/***************************************************************************
 *   Copyright (C) 2009 by Lothar May                                      *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/

#include <net/socket_helper.h>
#include <net/transferhelper.h>
#include <net/netexception.h>
#include <net/socket_msg.h>
#include <net/transferdata.h>

#include <cstdio>

using namespace std;


TransferHelper::TransferHelper()
{
	m_data.reset(new TransferData);
	m_data->curlHandle = NULL;
	m_data->curlMultiHandle = NULL;
	m_data->targetFile = NULL;
}

TransferHelper::~TransferHelper()
{
	Cleanup();
}

void
TransferHelper::Init(const string &url, const string &targetFileName, const string &user, const string &password, int filesize)
{
	// Initialise curl.
	m_data->curlHandle = curl_easy_init();
	if (!m_data->curlHandle)
		throw NetException(__FILE__, __LINE__, ERR_SOCK_TRANSFER_INIT_FAILED, 0);
	m_data->curlMultiHandle = curl_multi_init();
	if (!m_data->curlMultiHandle)
		throw NetException(__FILE__, __LINE__, ERR_SOCK_TRANSFER_INIT_FAILED, 0);

	// Use a copy of the url string, because some curl versions require a copy.
	m_data->curlUrl = url;
	if (curl_easy_setopt(m_data->curlHandle, CURLOPT_URL, m_data->curlUrl.c_str()) != CURLE_OK)
		throw NetException(__FILE__, __LINE__, ERR_SOCK_TRANSFER_INVALID_URL, 0);

	InternalInit(url, targetFileName, user, password, filesize);

	// Use the multi interface for better abort handling.
	if (curl_multi_add_handle(m_data->curlMultiHandle, m_data->curlHandle) != CURLM_OK)
		throw NetException(__FILE__, __LINE__, ERR_SOCK_TRANSFER_INIT_FAILED, 0);
}

bool
TransferHelper::Process()
{
	bool retVal = false;
	int runningHandles = 0;
	CURLMcode curlResult;
	do
	{
		curlResult = curl_multi_perform(m_data->curlMultiHandle, &runningHandles);
	} while (curlResult == CURLM_CALL_MULTI_PERFORM);

	if (curlResult != CURLM_OK)
		throw NetException(__FILE__, __LINE__, ERR_SOCK_TRANSFER_FAILED, 0);

	if (runningHandles)
	{
		struct timeval timeout;
		fd_set readSet;
		fd_set writeSet;
		fd_set exceptSet;
		int maxfd = -1;

		FD_ZERO(&readSet);
		FD_ZERO(&writeSet);
		FD_ZERO(&exceptSet);

		timeout.tv_sec = 0;
		timeout.tv_usec = RECV_TIMEOUT_MSEC * 1000;

		curl_multi_fdset(m_data->curlMultiHandle, &readSet, &writeSet, &exceptSet, &maxfd);

		if (maxfd >= 0)
		{
			int selectResult = select(maxfd+1, &readSet, &writeSet, &exceptSet, &timeout);
			if (!IS_VALID_SELECT(selectResult))
				throw NetException(__FILE__, __LINE__, ERR_SOCK_TRANSFER_SELECT_FAILED, SOCKET_ERRNO());
		}
	}
	else
	{
		// Retrieve actual error code.
		int numMsgs;
		CURLMsg *tmpMsg;
		CURLcode code = CURLE_FAILED_INIT;
		do {
			tmpMsg = curl_multi_info_read(m_data->curlMultiHandle, &numMsgs);
			if (tmpMsg)
				code = tmpMsg->data.result;
		} while (tmpMsg && tmpMsg->msg != CURLMSG_DONE);

		// Clean up the curl handles.
		Cleanup();

		// Throw exception if an error occured.
		if (code != CURLE_OK)
		{
			if (code == CURLE_URL_MALFORMAT)
				throw NetException(__FILE__, __LINE__, ERR_SOCK_TRANSFER_INVALID_URL, 0);
			else
				throw NetException(__FILE__, __LINE__, ERR_SOCK_TRANSFER_FAILED, 0);
		}

		retVal = true;
	}
	return retVal;
}

void
TransferHelper::Cleanup()
{
	if (m_data->curlMultiHandle)
	{
		curl_multi_cleanup(m_data->curlMultiHandle);
		m_data->curlMultiHandle = NULL;
	}
	if (m_data->curlHandle)
	{
		curl_easy_cleanup(m_data->curlHandle);
		m_data->curlHandle = NULL;
	}
	if (m_data->targetFile)
	{
		fflush(m_data->targetFile);
		fclose(m_data->targetFile);
		m_data->targetFile = NULL;
	}
}

boost::shared_ptr<TransferData>
TransferHelper::GetData()
{
	return m_data;
}