clear_calendar_events.rb

require "google/apis/calendar_v3"
require "googleauth"
require "googleauth/stores/file_token_store"
require "date"
require "fileutils"
require "active_support/all"

OOB_URI = "urn:ietf:wg:oauth:2.0:oob".freeze
APPLICATION_NAME = "Google Calendar API Ruby Quickstart".freeze
CREDENTIALS_PATH = "credentials.json".freeze
# The file token.yaml stores the user's access and refresh tokens, and is
# created automatically when the authorization flow completes for the first
# time.
TOKEN_PATH = "token.yaml".freeze
SCOPE = "https://www.googleapis.com/auth/calendar.events"

##
# Ensure valid credentials, either by restoring from the saved credentials
# files or intitiating an OAuth2 authorization. If authorization is required,
# the user's default browser will be launched to approve the request.
#
# @return [Google::Auth::UserRefreshCredentials] OAuth2 credentials
def authorize
  client_id = Google::Auth::ClientId.from_file CREDENTIALS_PATH
  token_store = Google::Auth::Stores::FileTokenStore.new file: TOKEN_PATH
  authorizer = Google::Auth::UserAuthorizer.new client_id, SCOPE, token_store
  user_id = "default"
  credentials = authorizer.get_credentials user_id
  if credentials.nil?
    url = authorizer.get_authorization_url base_url: OOB_URI
    puts "Open the following URL in the browser and enter the " \
         "resulting code after authorization:\n" + url
    code = gets
    credentials = authorizer.get_and_store_credentials_from_code(
      user_id: user_id, code: code, base_url: OOB_URI
    )
  end
  credentials
end

# Initialize the API
service = Google::Apis::CalendarV3::CalendarService.new
service.client_options.application_name = APPLICATION_NAME
service.authorization = authorize

# Fetch the next 10 events for the user
calendar_id = "primary"
response = service.list_events(calendar_id,
                               max_results:   2500,
                               single_events: true,
                               order_by:      "startTime",
                               time_min:      1.month.ago.to_datetime.rfc3339)
puts "Upcoming events:"
puts "No upcoming events found" if response.items.empty?
events = response.items.select{|event| event.summary.match(/^On Call/) && !event.summary.match(/Roberto/)};
events.map do |event|
  start = event.start.date || event.start.date_time
  puts "- #{event.summary} (#{start})"
  service.delete_event(calendar_id, event.id)
end