#include <Wt/WBootstrapTheme>
#include <Wt/WApplication>
#include <Wt/WContainerWidget>
#include <Wt/WPushButton>
#include <Wt/WFileUpload>
#include <Wt/WProgressBar>
#include <Wt/WHBoxLayout>

//#define USE_HBOX_LAYOUT

class BootstrapProgressBar : public Wt::WProgressBar
{
public:
	BootstrapProgressBar(Wt::WContainerWidget *parent = 0) : Wt::WProgressBar(parent)
	{
	}
	void setSuccess()
	{
		// How can the Progressbar be updated with the correct inner div style class?
		setValueStyleClass("progress-bar-success");
	}
	void setFailure()
	{
		// How can the Progressbar be updated with the correct inner div style class?
		setValueStyleClass("progress-bar-danger");
	}
	void reset()
	{
		setValueStyleClass("");
		hide();
		setValue(0);
	}
};

class FileUpload : public Wt::WContainerWidget
{
public:
	FileUpload() : progress_(new BootstrapProgressBar()),
		button_(new Wt::WPushButton("Upload Button"))
	{
#if defined USE_HBOX_LAYOUT
		auto hbox = new Wt::WHBoxLayout();
		setLayout(hbox);
		hbox->addWidget(progress_, 1);
		hbox->addWidget(button_);
#else
		addWidget(progress_);
		addWidget(button_);
#endif

		progress_->hide();
		button_->clicked().connect([this](const Wt::WMouseEvent&) {
			progress_->reset();
		});
		reset();
	}

	Wt::Signal<>& uploadSuccessful()
	{
		return uploadSuccessful_;
	}
	Wt::Signal<int64_t>& uploadFailed()
	{
		return uploadFailed_;
	}

	Wt::Http::UploadedFile getUploadedFile()
	{
		return upload_->uploadedFiles().front();
	}

	void reset()
	{
		upload_ = std::make_unique<Wt::WFileUpload>();
		upload_->setMultiple(false);
		upload_->setProgressBar(progress_);
		// connect fileupload signals
		upload_->changed()
			.connect(this, &FileUpload::upload);
		upload_->uploaded()
			.connect(this, &FileUpload::uploaded);
		upload_->fileTooLarge()
			.connect(this, &FileUpload::failed);
		// show fileupload widget
		addWidget(upload_.get());
		upload_->setDisplayWidget(button_);
	}
	void setFailed()
	{
		progress_->setFailure();
	}
	void setSuccessful()
	{
		progress_->setSuccess();
	}

private:
	Wt::Signal<> uploadSuccessful_;
	Wt::Signal<int64_t> uploadFailed_;

	std::unique_ptr<Wt::WFileUpload> upload_;
	BootstrapProgressBar* progress_;
	Wt::WPushButton* button_;

	void upload()
	{
		progress_->show();
		upload_->upload();
	}
	void uploaded()
	{
		uploadSuccessful().emit();
	}
	void failed(const int64_t filesize)
	{
		uploadFailed().emit(filesize);
	}
};

class TestApplication : public Wt::WApplication
{
	FileUpload* fileUpload_;
public:
	TestApplication(const Wt::WEnvironment& env)
		: WApplication(env)
	{
		Wt::WBootstrapTheme *bootstrapTheme = new Wt::WBootstrapTheme(this);
		bootstrapTheme->setVersion(Wt::WBootstrapTheme::Version3);
		bootstrapTheme->setResponsive(true);
		this->setTheme(bootstrapTheme);
		// load the default bootstrap3 (sub-)theme
		this->useStyleSheet("resources/themes/bootstrap/3/bootstrap-theme.min.css");

		setTitle("Test");

		auto container = new Wt::WContainerWidget(root());
		container->setWidth(Wt::WLength(200));
		fileUpload_ = new FileUpload();
		container->addWidget(fileUpload_);

		fileUpload_->uploadSuccessful().connect(this, &TestApplication::fileUploaded);
		fileUpload_->uploadFailed().connect(this, &TestApplication::uploadFailed);
	}
	void fileUploaded()
	{
		auto uploadedFile = fileUpload_->getUploadedFile();
		// validate file
		auto isValid = rand() % 2 == 1;
		if (isValid)
			fileUpload_->setSuccessful();
		else
			fileUpload_->setFailed();
		// recreate fileupload widget
		fileUpload_->reset();
	}
	void uploadFailed(const int64_t filesize)
	{
		fileUpload_->setFailed();
		// recreate fileupload widget
		fileUpload_->reset();
	}
};
Wt::WApplication *createApplication(const Wt::WEnvironment& env)
{
	return new TestApplication(env);
}

int main(int argc, char **argv)
{
	return Wt::WRun(argc, argv, &createApplication);
}