Add input handling on iOS

Gemini-iOS/BrowserWebViewController.swift

@@ -189,6 +189,10 @@ class BrowserWebViewController: UIViewController {
                     } else {
                         self.renderFallback(response: response)
                     }
+                } else if response.status.isInput {
+                    DispatchQueue.main.async {
+                        self.showInputPrompt(response: response)
+                    }
                 } else {
                     DispatchQueue.main.async {
                         self.showError(message: "Unknown error: \(response.header)")
@@ -208,6 +212,20 @@ class BrowserWebViewController: UIViewController {
         errorMessageLabel.text = message
     }
     
+    private func showInputPrompt(response: GeminiResponse) {
+        let alert = UIAlertController(title: "Input Requested", message: response.meta, preferredStyle: .alert)
+        alert.addTextField { field in
+            field.isSecureTextEntry = response.status == .sensitiveInput
+        }
+        alert.addAction(UIAlertAction(title: "Submit", style: .default, handler: { _ in
+            guard var components = URLComponents(url: self.navigator.currentURL, resolvingAgainstBaseURL: false) else { return }
+            components.query = alert.textFields!.first!.text
+            self.navigator.changeURL(components.url!)
+        }))
+        alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
+        present(alert, animated: true)
+    }
+    
     private func renderDocument(_ doc: Document) {
         self.document = doc