Allow relay selector to filter DAITA enabled relays

ios/MullvadREST/Relay/RelaySelectorWrapper.swift

@@ -11,11 +11,15 @@ import MullvadTypes
 
 public final class RelaySelectorWrapper: RelaySelectorProtocol {
     let relayCache: RelayCacheProtocol
-
     let tunnelSettingsUpdater: SettingsUpdater
     private var tunnelSettings = LatestTunnelSettings()
     private var observer: SettingsObserverBlock!
 
+    // TODO: Remove, Jon
+    func setDaita(state: MultihopState) {
+        daitaState = state
+    }
+
     deinit {
         self.tunnelSettingsUpdater.removeObserver(observer)
     }

ios/MullvadVPN.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -0,0 +1,23 @@
+{
+  "originHash" : "c15149b2d59d9e9c72375f65339c04f41a19943e1117e682df27fc9f943fdc56",
+  "pins" : [
+    {
+      "identity" : "swift-log",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-log.git",
+      "state" : {
+        "revision" : "173f567a2dfec11d74588eea82cecea555bdc0bc",
+        "version" : "1.4.0"
+      }
+    },
+    {
+      "identity" : "wireguard-apple",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/mullvad/wireguard-apple.git",
+      "state" : {
+        "revision" : "3c55cc305d30a02f87af5d6228ff416d3901d8dd"
+      }
+    }
+  ],
+  "version" : 3
+}

ios/MullvadVPNTests/MullvadREST/Relay/RelaySelectorWrapperTests.swift

@@ -138,4 +138,74 @@ class RelaySelectorWrapperTests: XCTestCase {
         let selectedRelays = try wrapper.selectRelays(connectionAttemptCount: 0)
         XCTAssertNotNil(selectedRelays.entry)
     }
+
+    func testCanSelectRelayWithMultihopOnAndDaitaOn() throws {
+        let wrapper = RelaySelectorWrapper(
+            relayCache: relayCache,
+            multihopUpdater: multihopUpdater
+        )
+
+        multihopStateListener.onNewMultihop?(.on)
+        wrapper.setDaita(state: .on)
+
+        let constraints = RelayConstraints(
+            entryLocations: .only(UserSelectedRelays(locations: [.country("es")])), // Relay with DAITA.
+            exitLocations: .only(UserSelectedRelays(locations: [.country("us")]))
+        )
+
+        XCTAssertNoThrow(try wrapper.selectRelays(with: constraints, connectionAttemptCount: 0))
+    }
+
+    func testCannotSelectRelayWithMultihopOnAndDaitaOn() throws {
+        let wrapper = RelaySelectorWrapper(
+            relayCache: relayCache,
+            multihopUpdater: multihopUpdater
+        )
+
+        multihopStateListener.onNewMultihop?(.on)
+        wrapper.setDaita(state: .on)
+
+        let constraints = RelayConstraints(
+            entryLocations: .only(UserSelectedRelays(locations: [.country("se")])), // Relay without DAITA.
+            exitLocations: .only(UserSelectedRelays(locations: [.country("us")]))
+        )
+
+        XCTAssertThrowsError(try wrapper.selectRelays(with: constraints, connectionAttemptCount: 0))
+    }
+
+    func testCanSelectRelayWithMultihopOffAndDaitaOn() throws {
+        let wrapper = RelaySelectorWrapper(
+            relayCache: relayCache,
+            multihopUpdater: multihopUpdater
+        )
+
+        multihopStateListener.onNewMultihop?(.off)
+        wrapper.setDaita(state: .on)
+
+        let constraints = RelayConstraints(
+            exitLocations: .only(UserSelectedRelays(locations: [.country("es")])) // Relay with DAITA.
+        )
+
+        let selectedRelays = try wrapper.selectRelays(with: constraints, connectionAttemptCount: 0)
+        XCTAssertNil(selectedRelays.entry)
+    }
+
+    // If DAITA is enabled and no supported relays are found, we should try to find the nearest
+    // available relay that supports DAITA and use it as entry in a multihop selection.
+    func testCanSelectRelayWithMultihopOffAndDaitaOnThroughMultihop() throws {
+        let wrapper = RelaySelectorWrapper(
+            relayCache: relayCache,
+            multihopUpdater: multihopUpdater
+        )
+
+        multihopStateListener.onNewMultihop?(.off)
+        wrapper.setDaita(state: .on)
+
+        let constraints = RelayConstraints(
+            exitLocations: .only(UserSelectedRelays(locations: [.country("se")])) // Relay without DAITA.
+        )
+
+        let selectedRelays = try wrapper.selectRelays(with: constraints, connectionAttemptCount: 0)
+        XCTAssertNotNil(selectedRelays.entry)
+    }
 }