Move validation logic to a new class and add tests

Riot/Utils/URLValidator.swift

@@ -0,0 +1,70 @@
+// 
+// Copyright 2022 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import Foundation
+import MatrixSDK
+
+@objcMembers
+/// URL validation result object
+class URLValidationResult: NSObject {
+
+    /// Should confirm the tapped url
+    let shouldShowConfirmationAlert: Bool
+    /// User visible string the user tapped
+    let visibleURLString: String?
+
+    init(shouldShowConfirmationAlert: Bool,
+         visibleURLString: String?) {
+        self.shouldShowConfirmationAlert = shouldShowConfirmationAlert
+        self.visibleURLString = visibleURLString
+        super.init()
+    }
+
+    static let passed = URLValidationResult(shouldShowConfirmationAlert: false,
+                                            visibleURLString: nil)
+}
+
+@objcMembers
+class URLValidator: NSObject {
+
+    /// Validated tapped url in the given event
+    /// - Parameters:
+    ///   - url: User tapped URL
+    ///   - event: Event containing the link
+    /// - Returns: Validation result
+    static func validateTappedURL(_ url: URL, in event: MXEvent) -> URLValidationResult {
+        if let format = event.content["format"] as? String,
+           let formattedBody = event.content["formatted_body"] as? String {
+            if format == kMXRoomMessageFormatHTML {
+                let visibleURL = FormattedBodyParser().getVisibleURL(forURL: url, inFormattedBody: formattedBody)
+                if url != visibleURL {
+                    //  urls are different, show confirmation alert
+                    return .init(shouldShowConfirmationAlert: true,
+                                 visibleURLString: visibleURL?.absoluteString)
+                }
+            }
+        }
+        if let body = event.content[kMXMessageBodyKey] as? String,
+            body.vc_containsRTLOverride(),
+            body != url.absoluteString {
+            //  we don't know where the url is in the body, assuming visibleString is just a reverse of the url
+            return .init(shouldShowConfirmationAlert: true,
+                         visibleURLString: url.absoluteString.vc_reversed())
+        }
+        return .passed
+    }
+
+}