Module: Common::Client::Concerns::MhvFhirSessionClient

Extended by:
ActiveSupport::Concern
Includes:
MHVJwtSessionClient
Included in:
MedicalRecords::Client
Defined in:
lib/common/client/concerns/mhv_fhir_session_client.rb

Overview

Module mixin for overriding session logic when making MHV JWT/FHIR-based client connections.

All refrences to “session” in this module refer to the upstream MHV/FHIR session.

See Also:

Constant Summary collapse

LOCK_RETRY_DELAY =

Number of seconds to wait between attempts to acquire a session lock

1
RETRY_ATTEMPTS =

How many times to attempt to acquire a session lock

10

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from MHVJwtSessionClient

#auth_body, #auth_headers, #decode_jwt_token, #extract_token_expiration, #get_jwt_from_headers, #get_session_tagged, #jwt_bearer_token, #patient_fhir_id, #session_config_key, #user_key, #validate_session_params

Methods included from MhvLockedSessionClient

#authenticate, #initialize, #lock_and_get_session, #obtain_redis_lock, #refresh_session, #release_redis_lock

Methods included from SentryLogging

#log_exception_to_sentry, #log_message_to_sentry, #non_nil_hash?, #normalize_level, #rails_logger, #set_sentry_metadata

Instance Attribute Details

#session ⇒ Hash (readonly)

Returns a hash containing session information.

Returns:

  • (Hash) —

    a hash containing session information



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# File 'lib/common/client/concerns/mhv_fhir_session_client.rb', line 19

module MhvFhirSessionClient
  extend ActiveSupport::Concern
  include MHVJwtSessionClient

  protected

  LOCK_RETRY_DELAY = 1 # Number of seconds to wait between attempts to acquire a session lock
  RETRY_ATTEMPTS = 10 # How many times to attempt to acquire a session lock

  def incomplete?(session)
    session.icn.blank? || session.patient_fhir_id.blank? || session.token.blank? || session.expires_at.blank?
  end

  def invalid?(session)
    session.expired? || incomplete?(session)
  end

  ##
  # Creates and saves an MHV/FHIR session for a patient. If any step along the way fails, save
  # the partial session before raising the exception.
  #
  # @return [MedicalRecords::ClientSession] if a MR (Medical Records) client session
  #
  def get_session
    exception = nil

    perform_phr_refresh

    begin
      # Call MHVJwtSessionClient's get_session method for JWT-session creation.
      jwt_session = super
      session.token = jwt_session.token
      session.expires_at = jwt_session.expires_at
    rescue => e
      exception ||= e
    end

    begin
      get_patient_fhir_id(session.token) if session.token && patient_fhir_id.nil?
    rescue MedicalRecords::PatientNotFound
      # Don't raise this exception, as it will bubble up to a shared class where we don't
      # want to handle it. Instead we simply don't set the Patient FHIR ID and raise an
      # exception later in medical_records/client.rb where it will be easier to handle.
    rescue => e
      exception ||= e
    end

    new_session = save_session
    raise exception if exception

    new_session
  end

  private

  ##
  # Checks to see if a PHR refresh is necessary, performs the refresh, and updates the refresh timestamp.
  #
  # @return [DateTime] the refresh timestamp
  #
  def perform_phr_refresh
    return unless session.refresh_time.nil?

    # Perform an async PHR refresh for the user. This job will not raise any errors, it only logs them.
    MHV::PhrUpdateJob.perform_async(session.icn, session.user_id)
    # Record that the refresh has happened for this session. Don't run this more than once per session duration.
    session.refresh_time = DateTime.now
  end

  ##
  # Decodes a JWT to get the patient's subjectId, then uses that to fetch their FHIR ID
  #
  # @param jwt_token [String] a JWT token
  # @return [String] the patient's FHIR ID
  #
  def get_patient_fhir_id(jwt_token)
    decoded_token = decode_jwt_token(jwt_token)
    session.patient_fhir_id = fetch_patient_by_subject_id(sessionless_fhir_client(jwt_token),
                                                          decoded_token[0]['subjectId'])
  end

  ##
  # Fetch a Patient FHIR record by subjectId
  #
  # @param fhir_client [FHIR::Client] a FHIR client with which to get the record
  # @param subject_id [String] the patient's subjectId from the JWT
  # @return [FHIR::Patient] the patient's FHIR record
  #
  def fetch_patient_by_subject_id(fhir_client, subject_id)
    raise Common::Exceptions::Unauthorized, detail: 'JWT token does not contain subjectId' if subject_id.nil?

    # Get the patient's FHIR ID
    patient = get_patient_by_identifier(fhir_client, subject_id)
    if patient.nil? || patient.entry.empty? || !patient.entry[0].resource.respond_to?(:id)
      raise Common::Exceptions::Unauthorized,
            detail: 'Patient record not found or does not contain a valid FHIR ID'
    end
    session.patient_fhir_id = patient.entry[0].resource.id
  end

  ##
  # Takes information from the session variable and saves a new session instance in redis.
  #
  # @return [MedicalRecords::ClientSession] the updated session
  #
  def save_session
    new_session = @session.class.new(user_id: session.user_id.to_s,
                                     patient_fhir_id: session.patient_fhir_id,
                                     icn: session.icn,
                                     expires_at: session.expires_at,
                                     token: session.token,
                                     refresh_time: session.refresh_time)
    new_session.save
    new_session
  end
end

Instance Method Details

#fetch_patient_by_subject_id(fhir_client, subject_id) ⇒ FHIR::Patient (private)

Fetch a Patient FHIR record by subjectId

Parameters:

  • fhir_client (FHIR::Client) —

    a FHIR client with which to get the record

  • subject_id (String) —

    the patient’s subjectId from the JWT

Returns:

  • (FHIR::Patient) —

    the patient’s FHIR record

Raises:



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# File 'lib/common/client/concerns/mhv_fhir_session_client.rb', line 107

def fetch_patient_by_subject_id(fhir_client, subject_id)
  raise Common::Exceptions::Unauthorized, detail: 'JWT token does not contain subjectId' if subject_id.nil?

  # Get the patient's FHIR ID
  patient = get_patient_by_identifier(fhir_client, subject_id)
  if patient.nil? || patient.entry.empty? || !patient.entry[0].resource.respond_to?(:id)
    raise Common::Exceptions::Unauthorized,
          detail: 'Patient record not found or does not contain a valid FHIR ID'
  end
  session.patient_fhir_id = patient.entry[0].resource.id
end

#get_patient_fhir_id(jwt_token) ⇒ String (private)

Decodes a JWT to get the patient’s subjectId, then uses that to fetch their FHIR ID

Parameters:

  • jwt_token (String) —

    a JWT token

Returns:

  • (String) —

    the patient’s FHIR ID



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# File 'lib/common/client/concerns/mhv_fhir_session_client.rb', line 94

def get_patient_fhir_id(jwt_token)
  decoded_token = decode_jwt_token(jwt_token)
  session.patient_fhir_id = fetch_patient_by_subject_id(sessionless_fhir_client(jwt_token),
                                                        decoded_token[0]['subjectId'])
end

#get_session ⇒ MedicalRecords::ClientSession (protected)

Creates and saves an MHV/FHIR session for a patient. If any step along the way fails, save the partial session before raising the exception.

Returns:



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# File 'lib/common/client/concerns/mhv_fhir_session_client.rb', line 42

def get_session
  exception = nil

  perform_phr_refresh

  begin
    # Call MHVJwtSessionClient's get_session method for JWT-session creation.
    jwt_session = super
    session.token = jwt_session.token
    session.expires_at = jwt_session.expires_at
  rescue => e
    exception ||= e
  end

  begin
    get_patient_fhir_id(session.token) if session.token && patient_fhir_id.nil?
  rescue MedicalRecords::PatientNotFound
    # Don't raise this exception, as it will bubble up to a shared class where we don't
    # want to handle it. Instead we simply don't set the Patient FHIR ID and raise an
    # exception later in medical_records/client.rb where it will be easier to handle.
  rescue => e
    exception ||= e
  end

  new_session = save_session
  raise exception if exception

  new_session
end

#incomplete?(session) ⇒ Boolean (protected)

Returns:

  • (Boolean) 


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# File 'lib/common/client/concerns/mhv_fhir_session_client.rb', line 28

def incomplete?(session)
  session.icn.blank? || session.patient_fhir_id.blank? || session.token.blank? || session.expires_at.blank?
end

#invalid?(session) ⇒ Boolean (protected)

Returns:

  • (Boolean) 


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# File 'lib/common/client/concerns/mhv_fhir_session_client.rb', line 32

def invalid?(session)
  session.expired? || incomplete?(session)
end

#perform_phr_refresh ⇒ DateTime (private)

Checks to see if a PHR refresh is necessary, performs the refresh, and updates the refresh timestamp.

Returns:

  • (DateTime) —

    the refresh timestamp



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# File 'lib/common/client/concerns/mhv_fhir_session_client.rb', line 79

def perform_phr_refresh
  return unless session.refresh_time.nil?

  # Perform an async PHR refresh for the user. This job will not raise any errors, it only logs them.
  MHV::PhrUpdateJob.perform_async(session.icn, session.user_id)
  # Record that the refresh has happened for this session. Don't run this more than once per session duration.
  session.refresh_time = DateTime.now
end

#save_session ⇒ MedicalRecords::ClientSession (private)

Takes information from the session variable and saves a new session instance in redis.

Returns:



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# File 'lib/common/client/concerns/mhv_fhir_session_client.rb', line 124

def save_session
  new_session = @session.class.new(user_id: session.user_id.to_s,
                                   patient_fhir_id: session.patient_fhir_id,
                                   icn: session.icn,
                                   expires_at: session.expires_at,
                                   token: session.token,
                                   refresh_time: session.refresh_time)
  new_session.save
  new_session
end