Generate first feed pages, images

CHDataManagement/Extensions/URL+Extensions.swift

@@ -0,0 +1,72 @@
+import Foundation
+
+extension URL {
+
+    func ensureParentFolderExistence() throws {
+        try deletingLastPathComponent().ensureFolderExistence()
+    }
+
+    func ensureFolderExistence() throws {
+        guard !exists else {
+            return
+        }
+        try FileManager.default.createDirectory(at: self, withIntermediateDirectories: true)
+    }
+
+    var isDirectory: Bool {
+        do {
+            let resources = try resourceValues(forKeys: [.isDirectoryKey])
+            guard let isDirectory = resources.isDirectory else {
+                print("No isDirectory info for \(path)")
+                return false
+            }
+            return isDirectory
+        } catch {
+            print("Failed to get directory information from \(path): \(error)")
+            return false
+        }
+    }
+
+    var exists: Bool {
+        FileManager.default.fileExists(atPath: path)
+    }
+
+    /**
+     Delete the file at the url.
+     */
+    func delete() throws {
+        try FileManager.default.removeItem(at: self)
+    }
+
+    func copy(to url: URL) throws {
+        if url.exists {
+            try url.delete()
+        }
+        try url.ensureParentFolderExistence()
+        try FileManager.default.copyItem(at: self, to: url)
+    }
+
+    var size: Int? {
+        let attributes = try? FileManager.default.attributesOfItem(atPath: path)
+        return (attributes?[.size] as? NSNumber)?.intValue
+    }
+
+    func resolvingFolderTraversal() -> URL? {
+        var components = [String]()
+        absoluteString.components(separatedBy: "/").forEach { part in
+            if part == ".." {
+                if !components.isEmpty {
+                    _ = components.popLast()
+                } else {
+                    components.append("..")
+                }
+                return
+            }
+            if part == "." {
+                return
+            }
+            components.append(part)
+        }
+        return URL(string: components.joined(separator: "/"))
+    }
+}