#include "htmlbrowser.h"

#include <QDebug>
#include <QNetworkRequest>
#include <QNetworkReply>
#include <QNetworkDiskCache>
#include <QStyle>
#include <QApplication>
#include <QDir>
#include <QDateTime>
#include <QScrollBar>

#include "fs_utils.h"

HtmlBrowser::HtmlBrowser(QWidget* parent)
	: QTextBrowser(parent)
{
	m_netManager = new QNetworkAccessManager(this);
	m_diskCache = new QNetworkDiskCache(this);
	m_diskCache->setCacheDirectory(QDir::cleanPath(fsutils::cacheLocation() + "/browser"));
	m_diskCache->setMaximumCacheSize(50 * 1024 * 1024);
	qDebug() << "HtmlBrowser  cache path:" << m_diskCache->cacheDirectory() << " max size:" << m_diskCache->maximumCacheSize() / 1024 / 1024 << "MB";
	m_netManager->setCache(m_diskCache);

	connect(m_netManager, SIGNAL(finished(QNetworkReply *)), this, SLOT(resourceLoaded(QNetworkReply*)));
}

HtmlBrowser::~HtmlBrowser()
{
}

QVariant HtmlBrowser::loadResource(int type, const QUrl &name)
{
	if(type == QTextDocument::ImageResource) {
		QUrl url(name);
		if(url.scheme().isEmpty())
			url.setScheme("http");

		QIODevice *dev = m_diskCache->data(url);
		if(dev != 0) {
			qDebug() << "HtmlBrowser::loadResource() cache " << url.toString();
			QByteArray res = dev->readAll();
			delete dev;
			return res;
		}

		if(!m_activeRequests.contains(url)) {
			m_activeRequests.insert(url, true);
			qDebug() << "HtmlBrowser::loadResource() get " << url.toString();
			QNetworkRequest req(url);
			req.setAttribute(QNetworkRequest::CacheLoadControlAttribute, QNetworkRequest::PreferCache);
			m_netManager->get(req);
		}

		return QVariant();
	}

	return QTextBrowser::loadResource(type, name);
}

void HtmlBrowser::resourceLoaded(QNetworkReply *reply)
{
	m_activeRequests.remove(reply->request().url());

	if(reply->error() == QNetworkReply::NoError && reply->size() > 0) {
		qDebug() << "HtmlBrowser::resourceLoaded() save " << reply->request().url().toString();
	} else {
		// If resource failed to load, replace it with warning icon and store it in cache for 1 day.
		// Otherwise HTMLBrowser will keep trying to download it every time article is displayed,
		// since it's not possible to cache error responses.
		QNetworkCacheMetaData metaData;
		QNetworkCacheMetaData::AttributesMap atts;
		metaData.setUrl(reply->request().url());
		metaData.setSaveToDisk(true);
		atts[QNetworkRequest::HttpStatusCodeAttribute] = 200;
		atts[QNetworkRequest::HttpReasonPhraseAttribute] = "Ok";
		metaData.setAttributes(atts);
		metaData.setLastModified(QDateTime::currentDateTime());
		metaData.setExpirationDate(QDateTime::currentDateTime().addDays(1));
		QIODevice *dev = m_diskCache->prepare(metaData);
		if(!dev)
			return;
		QApplication::style()->standardIcon(QStyle::SP_MessageBoxWarning).pixmap(32, 32).save(dev, "PNG");
		m_diskCache->insert(dev);
	}
	// Refresh the document display and keep scrollbars where they are
	int sx = horizontalScrollBar()->value();
	int sy = verticalScrollBar()->value();
	document()->setHtml(document()->toHtml());
	horizontalScrollBar()->setValue(sx);
	verticalScrollBar()->setValue(sy);
}