Improve VPN status reporting and recovery

app/Sources/LemanaVPN/SessionTiming.swift

@@ -0,0 +1,71 @@
+import Foundation
+
+enum VPNIndicatorStyle: String, CaseIterable, Identifiable {
+    case shield, ring, clock, time
+
+    var id: String { rawValue }
+    var title: String {
+        switch self {
+        case .shield: return "Щит"
+        case .ring: return "Кольцо"
+        case .clock: return "Часы"
+        case .time: return "Время"
+        }
+    }
+}
+
+struct SessionTiming {
+    enum Urgency { case normal, warning, critical, unknown }
+
+    private(set) var startedAt: Date?
+    private(set) var expiresAt: Date?
+
+    private var duration: TimeInterval? {
+        guard let start = startedAt, let end = expiresAt, end > start else { return nil }
+        return end.timeIntervalSince(start)
+    }
+
+    mutating func observe(startedAt: String?, expires: String?, now: Date = Date()) {
+        let formatter = ISO8601DateFormatter()
+        if let start = startedAt.flatMap({ formatter.date(from: $0) }) {
+            // The CLI timestamp is authoritative, including after a legacy fallback.
+            self.startedAt = start
+        } else if self.startedAt == nil {
+            self.startedAt = now
+        }
+        if let expires = expires {
+            expiresAt = formatter.date(from: expires)
+        }
+    }
+
+    func remaining(at now: Date) -> TimeInterval? {
+        guard duration != nil, let end = expiresAt else { return nil }
+        return max(0, end.timeIntervalSince(now))
+    }
+
+    func progress(at now: Date) -> Double? {
+        guard let duration = duration, let start = startedAt else { return nil }
+        return min(1, max(0, now.timeIntervalSince(start) / duration))
+    }
+
+    func urgency(at now: Date) -> Urgency {
+        guard let remaining = remaining(at: now) else { return .unknown }
+        if remaining <= 15 * 60 { return .critical }
+        if remaining <= 60 * 60 { return .warning }
+        return .normal
+    }
+
+    func compactRemaining(at now: Date) -> String? {
+        guard let seconds = remaining(at: now) else { return nil }
+        let minutes = Int(ceil(seconds / 60))
+        return String(format: "%d:%02d", minutes / 60, minutes % 60)
+    }
+
+    func remainingLabel(at now: Date) -> String {
+        guard let seconds = remaining(at: now) else { return "Срок сессии неизвестен" }
+        if seconds <= 0 { return "Время сессии истекло" }
+        let minutes = Int(ceil(seconds / 60))
+        if minutes < 60 { return "Осталось \(minutes) мин" }
+        return "Осталось \(minutes / 60) ч \(minutes % 60) мин"
+    }
+}