Download at url with progress

Sources/SMBClient/FileReader.swift

@@ -62,6 +62,42 @@ public class FileReader {
     return buffer
   }
 
+  public func download(toLocalFile localFile: URL, overwrite: Bool, progressHandler: (_ progress: Double) -> Void) async throws {
+    let fileProxy = try await fileProxy()
+
+    var offset: UInt64 = 0
+
+    let fileManger = FileManager.default
+    let filePath = localFile.path
+    let fileExists = fileManger.fileExists(atPath: filePath)
+    // If file does not exist, create an empty file so we can create a FileHandle
+    if !fileExists {
+      try Data().write(to: localFile)
+    }
+    guard let fileHandle = FileHandle(forWritingAtPath: filePath) else {
+      throw URLError(.cannotWriteToFile)
+    }
+    // If file did already exist and we are not overriding, throw an error
+    if fileExists, !overwrite {
+      throw CocoaError(.fileWriteFileExists)
+    }
+    defer {
+      fileHandle.closeFile()
+    }
+    var response: Read.Response
+    repeat {
+      response = try await session.read(
+        fileId: fileProxy.id,
+        offset: offset
+      )
+      fileHandle.seekToEndOfFile()
+      fileHandle.write(response.buffer)
+      offset += UInt64(response.buffer.count)
+      let progress = Double(offset) / Double(fileProxy.size)
+      progressHandler(progress)
+    } while NTStatus(response.header.status) != .endOfFile && offset < fileProxy.size
+  }
+
   public func close() async throws {
     if let createResponse {
       try await session.close(fileId: createResponse.fileId)

Sources/SMBClient/SMBClient.swift

@@ -125,6 +125,12 @@ public class SMBClient {
     return data
   }
 
+  public func download(path: String, localPath: URL, overwrite: Bool = false, progressHandler: (_ progress: Double) -> Void = { _ in }) async throws {
+    let fileReader = fileReader(path: Pathname.normalize(path))
+    try await fileReader.download(toLocalFile: localPath, overwrite: overwrite, progressHandler: progressHandler)
+    try await fileReader.close()
+  }
+
   public func upload(content: Data, path: String) async throws {
     try await upload(content: content, path: Pathname.normalize(path), progressHandler: { _ in })
   }

Tests/SMBClientTests/SMBClientTests.swift

@@ -379,6 +379,28 @@ final class SMBClientTests: XCTestCase {
     XCTAssertEqual(data, try Data(contentsOf: fixtureURL.appending(component: "\(user.sharePath)/\(path)")))
   }
 
+  func testDownloadIntoFile() async throws {
+    let user = bob
+    let client = SMBClient(host: "localhost", port: 4445)
+    try await client.login(username: user.username, password: user.password)
+    try await client.connectShare(user.share)
+
+    let path = "test_files/file_example_JPG_1MB.jpg"
+
+    var progressWasUpdated: Bool = false
+    let fileManager = FileManager.default
+    let tempFolder = URL(fileURLWithPath: NSTemporaryDirectory(), isDirectory: true)
+    let destinationFile = tempFolder.appending(path: "downloadedfile.jpg", directoryHint: .notDirectory)
+    try await client.download(path: path, localPath: destinationFile, overwrite: true) { progress in
+        progressWasUpdated = true
+    }
+
+    XCTAssertTrue(fileManager.fileExists(atPath: destinationFile.path))
+    let data = try Data(contentsOf: destinationFile)
+    XCTAssertEqual(data, try Data(contentsOf: fixtureURL.appending(component: "\(user.sharePath)/\(path)")))
+    XCTAssertTrue(progressWasUpdated)
+  }
+
   func testRandomRead01() async throws {
     let user = bob
     let client = SMBClient(host: "localhost", port: 4445)