From d540092bfcc7b02b8c8346570fbef7848320d1b7 Mon Sep 17 00:00:00 2001
From: Sasi Olin <hel@lcp.world>
Date: Sun, 14 Feb 2021 22:56:45 +0100
Subject: [PATCH] Add icalendar files (fixes #2147)

---
 Gemfile                                   |  2 ++
 Gemfile.lock                              |  4 +++
 app/controllers/conferences_controller.rb | 39 +++++++++++++++++++++++
 app/controllers/schedules_controller.rb   |  6 ++++
 app/helpers/conference_helper.rb          | 27 ++++++++++++++++
 config/routes.rb                          |  2 ++
 6 files changed, 80 insertions(+)

diff --git a/Gemfile b/Gemfile
index c7867eb2..8059b258 100644
--- a/Gemfile
+++ b/Gemfile
@@ -219,6 +219,8 @@ gem 'nokogiri', '>= 1.8.1'
 # memcached binary connector
 gem 'dalli'
 
+gem 'icalendar'
+
 # Use guard and spring for testing in development
 group :development do
   # to launch specs when files are modified
diff --git a/Gemfile.lock b/Gemfile.lock
index ea8191f6..eeb82f76 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -241,6 +241,9 @@ GEM
     image_processing (1.12.1)
       mini_magick (>= 4.9.5, < 5)
       ruby-vips (>= 2.0.17, < 3)
+    icalendar (2.7.0)
+      ice_cube (~> 0.16)
+    ice_cube (0.16.3)
     io-like (0.3.0)
     iso-639 (0.2.8)
     jaro_winkler (1.5.3)
@@ -652,6 +655,7 @@ DEPENDENCIES
   guard-rspec
   haml-rails
   haml_lint
+  icalendar
   iso-639
   jquery-datatables-rails
   jquery-rails
diff --git a/app/controllers/conferences_controller.rb b/app/controllers/conferences_controller.rb
index 90d1274b..41e43bfa 100644
--- a/app/controllers/conferences_controller.rb
+++ b/app/controllers/conferences_controller.rb
@@ -67,6 +67,45 @@ class ConferencesController < ApplicationController
     end
   end
 
+  def calendar
+    respond_to do |format|
+      format.ics do
+        calendar = Icalendar::Calendar.new
+        Conference.all.each do |conf|
+          if params[:full]
+            event_schedules = conf.program.selected_event_schedules(
+              includes: [{ event: %i[event_type speakers submitter] }]
+            )
+            calendar = icalendar_proposals(calendar, event_schedules.map(&:event), conf)
+          else
+            calendar.event do |e|
+              e.dtstart = conf.start_date
+              e.dtstart.ical_params = { 'VALUE'=>'DATE' }
+              e.dtend = conf.end_date
+              e.dtend.ical_params = { 'VALUE'=>'DATE' }
+              e.duration = "P#{(conf.end_date - conf.start_date + 1).floor}D"
+              e.created = conf.created_at
+              e.last_modified = conf.updated_at
+              e.summary = conf.title
+              e.description = conf.description
+              e.uid = conf.guid
+              e.url = conference_url(conf.short_title)
+              v = conf.venue
+              e.geo = v.latitude, v.longitude if v.latitude && v.longitude
+              location = ''
+              location += "#{v.street}, " if v.street
+              location += "#{v.postalcode} #{v.city}, " if v.postalcode && v.city
+              location += v.country_name if v.country_name
+              e.location = location if location
+            end
+          end
+        end
+        calendar.publish
+        render inline: calendar.to_ical
+      end
+    end
+  end
+
   private
 
   def conference_finder_conditions
diff --git a/app/controllers/schedules_controller.rb b/app/controllers/schedules_controller.rb
index 2d3f22ef..f7ff69eb 100644
--- a/app/controllers/schedules_controller.rb
+++ b/app/controllers/schedules_controller.rb
@@ -21,6 +21,12 @@ class SchedulesController < ApplicationController
       format.xml do
         @events_xml = event_schedules.map(&:event).group_by{ |event| event.time.to_date } if event_schedules
       end
+      format.ics do
+        cal = Icalendar::Calendar.new
+        cal = icalendar_proposals(cal, event_schedules.map(&:event), @conference)
+        cal.publish
+        render inline: cal.to_ical
+      end
 
       format.html do
         @rooms = @conference.venue.rooms if @conference.venue
diff --git a/app/helpers/conference_helper.rb b/app/helpers/conference_helper.rb
index a48bed54..6ec2449c 100644
--- a/app/helpers/conference_helper.rb
+++ b/app/helpers/conference_helper.rb
@@ -21,4 +21,31 @@ module ConferenceHelper
       '%20Sponsorship'
     ].join
   end
+
+  # adds events to icalendar for proposals in a conference
+  def icalendar_proposals(calendar, proposals, conference)
+    proposals.each do |proposal|
+      calendar.event do |e|
+        e.dtstart = proposal.time
+        e.dtend = proposal.time + proposal.event_type.length * 60
+        e.duration = "PT#{proposal.event_type.length}M"
+        e.created = proposal.created_at
+        e.last_modified = proposal.updated_at
+        e.summary = proposal.title
+        e.description = proposal.abstract
+        e.uid = proposal.guid
+        e.url = conference_program_proposal_url(conference.short_title, proposal.id)
+        v = conference.venue
+        e.geo = v.latitude, v.longitude if v.latitude && v.longitude
+        location = ''
+        location += "#{proposal.room.name} - " if proposal.room.name
+        location += " - #{v.street}, " if v.street
+        location += "#{v.postalcode} #{v.city}, " if v.postalcode && v.city
+        location += "#{v.country_name}, " if v.country_name
+        e.location = location
+        e.categories = conference.title, "Difficulty: #{proposal.difficulty_level.title}", "Track: #{proposal.track.name}"
+      end
+    end
+    calendar
+  end
 end
diff --git a/config/routes.rb b/config/routes.rb
index 57bfa630..f6c4566d 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -219,6 +219,8 @@ Osem::Application.routes.draw do
 
   get '/admin' => redirect('/admin/conferences')
 
+  get '/calendar' => 'conferences#calendar'
+
   unless ENV['OSEM_ROOT_CONFERENCE'].blank?
     root to: redirect("/conferences/#{ENV['OSEM_ROOT_CONFERENCE']}")
   else