From 3d2171d716f4fef09d4044fb25581742366d0bde Mon Sep 17 00:00:00 2001
From: Thomas Ricouard <ricouard77@gmail.com>
Date: Wed, 6 Dec 2023 08:05:26 +0100
Subject: [PATCH] Refactor auth to ASWebAuthenticationSession

---
 IceCubesApp/App/SafariRouter.swift            |  3 +-
 .../App/Tabs/Settings/AddAccountsView.swift   | 37 +++++++------------
 .../Sources/DesignSystem/SceneDelegate.swift  | 12 ++++++
 3 files changed, 28 insertions(+), 24 deletions(-)

diff --git a/IceCubesApp/App/SafariRouter.swift b/IceCubesApp/App/SafariRouter.swift
index b860a21b..9faef5c0 100644
--- a/IceCubesApp/App/SafariRouter.swift
+++ b/IceCubesApp/App/SafariRouter.swift
@@ -3,6 +3,7 @@ import Env
 import Observation
 import SafariServices
 import SwiftUI
+import Models
 
 extension View {
   @MainActor func withSafariRouter() -> some View {
@@ -26,7 +27,7 @@ private struct SafariRouter: ViewModifier {
       })
       .onOpenURL { url in
         // Open external URL (from icecubesapp://)
-        let urlString = url.absoluteString.replacingOccurrences(of: "icecubesapp://", with: "https://")
+        let urlString = url.absoluteString.replacingOccurrences(of: AppInfo.scheme, with: "https://")
         guard let url = URL(string: urlString), url.host != nil else { return }
         _ = routerPath.handle(url: url)
       }
diff --git a/IceCubesApp/App/Tabs/Settings/AddAccountsView.swift b/IceCubesApp/App/Tabs/Settings/AddAccountsView.swift
index 346952a0..b9efcd08 100644
--- a/IceCubesApp/App/Tabs/Settings/AddAccountsView.swift
+++ b/IceCubesApp/App/Tabs/Settings/AddAccountsView.swift
@@ -1,4 +1,5 @@
 import AppAccount
+import AuthenticationServices
 import Combine
 import DesignSystem
 import Env
@@ -27,7 +28,6 @@ struct AddAccountView: View {
   @State private var signInClient: Client?
   @State private var instances: [InstanceSocial] = []
   @State private var instanceFetchError: LocalizedStringKey?
-  @State private var oauthURL: URL?
 
   private let instanceNamePublisher = PassthroughSubject<String, Never>()
 
@@ -136,21 +136,6 @@ struct AddAccountView: View {
           break
         }
       }
-      .onOpenURL(perform: { url in
-        Task {
-          await continueSignIn(url: url)
-        }
-      })
-      .onChange(of: oauthURL) { _, newValue in
-        if newValue == nil {
-          isSigninIn = false
-        }
-      }
-      #if !targetEnvironment(macCatalyst)
-      .sheet(item: $oauthURL, content: { url in
-        SafariView(url: url)
-      })
-      #endif
     }
   }
 
@@ -233,11 +218,19 @@ struct AddAccountView: View {
     do {
       signInClient = .init(server: sanitizedName)
       if let oauthURL = try await signInClient?.oauthURL() {
-#if targetEnvironment(macCatalyst)
-        openURL(oauthURL)
-#else
-        self.oauthURL = oauthURL
-#endif
+        let session = ASWebAuthenticationSession(url: oauthURL,
+                                                 callbackURLScheme: AppInfo.scheme.replacingOccurrences(of: "://", with: ""))
+        { callbackURL, error in
+          if let callbackURL {
+            Task {
+              await continueSignIn(url: callbackURL)
+            }
+          } else {
+            isSigninIn = false
+          }
+        }
+        session.presentationContextProvider = SceneDelegate.authViewController
+        session.start()
       } else {
         isSigninIn = false
       }
@@ -252,7 +245,6 @@ struct AddAccountView: View {
       return
     }
     do {
-      oauthURL = nil
       let oauthToken = try await client.continueOauthFlow(url: url)
       let client = Client(server: client.server, oauthToken: oauthToken)
       let account: Account = try await client.get(endpoint: Accounts.verifyCredentials)
@@ -266,7 +258,6 @@ struct AddAccountView: View {
       isSigninIn = false
       dismiss()
     } catch {
-      oauthURL = nil
       isSigninIn = false
     }
   }
diff --git a/Packages/DesignSystem/Sources/DesignSystem/SceneDelegate.swift b/Packages/DesignSystem/Sources/DesignSystem/SceneDelegate.swift
index 61419be5..c6c8b32a 100644
--- a/Packages/DesignSystem/Sources/DesignSystem/SceneDelegate.swift
+++ b/Packages/DesignSystem/Sources/DesignSystem/SceneDelegate.swift
@@ -1,4 +1,5 @@
 import Combine
+import AuthenticationServices
 import UIKit
 
 @Observable
@@ -6,6 +7,9 @@ public class SceneDelegate: NSObject, UIWindowSceneDelegate, Sendable {
   public var window: UIWindow?
   public private(set) var windowWidth: CGFloat = UIScreen.main.bounds.size.width
   public private(set) var windowHeight: CGFloat = UIScreen.main.bounds.size.height
+  
+  public static var globalPresentationAnchor: ASPresentationAnchor? = nil
+  public static var authViewController = AuthViewController()
 
   public func scene(_ scene: UIScene,
                     willConnectTo _: UISceneSession,
@@ -13,6 +17,8 @@ public class SceneDelegate: NSObject, UIWindowSceneDelegate, Sendable {
   {
     guard let windowScene = scene as? UIWindowScene else { return }
     window = windowScene.keyWindow
+    
+    Self.globalPresentationAnchor = window
 
     #if targetEnvironment(macCatalyst)
       if let titlebar = windowScene.titlebar {
@@ -54,3 +60,9 @@ public class SceneDelegate: NSObject, UIWindowSceneDelegate, Sendable {
     }
   }
 }
+
+public class AuthViewController: UIViewController, ASWebAuthenticationPresentationContextProviding {
+  public func presentationAnchor(for session: ASWebAuthenticationSession) -> ASPresentationAnchor {
+    return SceneDelegate.globalPresentationAnchor ?? ASPresentationAnchor()
+  }
+}