// Shows how to read the full contents of an OPC UA file at once, using the file provider model.
//
// Find all latest examples here: https://opclabs.doc-that.com/files/onlinedocs/OPCLabs-OpcStudio/Latest/examples.html .
// OPC client and subscriber examples in C# on GitHub: https://github.com/OPCLabs/Examples-QuickOPC-CSharp .
// Missing some example? Ask us for it on our Online Forums, https://www.opclabs.com/forum/index ! You do not have to own
// a commercial license in order to use Online Forums, and we reply to every post.

using System;
using System.Text;
using OpcLabs.BaseLib.Extensions.FileProviders;
using OpcLabs.EasyOpc.UA;
using OpcLabs.EasyOpc.UA.FileTransfer;

namespace UADocExamples.FileProviders._FileInfo2
{
    class ReadAllBytes
    {
        public static void Main1()
        {
            // Unified Automation .NET based demo server (UaNETServer/UaServerNET.exe)
            UAEndpointDescriptor endpointDescriptor = "opc.tcp://localhost:48030";

            // A node that represents an instance of OPC UA FileType object.
            UANodeDescriptor fileNodeDescriptor = "nsu=http://www.unifiedautomation.com/DemoServer/ ;s=Demo.Files.TextFile";
            
            // Instantiate the file transfer client object
            var fileTransferClient = new EasyUAFileTransferClient();

            Console.WriteLine("Getting file info...");
            IFileInfo2 fileInfo2 = fileTransferClient.GetFileInfo2(endpointDescriptor, fileNodeDescriptor);
            // From this point onwards, the code is independent of the concrete realization of the file provider, and would
            // be identical e.g. for files in the physical file system, if the corresponding file provider was used.

            // Read in all contents from a specified file node.
            byte[] bytes;
            try
            {
                Console.WriteLine("Reading the whole file...");
                bytes = fileInfo2.ReadAllBytes();
            }
            // Methods in the file provider model throw IOException and other exceptions, but not UAException.
            catch (Exception exception)
            {
                Console.WriteLine($"*** Failure: {exception.GetBaseException().Message}");
                return;
            }

            // Display result
            Console.WriteLine();
            // We know that the file contains text, so we convert the received data to a string. If the file contents was
            // binary, you would process the data according to their format.
            string text = Encoding.UTF8.GetString(bytes);
            Console.WriteLine("File content:");
            Console.WriteLine(text);

            Console.WriteLine();
            Console.WriteLine("Finished...");
        }
    }
}