refactor: observability sdk (#25)

<!-- CURSOR_SUMMARY -->
> [!NOTE]
> Rearchitects the SDK into modular services
(logs/traces/metrics/session/crash) using OpenTelemetry exporters and
new domain models, adds sampling and URLSession instrumentation, and
replaces legacy modules and wiring.
> 
> - **Architecture**:
> - Split into `DomainModels`, `ApplicationServices`,
`OTelInstrumentation`, `ObservabilityServiceLive`, `iOSSessionService`,
and `KSCrashReportService` targets; remove legacy `Observability`,
`Instrumentation`, and `API/Observe` layers.
>   - Reorganize `Package.swift` to reflect new modules and tests.
> - **Core APIs**:
> - Introduce domain types: `AttributeValue`, `Severity`, `Span`,
`Metric`, and updated `SemanticConvention`.
> - Add service facades: `ObservabilityService` (aggregates
`MetricsService`, `TracesService`, `LogsService`), `SessionService`,
`UserInteractionService`, `CrashReportService` with async `flush`.
> - Redesign `Options` (feature flags for `logs`/`traces`/`metrics`,
`tracingOrigins`, `urlBlocklist`, `customHeaders` as dict, `OSLog`).
> - Update `LDObserve` to use `ObservabilityService` with concurrent
access and async `flush`.
> - **OTEL Instrumentation**:
> - Implement HTTP exporters for logs/metrics/traces, sampling
decorators, and resource propagation; add `URLSession` instrumentation
and span customization.
>   - Add user interaction spans (`user.tap`, `user.swipe`).
> - **Crash Reporting**:
> - Replace old crash reporter with `KSCrashReportService` and
`LDCrashFilter` that emits fatal logs via `LogsService` and awaits async
flush.
> - **Sampling**:
> - Refactor sampler into `SamplingLive`
(`ExportSampler.build/customSampler`), add helpers to sample logs/spans
and propagate `launchdarkly.sampling.ratio` attribute.
> - **LaunchDarkly integration**:
> - `Observability` plugin builds `ObservabilityService`, enriches
resource and headers with `launchdarkly.sdk.version` and
`highlight.project_id`.
>   - `EvalTracingHook` now starts/ends spans via `LDObserve`.
> - **Example App/Views**:
> - Adjust imports; `TraceView` ends span and triggers
`LDObserve.shared.flush()`; config uses new `Options` flags.
> 
> <sup>Written by [Cursor
Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit
d11f1b9. This will update automatically
on new commits. Configure
[here](https://cursor.com/dashboard?tab=bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Author: mario-launchdarkly

ExampleApp/ExampleApp/AppDelegate.swift

@@ -8,6 +8,19 @@ let config = { () -> LDConfig in
         mobileKey: mobileKey,
         autoEnvAttributes: .enabled
     )
+    config.plugins = [
+        Observability(
+            options: .init(
+                otlpEndpoint: "http://localhost:4318",
+                sessionBackgroundTimeout: 3,
+                isDebug: true,
+                logs: .enabled,
+                traces: .enabled,
+                metrics: .enabled
+            )
+        )
+    ]
+    /*
     config.plugins = [
         Observability(
             options: .init(
@@ -20,6 +33,7 @@ let config = { () -> LDConfig in
             )
         )
     ]
+    */
     return config
 }()
 

ExampleApp/ExampleApp/Instrumentation/Manual/InstrumentationView.swift

@@ -1,6 +1,5 @@
 import SwiftUI
 import LaunchDarklyObservability
-import OpenTelemetryApi
 
 struct InstrumentationView: View {
     var body: some View {

ExampleApp/ExampleApp/Instrumentation/Manual/LogsView.swift

@@ -1,6 +1,5 @@
 import SwiftUI
 import LaunchDarklyObservability
-import OpenTelemetryApi
 
 
 struct LogsView: View {

ExampleApp/ExampleApp/Instrumentation/Manual/TraceView.swift

@@ -1,6 +1,5 @@
 import SwiftUI
 import LaunchDarklyObservability
-import OpenTelemetryApi
 
 
 struct TraceView: View {
@@ -30,6 +29,7 @@ struct TraceView: View {
                 .task(id: started) {
                     guard started else {
                         span?.end()
+                        await LDObserve.shared.flush()
                         return name = ""
                     }
                     span = LDObserve.shared.startSpan(name: name)

Package.swift

@@ -15,31 +15,63 @@ let package = Package(
         .package(url: "https://github.com/kstenerud/KSCrash.git", from: "2.3.0"),
     ],
     targets: [
-        .target(name: "Common"),
         .target(
-            name: "API",
+            name: "DomainModels"
+        ),
+        .target(
+            name: "DomainServices",
             dependencies: [
-                .product(name: "OpenTelemetrySdk", package: "opentelemetry-swift"),
-                .product(name: "OpenTelemetryApi", package: "opentelemetry-swift"),
-                .product(name: "ResourceExtension", package: "opentelemetry-swift"),
+                "DomainModels"
             ]
         ),
-        .testTarget(
-            name: "CommonTests",
+        .target(
+            name: "ApplicationServices",
             dependencies: [
-                "Common"
-            ],
-            resources: [.process("GraphQL/Queries")]
+                "DomainModels",
+                "DomainServices"
+            ]
         ),
-        .target(name: "CrashReporter"),
         .target(
-            name: "CrashReporterLive",
+            name: "iOSSessionService",
+            dependencies: [
+                "DomainModels",
+                "DomainServices",
+                "ApplicationServices"
+            ]
+        ),
+        .target(
+            name: "KSCrashReportService",
+            dependencies: [
+                "DomainModels",
+                "DomainServices",
+                "ApplicationServices",
+                .product(name: "Installations", package: "KSCrash")
+            ]
+        ),
+        .target(
+            name: "OTelInstrumentation",
             dependencies: [
-                "CrashReporter",
                 "Common",
+                "DomainModels",
+                "DomainServices",
+                "ApplicationServices",
+                "Sampling",
+                .product(name: "OpenTelemetrySdk", package: "opentelemetry-swift"),
                 .product(name: "OpenTelemetryApi", package: "opentelemetry-swift"),
+                .product(name: "URLSessionInstrumentation", package: "opentelemetry-swift"),
+                .product(name: "ResourceExtension", package: "opentelemetry-swift"),
+                .product(name: "OpenTelemetryProtocolExporterHTTP", package: "opentelemetry-swift"),
+                .product(name: "InMemoryExporter", package: "opentelemetry-swift"),
+                .product(name: "OTelSwiftLog", package: "opentelemetry-swift"),   
+            ]
+        ),
+        .testTarget(
+            name: "OTelInstrumentationServiceTests",
+            dependencies: [
+                "OTelInstrumentation",
                 .product(name: "OpenTelemetrySdk", package: "opentelemetry-swift"),
-                .product(name: "Installations", package: "KSCrash")
+                .product(name: "OpenTelemetryApi", package: "opentelemetry-swift"),
+                .product(name: "OpenTelemetryProtocolExporterHTTP", package: "opentelemetry-swift"),
             ]
         ),
         .target(
@@ -52,6 +84,7 @@ let package = Package(
         .target(
             name: "SamplingLive",
             dependencies: [
+                "DomainModels",
                 "Sampling",
                 "Common",
                 .product(name: "OpenTelemetryApi", package: "opentelemetry-swift"),
@@ -61,6 +94,7 @@ let package = Package(
         .testTarget(
             name: "SamplingLiveTests",
             dependencies: [
+                "DomainModels",
                 "Sampling",
                 "SamplingLive",
                 "Common",
@@ -73,43 +107,34 @@ let package = Package(
             ]
         ),
         .target(
-            name: "Instrumentation",
+            name: "ObservabilityServiceLive",
             dependencies: [
-                "API",
-                "CrashReporter",
-                "Sampling",
-                .product(name: "OpenTelemetrySdk", package: "opentelemetry-swift"),
-                .product(name: "OpenTelemetryApi", package: "opentelemetry-swift"),
-            ]
-        ),
-        .target(
-            name: "Observability",
-            dependencies: [
-                "Common",
-                "API",
-                "CrashReporter",
-                "CrashReporterLive",
+                "ApplicationServices",
+                "OTelInstrumentation",
+                "KSCrashReportService",
+                "iOSSessionService",
                 "Sampling",
                 "SamplingLive",
-                "Instrumentation",
-                .product(name: "OpenTelemetrySdk", package: "opentelemetry-swift"),
-                .product(name: "OpenTelemetryApi", package: "opentelemetry-swift"),
-                .product(name: "OpenTelemetryProtocolExporterHTTP", package: "opentelemetry-swift"),
-                .product(name: "URLSessionInstrumentation", package: "opentelemetry-swift"),
+                "Common"
             ],
             resources: [
                 .process("Resources"),
             ]
         ),
+        .target(name: "Common"),
+        .testTarget(
+            name: "CommonTests",
+            dependencies: [
+                "Common"
+            ],
+            resources: [.process("GraphQL/Queries")]
+        ),
         .target(
             name: "LaunchDarklyObservability",
             dependencies: [
-                "Observability",
-                "API",
-                "Common",
-                .product(name: "LaunchDarkly", package: "ios-client-sdk"),
-                .product(name: "OpenTelemetrySdk", package: "opentelemetry-swift"),
-                .product(name: "OpenTelemetryApi", package: "opentelemetry-swift"),
+                "ApplicationServices",
+                "ObservabilityServiceLive",
+                .product(name: "LaunchDarkly", package: "ios-client-sdk")
             ]
         )
     ]

Sources/API/Observe.swift

@@ -1,12 +1,9 @@
-public struct CrashReporter {
-    public var install: () throws -> Void
+public struct CrashReportService {
     public var logPendingCrashReports: () -> Void
 
     public init(
-        install: @escaping () throws -> Void,
         logPendingCrashReports: @escaping () -> Void
     ) {
-        self.install = install
         self.logPendingCrashReports = logPendingCrashReports
     }
 }

Sources/CrashReporter/CrashReporter.swift renamed to Sources/ApplicationServices/CrashReportService.swift

@@ -0,0 +1,7 @@
+public enum InstrumentationError: Error {
+    case invalidTraceExporterUrl
+    case invalidLogExporterUrl
+    case invalidMetricExporterUrl
+    case invalidGraphQLUrl
+    case unableToLoadReportStore
+}

Sources/ApplicationServices/InstrumentationError.swift

@@ -0,0 +1,18 @@
+@_exported import DomainModels
+
+public struct LogsService {
+    public var recordLog: (_ message: String, _ severity: Severity, _ attributes: [String: AttributeValue]) -> Void
+    public var flush: () async -> Bool
+    
+    public init(
+        recordLog: @escaping (_: String, _: Severity, _: [String : AttributeValue]) -> Void,
+        flush: @escaping () async -> Bool
+    ) {
+        self.recordLog = recordLog
+        self.flush = flush
+    }
+
+    public func recordLog(message: String, severity: Severity, attributes: [String: AttributeValue]) {
+        recordLog(message, severity, attributes)
+    }
+}

Sources/ApplicationServices/LogsService.swift

@@ -1,38 +1,26 @@
-import OpenTelemetryApi
+@_exported import DomainModels
 
-import API
-import Sampling
-
-public struct Instrumentation {
+public struct MetricsService {
     public var recordMetric: (_ metric: Metric) -> Void
     public var recordCount: (_ metric: Metric) -> Void
     public var recordIncr: (_ metric: Metric) -> Void
     public var recordHistogram: (_ metric: Metric) -> Void
     public var recordUpDownCounter: (_ metric: Metric) -> Void
-    public var recordError: (_ error: Error, _ attributes: [String: AttributeValue]) -> Void
-    public var recordLog: (_ message: String, _ severity: Severity, _ attributes: [String: AttributeValue]) -> Void
-    public var startSpan: (_ name: String, _ attributes: [String: AttributeValue]) -> Span
-    public var flush: () -> Bool
+    public var flush: () async -> Bool
 
     public init(
         recordMetric: @escaping (_: Metric) -> Void,
         recordCount: @escaping (_: Metric) -> Void,
         recordIncr: @escaping (_: Metric) -> Void,
         recordHistogram: @escaping (_: Metric) -> Void,
         recordUpDownCounter: @escaping (_: Metric) -> Void,
-        recordError: @escaping (_: Error, _: [String : AttributeValue]) -> Void,
-        recordLog: @escaping (_: String, _: Severity, _: [String : AttributeValue]) -> Void,
-        startSpan: @escaping (_: String, _: [String : AttributeValue]) -> Span,
-        flush: @escaping () -> Bool
+        flush: @escaping () async -> Bool
     ) {
         self.recordMetric = recordMetric
         self.recordCount = recordCount
         self.recordIncr = recordIncr
         self.recordHistogram = recordHistogram
         self.recordUpDownCounter = recordUpDownCounter
-        self.recordError = recordError
-        self.recordLog = recordLog
-        self.startSpan = startSpan
         self.flush = flush
     }
 
@@ -55,16 +43,4 @@ public struct Instrumentation {
     public func recordUpDownCounter(metric: Metric) {
         recordUpDownCounter(metric)
     }
-
-    public func recordError(error: Error, attributes: [String: AttributeValue]) {
-        recordError(error, attributes)
-    }
-
-    public func recordLog(message: String, severity: Severity, attributes: [String: AttributeValue]) {
-        recordLog(message, severity, attributes)
-    }
-
-    public func startSpan(name: String, attributes: [String: AttributeValue]) -> Span {
-        startSpan(name, attributes)
-    }
 }