// Copyright © 2010-2012 b0ris
//.
// 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 <QtCore>
#include "DownloadClient.h"
#include "Utility.h"


DownloadClient::DownloadClient(): isDownloading(false), current(NULL), currentId(-1)
{
}

DownloadClient::DownloadClient(QString addr): SslClient(addr), isDownloading(false), current(NULL), currentId(-1)
{
}

void DownloadClient::Download(const string &filename)
{
	pair<string, string> file(filename, 0);
	vector<pair<string, string> > fileList;
	fileList.push_back(file);
	Download(fileList);		
}

void DownloadClient::Download(const pair<string, string> &file)
{
	vector<pair<string, string> > fileList;
	fileList.push_back(file);
	Download(fileList);	
}

void DownloadClient::Download(const vector<pair<string, string> > &fileList)
{
	if (server.isEmpty())
	{
		Logger::Error("Server address isn't set! Aborting.\n");
		return;
	}
	if (isDownloading)
	{
		Logger::Error("Previous downloading process wasn't finished! Aborting.\n");
		return;
	}
	
	connect(this, SIGNAL(ReplyRecieved(SslClient::RequestType&, QByteArray&)),
		this, SLOT(FileDataRecieved(SslClient::RequestType&, QByteArray&)));
	isDownloading = true;
	files = fileList;
	DoDownload();
}

void DownloadClient::DoDownload()
{
	currentId++;
	
	if (currentId < (int)files.size())
	{
		pair<string, string> file = files[currentId];
		QString filename = QString::fromLocal8Bit(file.first.c_str());		
		string md5 = file.second;
		current = new QFile(filename);
        if (! current->open(QIODevice::WriteOnly | QIODevice::Unbuffered))
        {
            Logger::Info("Can't open file: path isn't available\n");
            DoDownload();
        }

		Logger::Info("Downloading file (%d of %u): %s\n", currentId + 1, files.size(), file.first.c_str());
		SendFileRequest(file.first);
	}
	else
	{
		Logger::Info("All files have been downloaded.\n");
		isDownloading = false;
		emit downloadFinished();
	}
}

void DownloadClient::FileDataRecieved(SslClient::RequestType &type, QByteArray &data)
{
	Logger::Trace("Recieved file data: %u bytes\n", data.size());
	if (type != RegularFile)
	{
		Logger::Error("Invalid reply recieved: %x\n", type);
		return;
	}
	if ((current == NULL) || (! current->isOpen()))
	{
		Logger::Error("File isn't open or in invalid state.\n");
		return;
	}
	
	if (data.size() != 0)
	{
		current->write(data);
		current->waitForBytesWritten(-1);
	}
	else
	{
		Logger::Trace("Last (empty) packet recieved\n");
		current->close();
		
		// check file's md5 hash value
		pair<string, string> file = files[currentId];
		QString md5string = QString::fromLocal8Bit(file.second.c_str());
		QString filename = QString::fromLocal8Bit(file.first.c_str());
		QByteArray md5 = md5_sum(filename);
		if (md5 == md5string)
		{
			Logger::Trace("File %s was downloaded correctly!\n", filename.toStdString().c_str());
		}
		else
		{
			Logger::Error("File %s was downloaded incorrectly! Removing and trying again!\n", filename.toStdString().c_str());
			current->remove();
			currentId--;
		}
		// free pointer to the current file
		delete current;
		current = NULL;
		// proceed to the next file
		DoDownload();
	}
}