Add developer option for clearing the application cache (#852)

* Add developer option for clearing the application cache

* Tweaks following code review

ElementX/Sources/Application/AppCoordinator.swift

@@ -159,6 +159,8 @@ class AppCoordinator: AppCoordinatorProtocol {
                 self.logout(isSoft: isSoft)
             case (.signingOut, .completedSigningOut(let isSoft), .signedOut):
                 self.presentSplashScreen(isSoftLogout: isSoft)
+            case (.signedIn, .clearCache, .initial):
+                clearCache()
             default:
                 fatalError("Unknown transition: \(context)")
             }
@@ -238,6 +240,8 @@ class AppCoordinator: AppCoordinatorProtocol {
             switch action {
             case .signOut:
                 self?.stateMachine.processEvent(.signOut(isSoft: false))
+            case .clearCache:
+                self?.stateMachine.processEvent(.clearCache)
             }
         }
         
@@ -428,6 +432,25 @@ class AppCoordinator: AppCoordinatorProtocol {
             storedAppRoute = appRoute
         }
     }
+    
+    private func clearCache() {
+        showLoadingIndicator()
+        
+        defer {
+            hideLoadingIndicator()
+        }
+        
+        navigationRootCoordinator.setRootCoordinator(SplashScreenCoordinator())
+        
+        userSession.clientProxy.stopSync()
+        userSessionFlowCoordinator?.stop()
+        
+        userSessionStore.clearCacheFor(userSession: userSession)
+        
+        tearDownUserSession()
+        
+        stateMachine.processEvent(.startWithExistingSession)
+    }
 }
 
 // MARK: - AuthenticationCoordinatorDelegate

ElementX/Sources/Application/AppCoordinatorStateMachine.swift

@@ -52,6 +52,9 @@ class AppCoordinatorStateMachine {
         case signOut(isSoft: Bool)
         /// Signing out completed
         case completedSigningOut(isSoft: Bool)
+        
+        /// Request cache clearing
+        case clearCache
     }
     
     private let stateMachine: StateMachine<State, Event>
@@ -71,6 +74,8 @@ class AppCoordinatorStateMachine {
         stateMachine.addRoutes(event: .startWithExistingSession, transitions: [.initial => .restoringSession])
         stateMachine.addRoutes(event: .createdUserSession, transitions: [.restoringSession => .signedIn])
         stateMachine.addRoutes(event: .failedRestoringSession, transitions: [.restoringSession => .signedOut])
+        
+        stateMachine.addRoutes(event: .clearCache, transitions: [.signedIn => .initial])
 
         // Transitions with associated values need to be handled through `addRouteMapping`
         stateMachine.addRouteMapping { event, fromState, _ in