///<summary>Downloads the file from the server.</summary>
///<param name="basePath">The directory to download into.</param>
///<param name="ui">An optional IProgressReporter to report progress.</param>
///<exception cref="InvalidDataException">The hash didn't match.</exception>
public void DownloadFile(string basePath, IProgressReporter ui)
{
if (!Directory.Exists(basePath))
{
throw new DirectoryNotFoundException(basePath + " does not exist");
}
var filePath = Path.Combine(basePath, RelativePath);
if (File.Exists(filePath))
{
throw new InvalidOperationException(filePath + " already exists");
}
Directory.CreateDirectory(Path.GetDirectoryName(filePath)); //Won't throw
ui = ui ?? new EmptyProgressReporter();
long actualSize;
var request = WebRequest.Create(new Uri(UpdateConfig.Standard.BaseUri, RemoteUrl));
using (var hasher = hasherCreator()) {
using (var transform = UpdateChecker.CreateFileDecryptor())
using (var response = request.GetResponse())
using (var cypherStream = response.GetResponseStream())
using (var decryptingStream = new CryptoStream(cypherStream, transform, CryptoStreamMode.Read))
using (var unzipper = new GZipStream(decryptingStream, CompressionMode.Decompress))
using (var hashingStream = new CryptoStream(unzipper, hasher, CryptoStreamMode.Read))
using (var fileStream = File.Create(filePath)) {
actualSize = hashingStream.CopyTo(fileStream, Length, ui);
}
if (Length != actualSize)
{
File.Delete(filePath);
throw new InvalidDataException("Bad length");
}
if (!hasher.Hash.SequenceEqual(hash))
{
File.Delete(filePath);
throw new InvalidDataException("Bad hash");
}
File.SetLastWriteTimeUtc(filePath, DateModifiedUtc);
}
}
