MAP-1665 Migrate to the new Alerts API (#2363)

* Introduce Alerts API interface

NOTE: base class currently duplicates the
NomisClient::Base - refactor / DRY up

* Migrate Alerts to use the new AlertsApiClient

* DRY up the Oauth client

* Update the NomisAlerts Importer

* Prefer HMPPS over DPS for the oauth token

* Add ALERTS_API_BASE_URL to the test environment

* Fix specs to support the new AlertsApi::Client

* Generate wiremock responses for the AlertsApiClient

* Resolve Wiremock `__files` not found on CI

* Add:  ALERTS_API_BASE_URL: alerts_api_base_url_key

* Add ALERTS_API_BASE_URL to .env.example

.env.example

@@ -4,6 +4,7 @@ NOMIS_SITE_FOR_API='https://nomis-api.example.com'
 NOMIS_AUTH_SCHEME='basic_auth'
 NOMIS_SITE_FOR_AUTH='https://nomis-api.example.com/auth'
 NOMIS_PRISON_API_PATH_PREFIX='/api'
+ALERTS_API_BASE_URL=https://alerts-api-dev.hmpps.service.justice.gov.uk/
 SENTRY_DSN='https://sentry.example.com/'
 
 ENCRYPTOR_SALT="\x97\x19\xBF\xF6\xC2\x9DZ\x92D\xFFq\xFC\x9B\x1C\xC4\t\x95\xBA\xBF\xF7q<\xC9\xFC\x81\xBD;\xDEtH\xA4\xB2"

.env.test

@@ -3,3 +3,4 @@ NOMIS_SITE_FOR_API=http://localhost:8888
 NOMIS_PRISON_API_PATH_PREFIX='/api'
 NOMIS_SITE_FOR_AUTH='http://localhost:8888/auth'
 SENTRY_DSN='https://sentry.example.com/'
+ALERTS_API_BASE_URL=http://localhost:8888

app.json

@@ -15,6 +15,10 @@
       "description": "Name of the storage bucket to use on AWS S3",
       "required": true
     },
+    "ALERTS_API_BASE_URL": {
+      "description": "Base URL for Alerts API",
+      "required": true
+    },
     "NOMIS_SITE_FOR_API": {
       "description": "Base URL for NOMIS API",
       "required": true

app/lib/alerts_api_client/alert_types.rb

@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+
+module AlertsApiClient
+  class AlertTypes < AlertsApiClient::Base
+    class << self
+      def get
+        fetch_response.map { |alert_type|
+          alert_type['alertCodes'].map do |alert_code|
+            attributes_for(alert_type, alert_code)
+          end
+        }.flatten
+      end
+
+      def fetch_response
+        AlertsApiClient::Base.get(
+          'alert-types',
+          headers: { 'Page-Limit' => '1000' },
+        ).parsed
+      end
+
+      def attributes_for(alert_type, alert_code)
+        {
+          code: alert_code['code'],
+          type_code: alert_type['code'],
+          description: alert_code['description'],
+          type_description: alert_type['description'],
+          active_flag: alert_type['isActive'],
+        }
+      end
+    end
+  end
+end

app/lib/alerts_api_client/alerts.rb

@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+module AlertsApiClient
+  class Alerts < AlertsApiClient::Base
+    class << self
+      def get(prison_number)
+        JSON.parse(fetch_response(prison_number).body)['content'].map do |alert|
+          attributes_for(alert)
+        end
+      end
+
+      def fetch_response(prison_number)
+        AlertsApiClient::Base.get(
+          "/prisoners/#{prison_number}/alerts?isActive=true",
+        )
+      end
+
+      def attributes_for(alert)
+        {
+          alert_id: alert['alertUuid'],
+          alert_type: alert['alertCode']['alertTypeCode'],
+          alert_type_description: alert['alertCode']['alertTypeDescription'],
+          alert_code: alert['alertCode']['code'],
+          alert_code_description: alert['alertCode']['description'],
+          comment: (alert['comments'] || []).join('. '),
+          created_at: alert['createdAt'],
+          expires_at: alert['activeTo'],
+          expired: !alert['isActive'],
+          active: alert['isActive'],
+          prison_number: alert['prisonNumber'],
+        }
+      end
+    end
+  end
+end

app/lib/alerts_api_client/base.rb

@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+module AlertsApiClient
+  class Base < HmppsApiClient
+    class << self
+    protected
+
+      def site_for_api
+        ENV['ALERTS_API_BASE_URL']
+      end
+
+      def token_request_path_prefix
+        ''
+      end
+    end
+  end
+end

app/lib/hmpps_api_client.rb

@@ -0,0 +1,108 @@
+# frozen_string_literal: true
+
+class HmppsApiClient
+  HMPPS_TIMEOUT = 10 # in seconds
+
+  class << self
+    def get(path, params = {})
+      token_request(:get, path, params)
+    end
+
+    def post(path, params = {})
+      params = update_json_headers(params)
+      token_request(:post, path, params)
+    end
+
+    def put(path, params = {})
+      params = update_json_headers(params)
+      token_request(:put, path, params)
+    end
+
+  protected
+
+    def site_for_api
+      # expect a value in the subclass
+    end
+
+    def token_request_path_prefix
+      # expect a value in the subclass
+    end
+
+  private
+
+    REFRESH_TOKEN_TIMEFRAME_IN_SECONDS = 5
+
+    def token_request(method, path, params)
+      token.send(method, "#{token_request_path_prefix}#{path}", params)
+    rescue Faraday::ConnectionFailed, Faraday::TimeoutError => e
+      Rails.logger.warn "HMPPS Connection Error: #{e.message}"
+      raise e
+    rescue OAuth2::Error => e
+      Rails.logger.warn "HMPPS OAuth Client Error: #{e.message}"
+      raise e
+    end
+
+    def token
+      return @token if @token && !token_expired_or_to_expire?
+
+      @token = client.client_credentials.get_token
+    end
+
+    def client
+      @client ||= OAuth2::Client.new(
+        ENV['NOMIS_CLIENT_ID'],
+        ENV['NOMIS_CLIENT_SECRET'],
+        site: site_for_api,
+        auth_scheme: ENV['NOMIS_AUTH_SCHEME'],
+        token_url: "#{ENV['NOMIS_SITE_FOR_AUTH']}/oauth/token",
+        raise_errors: true,
+        connection_opts: { request: { timeout: HMPPS_TIMEOUT, open_timeout: HMPPS_TIMEOUT } },
+      )
+    end
+
+    def token_expired_or_to_expire?
+      # rubocop:disable Rails/TimeZone
+      @token.expires? &&
+        (@token.expires_at - REFRESH_TOKEN_TIMEFRAME_IN_SECONDS < Time.now.to_i)
+      # rubocop:enable Rails/TimeZone
+    end
+
+    def update_json_headers(params)
+      return unless params
+
+      {
+        headers:
+        {
+          'Accept': 'application/json',
+          'Content-Type': 'application/json',
+        },
+      }.deep_merge(params)
+    end
+
+    def sentry_extra(path, params, exception)
+      response = exception.response
+
+      message = begin
+        ActiveSupport::JSON.decode(response.body)['developerMessage']
+      rescue StandardError
+        nil
+      end
+
+      {
+        route: path,
+        body_params: params,
+        nomis_response_status: response.status,
+        nomis_response_body: response.body,
+        nomis_response_message: message,
+      }
+    end
+
+    def log_exception(description, path, params, exception)
+      Sentry.capture_message(
+        description,
+        extra: sentry_extra(path, params, exception),
+        level: 'error',
+      )
+    end
+  end
+end