Add SPM build tool plugin for embedding ID discovery

Package.swift

@@ -13,6 +13,10 @@ let package = Package(
             name: "Nubrick",
             targets: ["Nubrick"]
         ),
+        .plugin(
+            name: "NubrickDevTool",
+            targets: ["NubrickDevTool"]
+        ),
     ],
     dependencies: [
         .package(url: "https://github.com/facebook/yoga.git", .upToNextMinor(from: "3.2.1")),
@@ -47,6 +51,17 @@ let package = Package(
             name: "NubrickTests",
             dependencies: ["NubrickLocal"]
         ),
+
+        // Build tool plugin for extracting embedding IDs at compile time
+        .plugin(
+            name: "NubrickDevTool",
+            capability: .buildTool(),
+            dependencies: ["NubrickDevToolRunner"]
+        ),
+        .executableTarget(
+            name: "NubrickDevToolRunner",
+            path: "Plugins/NubrickDevToolRunner"
+        ),
     ],
     cxxLanguageStandard: CXXLanguageStandard(rawValue: "c++20")
 )

Plugins/NubrickDevTool/plugin.swift

@@ -0,0 +1,24 @@
+import PackagePlugin
+import Foundation
+
+@main
+struct NubrickDevTool: BuildToolPlugin {
+    func createBuildCommands(context: PluginContext, target: Target) async throws -> [Command] {
+        guard let sourceTarget = target as? SourceModuleTarget else { return [] }
+        let swiftFiles = sourceTarget.sourceFiles(withSuffix: "swift").map(\.path)
+        guard !swiftFiles.isEmpty else { return [] }
+
+        let tool = try context.tool(named: "NubrickDevToolRunner")
+        let output = context.pluginWorkDirectory.appending("NubrickEmbeddingIds.generated.swift")
+
+        return [
+            .buildCommand(
+                displayName: "NubrickDevTool: Extracting embedding IDs",
+                executable: tool.path,
+                arguments: ["--output", output.string] + swiftFiles.map { $0.string },
+                inputFiles: swiftFiles,
+                outputFiles: [output]
+            )
+        ]
+    }
+}

Plugins/NubrickDevToolRunner/main.swift

@@ -0,0 +1,61 @@
+import Foundation
+
+func extractEmbeddingIds(from source: String) -> [String] {
+    let pattern = #"NubrickSDK\s*\.\s*embedding(?:UIView)?\s*\(\s*"((?:[^"\\]|\\.)*)""#
+    guard let regex = try? NSRegularExpression(pattern: pattern) else { return [] }
+    let ns = source as NSString
+    let matches = regex.matches(in: source, range: NSRange(location: 0, length: ns.length))
+    return matches.compactMap { match -> String? in
+        guard match.numberOfRanges > 1, match.range(at: 1).location != NSNotFound else { return nil }
+        let raw = ns.substring(with: match.range(at: 1))
+        guard !raw.isEmpty else { return nil }
+        return raw.replacingOccurrences(of: #"\""#, with: "\"")
+                  .replacingOccurrences(of: #"\\"#, with: "\\")
+    }
+}
+
+func generateSwiftFile(ids: [String]) -> String {
+    let escaped = ids.joined(separator: ",")
+        .replacingOccurrences(of: "\\", with: "\\\\")
+        .replacingOccurrences(of: "\"", with: "\\\"")
+    return """
+    // Generated by NubrickDevTool — DO NOT EDIT.
+    import Foundation
+
+    @_cdecl("_nubrick_embedding_ids")
+    public func _nubrickEmbeddingIds() -> UnsafeMutablePointer<CChar>? {
+        strdup("\(escaped)")
+    }
+
+    """
+}
+
+// MARK: - Main
+
+guard CommandLine.arguments.count >= 3,
+      CommandLine.arguments[1] == "--output" else {
+    fputs("Usage: NubrickDevToolRunner --output <path> <swift files...>\n", stderr)
+    exit(1)
+}
+
+let outputPath = CommandLine.arguments[2]
+let inputFiles = Array(CommandLine.arguments.dropFirst(3))
+
+var allIds: [String] = []
+var seen = Set<String>()
+
+for filePath in inputFiles {
+    guard let data = FileManager.default.contents(atPath: filePath),
+          let source = String(data: data, encoding: .utf8) else {
+        continue
+    }
+    for id in extractEmbeddingIds(from: source) {
+        if seen.insert(id).inserted {
+            allIds.append(id)
+        }
+    }
+}
+
+let generated = generateSwiftFile(ids: allIds)
+let outputURL = URL(fileURLWithPath: outputPath)
+try! generated.write(to: outputURL, atomically: true, encoding: .utf8)

Sources/Nubrick/Data/embedding-discovery.swift

@@ -0,0 +1,15 @@
+import Foundation
+
+private typealias EmbeddingIdsFunc = @convention(c) () -> UnsafeMutablePointer<CChar>?
+
+func discoverBuildTimeEmbeddingIds() -> [String] {
+    guard let handle = dlopen(nil, RTLD_LAZY) else { return [] }
+    defer { dlclose(handle) }
+    guard let sym = dlsym(handle, "_nubrick_embedding_ids") else { return [] }
+    let fn = unsafeBitCast(sym, to: EmbeddingIdsFunc.self)
+    guard let cStr = fn() else { return [] }
+    defer { free(cStr) }
+    let joined = String(cString: cStr)
+    guard !joined.isEmpty else { return [] }
+    return joined.components(separatedBy: ",").filter { !$0.isEmpty }
+}

Sources/Nubrick/Data/track.swift

@@ -148,6 +148,7 @@ public enum CrashSeverity: String, Sendable {
 protocol TrackRepository2 : Actor {
     func trackExperimentEvent(_ event: TrackExperimentEvent)
     func trackEvent(_ event: TrackUserEvent)
+    func trackDiscoveredEmbeddingIds(_ ids: [String])
 
     func processMetricKitCrash(
         callStackTreeJSON: Data,
@@ -171,6 +172,7 @@ struct TrackEvent: Encodable {
         case Event = "event"
         case Experiment = "experiment"
         case Crash = "crash"
+        case EmbeddingDiscovery = "embedding_discovery"
     }
     var typename: Typename
     var experimentId: String?
@@ -182,6 +184,7 @@ struct TrackEvent: Encodable {
     var platform: String?
     var flutterSdkVersion: String?
     var severity: String?
+    var embeddingIds: [String]?
 }
 
 @_spi(FlutterBridge)
@@ -255,6 +258,15 @@ actor TrackRespositoryImpl: TrackRepository2 {
             timestamp: getCurrentDate().ISO8601Format()
         ))
     }
+
+    func trackDiscoveredEmbeddingIds(_ ids: [String]) {
+        guard !ids.isEmpty else { return }
+        self.pushToQueue(TrackEvent(
+            typename: .EmbeddingDiscovery,
+            timestamp: getCurrentDate().ISO8601Format(),
+            embeddingIds: ids
+        ))
+    }
 
     private func scheduleFlushTaskIfNeeded() {
         guard self.flushTask == nil else {return }

Sources/Nubrick/sdk.swift

@@ -220,6 +220,12 @@ final class NubrickCore {
         }
     }
 
+    func sendDiscoveredEmbeddingIds(_ ids: [String]) {
+        Task {
+            await self.dependencies.trackRepository.trackDiscoveredEmbeddingIds(ids)
+        }
+    }
+
     func setUserProperties(_ properties: [String: Any]) {
         self.dependencies.user.setProperties(properties)
     }
@@ -469,6 +475,13 @@ public enum NubrickSDK {
 
         self.runtime = runtime
 
+        #if DEBUG
+        let discoveredIds = discoverBuildTimeEmbeddingIds()
+        if !discoveredIds.isEmpty {
+            runtime.sendDiscoveredEmbeddingIds(discoveredIds)
+        }
+        #endif
+
         if trackCrashes {
             AppMetrics.shared.register()
         }