upload.rb

require 'google/apis/sheets_v4'
require 'googleauth'
require 'googleauth/stores/file_token_store'
require 'fileutils'
require './interpret'

OOB_URI = 'urn:ietf:wg:oauth:2.0:oob'.freeze
APPLICATION_NAME = 'Gas Readings Upload'.freeze
CREDENTIALS_PATH = 'credentials.json'.freeze
TOKEN_PATH = 'token.yaml'.freeze
SCOPE = Google::Apis::SheetsV4::AUTH_SPREADSHEETS

##
# 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::SheetsV4::SheetsService.new
service.client_options.application_name = APPLICATION_NAME
service.authorization = authorize

values = readings(ARGV[0]).map do |(time, value)|
  next unless time # Skip references
  [time&.strftime('%m/%d/%y %H:%M'), value]
end.compact

spreadsheet_id = '12fqDIt1wwoOT8UJCky7jRMrSOtMOyGWCskqYO3974Go'
value_range = Google::Apis::SheetsV4::ValueRange.new(values: values)
result = service.update_spreadsheet_value(spreadsheet_id,
                                          'Readings!A2',
                                          value_range,
                                          value_input_option: 'USER_ENTERED')
puts "#{result.updated_cells} cells updated."