// $Header: /cvsroot/sourcenav/src/snavigator/demo/c++_demo/glish/Task.cc,v 1.1.1.1 2002/04/18 23:35:25 mdejong Exp $

#include <stream.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <osfcn.h>
#include <string.h>
#include <errno.h>

#include "system.h"

#include "Channel.h"
#include "Select.h"
#include "LocalExec.h"
#include "RemoteExec.h"
#include "Task.h"
#include "Sequencer.h"
#include "Reporter.h"


Task::Task( TaskAttr* task_attrs, Sequencer* s ) : Agent(s)
	{
	attrs = task_attrs;
	pending_events = 0;
	channel = 0;
	local_channel = 0;
	selector = 0;
	task_error = 1;
	no_such_program = 1;
	executable = 0;
	name = 0;
	read_pipe_str = write_pipe_str = 0;
	pipes_used = 0;

	active = 0;	// not true till we get a .established event
	protocol = 0;	// not set until Client establishes itself

	id = sequencer->RegisterTask( this );

	if ( attrs->task_var_ID )
		agent_ID = attrs->task_var_ID;
	else
		agent_ID = id;
	}

Task::~Task()
	{
	sequencer->DeleteTask( this );

	CloseChannel();

	delete pending_events;

	delete attrs;
	delete name;
	delete executable;

	delete read_pipe_str;
	delete write_pipe_str;
	}

Value* Task::SendEvent( const char* event_name, parameter_list* args,
			int is_request, int log )
	{
	if ( task_error )
		return is_request ? error_value() : 0;

	Value* event_val = BuildEventValue( args, 1 );
	Value* result = 0;

	if ( is_request && ! channel )
		{ // We need to synchronize; wait for the task to connect.
		if ( local_channel )
			{ // Okay, already have a channel, just connect.
			(void) sequencer->NewConnection( local_channel );
			channel = local_channel;
			}

		else
			channel = sequencer->WaitForTaskConnection( this );

		if ( ! channel )
			// Connection problem, bail out.
			return error_value();
		}

	if ( ! channel )
		{
		if ( ! pending_events )
			pending_events = new glish_event_list;

		GlishEvent* e = new GlishEvent( strdup( event_name ),
						copy_value( event_val ) );
		if ( is_request )
			e->SetIsRequest();

		pending_events->append( e );
		}

	else
		{
		int fd = channel->WriteFD();

		if ( log )
			sequencer->LogEvent( id, name, event_name, event_val, 0 );

		if ( is_request )
			{
			const char* fmt = "*%s-reply*";
			char* reply_name =
				new char[strlen( event_name ) +
					 strlen( fmt ) + 1];
			sprintf( reply_name, fmt, event_name );

			Value* new_val = create_record();
			new_val->SetField( "*request*", event_val );
			new_val->SetField( "*reply*", reply_name );

			Unref( event_val );
			event_val = new_val;

			GlishEvent e( event_name, event_val );
			e.SetIsRequest();
			send_event( fd, &e );

			result = sequencer->AwaitReply( this, event_name,
							reply_name );
			delete reply_name;
			}

		else
			{
			GlishEvent e( event_name, (const Value*) event_val );
			send_event( fd, &e );
			}
		}

	Unref( event_val );

	return result;
	}

void Task::SetChannel( Channel* c, Selector* s )
	{
	channel = c;
	selector = s;

	if ( pending_events )
		{
		loop_over_list( *pending_events, i )
			{
			GlishEvent* e = (*pending_events)[i];

			sequencer->LogEvent( id, name, e, 0 );
			send_event( channel->WriteFD(), e );

			Unref( e );
			}

		pending_events = 0;
		}
	}

void Task::CloseChannel()
	{
	if ( channel )
		{
		if ( channel->ChannelState() == CHAN_IN_USE )
			// don't delete the channel now; just mark it for
			// later deletion
			channel->ChannelState() = CHAN_INVALID;

		else
			{
			selector->DeleteSelectee( channel->ReadFD() );
			delete channel;
			}

		channel = 0;
		}
	}

Task* Task::AgentTask()
	{
	return this;
	}

void Task::DescribeSelf( ostream& s ) const
	{
	s << "task " << Name();
	}


const char** Task::CreateArgs( const char* prog, int num_args, int& argc )
	{
	argc = num_args;

	int use_socket = attrs->daemon_channel || attrs->async_flag;

	// Leave room for the executable's name, the -id flag, the id,
	// the -interpreter flag, and the interpreter's tag.
	argc += 5;

	if ( use_socket )
		// Leave room for -host <host> -port <port>
		argc += 4;
	else
		// Local exec, leave room for -pipes <input> <output>
		argc += 3;

	if ( attrs->suspend_flag )
		++argc;		// room for -suspend flag

	if ( attrs->ping_flag )
		++argc;		// room for -ping flag

	const char** argv = new string[argc + 1];	// + 1 for final nil
	int argp = 0;

	argv[argp++] = prog;

	argv[argp++] = "-id";
	argv[argp++] = id;

	if ( use_socket )
		{
		pipes_used = 0;

		argv[argp++] = "-host";
		argv[argp++] = sequencer->ConnectionHost();

		argv[argp++] = "-port";
		argv[argp++] = sequencer->ConnectionPort();
		}

	else
		{
		if ( pipe( read_pipe ) < 0 || pipe( write_pipe ) < 0 )
			perror( "glish: problem creating pipe" );

		pipes_used = 1;

		mark_close_on_exec( read_pipe[0] );
		mark_close_on_exec( write_pipe[1] );

		argv[argp++] = "-pipes";

		char buf[64];
		sprintf( buf, "%d", write_pipe[0] );
		argv[argp++] = write_pipe_str = strdup( buf );

		sprintf( buf, "%d", read_pipe[1] );
		argv[argp++] = read_pipe_str = strdup( buf );
		}

	argv[argp++] = "-interpreter";
	argv[argp++] = sequencer->InterpreterTag();

	if ( attrs->suspend_flag )
		argv[argp++] = "-suspend";

	if ( attrs->ping_flag )
		argv[argp++] = "-ping";

	if ( argp != argc - num_args )
		fatal->Report( "inconsistent argv in Task::CreateArgs" );

	argv[argc] = 0;

	return argv;
	}

void Task::Exec( const char** argv )
	{
	char* exec_name = 0;

	if ( attrs->daemon_channel )
		executable =
			new RemoteExec( attrs->daemon_channel, argv[0], argv );
	else
		{
		exec_name = which_executable( argv[0] );

		if ( ! exec_name )
			return;

		executable = new LocalExec( exec_name, argv );

		close( read_pipe[1] );
		close( write_pipe[0] );

		local_channel = sequencer->AddLocalClient( read_pipe[0],
								write_pipe[1] );
		}

	no_such_program = 0;
	task_error = executable->ExecError();

	if ( ! task_error )
		// This is a little buggy - we'd like the sequencer to know
		// about this client only after the client makes its
		// initial rendezvous with the Sequencer.  But the sequencer
		// will only accept such a rendezvous in its event loop
		// *after* it has determined that there are still some
		// active clients out there and thus it's worth waiting
		// for external events to arrive.  Thus if the sequencer
		// only counted the client as active after its rendezvous
		// there would be a race: if no clients were active but
		// a new one had just been started, the sequencer wouldn't
		// wait for its rendezvous.  So instead we tell the sequencer
		// about the client as soon as we've created it.  If the
		// client fails to make its rendezvous then the sequencer's
		// count of active clients will always be too high; this
		// can be fixed if&when we add timeouts to the sequencer so
		// it can detect clients that have never managed to
		// rendezvous.
		sequencer->NewClientStarted();

	delete exec_name;
	}

void Task::SetActivity( int is_active )
	{
	active = is_active;
	CreateEvent( "active", new Value( is_active ) );

	if ( ! is_active )
		CloseChannel();
	}


ShellTask::ShellTask( const_args_list* args, TaskAttr* task_attrs,
			Sequencer* s )
    : Task( task_attrs, s )
	{
	char* arg_string = paste( args );

	name = strdup( "shell_client" );

	// Turn off async attribute; we don't want the shell_client
	// program to run asynchronously.
	attrs->async_flag = 0;

	int argc;
	// Need three arguments: sh, -c, arg-string
	const char** argv = CreateArgs( name, 3, argc );

	int argp = argc - 3;

	argv[argp++] = "sh";
	argv[argp++] = "-c";
	argv[argp++] = arg_string;
	argv[argp] = 0;

	Exec( argv );

	delete argv;
	delete arg_string;
	}


ClientTask::ClientTask( const_args_list* args, TaskAttr* task_attrs,
			Sequencer* s  )
    : Task( task_attrs, s )
	{
	// Get the program name.
	const Value* arg = (*args)[0]->Deref();

	if ( arg->Type() == TYPE_STRING )
		name = strdup( arg->StringPtr()[0] );
	else
		name = arg->StringVal();

	// See if based on its name we should suspend this client.
	if ( s->ShouldSuspend( name ) )
		task_attrs->suspend_flag = 1;

	// Count up how many arguments there are.
	int num_args = 0;

	loop_over_list( *args, i )
		{
		arg = (*args)[i]->Deref();

		if ( arg->Type() == TYPE_STRING )
			num_args += arg->Length();
		else
			++num_args;
		}

	int argc;
	const char** argv = CreateArgs( name, num_args, argc );

	int argp = argc - num_args;
	int first_arg_pos = argp;
	int saw_name = 0;

	loop_over_list( *args, j )
		{
		arg = (*args)[j]->Deref();

		if ( arg->Type() == TYPE_STRING )
			{
			charptr* words = arg->StringPtr();
			int n = arg->Length();

			for ( int k = 0; k < n; ++k )
				{
				if ( saw_name )
					argv[argp++] = strdup( words[k] );
				else
					// Skip over name.
					saw_name = 1;
				}
			}

		else
			{
			if ( saw_name )
				argv[argp++] = arg->StringVal();
			else
				// Skip over name.
				saw_name = 1;
			}
		}

	argv[argp] = 0;

	if ( attrs->async_flag )
		CreateAsyncClient( argv );
	else
		Exec( argv );

	for ( argp = first_arg_pos; argp < first_arg_pos + num_args; ++argp )
		delete ((char**) argv)[argp];

	delete argv;
	}


void ClientTask::CreateAsyncClient( const char** argv )
	{
	no_such_program = 0;
	task_error = 0;

	sequencer->NewClientStarted();

	for ( int argc = 0; argv[argc]; ++argc )
		;

	(void) CreateEvent( "activate", new Value( argv, argc, COPY_ARRAY ) );
	}


TaskAttr::TaskAttr( char* arg_ID, char* arg_hostname,
		    Channel* arg_daemon_channel, int arg_async_flag,
		    int arg_ping_flag, int arg_suspend_flag )
	{
	task_var_ID = arg_ID;
	hostname = arg_hostname;
	daemon_channel = arg_daemon_channel;
	async_flag = arg_async_flag;
	ping_flag = arg_ping_flag;
	suspend_flag = arg_suspend_flag;
	}

TaskAttr::~TaskAttr()
	{
	delete task_var_ID;
	delete hostname;
	}


Value* CreateTaskBuiltIn::DoCall( const_args_list* args_val )
	{
	// Arguments are:
	//
	//	var-ID hostname client async ping suspend args...
	//
	// where "var-ID" and "hostname" are string values, and
	// client/async/ping/suspend are boolean flags.

	const_args_list& args = *args_val;

	int task_args_start = 7;

	if ( args.length() <= task_args_start )
		{
		error->Report( "too few arguments given to create_task" );
		return error_value();
		}

	char* var_ID = GetString( args[0] );
	char* hostname = GetString( args[1] );

	// If the following values are changed, be sure to also change
	// them in CreateTaskBuiltIn::DoSideEffectsCall().
	int client_flag = args[2]->IntVal();
	int async_flag = args[3]->IntVal();
	int ping_flag = args[4]->IntVal();
	int suspend_flag = args[5]->IntVal();
	Value* input = 0;

	if ( args[6]->Type() != TYPE_BOOL || args[6]->BoolVal() )
		input = new Value( (Value*) args[6], VAL_CONST );

	Channel* channel = sequencer->GetHostDaemon( hostname );

	attrs = new TaskAttr( var_ID, hostname, channel, async_flag, ping_flag,
				suspend_flag );

	// Collect the arguments to the task.
	const_args_list task_args;
	for ( int i = task_args_start; i < args.length(); ++i )
		task_args.append( args[i] );

	Value* result;

	if ( client_flag )
		result = CreateClient( &task_args );

	else
		{ // Shell client.
		if ( async_flag )
			result = CreateAsyncShell( &task_args );

		else
			{
			char* command = paste( &task_args );

			if ( hostname )
				result = RemoteSynchronousShell( command,
								input );
			else
				{
				char* input_str;

				if ( ! input || (input->Type() == TYPE_BOOL &&
						 ! input->BoolVal()) )
					input_str = 0;
				else
					input_str = input->StringVal( '\n' );

				result = SynchronousShell( command, input_str );

				delete input_str;
				}

			delete attrs;
			delete command;
			}
		}

	Unref( input );
	return result;
	}

void CreateTaskBuiltIn::DoSideEffectsCall( const_args_list* args_val,
						int& side_effects_okay )
	{
	// Check for synchronous shell call; we allow those to be
	// for side-effects only.  The corresponding arguments are
	// numbers 2 (client/shell flag) and 3 (async flag).

	const_args_list& args = *args_val;
	if ( args.length() > 3 )
		{
		int client_flag = args[2]->IntVal();
		int async_flag = args[3]->IntVal();

		if ( ! client_flag && ! async_flag )
			side_effects_okay = 1;
		}

	Unref( DoCall( args_val ) );
	}


char* CreateTaskBuiltIn::GetString( const Value* val )
	{
	if ( val->Type() == TYPE_BOOL && ! val->BoolVal() )
		// False means "default".
		return 0;
	else
		return val->StringVal();
	}


Value* CreateTaskBuiltIn::SynchronousShell( const char* command,
						const char* input )
	{
	FILE* shell = popen_with_input( command, input );

	if ( ! shell )
		{
		warn->Report( "could not execute shell command \"", command,
				"\"" );
		return error_value();
		}

	Value* result = GetShellCmdOutput( command, shell, 0 );

	int status = pclose_with_input( shell );

	if ( status )
		{
		char status_buf[128];
		sprintf( status_buf, "0x%x", status >> 8 );
		warn->Report( "shell command \"", command,
				"\" terminated with status = ", status_buf );
		}

	return result;
	}


Value* CreateTaskBuiltIn::RemoteSynchronousShell( const char* command,
							Value* input )

	{
	int fd = attrs->daemon_channel->WriteFD();

	Value* r = create_record();
	r->SetField( "command", command );

	if ( input )
		r->SetField( "input", input );

	send_event( fd, "shell", r );
	Unref( r );

	GlishEvent* e = recv_event( attrs->daemon_channel->ReadFD() );
	if ( ! e )
		{
		warn->Report( "remote daemon died" );
		return error_value();
		}

	int was_okay = e->value->IntVal();
	delete e;

	if ( ! was_okay )
		{
		warn->Report( "could not execute shell command \"", command,
				"\" on host ", attrs->hostname );

		return error_value();
		}

	Value* result = GetShellCmdOutput( command, 0, 1 );

	e = recv_event( attrs->daemon_channel->ReadFD() );
	if ( ! e )
		{
		warn->Report( "remote daemon died" );
		return error_value();
		}

	int status = e->value->IntVal();
	delete e;

	if ( status )
		{
		char status_buf[128];
		sprintf( status_buf, "0x%x", status >> 8 );
		warn->Report( "shell command \"", command,
				"\" on host ", attrs->hostname,
				" terminated with status = ", status_buf );
		}

	return result;
	}


Value* CreateTaskBuiltIn::GetShellCmdOutput( const char* command, FILE* shell,
						int is_remote )
	{
#define MAX_CMD_OUTPUT_LINES 8192
	charptr event_values[MAX_CMD_OUTPUT_LINES];
#define MAX_SHELL_LINE_LEN 8192
	char line_buf[MAX_SHELL_LINE_LEN];
	int line_num = 0;

#define NEXT_CMD_LINE							\
	(is_remote ? NextRemoteShellCmdLine( line_buf ) :		\
			NextLocalShellCmdLine( shell, line_buf ))

	while ( NEXT_CMD_LINE )
		{
		int len = strlen( line_buf );

		// Remove trailing newline.
		if ( len > 0 && line_buf[len - 1] == '\n' )
			line_buf[len - 1] = '\0';

		if ( ++line_num >= MAX_CMD_OUTPUT_LINES )
			{
			warn->Report(
			"too much data generated by shell command \"",
					command, "\"" );

			// throw away the remainder of the input
			while ( NEXT_CMD_LINE )
				;

			break;
			}

		event_values[line_num - 1] = strdup( line_buf );
		}

	charptr* event_values_copy = new charptr[line_num];

	copy_array( event_values, event_values_copy, line_num, charptr );

	return new Value( event_values_copy, line_num );
	}


char* CreateTaskBuiltIn::NextLocalShellCmdLine( FILE* shell, char* line_buf )
	{
	return fgets( line_buf, MAX_SHELL_LINE_LEN, shell );
	}

char* CreateTaskBuiltIn::NextRemoteShellCmdLine( char* line_buf )
	{
	GlishEvent* e = recv_event( attrs->daemon_channel->ReadFD() );

	if ( ! e )
		{
		warn->Report( "remote daemon died" );
		return 0;
		}

	Value* v = e->value;

	if ( v->Type() != TYPE_STRING )
		{
		// This is the "done" event, with a boolean true as value.
		delete e;
		return 0;
		}

	char* next_line = v->StringVal();
	strcpy( line_buf, next_line );

	delete next_line;
	delete e;

	return line_buf;
	}


Value* CreateTaskBuiltIn::CreateAsyncShell( const_args_list* args )
	{
	Task* task = new ShellTask( args, attrs, sequencer );

	CheckTaskStatus( task );

	return task->AgentRecord();
	}


Value* CreateTaskBuiltIn::CreateClient( const_args_list* args )
	{
	if ( attrs->async_flag )
		{
		if ( attrs->hostname && strcmp( attrs->hostname, "localhost" ) )
			error->Report(
		"hostname option is incompatible with asynchronous client" );

		if ( attrs->suspend_flag )
			warn->Report(
		"suspend option is not supported for asynchronous clients" );
		}

	Task* task = new ClientTask( args, attrs, sequencer );

	CheckTaskStatus( task );

	return task->AgentRecord();
	}


void CreateTaskBuiltIn::CheckTaskStatus( Task* task )
	{
	if ( task->NoSuchProgram() )
		warn->Report( "no such program, \"", task->Name(), "\"" );

	else if ( task->Exec() && task->Exec()->ExecError() )
		warn->Report( "could not exec program, \"",
				task->Name(), "\"" );
	}


int same_host( Task* t1, Task* t2 )
	{
	const char* t1_host = t1->Host();
	const char* t2_host = t2->Host();

	if ( ! t1_host )
		t1_host = "localhost";

	if ( ! t2_host )
		t2_host = "localhost";

	return ! strcmp( t1_host, t2_host );
	}
