MAT-7233: On non-OK replies from VSAC FHIR Term Serv, parse the Opera…

…tionOutcome Resource and return the diagnostic message to the caller.

src/main/java/gov/cms/madie/terminology/controller/VsacControllerAdvice.java

@@ -1,7 +1,11 @@
 package gov.cms.madie.terminology.controller;
 
+import ca.uhn.fhir.context.FhirContext;
+import ca.uhn.fhir.parser.IParser;
+import gov.cms.madie.terminology.exceptions.VsacValueSetExpansionException;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import org.hl7.fhir.r4.model.OperationOutcome;
 import org.springframework.boot.web.error.ErrorAttributeOptions;
 import org.springframework.boot.web.servlet.error.ErrorAttributes;
 import org.springframework.http.HttpStatus;
@@ -27,6 +31,7 @@
 public class VsacControllerAdvice {
 
   private final ErrorAttributes errorAttributes;
+  private final FhirContext fhirContext;
 
   @ExceptionHandler(WebClientResponseException.class)
   public ResponseEntity<Map<String, Object>> handleWebClientResponseException(
@@ -60,6 +65,30 @@ Map<String, Object> onMissingServletRequestParameterException(
     return errorAttributes;
   }
 
+  @ExceptionHandler(VsacValueSetExpansionException.class)
+  @ResponseStatus(HttpStatus.BAD_REQUEST)
+  ResponseEntity<Map<String, Object>> onVsacValueSetExpansionException(
+      VsacValueSetExpansionException ex, WebRequest request) {
+    IParser parser = fhirContext.newJsonParser();
+    OperationOutcome outcome = parser.parseResource(OperationOutcome.class, ex.getBody());
+    String filter = ex.getFilter();
+    if (filter.contains("Manifest")) {
+      filter += " " + ex.getValueSetUrl().substring(ex.getValueSetUrl().lastIndexOf("Library/"));
+    }
+    String message =
+        String.format(
+            "Value Set %s could not be expanded using %s. Per VSAC, \"%s\"\n\n (DEBUG) URL: %s",
+            ex.getValueSetUrl()
+                .substring("ValueSet/".length() + 1, ex.getValueSetUrl().lastIndexOf("/$")),
+            filter,
+            outcome.getIssueFirstRep().getDiagnostics(),
+            ex.getValueSetUrl());
+    return handleWebClientResponseException(
+        new WebClientResponseException(
+            message, ex.getStatusCode(), ex.getStatusText(), null, null, null, null),
+        request);
+  }
+
   @ExceptionHandler(VsacGenericException.class)
   @ResponseStatus(HttpStatus.BAD_REQUEST)
   @ResponseBody

src/main/java/gov/cms/madie/terminology/exceptions/VsacValueSetExpansionException.java

@@ -0,0 +1,30 @@
+package gov.cms.madie.terminology.exceptions;
+
+import lombok.Getter;
+import lombok.Setter;
+import org.springframework.http.HttpStatusCode;
+import org.springframework.web.reactive.function.client.WebClientResponseException;
+
+import java.nio.charset.Charset;
+
+@Getter
+@Setter
+public class VsacValueSetExpansionException extends WebClientResponseException {
+
+  private String body;
+  private String filter;
+  private String valueSetUrl;
+
+  public VsacValueSetExpansionException(
+      String message,
+      HttpStatusCode status,
+      String statusText,
+      String body,
+      String filter,
+      String valueSetUrl) {
+    super(message, status, statusText, null, body.getBytes(), Charset.defaultCharset(), null);
+    this.body = body;
+    this.filter = filter;
+    this.valueSetUrl = valueSetUrl;
+  }
+}

src/main/java/gov/cms/madie/terminology/webclient/FhirTerminologyServiceWebClient.java

@@ -1,5 +1,6 @@
 package gov.cms.madie.terminology.webclient;
 
+import gov.cms.madie.terminology.exceptions.VsacValueSetExpansionException;
 import gov.cms.madie.terminology.models.CodeSystem;
 import gov.cms.madie.terminology.util.TerminologyServiceUtil;
 import gov.cms.madie.models.measure.ManifestExpansion;
@@ -124,7 +125,18 @@ private String fetchResourceFromVsac(String uri, String apiKey, String resourceT
                 return clientResponse.bodyToMono(String.class);
               } else {
                 log.debug("Received NON-OK response while retrieving {}", resourceType);
-                return clientResponse.createException().flatMap(Mono::error);
+                return clientResponse
+                    .createException()
+                    .flatMap(
+                        ex ->
+                            Mono.error(
+                                new VsacValueSetExpansionException(
+                                    "",
+                                    ex.getStatusCode(),
+                                    ex.getStatusText(),
+                                    ex.getResponseBodyAsString(),
+                                    uri.contains("manifest") ? "Manifest" : "Latest",
+                                    uri)));
               }
             })
         .block();