Pick preset from pool supported presets only

Fixes #78

CHANGELOG.md

@@ -15,6 +15,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Host compression framing and algorithm are now editable.
 
+### Fixed
+
+- NordVPN double servers not connecting out of the box. [#78](https://github.com/passepartoutvpn/passepartout-ios/issues/78)
+
 ## 1.6.0 (2019-05-01)
 
 ### Added

Passepartout-iOS/Scenes/ServiceViewController.swift

@@ -162,8 +162,13 @@ class ServiceViewController: UIViewController, TableModelHost {
             vc?.modificationDelegate = self
             
         case .providerPresetSegueIdentifier:
+            let infra = uncheckedProviderProfile.infrastructure
+            let presets: [InfrastructurePreset] = uncheckedProviderProfile.pool?.supportedPresetIds(in: uncheckedProviderProfile.infrastructure).map {
+                return infra.preset(for: $0)!
+            } ?? []
+
             let vc = destination as? ProviderPresetViewController
-            vc?.presets = uncheckedProviderProfile.infrastructure.presets
+            vc?.presets = presets
             vc?.currentPresetId = uncheckedProviderProfile.presetId
             vc?.delegate = self
             
@@ -631,6 +636,13 @@ extension ServiceViewController: UITableViewDataSource, UITableViewDelegate, Tog
         return ip
     }
     
+    private var providerPresetIndexPath: IndexPath {
+        guard let ip = model.indexPath(row: .providerPreset, section: .configuration) else {
+            fatalError("Could not locate presetIndexPath")
+        }
+        return ip
+    }
+    
     private func mappedTrustedNetworksRow(_ from: TrustedNetworksModel.RowType) -> RowType {
         switch from {
         case .trustsMobile:
@@ -1122,13 +1134,13 @@ extension ServiceViewController: UITableViewDataSource, UITableViewDelegate, Tog
         tableView.reloadRows(at: [dataCountIndexPath], with: .none)
     }
     
-    func reloadSelectedRow(andRowAt indexPath: IndexPath? = nil) {
+    func reloadSelectedRow(andRowsAt indexPaths: [IndexPath]? = nil) {
         guard let selectedIP = tableView.indexPathForSelectedRow else {
             return
         }
         var outdatedIPs = [selectedIP]
-        if let otherIP = indexPath {
-            outdatedIPs.append(otherIP)
+        if let otherIPs = indexPaths {
+            outdatedIPs.append(contentsOf: otherIPs)
         }
         tableView.reloadRows(at: outdatedIPs, with: .none)
         tableView.selectRow(at: selectedIP, animated: false, scrollPosition: .none)
@@ -1254,7 +1266,21 @@ extension ServiceViewController: ProviderPoolViewControllerDelegate {
             return
         }
         uncheckedProviderProfile.poolId = pool.id
-        reloadSelectedRow(andRowAt: endpointIndexPath)
+        
+        var extraReloadedRows = [endpointIndexPath]
+
+        // fall back to a supported preset and reload preset row too
+        let supportedPresets = pool.supportedPresetIds(in: uncheckedProviderProfile.infrastructure)
+        if let presetId = uncheckedProviderProfile.preset?.id, !supportedPresets.contains(presetId),
+            let fallback = supportedPresets.first {
+
+            if fallback != uncheckedProviderProfile.presetId {
+                extraReloadedRows.append(providerPresetIndexPath)
+            }
+            uncheckedProviderProfile.presetId = fallback
+        }
+
+        reloadSelectedRow(andRowsAt: extraReloadedRows)
         vpn.reinstallIfEnabled()
 
         if #available(iOS 12, *) {
@@ -1271,7 +1297,7 @@ extension ServiceViewController: ProviderPresetViewControllerDelegate {
             return
         }
         uncheckedProviderProfile.presetId = preset.id
-        reloadSelectedRow(andRowAt: endpointIndexPath)
+        reloadSelectedRow(andRowsAt: [endpointIndexPath])
         vpn.reinstallIfEnabled()
     }
 }

Passepartout/Sources/Services/Pool.swift

@@ -69,6 +69,25 @@ public struct Pool: Codable, Hashable {
     
     public let numericAddresses: [UInt32]?
     
+    // XXX: inefficient but convenient field (not serialized)
+    public func category(in infrastructure: Infrastructure) -> PoolCategory? {
+        for category in infrastructure.categories {
+            for group in category.groups {
+                for pool in group.pools {
+                    if pool.id == id {
+                        return category
+                    }
+                }
+            }
+        }
+        return nil
+    }
+
+    public func supportedPresetIds(in infrastructure: Infrastructure) -> [String] {
+        let poolCategory = category(in: infrastructure)
+        return poolCategory?.presets ?? infrastructure.presets.map { $0.id }
+    }
+    
     public func hasAddress(_ address: String) -> Bool {
         guard let numericAddresses = numericAddresses else {
             return false
@@ -88,6 +107,12 @@ public struct Pool: Codable, Hashable {
         return addrs
     }
     
+    // MARK: Equatable
+
+    public static func == (lhs: Pool, rhs: Pool) -> Bool {
+        return lhs.id == rhs.id
+    }
+    
     // MARK: Hashable
     
     public func hash(into hasher: inout Hasher) {