/*
 * This file is a part of Winix
 * and is distributed under the 2-Clause BSD licence.
 * Author: Tomasz Sowa <t.sowa@ttmath.org>
 */

/* 
 * Copyright (c) 2011-2014, Tomasz Sowa
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 */
 
#include <sys/types.h>
#include <sys/uio.h>
#include <unistd.h>
#include <sys/wait.h>
#include <cstring>
#include "run.h"



namespace Winix
{




Run::Run()
{
	Clear();
}



void Run::Clear()
{
	parlen  = 0; 
	envlen  = 0;
	command = 0;
	last_status = 0;
	last_return = 255;
}



void Run::SetName()
{
	size_t i=0;

	while( command[i] )
		i += 1;

	while( i>0 && command[i-1]!='/' )
		i -= 1;

	par[0] = const_cast<char*>(command + i);
}



void Run::Par(const char * p)
{
	if( parlen < WINIX_RUN_MAX_PARAMETERS )
	{
		// they will be copied (fork)
		// the first (zero) parameter is a program name
		par[1 + parlen++] = const_cast<char*>(p);
	}
}



void Run::Env(const char * e)
{
	if( envlen < WINIX_RUN_MAX_PARAMETERS )
	{
		// they will be copied (fork)
		env[envlen++] = const_cast<char*>(e);
	}
}



void Run::Cmd(const char * c)
{
	command = c;
	SetName();
}



void Run::Par(const std::string & p)
{
	Par(p.c_str());
}



void Run::Env(const std::string & e)
{
	Env(e.c_str());
}



void Run::Cmd(const std::string & c)
{
	Cmd(c.c_str());
}




int Run::LastStatus()
{
	return last_status;
}



int Run::LastReturn()
{
	return last_return;
}



void Run::Write(const char * in, size_t inlen)
{
ssize_t len;

	while( inlen > 0 )
	{
		len = write(desout[1], in, inlen);
	
		if( len < 0 || len > (ssize_t)inlen )
		{
			// something wrong
			last_status = 3;
			break;
		}

		in    += len;
		inlen -= len;
	}
}



void Run::Read(std::string & out)
{
char buf[1024];
size_t buflen = sizeof(buf) / sizeof(char);
ssize_t len;

	do
	{
		len = read(desin[0], buf, buflen);

		if( len < 0 || len > (ssize_t)buflen )
		{
			// something wrong
			last_status = 4;
			break;
		}

		if( len > 0 )
			out.append(buf, len);
	}
	while( len > 0 );
}



void Run::ChildThrow()
{
	if( dup2(desout[0], 0) == -1 )
		return;

	if( dup2(desin[1], 1) == -1 )
		return;

	close(2);
	close(desin[0]);
	close(desout[1]);

	par[parlen+1] = 0;
	env[envlen]   = 0;

	execve(command, par, env);
	// if we are here then there is something wrong (execve failed)
	// !! IMPROVE ME may add exit() ?
}



void Run::Child()
{
	try
	{
		ChildThrow();
	}
	catch(...)
	{
	}

	exit(255);
}



bool Run::CreatePipes()
{
	int res = pipe(desin);

	if( res != 0 )
	{
		log << log1 << "Run: pipe failed (desin)" << logend;
		last_status = 1;
		return false;
	}

	res = pipe(desout);

	if( res != 0 )
	{
		log << log1 << "Run: pipe failed (desout)" << logend;
		last_status = 1;
		close(desin[0]);
		close(desin[1]);
		return false;
	}

return true;
}



bool Run::Fork()
{
	childpid = fork();

	if( childpid == -1 )
	{
		log << log1 << "Run: fork failed" << logend;
		last_status = 2;
		close(desin[0]);
		close(desin[1]);
		close(desout[0]);
		close(desout[1]);
		return false;
	}

	if( childpid == 0 )
		Child();

return true;
}



void Run::WriteRead(const char * in, size_t inlen, std::string * out)
{
	if( in && inlen>0 )
		Write(in, inlen);

	close(desout[1]);

	if( out )
		Read(*out);

	close(desin[0]);
}



void Run::CheckStatus()
{
int status;

	pid_t res = waitpid(childpid, &status, 0);

	if( res == -1 )
	{
		log << log1 << "Run: waitpid failed" << logend;
		last_status = 6;
	}
	else
	{
		if( WIFEXITED(status) )
		{
			last_return = WEXITSTATUS(status);
		}
		else
		{
			if( WIFCONTINUED(status) )
				log << log1 << "Run: child error: WIFCONTINUED" << logend;
			else
			if( WIFSIGNALED(status) )
				log << log1 << "Run: child error: WIFSIGNALED" << logend;
			else
			if( WIFSTOPPED(status) )
				log << log1 << "Run: child error: WIFSTOPPED" << logend;

			last_status = 5;
		}
	}
}



int Run::Go(const char * in, size_t inlen, std::string * out)
{
	last_status = 0;
	last_return = 255;

	if( out )
		out->clear();

	if( !command )
	{
		last_status = 7;
		return last_return;
	}

	if( !CreatePipes() )
		return last_return;

	if( !Fork() )
		return last_return;

	// here goes the parent
	close(desin[1]);
	close(desout[0]);
	WriteRead(in, inlen, out);
	CheckStatus();

	if( last_status != 0 )
		log << log1 << "Run: a problem with the command, last_status: " << last_status << logend;

return last_return;
}


int Run::Go(const char * in, size_t inlen, std::string & out)
{
	return Go(in, inlen, &out);
}


int Run::Go(const char * in, std::string & out)
{
	size_t len = strlen(in);
	return Go(in, len, &out);
}


int Run::Go(const char * in, size_t inlen)
{
	return Go(in, inlen, 0);
}


int Run::Go(const char * in)
{
	size_t len = strlen(in);
	return Go(in, len, 0);
}


int Run::Go()
{
	return Go(0, 0, 0);
}


int Run::Go(const std::string in, std::string & out)
{
	return Go(in.c_str(), in.size(), &out);
}


int Run::Go(const std::string in)
{
	return Go(in.c_str(), in.size(), 0);
}


int Run::Go(std::string & out)
{
	return Go(0, 0, &out);
}



} // namespace Winix