From 2e7d1eaa8b94d2772b9b0fe8f86ca4ffc68a204a Mon Sep 17 00:00:00 2001
From: Mark Murray <mark.murray@shopify.com>
Date: Tue, 5 Mar 2024 14:32:33 +0000
Subject: [PATCH] Implement SFSafariViewController as fallback when
 checkoutDidFail

---
 .../CartViewController.swift                  | 26 ++++++-------
 .../CheckoutBridge.swift                      |  5 ++-
 .../CheckoutDelegate.swift                    |  4 +-
 .../CheckoutWebViewController.swift           | 39 ++++++++++++++++---
 .../Configuration.swift                       |  4 ++
 5 files changed, 56 insertions(+), 22 deletions(-)

diff --git a/Samples/MobileBuyIntegration/MobileBuyIntegration/CartViewController.swift b/Samples/MobileBuyIntegration/MobileBuyIntegration/CartViewController.swift
index dfd71f1e..d3d11bb5 100644
--- a/Samples/MobileBuyIntegration/MobileBuyIntegration/CartViewController.swift
+++ b/Samples/MobileBuyIntegration/MobileBuyIntegration/CartViewController.swift
@@ -162,9 +162,9 @@ extension CartViewController: CheckoutDelegate {
 		dismiss(animated: true)
 	}
 
-	func checkoutDidFail(errors: [ShopifyCheckoutSheetKit.CheckoutError]) {
-		print(#function, errors)
-	}
+//	func checkoutDidFail(errors: [ShopifyCheckoutSheetKit.CheckoutError]) {
+//		print(#function, errors)
+//	}
 
 	func checkoutDidClickContactLink(url: URL) {
 		if UIApplication.shared.canOpenURL(url) {
@@ -173,16 +173,16 @@ extension CartViewController: CheckoutDelegate {
 	}
 
 	func checkoutDidFail(error: ShopifyCheckoutSheetKit.CheckoutError) {
-		switch error {
-		case .sdkError(let underlying):
-			print(#function, underlying)
-			forceCloseCheckout("Checkout Unavailable")
-		case .checkoutExpired(let message): forceCloseCheckout(message)
-		case .checkoutUnavailable(let message): forceCloseCheckout(message)
-		case .checkoutLiquidNotMigrated(let message):
-			print(#function, message)
-			forceCloseCheckout("Checkout Unavailable")
-		}
+//		switch error {
+//		case .sdkError(let underlying):
+//			print(#function, underlying)
+//			forceCloseCheckout("Checkout Unavailable")
+//		case .checkoutExpired(let message): forceCloseCheckout(message)
+//		case .checkoutUnavailable(let message): forceCloseCheckout(message)
+//		case .checkoutLiquidNotMigrated(let message):
+//			print(#function, message)
+//			forceCloseCheckout("Checkout Unavailable")
+//		}
 	}
 
 	func checkoutDidEmitWebPixelEvent(event: ShopifyCheckoutSheetKit.PixelEvent) {
diff --git a/Sources/ShopifyCheckoutSheetKit/CheckoutBridge.swift b/Sources/ShopifyCheckoutSheetKit/CheckoutBridge.swift
index 58e9308b..9da1a220 100644
--- a/Sources/ShopifyCheckoutSheetKit/CheckoutBridge.swift
+++ b/Sources/ShopifyCheckoutSheetKit/CheckoutBridge.swift
@@ -95,10 +95,13 @@ extension CheckoutBridge {
 		}
 
 		init(from decoder: Decoder) throws {
-			let container = try decoder.container(keyedBy: CodingKeys.self)
 
+			throw NSError(domain: "com.shopify", code: 1, userInfo: [NSLocalizedDescriptionKey: "Fake Error"])
+
+			let container = try decoder.container(keyedBy: CodingKeys.self)
 			let name = try container.decode(String.self, forKey: .name)
 
+
 			switch name {
 			case "completed":
 				let checkoutCompletedEventDecoder = CheckoutCompletedEventDecoder()
diff --git a/Sources/ShopifyCheckoutSheetKit/CheckoutDelegate.swift b/Sources/ShopifyCheckoutSheetKit/CheckoutDelegate.swift
index a2556b3c..86e58cdc 100644
--- a/Sources/ShopifyCheckoutSheetKit/CheckoutDelegate.swift
+++ b/Sources/ShopifyCheckoutSheetKit/CheckoutDelegate.swift
@@ -52,9 +52,7 @@ extension CheckoutDelegate {
 		handleUrl(url)
 	}
 
-	public func checkoutDidFail(error: CheckoutError) throws {
-		throw error
-	}
+	public func checkoutDidFail(error: CheckoutError) throws {}
 
 	private func handleUrl(_ url: URL) {
 		if UIApplication.shared.canOpenURL(url) {
diff --git a/Sources/ShopifyCheckoutSheetKit/CheckoutWebViewController.swift b/Sources/ShopifyCheckoutSheetKit/CheckoutWebViewController.swift
index c8559e48..d9e065d8 100644
--- a/Sources/ShopifyCheckoutSheetKit/CheckoutWebViewController.swift
+++ b/Sources/ShopifyCheckoutSheetKit/CheckoutWebViewController.swift
@@ -23,6 +23,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SO
 
 import UIKit
 import WebKit
+import SafariServices
 
 class CheckoutWebViewController: UIViewController, UIAdaptivePresentationControllerDelegate {
 
@@ -176,11 +177,6 @@ extension CheckoutWebViewController: CheckoutWebViewDelegate {
 		delegate?.checkoutDidComplete(event: event)
 	}
 
-	func checkoutViewDidFailWithError(error: CheckoutError) {
-		CheckoutWebView.invalidate()
-		delegate?.checkoutDidFail(error: error)
-	}
-
 	func checkoutViewDidClickLink(url: URL) {
 		delegate?.checkoutDidClickLink(url: url)
 	}
@@ -193,4 +189,37 @@ extension CheckoutWebViewController: CheckoutWebViewDelegate {
 	func checkoutViewDidEmitWebPixelEvent(event: PixelEvent) {
 		delegate?.checkoutDidEmitWebPixelEvent(event: event)
 	}
+
+	func checkoutViewDidFailWithError(error: CheckoutError) {
+		CheckoutWebView.invalidate()
+		delegate?.checkoutDidFail(error: error)
+
+		guard ShopifyCheckoutSheetKit.configuration.handleFallbackOnError else {
+			return
+		}
+
+		switch error {
+		case .sdkError: fallthrough
+		case .checkoutUnavailable: fallthrough
+		case .checkoutLiquidNotMigrated:
+			self.fallbackToSafariViewController()
+		default:
+				break
+		}
+	}
+
+	/// Private
+
+	private func getRootViewController() -> UIViewController? {
+		return UIApplication.shared.windows.first(where: { $0.isKeyWindow })?.rootViewController
+	}
+
+	private func fallbackToSafariViewController() {
+		dismiss(animated: true) {
+			let safariViewController = SFSafariViewController(url: self.checkoutURL)
+			if let rootViewController = self.getRootViewController() {
+				rootViewController.present(safariViewController, animated: true)
+			}
+		}
+	}
 }
diff --git a/Sources/ShopifyCheckoutSheetKit/Configuration.swift b/Sources/ShopifyCheckoutSheetKit/Configuration.swift
index ac10aeaa..971c8746 100644
--- a/Sources/ShopifyCheckoutSheetKit/Configuration.swift
+++ b/Sources/ShopifyCheckoutSheetKit/Configuration.swift
@@ -49,6 +49,10 @@ public struct Configuration {
 	public var logger: Logger = NoOpLogger()
 
 	public var title: String = NSLocalizedString("shopify_checkout_sheet_title", value: "Checkout", comment: "The title of the checkout sheet.")
+
+	/// Trigger a SafariViewController in the event of a checkout error.
+	/// Set to "false" to disable this feature.
+	public var handleFallbackOnError = true
 }
 
 extension Configuration {