timezone
+          remove_timezone: No timezone (UTC)
         reminders:
           label: "Reminders"
         recurrence:
diff --git a/db/migrate/20220228163400_adds_timezone_to_discourse_post_event_event.rb b/db/migrate/20220228163400_adds_timezone_to_discourse_post_event_event.rb
new file mode 100644
index 00000000..7997eff2
--- /dev/null
+++ b/db/migrate/20220228163400_adds_timezone_to_discourse_post_event_event.rb
@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddsTimezoneToDiscoursePostEventEvent < ActiveRecord::Migration[6.1]
+  def change
+    add_column :discourse_post_event_events, :timezone, :string
+  end
+end
diff --git a/lib/discourse_post_event/event_parser.rb b/lib/discourse_post_event/event_parser.rb
index bc772d12..e1d10ff1 100644
--- a/lib/discourse_post_event/event_parser.rb
+++ b/lib/discourse_post_event/event_parser.rb
@@ -8,7 +8,8 @@ VALID_OPTIONS = [
   :url,
   :name,
   :reminders,
-  :recurrence
+  :recurrence,
+  :timezone
 ]
 
 module DiscoursePostEvent
diff --git a/lib/discourse_post_event/event_validator.rb b/lib/discourse_post_event/event_validator.rb
index 9c55799f..2d5d997c 100644
--- a/lib/discourse_post_event/event_validator.rb
+++ b/lib/discourse_post_event/event_validator.rb
@@ -75,6 +75,12 @@ module DiscoursePostEvent
         end
       end
 
+      if extracted_event[:timezone].present?
+        if !ActiveSupport::TimeZone[extracted_event[:timezone]].present?
+          @post.errors.add(:base, I18n.t("discourse_post_event.errors.models.event.invalid_timezone", timezone: extracted_event[:timezone]))
+        end
+      end
+
       true
     end
   end
diff --git a/lib/discourse_post_event/rrule_generator.rb b/lib/discourse_post_event/rrule_generator.rb
index 785fa435..7334bbdb 100644
--- a/lib/discourse_post_event/rrule_generator.rb
+++ b/lib/discourse_post_event/rrule_generator.rb
@@ -3,11 +3,11 @@
 require 'rrule'
 
 class RRuleGenerator
-  def self.generate(base_rrule, starts_at)
+  def self.generate(base_rrule, starts_at, tzid: 'UTC')
     rrule = generate_hash(base_rrule)
     rrule = set_mandatory_options(rrule, starts_at)
 
-    ::RRule::Rule.new(stringify(rrule), dtstart: starts_at, exdate: [starts_at])
+    ::RRule::Rule.new(stringify(rrule), dtstart: starts_at, exdate: [starts_at], tzid: tzid)
       .between(Time.current, Time.current + 2.months)
       .first
   end
diff --git a/plugin.rb b/plugin.rb
index 4e2da390..cf321347 100644
--- a/plugin.rb
+++ b/plugin.rb
@@ -551,8 +551,8 @@ after_initialize do
         fragment.css('.discourse-post-event').each do |event_node|
           starts_at = event_node['data-start']
           ends_at = event_node['data-end']
-          dates = "#{starts_at} (UTC)"
-          dates = "#{dates} → #{ends_at} (UTC)" if ends_at
+          dates = "#{starts_at} (#{event_node['data-timezone'] || 'UTC'})"
+          dates = "#{dates} → #{ends_at} (#{event_node['data-timezone'] || 'UTC'})" if ends_at
 
           event_name = event_node['data-name'] || post.topic.title
           event_node.replace <<~TXT
diff --git a/spec/acceptance/recurrence_spec.rb b/spec/acceptance/recurrence_spec.rb
index 49f456f6..c09bf021 100644
--- a/spec/acceptance/recurrence_spec.rb
+++ b/spec/acceptance/recurrence_spec.rb
@@ -18,7 +18,7 @@ describe 'discourse_post_event_recurrence' do
 
   it 'delete previous notifications before creating a new one for invites' do
     going_user = Fabricate(:user)
-    Invitee.create_attendance!(going_user.id, post_event_1.id, :going)
+    DiscoursePostEvent::Invitee.create_attendance!(going_user.id, post_event_1.id, :going)
     post_event_1.update!(recurrence: 'every_month')
 
     post_event_1.set_next_date
@@ -91,4 +91,20 @@ describe 'discourse_post_event_recurrence' do
       expect(post_event_1.starts_at).to eq_time(Time.zone.parse('2020-09-14 19:00'))
     end
   end
+
+  context 'the event has a timezone' do
+    context 'every_month' do
+      before do
+        post_event_1.update!(recurrence: 'every_month', timezone: 'America/New_York')
+      end
+
+      it 'sets the next month at the same weekday' do
+        freeze_time(starts_at + 1.day)
+
+        post_event_1.set_next_date
+
+        expect(post_event_1.starts_at).to eq_time(Time.zone.parse('2020-10-08 23:00'))
+      end
+    end
+  end
 end
diff --git a/spec/lib/discourse_post_event/pretty_text_spec.rb b/spec/lib/discourse_post_event/pretty_text_spec.rb
index 24930230..4b3f8412 100644
--- a/spec/lib/discourse_post_event/pretty_text_spec.rb
+++ b/spec/lib/discourse_post_event/pretty_text_spec.rb
@@ -57,6 +57,21 @@ describe PrettyText do
           HTML
         end
       end
+
+      context 'The event has a timezone' do
+        let(:post_1) { create_post_with_event(user_1, 'timezone="America/New_York"') }
+
+        it 'uses the timezone' do
+          cooked = PrettyText.cook(post_1.raw)
+
+          expect(PrettyText.format_for_email(cooked, post_1)).to match_html(<<~HTML)
+            <div style='border:1px solid #dedede'>
+              <p><a href="#{Discourse.base_url}#{post_1.url}">#{post_1.topic.title}</a></p>
+              <p>2018-06-05T18:39:50.000Z (America/New_York)</p>
+            </div>
+          HTML
+        end
+      end
     end
   end
 end
diff --git a/spec/lib/discourse_post_event/rrule_generator_spec.rb b/spec/lib/discourse_post_event/rrule_generator_spec.rb
index 9aac3380..1b170d10 100644
--- a/spec/lib/discourse_post_event/rrule_generator_spec.rb
+++ b/spec/lib/discourse_post_event/rrule_generator_spec.rb
@@ -27,6 +27,25 @@ describe RRuleGenerator do
     end
   end
 
+  context 'tzid given' do
+    let(:sample_rrule) { 'FREQ=WEEKLY;BYDAY=MO' }
+
+    it 'it correctly computes the next date using the timezone' do
+      tzid = 'Europe/Paris'
+      time = Time.utc(2020, 1, 25, 15, 36)
+
+      freeze_time DateTime.parse('2020-02-25 15:36')
+
+      rrule = RRuleGenerator.generate(sample_rrule, time, tzid: tzid)
+      expect(rrule.to_s).to eq('2020-03-02 15:36:00 +0100')
+
+      freeze_time DateTime.parse('2020-09-25 15:36')
+
+      rrule = RRuleGenerator.generate(sample_rrule, time, tzid: tzid)
+      expect(rrule.to_s).to eq('2020-09-28 15:36:00 +0200')
+    end
+  end
+
   context 'every day' do
     let(:sample_rrule) { 'FREQ=DAILY' }