#include "downloadManager.h"
#include <QFileInfo>
#include <QByteArray>

int downloadManager::downloaded = 0;
// ----------------------------------------------------------------------------------------
downloadManager::downloadManager()
{
	qnam = new QNetworkAccessManager();
	dip = false;
	infoSent = false;
	downloadDir = QDir(downloadPath);
	/* Check if downloadPath exists, if not create it. */
	if (!downloadDir.exists()){
		if (debug) qDebug() << "Download directory: " << downloadDir.path() << "doesn't exist.";
		QDir::current().mkdir(downloadPath);
		if (downloadDir.exists() && debug)
			qDebug() << "Created download directory: " << downloadDir.path();
	}
	else if (debug) qDebug() << "Download directory: " << downloadDir.path() << "exists.";
}
// ----------------------------------------------------------------------------------------
void downloadManager::downloadFile(QString& filename)
{
	if (debug) qDebug() << "Received downloadFile signal for:" << filename;
	QUrl fileUrl;
	fileUrl = baseURL.resolved(QUrl(filename));
	if (debug) qDebug() << "fileUrl: " << fileUrl;
	this->processDownloadRequest(fileUrl);
}
// ----------------------------------------------------------------------------------------
void downloadManager::downloadFile(QUrl& fileUrl)
{
	if (debug) qDebug() << "Received downloadFile signal for:" << fileUrl;
	this->processDownloadRequest(fileUrl);
}
// ----------------------------------------------------------------------------------------
void downloadManager::processDownloadRequest(QUrl& url)
{
	if (url.isEmpty()){
		if (debug) qDebug() << "No URL specified for download.";
		return;
	}
	/* If download in progress, enqueue file and return. */
	if (dip)
	{
		if (debug) qDebug() << "Download in progress! Enqueueing:" << url.toString()
				 << "(" << dlQ.size() << "in queue)";
		dlQ.enqueue(url);
		return;
	}
	/* No running downloads: enqueue and start next download. */
	dlQ.enqueue(url);
	if (debug) qDebug() << "Enqueueing:" << url.toString() << endl;
	startNextDownload();
}
// ----------------------------------------------------------------------------------------
void downloadManager::startNextDownload()
{

	if (dlQ.isEmpty())
	{
		emit downloadQueueEmpty();
		if (debug) qDebug() << "Download manager ready. (1)";
		return;
	}
	if (debug) qDebug() << "Starting next download: " << dlQ.head().toString()
			 << "(" << dlQ.size() << "in queue.)";

	/* Dequeue next URL to download. */
	QUrl url = dlQ.dequeue();

	/* Get temporary filename from URL. */
	QString tmp = url.path();
	tmp.remove(0, tmp.lastIndexOf(QChar('/')) + 1);
	if (debug) qDebug() << "Extracted " << tmp << "from " << url.toString();

	outfile.setFileName(downloadPath + "/" + tmp);
	if (!outfile.open(QIODevice::WriteOnly))
	{
		if (debug) qDebug() << "Couldn't open file! Skipping...";
		return;
	}

	/* Send the request for the file */
	QNetworkRequest request(url);
	currentDownload = qnam->get(request);
	lastProgress = 0;
	currentProgress = 0;
	dip = true;
	dltime.start();
	QObject::connect(currentDownload, SIGNAL(readyRead()), this, SLOT(downloadReady()));
	QObject::connect(currentDownload, SIGNAL(metaDataChanged()), this, SLOT(processMetaInfo()));
	QObject::connect(currentDownload, SIGNAL(downloadProgress(qint64, qint64)),
					 this, SLOT(downloadProgress(qint64, qint64)));
	QObject::connect(currentDownload, SIGNAL(finished()), this, SLOT(downloadFinished()));
}
// ----------------------------------------------------------------------------------------
//                                   Private slots
// ----------------------------------------------------------------------------------------
void downloadManager::processMetaInfo(){
	const QByteArray cltag = "Content-Length";
	QByteArray clinfo = currentDownload->rawHeader(cltag);
	qDebug() << "feel spammy?";
	if (!infoSent){
		if (debug) qDebug() << "MetaChanged: " << outfile.fileName() << "";
		QFileInfo fi(outfile);
		emit downloadInfo(outfile.fileName(), clinfo.toDouble());
		infoSent = true;
	}
}
// ----------------------------------------------------------------------------------------
void downloadManager::downloadReady()
{
	/* Send file information */

	/* Data ready, save it */
	outfile.write(currentDownload->readAll());
}
// ----------------------------------------------------------------------------------------
void downloadManager::downloadProgress(qint64 bytesIn, qint64 bytesTotal)
{
	// "fix" for the weird bytesTotal = -1 initial reading...
	if (bytesIn > bytesTotal)
		return;
	/* Calculate current speed */
	double speed = bytesIn * 1000 / dltime.elapsed();
	QString unit;
	if (speed < 1024) {
		unit = "bytes/sec";
    } else if (speed < 1024*1024) {
        speed /= 1024;
        unit = "KB/s";
    } else {
        speed /= 1024*1024;
        unit = "MB/s";
    }
	/* Update progress only if difference higher than the updateInterval setting */
	currentProgress = ((bytesIn * 100) / bytesTotal);
	if (currentProgress - lastProgress >= updateInterval){
		lastProgress = currentProgress;
		emit updateProgress(currentProgress, speed, unit);
		if (debug) qDebug() << "Download progress of " << currentDownload->url().toString()
				 << ": " << bytesIn << "/" << bytesTotal << "(" << currentProgress << "\%)";
	}
	return;
}
// ----------------------------------------------------------------------------------------
void downloadManager::downloadFinished()
{

	if (currentDownload->error()){
		if (debug) qDebug() << "Download of" << currentDownload->url().toString()
							<< "failed with status code: " << currentDownload->error();
		currentDownload->deleteLater();
		outfile.remove();
		return;
	}
	// TODO Handle errors.
	if (debug) qDebug() << "NetworkCode: " << currentDownload->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();

	outfile.close();
	currentDownload->deleteLater();
	downloaded++;
	dip = false;
	infoSent = false;
	if (debug) qDebug() << "Download of " << currentDownload->url().toString()
							<< "finished. (dlcount = "<< downloaded << ")";
	if (dlQ.isEmpty()){
		emit downloadQueueEmpty();
		if (debug) qDebug() << "Download manager ready. (2)";
		return;
	}
	startNextDownload();
}
/* ----------------------------------------------------------------------------------------
*
            ** dead code: Header filename fetching & renaming **

const QByteArray cd = "Content-Disposition";
QByteArray cdc = currentDownload->rawHeader(cd);
int x = cdc.indexOf("filename=\"") + 10;
cdc.remove(0, x).chop(1);
if (!cdc.isEmpty())
	currentTargetFilename = cdc;
else
	currentTargetFilename = QString("download.\%1").arg(downloaded);

QString tmp = outfile.fileName();
tmp.remove(0, tmp.lastIndexOf(QChar('/')) + 1);
qDebug() << "Trying to rename " << tmp << " to --> " << currentTargetFilename;

if (outfile.rename(downloadPath + "/" + currentTargetFilename)) {
	if (debug) qDebug() << "Renamed file!";
}
else {
	if (debug) qDebug() << "Failure to rename file!";
}
*/