/**
 * data file browser
 * @author Tobias Weber <tweber@ill.fr>
 * @date 9-Apr-2018
 * @license see 'LICENSE' file
 */

#include "filebrowser.h"

#include <QtCore/QDirIterator>
#include <QtWidgets/QGridLayout>
#include <QtWidgets/QPushButton>
#include <QtWidgets/QFileDialog>
#include <algorithm>

#include "tlibs/file/loadinstr.h"


using t_real = double;


// ----------------------------------------------------------------------------

FileBrowserWidget::FileBrowserWidget(QWidget *pParent, QSettings *pSettings)
	: QWidget(pParent), m_pSettings(pSettings)
{
	m_pListFiles->setAlternatingRowColors(true);

	// ------------------------------------------------------------------------
	// layout
	auto *pBtnFolders = new QPushButton("Folder...", this);

	auto *pGrid = new QGridLayout(this);
	pGrid->addWidget(pBtnFolders, 0, 0, 1, 1);
	pGrid->addWidget(m_pEditFolder, 0, 1, 1, 1);
	pGrid->addWidget(m_pListFiles, 1, 0, 2, 2);
	// ------------------------------------------------------------------------


	// ------------------------------------------------------------------------
	// connections
	connect(pBtnFolders, &QPushButton::clicked, this, &FileBrowserWidget::SelectFolder);
	connect(m_pEditFolder, &QLineEdit::textChanged, this, &FileBrowserWidget::SetFolder);
	// ------------------------------------------------------------------------


	// ------------------------------------------------------------------------
	// settings
	if(m_pSettings)
	{
		m_pEditFolder->setText(m_pSettings->value("filebrowser/dir", "").toString());
	}
	// ------------------------------------------------------------------------
}


FileBrowserWidget::~FileBrowserWidget()
{
}


/**
 * open a folder selection dialog
 */
void FileBrowserWidget::SelectFolder()
{
	QString dir;
	if(m_pSettings)
		dir = m_pSettings->value("filebrowser/dir", "").toString();
	dir = QFileDialog::getExistingDirectory(this, "Select Folder", dir);
	if(dir != "")
		m_pEditFolder->setText(dir);
}


/**
 * set a given folder as working dir and populate file list
 */
void FileBrowserWidget::SetFolder(const QString& dir)
{
	m_pListFiles->clear();

	if(dir == "" || !QDir(dir).exists())
		return;

	// create file list
	std::vector<QString> vecFiles;
	for(QDirIterator iter(dir); ; iter.next())
	{
		if(iter.fileInfo().isFile())
			vecFiles.push_back(iter.fileName());

		if(!iter.hasNext())
			break;
	}


	// sort file list
	std::sort(vecFiles.begin(), vecFiles.end(),
	[](const auto& str1, const auto& str2) -> bool
	{
		return std::lexicographical_compare(str1.begin(), str1.end(), str2.begin(), str2.end());
	});


	// add files to list widget
	for(const auto& strFile : vecFiles)
	{
		QString fileFull = dir + "/" + strFile;

		// load file to get a description
		std::unique_ptr<tl::FileInstrBase<t_real>> pInstr(tl::FileInstrBase<t_real>::LoadInstr(fileFull.toStdString().c_str()));
		if(pInstr && pInstr->GetColNames().size())	// only valid files with a non-zero column count
		{
			QString strDescr;
			auto vecScanVars = pInstr->GetScannedVars();
			if(vecScanVars.size())
			{
				strDescr += ": ";
				for(std::size_t iScVar=0; iScVar<vecScanVars.size(); ++iScVar)
				{
					strDescr += vecScanVars[iScVar].c_str();
					if(iScVar < vecScanVars.size()-1)
						strDescr += ", ";
				}
				strDescr += " scan";
			}

			auto *pItem = new QListWidgetItem(m_pListFiles);
			pItem->setText(strFile + strDescr);
			pItem->setData(Qt::UserRole, fileFull);
		}
	}

	if(m_pSettings)
		m_pSettings->setValue("filebrowser/dir", dir);
}
// ----------------------------------------------------------------------------





// ----------------------------------------------------------------------------

FileBrowser::FileBrowser(QWidget* pParent, QSettings *pSettings)
	: QDockWidget(pParent), m_pBrowser(std::make_unique<FileBrowserWidget>(this, pSettings))
{
	this->setObjectName("fileBrowser");
	this->setWindowTitle("File Browser");
	this->setWidget(m_pBrowser.get());
}

FileBrowser::~FileBrowser()
{
}

// ----------------------------------------------------------------------------