fix: address code review feedback (PR #20)

- Fix #1: Update doc comments to reflect precise ms (not bucketed)
  design decision; remove unused fineLatencyBucket()
- Fix #2: Always initialize TelemetryDeck SDK regardless of enabled
  state, eliminating uninitialized-signal risk on toggle
- Fix #3: Extract trackPostProcessingCompleted() helper to eliminate
  copy-paste analytics params between pipeline branches
- Fix #4: Extract hasCloudRewriteAPIKey computed property for clarity

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: ZhaoChaoqun

Sources/AnalyticsService.swift

@@ -7,24 +7,28 @@ private let analyticsLogger = Logger(subsystem: "com.typeless.app", category: "A
 /// Lightweight wrapper around TelemetryDeck for privacy-first analytics.
 ///
 /// Design principles:
-/// - All numeric values are bucketed (e.g. "500-1000ms" not "743ms") to prevent re-identification
-/// - Text content is NEVER sent
+/// - Latency values use precise milliseconds for maximum diagnostic value
+/// - Text content is NEVER sent; text lengths are bucketed (e.g. "11-50" not "37")
 /// - Users can opt out via Settings toggle (UserDefaults "analyticsEnabled", default true)
 /// - DEBUG builds are automatically tagged as test signals by TelemetryDeck
 enum AnalyticsService {
 
     private static let appID = "6EB06114-0222-4BE1-9DDC-BB283B640436"
 
     /// Initialize TelemetryDeck. Call once from AppDelegate.applicationDidFinishLaunching.
+    ///
+    /// Always initializes the SDK regardless of enabled state, so that toggling
+    /// analytics on later doesn't require re-initialization. The `track()` method
+    /// checks `isEnabled` before sending any signals.
     static func initialize() {
-        guard isEnabled else {
-            analyticsLogger.info("Analytics disabled by user preference")
-            return
-        }
-
         let config = TelemetryDeck.Config(appID: appID)
         TelemetryDeck.initialize(config: config)
-        analyticsLogger.info("Analytics initialized (TelemetryDeck)")
+
+        if isEnabled {
+            analyticsLogger.info("Analytics initialized (TelemetryDeck)")
+        } else {
+            analyticsLogger.info("Analytics initialized but disabled by user preference")
+        }
     }
 
     /// Whether analytics is enabled (opt-out model: default true).
@@ -37,15 +41,11 @@ enum AnalyticsService {
         return true
     }
 
-    /// Update enabled state and reinitialize if needed.
+    /// Update enabled state. TelemetryDeck is already initialized;
+    /// this only controls whether `track()` sends signals.
     static func setEnabled(_ enabled: Bool) {
         UserDefaults.standard.set(enabled, forKey: "analyticsEnabled")
-        if enabled {
-            let config = TelemetryDeck.Config(appID: appID)
-            TelemetryDeck.initialize(config: config)
-            analyticsLogger.info("Analytics re-enabled")
-        }
-        // TelemetryDeck doesn't have a teardown; disabled state is checked in track()
+        analyticsLogger.info("Analytics \(enabled ? "enabled" : "disabled")")
     }
 
     /// Track an analytics event with optional parameters.
@@ -56,7 +56,7 @@ enum AnalyticsService {
         var params = parameters
         params["appVersion"] = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as? String ?? "unknown"
         params["selectedEngine"] = UserDefaults.standard.string(forKey: "selectedASRModel") ?? "streamingParaformer"
-        params["cloudRewriteEnabled"] = "\(!((UserDefaults.standard.string(forKey: "cloudRewriteAPIKey") ?? "").isEmpty) || GeneratedSecrets.cloudRewriteAPIKey != nil)"
+        params["cloudRewriteEnabled"] = "\(hasCloudRewriteAPIKey)"
 
         TelemetryDeck.signal(event, parameters: params)
     }
@@ -89,19 +89,6 @@ enum AnalyticsService {
         }
     }
 
-    /// Fine-grained latency bucket for fast pipeline stages (TermNorm, ITN, etc.).
-    static func fineLatencyBucket(ms: Int) -> String {
-        switch ms {
-        case ..<10: return "0-10ms"
-        case 10..<50: return "10-50ms"
-        case 50..<100: return "50-100ms"
-        case 100..<200: return "100-200ms"
-        case 200..<500: return "200-500ms"
-        case 500..<1000: return "500-1000ms"
-        default: return "1000ms+"
-        }
-    }
-
     /// Map recording duration (seconds) to a privacy-safe bucket.
     static func durationBucket(seconds: Double) -> String {
         switch seconds {
@@ -123,4 +110,12 @@ enum AnalyticsService {
         default: return "200+"
         }
     }
+
+    // MARK: - Private Helpers
+
+    /// Whether a Cloud Rewrite API key is configured (user-provided or built-in).
+    private static var hasCloudRewriteAPIKey: Bool {
+        let userKey = UserDefaults.standard.string(forKey: "cloudRewriteAPIKey") ?? ""
+        return !userKey.isEmpty || GeneratedSecrets.cloudRewriteAPIKey != nil
+    }
 }

Sources/PostProcessingPipeline.swift

@@ -93,19 +93,14 @@ final class PostProcessingPipeline {
                     let rewrittenText = await self.cloudRewriteService.rewriteOrPassthrough(processedText)
                     let cloudRewriteMs = AnalyticsService.elapsedMs(since: cloudRewriteStart)
                     self.processingQueue.async {
-                        let totalMs = AnalyticsService.elapsedMs(since: pipelineStart)
-                        AnalyticsService.track("PostProcessing.Completed", parameters: [
-                            "itnApplied": "\(itnApplied)",
-                            "cscApplied": "false",
-                            "punctuationApplied": "false",
-                            "totalLatencyMs": "\(totalMs)",
-                            "termNormLatencyMs": "\(termNormMs)",
-                            "itnLatencyMs": "\(itnMs)",
-                            "cscLatencyMs": "0",
-                            "punctLatencyMs": "0",
-                            "cloudRewriteLatencyMs": "\(cloudRewriteMs)",
-                            "termNormChanged": "\(termNormChanged)",
-                        ])
+                        Self.trackPostProcessingCompleted(
+                            pipelineStart: pipelineStart,
+                            termNormMs: termNormMs, termNormChanged: termNormChanged,
+                            itnMs: itnMs, itnApplied: itnApplied,
+                            cscMs: 0, cscApplied: false,
+                            punctMs: 0, punctuationApplied: false,
+                            cloudRewriteMs: cloudRewriteMs
+                        )
                         logger.info("最终结果: \(rewrittenText, privacy: .public)")
                         completion(rewrittenText)
                     }
@@ -139,22 +134,44 @@ final class PostProcessingPipeline {
                 let rewrittenText = await self.cloudRewriteService.rewriteOrPassthrough(punctuatedText)
                 let cloudRewriteMs = AnalyticsService.elapsedMs(since: cloudRewriteStart)
                 self.processingQueue.async {
-                    let totalMs = AnalyticsService.elapsedMs(since: pipelineStart)
-                    AnalyticsService.track("PostProcessing.Completed", parameters: [
-                        "itnApplied": "\(itnApplied)",
-                        "cscApplied": "\(cscApplied)",
-                        "punctuationApplied": "\(punctuationApplied)",
-                        "totalLatencyMs": "\(totalMs)",
-                        "termNormLatencyMs": "\(termNormMs)",
-                        "itnLatencyMs": "\(itnMs)",
-                        "cscLatencyMs": "\(cscMs)",
-                        "punctLatencyMs": "\(punctMs)",
-                        "cloudRewriteLatencyMs": "\(cloudRewriteMs)",
-                        "termNormChanged": "\(termNormChanged)",
-                    ])
+                    Self.trackPostProcessingCompleted(
+                        pipelineStart: pipelineStart,
+                        termNormMs: termNormMs, termNormChanged: termNormChanged,
+                        itnMs: itnMs, itnApplied: itnApplied,
+                        cscMs: cscMs, cscApplied: cscApplied,
+                        punctMs: punctMs, punctuationApplied: punctuationApplied,
+                        cloudRewriteMs: cloudRewriteMs
+                    )
                     completion(rewrittenText)
                 }
             }
         }
     }
+
+    // MARK: - Analytics Helper
+
+    /// Build and send the PostProcessing.Completed event with per-stage latency.
+    /// Single source of truth — called from both pipeline branches.
+    private static func trackPostProcessingCompleted(
+        pipelineStart: ContinuousClock.Instant,
+        termNormMs: Int, termNormChanged: Bool,
+        itnMs: Int, itnApplied: Bool,
+        cscMs: Int, cscApplied: Bool,
+        punctMs: Int, punctuationApplied: Bool,
+        cloudRewriteMs: Int
+    ) {
+        let totalMs = AnalyticsService.elapsedMs(since: pipelineStart)
+        AnalyticsService.track("PostProcessing.Completed", parameters: [
+            "itnApplied": "\(itnApplied)",
+            "cscApplied": "\(cscApplied)",
+            "punctuationApplied": "\(punctuationApplied)",
+            "totalLatencyMs": "\(totalMs)",
+            "termNormLatencyMs": "\(termNormMs)",
+            "itnLatencyMs": "\(itnMs)",
+            "cscLatencyMs": "\(cscMs)",
+            "punctLatencyMs": "\(punctMs)",
+            "cloudRewriteLatencyMs": "\(cloudRewriteMs)",
+            "termNormChanged": "\(termNormChanged)",
+        ])
+    }
 }