feat: add stats for using vocamac

Sources/VocaMac/Models/AppState.swift

@@ -117,6 +117,7 @@ final class AppState: ObservableObject {
     let modelManager: ModelManaging
     let soundManager: SoundPlaying
     let cursorOverlay: CursorOverlayManaging
+    let statsManager: StatsManaging
     let updateChecker = UpdateChecker()
     let permissionManager: any PermissionManaging
 
@@ -147,6 +148,7 @@ final class AppState: ObservableObject {
         modelManager: ModelManaging = ModelManager(),
         soundManager: SoundPlaying = SoundManager(),
         cursorOverlay: CursorOverlayManaging,
+        statsManager: StatsManaging,
         permissionManager: (any PermissionManaging)? = nil,
         skipSystemIntegration: Bool = false
     ) {
@@ -157,6 +159,7 @@ final class AppState: ObservableObject {
         self.modelManager = modelManager
         self.soundManager = soundManager
         self.cursorOverlay = cursorOverlay
+        self.statsManager = statsManager
         self.permissionManager = permissionManager ?? PermissionManager(audioEngine: audioEngine, hotKeyManager: hotKeyManager)
         self.skipSystemIntegration = skipSystemIntegration
 
@@ -172,6 +175,14 @@ final class AppState: ObservableObject {
             .receive(on: DispatchQueue.main)
             .sink { [weak self] _ in self?.objectWillChange.send() }
             .store(in: &cancellables)
+
+        // Forward statsManager changes
+        statsManager.objectWillChangePublisher
+            .receive(on: DispatchQueue.main)
+            .sink { [weak self] _ in
+                self?.objectWillChange.send()
+            }
+            .store(in: &cancellables)
     }
 
     /// Single production AppState instance for the process.
@@ -181,7 +192,10 @@ final class AppState: ObservableObject {
     /// stored-property initialization prevents duplicate service graphs, event
     /// taps, audio observers, and stale SwiftUI environment objects.
     @MainActor
-    private static let sharedProductionInstance = AppState(cursorOverlay: CursorOverlayManager())
+    private static let sharedProductionInstance = AppState(
+        cursorOverlay: CursorOverlayManager(),
+        statsManager: StatsManager()
+    )
 
     /// Convenience factory for creating AppState with all real services.
     /// Needed because CursorOverlayManager is @MainActor and can't be a default parameter.
@@ -513,7 +527,10 @@ final class AppState: ObservableObject {
 
             lastTranscription = result
 
-            // Inject text at cursor position (text is already filtered
+            // Update stats
+            statsManager.recordTranscription(result)
+
+            // Inject text at cursor position
             // by WhisperService to remove hallucination tokens like [BLANK_AUDIO])
             let trimmedText = result.text.trimmingCharacters(in: .whitespacesAndNewlines)
             if !trimmedText.isEmpty {

Sources/VocaMac/Models/UserStats.swift

@@ -0,0 +1,40 @@
+// UserStats.swift
+// VocaMac
+//
+// Data model for tracking user usage statistics.
+
+import Foundation
+
+struct UserStats: Codable {
+    /// Total number of words transcribed across all sessions
+    var totalWords: Int = 0
+
+    /// Total number of successful transcriptions performed
+    var totalTranscriptions: Int = 0
+
+    /// Total duration of audio recorded in seconds
+    var totalAudioDurationSeconds: Double = 0
+
+    /// Date of the most recent transcription
+    var lastUsageDate: Date?
+
+    /// Current consecutive days of usage
+    var currentStreak: Int = 0
+
+    /// Highest consecutive days of usage recorded
+    var bestStreak: Int = 0
+
+    /// Daily word counts to calculate trends and streaks
+    /// Key is date string in "yyyy-MM-dd" format
+    var dailyWordCounts: [String: Int] = [:]
+
+    /// Daily duration to calculate WPM history
+    var dailyDurationSeconds: [String: Double] = [:]
+
+    /// Calculated average Words Per Minute (WPM)
+    var averageWPM: Double {
+        guard totalAudioDurationSeconds > 0 else { return 0 }
+        let minutes = totalAudioDurationSeconds / 60.0
+        return Double(totalWords) / minutes
+    }
+}

Sources/VocaMac/Services/ServiceProtocols.swift

@@ -138,3 +138,13 @@ extension SpeechTranscribing {
 protocol TextInjecting: AnyObject {
     func inject(text: String, preserveClipboard: Bool)
 }
+
+// MARK: - StatsManaging
+
+@MainActor
+protocol StatsManaging: AnyObject {
+    var stats: UserStats { get }
+    var objectWillChangePublisher: AnyPublisher<Void, Never> { get }
+    func recordTranscription(_ transcription: VocaTranscription)
+    func resetStats()
+}

Sources/VocaMac/Services/StatsManager.swift

@@ -0,0 +1,126 @@
+// StatsManager.swift
+// VocaMac
+//
+// Manages the persistence and updating of user statistics.
+
+import Foundation
+import Combine
+
+@MainActor
+class StatsManager: StatsManaging, ObservableObject {
+    @Published private(set) var stats: UserStats = UserStats()
+
+    var objectWillChangePublisher: AnyPublisher<Void, Never> {
+        objectWillChange.eraseToAnyPublisher()
+    }
+
+    private let fileManager = FileManager.default
+    private let statsFileName = "stats.json"
+
+    init() {
+        loadStats()
+    }
+
+    private var statsFileURL: URL {
+        let appSupport = fileManager.urls(for: .applicationSupportDirectory, in: .userDomainMask).first!
+        let vMacDir = appSupport.appendingPathComponent("VocaMac", isDirectory: true)
+
+        // Ensure directory exists
+        if !fileManager.fileExists(atPath: vMacDir.path) {
+            try? fileManager.createDirectory(at: vMacDir, withIntermediateDirectories: true)
+        }
+
+        return vMacDir.appendingPathComponent(statsFileName)
+    }
+
+    private func loadStats() {
+        do {
+            if fileManager.fileExists(atPath: statsFileURL.path) {
+                let data = try Data(contentsOf: statsFileURL)
+                stats = try JSONDecoder().decode(UserStats.self, from: data)
+                VocaLogger.debug(.general, "User stats loaded from disk")
+            } else {
+                VocaLogger.info(.general, "No stats file found, starting fresh")
+            }
+        } catch {
+            VocaLogger.error(.general, "Failed to load stats: \(error.localizedDescription)")
+        }
+    }
+
+    private func saveStats() {
+        do {
+            let data = try JSONEncoder().encode(stats)
+            try data.write(to: statsFileURL, options: .atomic)
+            VocaLogger.debug(.general, "User stats saved to disk")
+        } catch {
+            VocaLogger.error(.general, "Failed to save stats: \(error.localizedDescription)")
+        }
+    }
+
+    func recordTranscription(_ transcription: VocaTranscription) {
+        let text = transcription.text.trimmingCharacters(in: .whitespacesAndNewlines)
+        guard !text.isEmpty else { return }
+
+        // Estimate word count
+        let words = text.components(separatedBy: .whitespacesAndNewlines)
+            .filter { !$0.isEmpty }
+            .count
+
+        let dateKey = formatDate(transcription.timestamp)
+
+        // Update basic counts
+        stats.totalWords += words
+        stats.totalTranscriptions += 1
+        stats.totalAudioDurationSeconds += transcription.audioLengthSeconds
+
+        // Update daily stats
+        stats.dailyWordCounts[dateKey, default: 0] += words
+        stats.dailyDurationSeconds[dateKey, default: 0] += transcription.audioLengthSeconds
+
+        // Update streaks
+        updateStreaks(currentDate: transcription.timestamp)
+
+        stats.lastUsageDate = transcription.timestamp
+
+        saveStats()
+    }
+
+    func resetStats() {
+        stats = UserStats()
+        saveStats()
+    }
+
+    private func updateStreaks(currentDate: Date) {
+        guard let lastDate = stats.lastUsageDate else {
+            // First time usage
+            stats.currentStreak = 1
+            stats.bestStreak = 1
+            return
+        }
+
+        let calendar = Calendar.current
+
+        // Check if last usage was yesterday
+        if calendar.isDateInYesterday(lastDate) {
+            // Continuation of streak
+            if !calendar.isDate(lastDate, inSameDayAs: currentDate) {
+                stats.currentStreak += 1
+            }
+        } else if calendar.isDate(lastDate, inSameDayAs: currentDate) {
+            // Already used today, streak remains same
+        } else {
+            // Streak broken
+            stats.currentStreak = 1
+        }
+
+        if stats.currentStreak > stats.bestStreak {
+            stats.bestStreak = stats.currentStreak
+        }
+    }
+
+    private func formatDate(_ date: Date) -> String {
+        let formatter = DateFormatter()
+        formatter.dateFormat = "yyyy-MM-dd"
+        return formatter.string(from: date)
+    }
+}

Sources/VocaMac/Views/SettingsView.swift

@@ -23,6 +23,11 @@ struct SettingsView: View {
                     Label("Models", systemImage: "brain")
                 }
 
+            StatsSettingsTab()
+                .tabItem {
+                    Label("Stats", systemImage: "chart.xyaxis.line")
+                }
+
             AudioSettingsTab()
                 .tabItem {
                     Label("Audio", systemImage: "waveform")