telemetry(amazonq inline): perceivedLatency calculated incorrectly #5871

The perceivedLatency is currently calculated and sent when we send STE,
by then lastUserModificationTime is no longer accurate. Instead
calculate perceivedLatency when we show the suggestions and use the
lastUserModificationTime at that time to be accurate.

JB PR: aws/aws-toolkit-jetbrains#5013

Author: andrewyuq

packages/core/src/codewhisperer/service/inlineCompletionItemProvider.ts

@@ -169,6 +169,7 @@ export class CWInlineCompletionItemProvider implements vscode.InlineCompletionIt
             ImportAdderProvider.instance.onShowRecommendation(document, this.startPos.line, r)
             this.nextMove = 0
             TelemetryHelper.instance.setFirstSuggestionShowTime()
+            session.setPerceivedLatency()
             this._onDidShow.fire()
             if (matchedCount >= 2 || this.nextToken !== '') {
                 const result = [item]

packages/core/src/codewhisperer/util/codeWhispererSession.ts

@@ -43,6 +43,7 @@ class CodeWhispererSession {
     invokeSuggestionStartTime = 0
     timeToFirstRecommendation = 0
     firstSuggestionShowTime = 0
+    perceivedLatency = 0
 
     public static get instance() {
         return (this.#instance ??= new CodeWhispererSession())
@@ -91,6 +92,17 @@ class CodeWhispererSession {
         }
     }
 
+    setPerceivedLatency() {
+        if (this.perceivedLatency !== 0) {
+            return
+        }
+        if (this.triggerType === 'OnDemand') {
+            this.perceivedLatency = this.timeToFirstRecommendation
+        } else {
+            this.perceivedLatency = this.firstSuggestionShowTime - vsCodeState.lastUserModificationTime
+        }
+    }
+
     reset() {
         this.sessionId = ''
         this.requestContext = { request: {} as any, supplementalMetadata: {} as any }

packages/core/src/codewhisperer/util/telemetryHelper.ts

@@ -325,9 +325,7 @@ export class TelemetryHelper {
                         suggestionState: this.getSendTelemetrySuggestionState(aggregatedSuggestionState),
                         recommendationLatencyMilliseconds: e2eLatency,
                         triggerToResponseLatencyMilliseconds: session.timeToFirstRecommendation,
-                        perceivedLatencyMilliseconds: session.getPerceivedLatency(
-                            this.sessionDecisions[0].codewhispererTriggerType
-                        ),
+                        perceivedLatencyMilliseconds: session.perceivedLatency,
                         timestamp: new Date(Date.now()),
                         suggestionReferenceCount: referenceCount,
                         generatedLine: generatedLines,
@@ -388,6 +386,7 @@ export class TelemetryHelper {
         this.typeAheadLength = 0
         this.timeSinceLastModification = 0
         session.timeToFirstRecommendation = 0
+        session.perceivedLatency = 0
         this.classifierResult = undefined
         this.classifierThreshold = undefined
     }