Add home dashboard with usage stats and activity charts

Wave/Services/HistoryManager.swift

@@ -3,14 +3,20 @@ import Foundation
 @Observable
 final class HistoryManager {
     private(set) var records: [TranscriptionRecord] = []
+    private var usageStats = UsageStats()
 
-    init() { load() }
+    init() {
+        load()
+        backfillUsageFromRecords()
+    }
 
     func add(_ text: String) {
         let record = TranscriptionRecord(id: UUID(), text: text, date: Date())
         records.insert(record, at: 0)
         if records.count > 50 { records = Array(records.prefix(50)) }
+        usageStats.record(words: record.wordCount, at: record.date)
         save()
+        saveUsage()
     }
 
     func remove(_ id: UUID) {
@@ -24,14 +30,75 @@ final class HistoryManager {
     }
 
     var wordsToday: Int {
-        records.filter { Calendar.current.isDateInToday($0.date) }
+        let key = UsageStats.dayKey(for: Date())
+        return usageStats.dailyWords[key] ?? records.filter { Calendar.current.isDateInToday($0.date) }
             .reduce(0) { $0 + $1.wordCount }
     }
 
     var wordsThisWeek: Int {
-        let start = Calendar.current.date(byAdding: .day, value: -7, to: Date())!
-        return records.filter { $0.date >= start }
-            .reduce(0) { $0 + $1.wordCount }
+        let calendar = Calendar.current
+        let start = calendar.date(byAdding: .day, value: -6, to: calendar.startOfDay(for: Date()))!
+        return usageStats.dailyWords.reduce(0) { total, entry in
+            guard let date = Self.date(fromDayKey: entry.key), date >= start else { return total }
+            return total + entry.value
+        }
+    }
+
+    var totalWords: Int { usageStats.totalWords }
+
+    var estimatedTimeSavedSeconds: Int { usageStats.estimatedTimeSavedSeconds }
+
+    var activityHeatmap: [[Int]] {
+        var grid = Array(repeating: Array(repeating: 0, count: 24), count: 7)
+        for weekday in 1...7 {
+            for hour in 0..<24 {
+                let key = UsageStats.gridKey(weekday: weekday, hour: hour)
+                grid[weekday - 1][hour] = usageStats.hourGrid[key] ?? 0
+            }
+        }
+        return grid
+    }
+
+    var activityHeatmapMax: Int {
+        activityHeatmap.flatMap { $0 }.max() ?? 0
+    }
+
+    var wordsLast7Days: [Int] {
+        let calendar = Calendar.current
+        let today = calendar.startOfDay(for: Date())
+        return (0..<7).reversed().map { offset in
+            guard let date = calendar.date(byAdding: .day, value: -offset, to: today) else { return 0 }
+            return usageStats.dailyWords[UsageStats.dayKey(for: date)] ?? 0
+        }
+    }
+
+    var wordsLast7DayLabels: [String] {
+        let calendar = Calendar.current
+        let today = calendar.startOfDay(for: Date())
+        let formatter = DateFormatter()
+        formatter.dateFormat = "EEE"
+        return (0..<7).reversed().map { offset in
+            guard let date = calendar.date(byAdding: .day, value: -offset, to: today) else { return "" }
+            return formatter.string(from: date)
+        }
+    }
+
+    var wordsLast7DaysMax: Int {
+        wordsLast7Days.max() ?? 0
+    }
+
+    private func backfillUsageFromRecords() {
+        guard usageStats.totalWords == 0, !records.isEmpty else { return }
+        for record in records {
+            usageStats.record(words: record.wordCount, at: record.date)
+        }
+        saveUsage()
+    }
+
+    private static func date(fromDayKey key: String) -> Date? {
+        let parts = key.split(separator: "-").compactMap { Int($0) }
+        guard parts.count == 3 else { return nil }
+        return Calendar.current.date(from: DateComponents(year: parts[0], month: parts[1], day: parts[2]))
     }
 
     private func save() {
@@ -41,9 +108,19 @@ final class HistoryManager {
     }
 
     private func load() {
-        guard let data = UserDefaults.standard.data(forKey: "transcriptionHistory"),
-              let decoded = try? JSONDecoder().decode([TranscriptionRecord].self, from: data)
-        else { return }
-        records = decoded
+        if let data = UserDefaults.standard.data(forKey: "transcriptionHistory"),
+           let decoded = try? JSONDecoder().decode([TranscriptionRecord].self, from: data) {
+            records = decoded
+        }
+        if let data = UserDefaults.standard.data(forKey: "usageStats"),
+           let decoded = try? JSONDecoder().decode(UsageStats.self, from: data) {
+            usageStats = decoded
+        }
+    }
+
+    private func saveUsage() {
+        if let data = try? JSONEncoder().encode(usageStats) {
+            UserDefaults.standard.set(data, forKey: "usageStats")
+        }
     }
-}
+}

Wave/Services/UsageStats.swift

@@ -0,0 +1,37 @@
+import Foundation
+
+struct UsageStats: Codable {
+    var hourGrid: [String: Int] = [:]
+    var dailyWords: [String: Int] = [:]
+    var totalWords: Int = 0
+
+    static let typingWPM = 40.0
+    static let dictationWPM = 140.0
+
+    static func gridKey(weekday: Int, hour: Int) -> String {
+        "\(weekday)-\(hour)"
+    }
+
+    static func dayKey(for date: Date, calendar: Calendar = .current) -> String {
+        let components = calendar.dateComponents([.year, .month, .day], from: date)
+        return String(format: "%04d-%02d-%02d", components.year!, components.month!, components.day!)
+    }
+
+    var estimatedTimeSavedSeconds: Int {
+        let typingSecondsPerWord = 60.0 / Self.typingWPM
+        let dictationSecondsPerWord = 60.0 / Self.dictationWPM
+        let saved = Double(totalWords) * (typingSecondsPerWord - dictationSecondsPerWord)
+        return max(0, Int(saved.rounded()))
+    }
+
+    mutating func record(words: Int, at date: Date, calendar: Calendar = .current) {
+        guard words > 0 else { return }
+        let weekday = calendar.component(.weekday, from: date)
+        let hour = calendar.component(.hour, from: date)
+        let gridKey = Self.gridKey(weekday: weekday, hour: hour)
+        hourGrid[gridKey, default: 0] += words
+        let dayKey = Self.dayKey(for: date, calendar: calendar)
+        dailyWords[dayKey, default: 0] += words
+        totalWords += words
+    }
+}