Add SpecialCases.swift to have a single place for code for special cases such as openrss.org URLs.

RSWeb/Sources/RSWeb/SpecialCases.swift

@@ -0,0 +1,98 @@
+//
+//  SpecialCases.swift
+//  RSWeb
+//
+//  Created by Brent Simmons on 12/12/24.
+//
+
+import Foundation
+import os
+
+extension URL {
+
+	private static let openRSSOrgURLCache = OSAllocatedUnfairLock(initialState: [URL: Bool]())
+
+	public var isOpenRSSOrgURL: Bool {
+
+		Self.openRSSOrgURLCache.withLock { cache in
+			if let cachedResult = cache[self] {
+				return cachedResult
+			}
+
+			let result: Bool
+			if let host = host(), host.contains("openrss.org") {
+				result = true
+			}
+			else {
+				result = false
+			}
+
+			cache[self] = result
+			return result
+		}
+	}
+}
+
+extension Set where Element == URL {
+
+	func byRemovingOpenRSSOrgURLs() -> Set<URL> {
+
+		filter { !$0.isOpenRSSOrgURL }
+	}
+
+	func openRSSOrgURLs() -> Set<URL> {
+
+		filter { $0.isOpenRSSOrgURL }
+	}
+
+	func byRemovingAllButOneRandomOpenRSSOrgURL() -> Set<URL> {
+
+		if self.isEmpty || self.count == 1 {
+			return self
+		}
+
+		let openRSSOrgURLs = openRSSOrgURLs()
+		if openRSSOrgURLs.isEmpty || openRSSOrgURLs.count == 1 {
+			return self
+		}
+
+		let randomIndex = Int.random(in: 0..<openRSSOrgURLs.count)
+		let singleOpenRSSOrgURLToRead = (Array(openRSSOrgURLs))[randomIndex]
+
+		var urls = byRemovingOpenRSSOrgURLs()
+		urls.insert(singleOpenRSSOrgURLToRead)
+
+		return urls
+	}
+}
+
+extension UserAgent {
+
+	static let openRSSOrgUserAgent = {
+
+#if os(iOS)
+		let platform = "iOS"
+#else
+		let platform = "Mac"
+#endif
+		let version = stringFromInfoPlist("CFBundleShortVersionString") ?? "Unknown"
+		let build = stringFromInfoPlist("CFBundleVersion") ?? "Unknown"
+
+		let template = Bundle.main.object(forInfoDictionaryKey: "UserAgentExtended") as? String
+
+		var userAgent = template!.replacingOccurrences(of: "[platform]", with: platform)
+		userAgent = userAgent.replacingOccurrences(of: "[version]", with: version)
+		userAgent = userAgent.replacingOccurrences(of: "[build]", with: build)
+
+		return userAgent
+	}()
+
+	private static func stringFromInfoPlist(_ key: String) -> String? {
+
+		guard let s = Bundle.main.object(forInfoDictionaryKey: key) as? String else {
+			assertionFailure("Expected to get \(key) from infoDictionary.")
+			return nil
+		}
+		return s
+	}
+}