Book&Table - Mobile API - Ruby client program using the Request a Tutor private end point

send_signed_rat_request.rb

require 'rest-client'

user_id    = 5
secret_key = 'secret key of user with id 5'

def calculate_canonical_string(content_type, content_md5, path, timestamp)
  [ content_type,
    content_md5,
    path,
    timestamp
  ].join(",")
end

def hmac_signature(content_type, content_md5, path, timestamp, secret_key)
  canonical_string = calculate_canonical_string(content_type, content_md5, path, timestamp)
  digest = OpenSSL::Digest.new('sha1')
  hmac_digest = OpenSSL::HMAC.digest(digest, secret_key, canonical_string)
  Base64.strict_encode64(hmac_digest)
end

params = ""

{"q[number_of_students]"  => 1,
 "q[standard_subject_id]" => 101,
 "q[state_id]"            => 301,
 "q[student_grade]"       => 'College',
 "q[when]"                => 'Immediately'}.each do |k, v|

  item_built = "#{CGI.escape(k)}=#{CGI.escape(v.to_s)}"
  if params == ""
    params = item_built
  else
    params = "#{params}&#{item_built}"
  end

end

path_with_params = "/mobile/1.0/request_tutor?#{params}"
timestamp = Time.now.utc.httpdate # Example: "Mon, 03 Aug 2015 20:15:56 GMT"

signature = hmac_signature('', '', path_with_params, timestamp, secret_key)

headers = {'X-BOOK-AND-TABLE-API-KEY-TYPE' => 'IOS_IPHONE',
           'X-BOOK-AND-TABLE-API-KEY'      => ENV['BOOK_AND_TABLE_API_KEY_IOS_IPHONE'],
           'Accept'                        => 'application/json',
           'Date'                          => timestamp,
           'Authorization'                 => "APIAuth #{user_id}:#{signature}"}

request = RestClient::Request.new(url: "http://localhost:3000#{path_with_params}",
                                  headers: headers,
                                  method: :get)

response = request.execute

response_decoded = ActiveSupport::JSON.decode(response.body)
puts "The results of the request are: #{response_decoded.inspect}"