///////////////////////////////////////////////////////////////////////////////
//
//  Copyright (c) Microsoft Corporation.  All rights reserved.
//

/*

This file contains contracts and structure definitions for use with the SMB client.
The most important contract is SmbClientControlContract, which allows processes,
such as the SMB status / control tool, to query and display the state of an SMB
client process, and to send control requests to the client process.

*/

using System;
using Microsoft.Singularity.Channels;
using Microsoft.SingSharp;
using Microsoft.Singularity.Directory;

namespace Smb.PublicChannels
{
	/*
		This contract allows control / management tools to communicate with the
		SMB Client Manager service.  The service is a singleton, which manages
		(creates, configures, stops) the SMB client processes (instances of
		SmbClient.exe).  The importer of this contract is usually net.exe.
	*/
	public contract SmbClientManagerContract : ServiceContract
	{
        out message Success();
        
        override state Start: one {
            Success! -> Ready;
        }

		in message CreateClient(SmbClientConfig config);
		
		in message StopClient(char[]! in ExHeap clientId);
		
		in message BindClient(char[]! in ExHeap clientId, ServiceContract.Exp:Start! exp);
		
		in message EnumClients();
		out message ClientList(char[][]! in ExHeap clientIdList);
		
		out message Ok();
		out message RequestFailed(SmbErrorCode error, char[] in ExHeap errortext);
		
		in message QueryClientStatus(char[]! in ExHeap clientId);
		out message ClientStatusReport(SmbClientStatus status);

		in message QueryClientConfig(char[]! in ExHeap clientId);
		out message ClientConfigReport(SmbClientConfig status);

		state Ready : one
		{
			CreateClient? -> CreatingClient;
			StopClient? -> (Ok! or RequestFailed!) -> Ready;
			EnumClients? -> (ClientList! or RequestFailed!) -> Ready;
			BindClient? -> (Ok! or RequestFailed!) -> Ready;
			QueryClientStatus? -> (ClientStatusReport! or RequestFailed!) -> Ready;
			QueryClientConfig? -> (ClientConfigReport! or RequestFailed!) -> Ready;
		}
		
		state CreatingClient : one {
			Ok! -> Ready;
			RequestFailed! -> Ready;
		}
		
		public const string ManagerControlPath = "/dev/smb-client-manager";
	}
	
	public enum SmbErrorCode
	{
		Success = 0,
		MountPathAlreadyExists,			// a client with the same mount path already exists
		ClientExists,			
		AuthorizationDenied,
		MountPathNotFound,
		InternalError,
		InvalidState,
		
	}

	// Each instance of the SMB client process (smbclient.exe) registers an instance of this
	// endpoint, usually as /dev/smb.xxx, where xxx is some arbitrary unique identifier.
	// This contract allows control / management tools, such as smb.exe, to query and display
	// information about running SMB clients, to send control requests to them (e.g. reconnect),
	// and to terminate (unmount) them.
	//
	// Note: This contract will be eliminated, and its equivalent control functions will be moved
	// to SmbClientManagerContract.
	public contract SmbClientControlContract : ServiceContract
	{
	#if false
		// This method polls the status of the client.  The status can change
		// over time.
		in message GetStatus();
		out message StatusReport(SmbClientStatus status);
		
		// This method polls the configuration of the client.  The configuration
		// does not (currently) change over time.
		in message GetConfig();
		out message ConfigReport(SmbClientConfig config);
	#endif
		
		// This method requests that the client disconnect from the remote
		// server (if it is connected), terminate all channel service threads,
		// and terminate the process.
		in message Terminate();
		out message AckTerminate();
		
		// This method disconnects the client from the remote server.
		// The client does not terminate.  If the client receives any
		// requests (from local processes), then the client will attempt
		// to reconnect to the server.
		in message Disconnect();
		out message AckDisconnect();

		// This method disconnects the client and attempts to reconnect.		
		in message Reconnect();
		out message AckReconnect();
		
        out message Success();
        
        override state Start: one {
            Success! -> Ready;
        }

		state Ready : one
		{
		#if false
			GetStatus? -> StatusReport! -> Ready;
			GetConfig? -> ConfigReport! -> Ready;
		#endif
			Terminate? -> AckTerminate! -> Terminating;
			Disconnect? -> AckDisconnect! -> Ready;
			Reconnect? -> AckReconnect! -> Ready;
		}
		
		state Terminating : one
		{
		}
	}

	public enum SmbClientConnectionStatus
	{
		Invalid = 0,
		Disconnected,				// no activity, so we are not connected
		TransportConnecting,		// we're trying to establish connectivity at the transport level (TCP/IP or NBT)
		Negotiating,				// transport is connected, now doing SMB negotiation, SESSION SETUP, etc.
		Authenticating,				//
		Connected,					// connected and ready to use
	}
	
	public enum SmbReasonDisconnected
	{
		Invalid = 0,
		Idle,						// no one has asked to connect to the server yet
		TransportConnectFailed,		// failed to connect
		NegotiationFailed,			// SMB-level negotiation failed
		ResourceConnectFailed,		// SMB server rejected TreeConnect
		AuthenticationFailed,		// failed to prove identity
		AuthorizationFailed,		// authenticated, but user is not authorized to use resource
		NoResponse,					// no response to transport-level messages; assuming server is dead or unreachable
		ProtocolViolation,			// received invalid SMB messages
		TransportFailure,			// transport failure of some kind, after successful connection
	}

	// This structure describes the configuration of the SMB client.	
	// It represents the "goal state" of the client.
	// The client will attempt to connect and service SMB requests, using
	// this configuration information.  If any errors occur (TCP-level
	// connection failures, authentication failures, etc.), then the
	// client will periodically retry the connection.
	public rep struct SmbClientConfig : ITracked
	{
		public char[]! in ExHeap UncPath;			// UNC of resource, such as \\foo\bar
		public char[]! in ExHeap MountPath;			// local mount path, e.g. /share, implements DirectoryServiceContract
		public char[]! in ExHeap ControlPath;		// local path of SmbClientControlContract, e.g. /dev/smb.xxx
		public char[]! in ExHeap CredentialsName;	// auth principal name, e.g. domain\user, user@domain.com, OPTIONAL
		public char[]! in ExHeap Tag;				// credentials tag, only set if CredentialsName != null
	}
	
	// This structure describes the current status of the SMB client.
	// The status is always sampled as a single snapshot in time, rather
	// than having multiple round-trips to query individual fields.
	public rep struct SmbClientStatus : ITracked
	{
		public SmbClientConnectionStatus ConnectionStatus;
		public SmbReasonDisconnected ReasonDisconnected;
		
		// If the client successfully connects to the SMB server, then these values
		// contain information that was received during SMB negotiation.  These values
		// are useful for status displays.
		public char[] in ExHeap ServerMachineName;
		public char[] in ExHeap ServerDomainName;
		public char[] in ExHeap ServerOperatingSystem;
		public char[] in ExHeap ActiveCredentialsName;
	}
	
	/*
	This contract is used for communication between the SMB Client Manager service
	(SmbClientManager) and instances SMB Client Process (SmbClient).  The SMB Client Manager
	service is the only process that creates any instances of the SmbClient executable;
	it uses this contract to control the SmbClient processes.  This allows detailed,
	typed configuration information to be conveyed to the SmbClient (rather than relying
	on command-line parameters), and also control messages (stop, etc.).

	The SmbClient process uses Process.GetStartupEndpoint (at index 0) to bind to its instance
	of SmbClientControllerContract.Exp.
	
	The importer of this contract is always SmbClientManager.
	The exporter of this contract is always SmbClient.
	*/
	public contract SmbClientControllerContract
	{
		in message Configure(SmbClientConfig config);

		in message Bind(ServiceContract.Exp:Start! exp);
		
		out message Ok();
		out message RequestFailed(SmbErrorCode error, char[] in ExHeap optionalErrorText);
		
		state Created : one
		{
			Configure? -> Configuring;
		}
		
		state Configuring : one
		{
			Ok! -> Running;
			RequestFailed! -> Created;
		}
		
		in message Stop();
		
		state Running : one
		{
			Bind? -> (Ok! or RequestFailed!) -> Running;
			Stop? -> Ok! -> Stopped;
		}
		
		state Stopped : one
		{
		}
	}


	public contract SmbMuxNotifier
	{
		in message StatusChanged(SmbClientStatus muxstate);
		
		out message Ack();
		
		state Ready : one
		{
			StatusChanged? -> Ack! -> Ready;
		}
	}

}