From 6eab893a77f95ca121122eb56901676eb4cf0626 Mon Sep 17 00:00:00 2001
From: Rieman Li <riemanli@google.com>
Date: Thu, 25 May 2023 20:53:23 +0000
Subject: [PATCH] Add getReport.

---
 .../service/api/v2alpha/ReportsService.kt     | 50 +++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/src/main/kotlin/org/wfanet/measurement/reporting/service/api/v2alpha/ReportsService.kt b/src/main/kotlin/org/wfanet/measurement/reporting/service/api/v2alpha/ReportsService.kt
index 5dbd8a11a33..193ace569fb 100644
--- a/src/main/kotlin/org/wfanet/measurement/reporting/service/api/v2alpha/ReportsService.kt
+++ b/src/main/kotlin/org/wfanet/measurement/reporting/service/api/v2alpha/ReportsService.kt
@@ -40,6 +40,7 @@ import org.wfanet.measurement.internal.reporting.v2.report as internalReport
 import org.wfanet.measurement.reporting.v2alpha.BatchCreateMetricsRequest
 import org.wfanet.measurement.reporting.v2alpha.CreateMetricRequest
 import org.wfanet.measurement.reporting.v2alpha.CreateReportRequest
+import org.wfanet.measurement.reporting.v2alpha.GetReportRequest
 import org.wfanet.measurement.reporting.v2alpha.Metric
 import org.wfanet.measurement.reporting.v2alpha.MetricsGrpcKt.MetricsCoroutineStub
 import org.wfanet.measurement.reporting.v2alpha.Report
@@ -73,6 +74,55 @@ class ReportsService(
 
   private val metricSpecBuilder = MetricSpecBuilder(metricSpecConfig)
 
+  override suspend fun getReport(request: GetReportRequest): Report {
+    val reportKey =
+      grpcRequireNotNull(ReportKey.fromName(request.name)) {
+        "Report name is either unspecified or invalid"
+      }
+
+    val principal: ReportingPrincipal = principalFromCurrentContext
+    when (principal) {
+      is MeasurementConsumerPrincipal -> {
+        if (reportKey.cmmsMeasurementConsumerId != principal.resourceKey.measurementConsumerId) {
+          failGrpc(Status.PERMISSION_DENIED) {
+            "Cannot get Report belonging to other MeasurementConsumers."
+          }
+        }
+      }
+    }
+
+    val internalReport =
+      try {
+        internalReportsStub.getReport(
+          internalGetReportRequest {
+            cmmsMeasurementConsumerId = reportKey.cmmsMeasurementConsumerId
+            externalReportId = apiIdToExternalId(reportKey.reportId)
+          }
+        )
+      } catch (e: StatusException) {
+        throw Exception("Unable to get the report from the reporting database.", e)
+      }
+
+    // Create metrics.
+    val metricNames: List<String> =
+      internalReport.reportingMetricEntriesMap.flatMap { (_, reportingMetricCalculationSpec) ->
+        reportingMetricCalculationSpec.metricCalculationSpecsList.flatMap { metricCalculationSpec ->
+          metricCalculationSpec.reportingMetricsList.map { reportingMetric ->
+            MetricKey(
+                principal.resourceKey.measurementConsumerId,
+                externalIdToApiId(reportingMetric.externalMetricId)
+              )
+              .toName()
+          }
+        }
+      }
+    val metrics: List<Metric> =
+      batchGetMetrics(principal.resourceKey.toName(), principal.config.apiKey, metricNames)
+
+    // Convert the internal report to public and return.
+    return convertInternalReportToPublic(internalReport, metrics)
+  }
+
   override suspend fun createReport(request: CreateReportRequest): Report {
     grpcRequireNotNull(MeasurementConsumerKey.fromName(request.parent)) {
       "Parent is either unspecified or invalid."