ensl.org/app/services/google_calendar.rb

require 'google/apis/calendar_v3'

CALENDAR = Google::Apis::CalendarV3

class GoogleCalendar

  def initialize (calendar_id, timezone_offset = Time.zone.name)
    @id = calendar_id
    @timezone_offset = timezone_offset
    @events = nil
    @service = CALENDAR::CalendarService.new
    #@service.authorization = CALENDAR::AUTH_CALENDAR # change this if write access needed
    @service.key = ENV['GOOGLE_API_KEY']
    query_events
  end


  def upcoming
    @events && @events.select do |event|
      (not nsltv_regex =~ event.summary)
    end
  end

  def upcoming_nsltv
    @events && @events.select do |event|
      (nsltv_regex =~ event.summary)
    end
  end

  def query_events
    list = nil
    @events.nil? and @service.list_events(@id, time_zone: ActiveSupport::TimeZone::MAPPING[@timezone_offset], time_min: (2.hours.ago).utc.iso8601 ) {|result, err|
      if err
        puts err.inspect
      else
        list = result
      end
    }
    @events = (list) ? list.items.sort_by { |event| event.start.date_time } : nil
  end

  def nsltv_regex
    /\[NSLTV\]/i
  end

end