using System; using System.Collections.Generic; using System.Diagnostics.CodeAnalysis; using System.IO; using System.Net; using System.Text; using Renci.SshNet.Common; namespace Renci.SshNet { ///

/// Provides client connection to SSH server. ///

public class SshClient : BaseClient { ///

/// Holds the list of forwarded ports. ///

private readonly List _forwardedPorts; ///

/// Holds a value indicating whether the current instance is disposed. ///

/// /// true if the current instance is disposed; otherwise, false. /// private bool _isDisposed; private Stream _inputStream; ///

/// Gets the list of forwarded ports. ///

public IEnumerable ForwardedPorts { get { return _forwardedPorts.AsReadOnly(); } } ///

/// Initializes a new instance of the class. ///

/// The connection info. /// ///


        ///  is null.
        public SshClient(ConnectionInfo connectionInfo)
            : this(connectionInfo, ownsConnectionInfo: false)
        {
        }

        /// 
        /// Initializes a new instance of the  class.
        /// 
        /// Connection host.
        /// Connection port.
        /// Authentication username.
        /// Authentication password.
        ///  is null.
        ///  is invalid, or  is null or contains only whitespace characters.
        ///  is not within  and .
        [SuppressMessage("Microsoft.Reliability", "C2A000:DisposeObjectsBeforeLosingScope", Justification = "Disposed in Dispose(bool) method.")]
        public SshClient(string host, int port, string username, string password)
            : this(new PasswordConnectionInfo(host, port, username, password), ownsConnectionInfo: true)
        {
        }

        /// 
        /// Initializes a new instance of the  class.
        /// 
        /// Connection host.
        /// Authentication username.
        /// Authentication password.
        /// 
        ///     
        /// 
        ///  is null.
        ///  is invalid, or  is null or contains only whitespace characters.
        public SshClient(string host, string username, string password)
            : this(host, ConnectionInfo.DefaultPort, username, password)
        {
        }

        /// 
        /// Initializes a new instance of the  class.
        /// 
        /// Connection host.
        /// Connection port.
        /// Authentication username.
        /// Authentication private key file(s) .
        /// 
        ///     
        ///     
        /// 
        ///  is null.
        ///  is invalid, -or-  is null or contains only whitespace characters.
        ///  is not within  and .
        [SuppressMessage("Microsoft.Reliability", "CA2000:DisposeObjectsBeforeLosingScope", Justification = "Disposed in Dispose(bool) method.")]
        public SshClient(string host, int port, string username, params IPrivateKeySource[] keyFiles)
            : this(new PrivateKeyConnectionInfo(host, port, username, keyFiles), ownsConnectionInfo: true)
        {
        }

        /// 
        /// Initializes a new instance of the  class.
        /// 
        /// Connection host.
        /// Authentication username.
        /// Authentication private key file(s) .
        /// 
        ///     
        ///     
        /// 
        ///  is null.
        ///  is invalid, -or-  is null or contains only whitespace characters.
        public SshClient(string host, string username, params IPrivateKeySource[] keyFiles)
            : this(host, ConnectionInfo.DefaultPort, username, keyFiles)
        {
        }

        /// 
        /// Initializes a new instance of the  class.
        /// 
        /// The connection info.
        /// Specified whether this instance owns the connection info.
        ///  is null.
        /// 
        /// If  is true, then the
        /// connection info will be disposed when this instance is disposed.
        /// 
        private SshClient(ConnectionInfo connectionInfo, bool ownsConnectionInfo)
            : this(connectionInfo, ownsConnectionInfo, new ServiceFactory())
        {
        }

        /// 
        /// Initializes a new instance of the  class.
        /// 
        /// The connection info.
        /// Specified whether this instance owns the connection info.
        /// The factory to use for creating new services.
        ///  is null.
        ///  is null.
        /// 
        /// If  is true, then the
        /// connection info will be disposed when this instance is disposed.
        /// 
        internal SshClient(ConnectionInfo connectionInfo, bool ownsConnectionInfo, IServiceFactory serviceFactory)
            : base(connectionInfo, ownsConnectionInfo, serviceFactory)
        {
            _forwardedPorts = new List();
        }

        /// 
        /// Called when client is disconnecting from the server.
        /// 
        protected override void OnDisconnecting()
        {
            base.OnDisconnecting();

            foreach (var port in _forwardedPorts)
            {
                port.Stop();
            }
        }

        /// 
        /// Adds the forwarded port.
        /// 
        /// The port.
        /// 
        ///     
        ///     
        /// 
        /// Forwarded port is already added to a different client.
        ///  is null.
        /// Client is not connected.
        public void AddForwardedPort(ForwardedPort port)
        {
            if (port is null)
            {
                throw new ArgumentNullException(nameof(port));
            }

            EnsureSessionIsOpen();

            AttachForwardedPort(port);
            _forwardedPorts.Add(port);
        }

        /// 
        /// Stops and removes the forwarded port from the list.
        /// 
        /// Forwarded port.
        ///  is null.
        public void RemoveForwardedPort(ForwardedPort port)
        {
            if (port is null)
            {
                throw new ArgumentNullException(nameof(port));
            }

            // Stop port forwarding before removing it
            port.Stop();

            DetachForwardedPort(port);
            _ = _forwardedPorts.Remove(port);
        }

        private void AttachForwardedPort(ForwardedPort port)
        {
            if (port.Session != null && port.Session != Session)
            {
                throw new InvalidOperationException("Forwarded port is already added to a different client.");
            }

            port.Session = Session;
        }

        private static void DetachForwardedPort(ForwardedPort port)
        {
            port.Session = null;
        }

        /// 
        /// Creates the command to be executed.
        /// 
        /// The command text.
        ///  object.
        /// Client is not connected.
        public SshCommand CreateCommand(string commandText)
        {
            return CreateCommand(commandText, ConnectionInfo.Encoding);
        }

        /// 
        /// Creates the command to be executed with specified encoding.
        /// 
        /// The command text.
        /// The encoding to use for results.
        ///  object which uses specified encoding.
        /// This method will change current default encoding.
        /// Client is not connected.
        ///  or  is null.
        public SshCommand CreateCommand(string commandText, Encoding encoding)
        {
            EnsureSessionIsOpen();

            ConnectionInfo.Encoding = encoding;
            return new SshCommand(Session, commandText, encoding);
        }

        /// 
        /// Creates and executes the command.
        /// 
        /// The command text.
        /// Returns an instance of  with execution results.
        /// This method internally uses asynchronous calls.
        /// 
        ///     
        ///     
        /// 
        /// CommandText property is empty.
        /// Invalid Operation - An existing channel was used to execute this command.
        /// Asynchronous operation is already in progress.
        /// Client is not connected.
        ///  is null.
        public SshCommand RunCommand(string commandText)
        {
            var cmd = CreateCommand(commandText);
            _ = cmd.Execute();
            return cmd;
        }

        /// 
        /// Creates the shell.
        /// 
        /// The input.
        /// The output.
        /// The extended output.
        /// Name of the terminal.
        /// The columns.
        /// The rows.
        /// The width.
        /// The height.
        /// The terminal mode.
        /// Size of the internal read buffer.
        /// 
        /// Returns a representation of a  object.
        /// 
        /// Client is not connected.
        public Shell CreateShell(Stream input, Stream output, Stream extendedOutput, string terminalName, uint columns, uint rows, uint width, uint height, IDictionary terminalModes, int bufferSize)
        {
            EnsureSessionIsOpen();

            return new Shell(Session, input, output, extendedOutput, terminalName, columns, rows, width, height, terminalModes, bufferSize);
        }

        /// 
        /// Creates the shell.
        /// 
        /// The input.
        /// The output.
        /// The extended output.
        /// Name of the terminal.
        /// The columns.
        /// The rows.
        /// The width.
        /// The height.
        /// The terminal mode.
        /// 
        /// Returns a representation of a  object.
        /// 
        /// Client is not connected.
        public Shell CreateShell(Stream input, Stream output, Stream extendedOutput, string terminalName, uint columns, uint rows, uint width, uint height, IDictionary terminalModes)
        {
            return CreateShell(input, output, extendedOutput, terminalName, columns, rows, width, height, terminalModes, 1024);
        }

        /// 
        /// Creates the shell.
        /// 
        /// The input.
        /// The output.
        /// The extended output.
        /// 
        /// Returns a representation of a  object.
        /// 
        /// Client is not connected.
        public Shell CreateShell(Stream input, Stream output, Stream extendedOutput)
        {
            return CreateShell(input, output, extendedOutput, string.Empty, 0, 0, 0, 0, terminalModes: null, 1024);
        }

        /// 
        /// Creates the shell.
        /// 
        /// The encoding to use to send the input.
        /// The input.
        /// The output.
        /// The extended output.
        /// Name of the terminal.
        /// The columns.
        /// The rows.
        /// The width.
        /// The height.
        /// The terminal mode.
        /// Size of the internal read buffer.
        /// 
        /// Returns a representation of a  object.
        /// 
        /// Client is not connected.
        public Shell CreateShell(Encoding encoding, string input, Stream output, Stream extendedOutput, string terminalName, uint columns, uint rows, uint width, uint height, IDictionary terminalModes, int bufferSize)
        {
            // TODO let shell dispose of input stream when we own the stream!

            _inputStream = new MemoryStream();
            var writer = new StreamWriter(_inputStream, encoding);
            writer.Write(input);
            writer.Flush();
            _ = _inputStream.Seek(0, SeekOrigin.Begin);

            return CreateShell(_inputStream, output, extendedOutput, terminalName, columns, rows, width, height, terminalModes, bufferSize);
        }

        /// 
        /// Creates the shell.
        /// 
        /// The encoding.
        /// The input.
        /// The output.
        /// The extended output.
        /// Name of the terminal.
        /// The columns.
        /// The rows.
        /// The width.
        /// The height.
        /// The terminal modes.
        /// 
        /// Returns a representation of a  object.
        /// 
        /// Client is not connected.
        public Shell CreateShell(Encoding encoding, string input, Stream output, Stream extendedOutput, string terminalName, uint columns, uint rows, uint width, uint height, IDictionary terminalModes)
        {
            return CreateShell(encoding, input, output, extendedOutput, terminalName, columns, rows, width, height, terminalModes, 1024);
        }

        /// 
        /// Creates the shell.
        /// 
        /// The encoding.
        /// The input.
        /// The output.
        /// The extended output.
        /// 
        /// Returns a representation of a  object.
        /// 
        /// Client is not connected.
        public Shell CreateShell(Encoding encoding, string input, Stream output, Stream extendedOutput)
        {
            return CreateShell(encoding, input, output, extendedOutput, string.Empty, 0, 0, 0, 0, terminalModes: null, 1024);
        }

        /// 
        /// Creates the shell stream.
        /// 
        /// The TERM environment variable.
        /// The terminal width in columns.
        /// The terminal width in rows.
        /// The terminal width in pixels.
        /// The terminal height in pixels.
        /// The size of the buffer.
        /// 
        /// The created  instance.
        /// 
        /// Client is not connected.
        /// 
        /// 
        /// The TERM environment variable contains an identifier for the text window's capabilities.
        /// You can get a detailed list of these cababilities by using the ‘infocmp’ command.
        /// 
        /// 
        /// The column/row dimensions override the pixel dimensions(when nonzero). Pixel dimensions refer
        /// to the drawable area of the window.
        /// 
        /// 
        public ShellStream CreateShellStream(string terminalName, uint columns, uint rows, uint width, uint height, int bufferSize)
        {
            return CreateShellStream(terminalName, columns, rows, width, height, bufferSize, terminalModeValues: null);
        }

        /// 
        /// Creates the shell stream.
        /// 
        /// The TERM environment variable.
        /// The terminal width in columns.
        /// The terminal width in rows.
        /// The terminal width in pixels.
        /// The terminal height in pixels.
        /// The size of the buffer.
        /// The terminal mode values.
        /// 
        /// The created  instance.
        /// 
        /// Client is not connected.
        /// 
        /// 
        /// The TERM environment variable contains an identifier for the text window's capabilities.
        /// You can get a detailed list of these cababilities by using the ‘infocmp’ command.
        /// 
        /// 
        /// The column/row dimensions override the pixel dimensions(when non-zero). Pixel dimensions refer
        /// to the drawable area of the window.
        /// 
        /// 
        public ShellStream CreateShellStream(string terminalName, uint columns, uint rows, uint width, uint height, int bufferSize, IDictionary terminalModeValues)
        {
            EnsureSessionIsOpen();

            return ServiceFactory.CreateShellStream(Session, terminalName, columns, rows, width, height, terminalModeValues, bufferSize);
        }

        /// 
        /// Stops forwarded ports.
        /// 
        protected override void OnDisconnected()
        {
            base.OnDisconnected();

            for (var i = _forwardedPorts.Count - 1; i >= 0; i--)
            {
                var port = _forwardedPorts[i];
                DetachForwardedPort(port);
                _forwardedPorts.RemoveAt(i);
            }
        }

        /// 
        /// Releases unmanaged and - optionally - managed resources.
        /// 
        /// true to release both managed and unmanaged resources; false to release only unmanaged resources.
        protected override void Dispose(bool disposing)
        {
            base.Dispose(disposing);

            if (_isDisposed)
            {
                return;
            }

            if (disposing)
            {
                if (_inputStream != null)
                {
                    _inputStream.Dispose();
                    _inputStream = null;
                }

                _isDisposed = true;
            }
        }

        private void EnsureSessionIsOpen()
        {
            if (Session is null)
            {
                throw new SshConnectionException("Client not connected.");
            }
        }
    }
}