centralized lock logic into a new lock service to be shared to extension

src/App/Services/LockService.cs

@@ -0,0 +1,69 @@
+using System;
+using Bit.App.Abstractions;
+using Plugin.Settings.Abstractions;
+using Plugin.Fingerprint.Abstractions;
+using Bit.App.Enums;
+
+namespace Bit.App.Services
+{
+    public class LockService : ILockService
+    {
+        private readonly ISettings _settings;
+        private readonly IAuthService _authService;
+        private readonly IFingerprint _fingerprint;
+
+        public LockService(
+            ISettings settings,
+            IAuthService authService,
+            IFingerprint fingerprint)
+        {
+            _settings = settings;
+            _authService = authService;
+            _fingerprint = fingerprint;
+        }
+
+        public LockType GetLockType(bool forceLock)
+        {
+            // Only lock if they are logged in
+            if(!_authService.IsAuthenticated)
+            {
+                return LockType.None;
+            }
+
+            // Are we forcing a lock? (i.e. clicking a button to lock the app manually, immediately)
+            if(!forceLock && !_settings.GetValueOrDefault(Constants.SettingLocked, false))
+            {
+                // Lock seconds tells if if they want to lock the app or not
+                var lockSeconds = _settings.GetValueOrDefault<int?>(Constants.SettingLockSeconds);
+                if(!lockSeconds.HasValue)
+                {
+                    return LockType.None;
+                }
+
+                // Has it been longer than lockSeconds since the last time the app was backgrounded?
+                var now = DateTime.UtcNow;
+                var lastBackground = _settings.GetValueOrDefault(Constants.SettingLastBackgroundedDate, now.AddYears(-1));
+                if((now - lastBackground).TotalSeconds < lockSeconds.Value)
+                {
+                    return LockType.None;
+                }
+            }
+
+            // What method are we using to unlock?
+            var fingerprintUnlock = _settings.GetValueOrDefault<bool>(Constants.SettingFingerprintUnlockOn);
+            var pinUnlock = _settings.GetValueOrDefault<bool>(Constants.SettingPinUnlockOn);
+            if(fingerprintUnlock && _fingerprint.IsAvailable)
+            {
+                return LockType.Fingerprint;
+            }
+            else if(pinUnlock && !string.IsNullOrWhiteSpace(_authService.PIN))
+            {
+                return LockType.PIN;
+            }
+            else
+            {
+                return LockType.Password;
+            }
+        }
+    }
+}