#include "mainwindow.h"
#include "ui_mainwindow.h"

#include "QueryResultModel.h"
#include "QueryExplainModel.h"
#include "sqlhighlighter.h"
#include <QStandardPaths>
#include <QFileDialog>
#include <QMessageBox>
#include <QTextDocumentFragment>
#include <QTextStream>
#include <QTextTable>
#include <QTimer>
#include <windows.h>
#include "json/json.h"
#include "explaintreemodelitem.h"
#include <algorithm>
#include <QCloseEvent>
#include <querytab.h>

//#include <thread>

namespace {

	// Supported range from microseconds to seconds
	// min:sec to hours::min::sec
	QString msfloatToHumanReadableString(float ms)
	{
		QString unit;
		float val;
		int deci = 2;
		if (ms < 1.0f) {
			val = ms * 1000.f;
			//result = QString::asprintf("%0.3f", ms * 1000.0f);
			unit = u8"μs";
		}
		else if (ms >= 1000.0) {
			val = ms / 1000.0f;
			unit = "s";
			if (val >= 60.0) {
				int secs = val;
				int min = secs / 60.0;
				secs -= min * 60;
				if (min >= 60) {
					int hour = min / 60;
					min -= hour * 60;
					return QString::asprintf("%d:%02d:%02d", hour, min, secs);
				}
				else {
					return QString::asprintf("%02d:%02d", min, secs);
				}
			}
		}
		else {
			val = ms;
			unit = "ms";
		}

//		if (val >= 1000.f) {
//			deci = 0;
//		}
//		else
		if (val >= 100.f) {
			deci = 0;
		}
		else if (val >= 10.f) {
			deci = 1;
		}
		QString result = QString::asprintf("%0.*f", deci, val);
		return result + unit;
	}

}

namespace pg = Pgsql;

const char * test_query =

//"SELECT id, program, version, lic_bedrijf, lic_plaats, "
//"lic_number, callstack_crc_1, callstack_crc_2, callstack_crc_3, exception_class, "
//"exception_message \nFROM foutrapport"

"SELECT f1.id, f1.program, f1.version, f1.lic_number, f1.callstack_crc_1, f1.callstack_crc_2, array_agg(f2.id) \n"
"FROM foutrapport f1 JOIN foutrapport f2 USING (callstack_crc_2) \n"
"WHERE f1.actief  \n"
"GROUP BY f1.id"
;

MainWindow::MainWindow(QWidget *parent)
	: QMainWindow(parent)
	, ui(new Ui::MainWindow)
	, m_queryTab(new QueryTab)
{
	ui->setupUi(this);

	QFont font;
	font.setFamily("Source Code Pro");
	font.setFixedPitch(true);
	font.setPointSize(10);
	ui->queryEdit->setFont(font);
	highlighter.reset(new SqlHighlighter(ui->queryEdit->document()));

//	ui->queryEdit->setPlainText(test_query);
//	ui->connectionStringEdit->setText("user=postgres dbname=foutrapport password=admin");

//	QAction *action;
//	action = ui->mainToolBar->addAction("connect");
//	connect(action, &QAction::triggered, this, &MainWindow::startConnect);

//	action = ui->mainToolBar->addAction("explain");
//	connect(action, &QAction::triggered, this, &MainWindow::performExplain);

//	action = ui->mainToolBar->addAction("cancel");
//	connect(action, &QAction::triggered, this, &MainWindow::cancel_query);

	//ui->ResultView->setItemDelegate();

	m_dbConnection.setStateCallback([this](ASyncDBConnection::State st)
		{
			QueueTask([this, st]() { connectionStateChanged(st); });
		});

	m_dbConnection.setNoticeCallback([this](Pgsql::ErrorDetails details)
		{
			QueueTask([this, details]() { receiveNotice(details); });
		});

	connect(ui->queryEdit, &QPlainTextEdit::textChanged, this, &MainWindow::queryTextChanged);

	m_timeElapsedLabel = new QLabel(this);
	statusBar()->addPermanentWidget(m_timeElapsedLabel);


	{
		QVBoxLayout *layout = new QVBoxLayout;
		layout->addWidget(m_queryTab);
		layout->setMargin(4);
		ui->tab_2->setLayout(layout);
	}

}

MainWindow::~MainWindow()
{
	m_dbConnection.closeConnection();
	m_dbConnection.setStateCallback(nullptr);
	delete ui;
}

void MainWindow::setConfig(const ConnectionConfig &config)
{
	m_config = config;
	QString title = "pglab - ";
	title += m_config.name().c_str();
	setWindowTitle(title);
	QueueTask([this]() { startConnect(); });
}

void MainWindow::QueueTask(TSQueue::t_Callable c)
{
	m_taskQueue.add(c);
	// Theoretically this needs to be only called if the queue was empty because otherwise it already would
	// be busy emptying the queue. For now however I think it is safer to call it just to make sure.
	QMetaObject::invokeMethod(this, "processCallableQueue",	Qt::QueuedConnection); // queues on main thread
}

void MainWindow::processCallableQueue()
{
	if (!m_taskQueue.empty()) {
		auto c = m_taskQueue.pop();
		c();
		if (!m_taskQueue.empty()) {
			QTimer::singleShot(0, this, SLOT(processCallableQueue()));
		}
	}
}

void MainWindow::connectionStateChanged(ASyncDBConnection::State state)
{
	QString status_str;
	switch (state) {
	case ASyncDBConnection::State::NotConnected:
		status_str = tr("Geen verbinding");
		break;
	case ASyncDBConnection::State::Connecting:
		status_str = tr("Verbinden");
		break;
	case ASyncDBConnection::State::Connected:
		status_str = tr("Verbonden");
		break;
	case ASyncDBConnection::State::QuerySend:
		status_str = tr("Query verstuurd");
		break;
	case ASyncDBConnection::State::CancelSend:
		status_str = tr("Query geannuleerd");
		break;
	}
	addLog(status_str);
	statusBar()->showMessage(status_str);

	bool connected = ASyncDBConnection::State::Connected == state;
	ui->actionExecute_SQL->setEnabled(connected);
	ui->actionExplain_Analyze->setEnabled(connected);
	ui->actionCancel->setEnabled(ASyncDBConnection::State::QuerySend == state);
}

void MainWindow::startConnect()
{
	m_dbConnection.setupConnection(m_config);
}

std::string MainWindow::getCommand() const
{
	QString command;
	QTextCursor cursor = ui->queryEdit->textCursor();
	if (cursor.hasSelection()) {
		command = cursor.selection().toPlainText();
	}
	else {
		command = ui->queryEdit->toPlainText();
	}
	return command.toUtf8().data();
}

void MainWindow::performQuery()
{
	if (m_dbConnection.state() == ASyncDBConnection::State::Connected) {
		addLog("Query clicked");

		ui->ResultView->setModel(nullptr);
		resultModel.reset();
		ui->messagesEdit->clear();

		std::string cmd = getCommand();
		startTimer();
		m_dbConnection.send(cmd,
			[this](std::shared_ptr<Pgsql::Result> res)
			{
				QueueTask([this, res]() { query_ready(res); });
			});
	}
}

void MainWindow::query_ready(std::shared_ptr<Pgsql::Result> dbres)
{
	endTimer();
	if (dbres) {
		addLog("query_ready with result");
		auto st = dbres->resultStatus();
		if (st == PGRES_TUPLES_OK) {
			resultModel.reset(new QueryResultModel(nullptr , dbres));
			ui->ResultView->setModel(resultModel.get());
			ui->tabWidget->setCurrentWidget(ui->dataTab);
			statusBar()->showMessage(tr("Query ready."));
		}
		else {
			if (st == PGRES_COMMAND_OK) {
				statusBar()->showMessage(tr("Command OK."));
				QString msg = tr("Query returned succesfully: %1 rows affected, %2 execution time.")
						.arg(QString::number(dbres->tuplesAffected()))
						.arg(msfloatToHumanReadableString(elapsedTime.count()));
				ui->messagesEdit->append(msg);

				ui->tabWidget->setCurrentWidget(ui->messageTab);
			}
			else {
				if (st == PGRES_EMPTY_QUERY) {
					statusBar()->showMessage(tr("Empty query."));
				}
				else if (st == PGRES_COPY_OUT) {
					statusBar()->showMessage(tr("COPY OUT."));
				}
				else if (st == PGRES_COPY_IN) {
					statusBar()->showMessage(tr("COPY IN."));
				}
				else if (st == PGRES_BAD_RESPONSE) {
					statusBar()->showMessage(tr("BAD RESPONSE."));
				}
				else if (st == PGRES_NONFATAL_ERROR) {
					statusBar()->showMessage(tr("NON FATAL ERROR."));
				}
				else if (st == PGRES_FATAL_ERROR) {
					statusBar()->showMessage(tr("FATAL ERROR."));
				}
				else if (st == PGRES_COPY_BOTH) {
					statusBar()->showMessage(tr("COPY BOTH shouldn't happen is for replication."));
				}
				else if (st == PGRES_SINGLE_TUPLE) {
					statusBar()->showMessage(tr("SINGLE TUPLE result."));
				}
				else {
					statusBar()->showMessage(tr("No tuples returned, possibly an error..."));
				}
				ui->tabWidget->setCurrentWidget(ui->messageTab);
				receiveNotice(dbres->diagDetails());
			}
		}
	}
	else {
		addLog("query_ready with NO result");
		statusBar()->showMessage(tr("Query cancelled."));
	}
}

void MainWindow::performExplain()
{
	ui->explainTreeView->setModel(nullptr);
	explainModel.reset();
	ui->messagesEdit->clear();

	addLog("Explain clicked");

	startTimer();
	std::string cmd = "EXPLAIN (ANALYZE, VERBOSE, BUFFERS, FORMAT JSON) " + getCommand();
	m_dbConnection.send(cmd,
		[this](std::shared_ptr<Pgsql::Result> res)
		{
			if (res) {
				// Process explain data seperately
				std::thread([this,res]()
				{
					std::shared_ptr<ExplainRoot> explain;
					if (res->getCols() == 1 && res->getRows() == 1) {
						std::string s = res->getVal(0, 0);
						Json::Value root;   // will contains the root value after parsing.
						Json::Reader reader;
						bool parsingSuccessful = reader.parse(s, root);
						if (parsingSuccessful) {
							explain = ExplainRoot::createFromJson(root);
						}
					}
					QueueTask([this, explain]() { explain_ready(explain); });
				}).detach();
			}
		});
}

void MainWindow::explain_ready(ExplainRoot::SPtr explain)
{
	endTimer();
	if (explain) {
		addLog("Explain ready");
		QString times_str = QString("Execution time: %1, Planning time: %2")
						.arg(
					msfloatToHumanReadableString(explain->executionTime)
					, msfloatToHumanReadableString(explain->planningTime));
		ui->lblTimes->setText(times_str);
		explainModel.reset(new QueryExplainModel(nullptr, explain));
		ui->explainTreeView->setModel(explainModel.get());
		ui->explainTreeView->expandAll();
		ui->explainTreeView->setColumnWidth(0, 200);
		ui->explainTreeView->setColumnWidth(1, 80);
		ui->explainTreeView->setColumnWidth(2, 80);
		ui->explainTreeView->setColumnWidth(3, 80);
		ui->explainTreeView->setColumnWidth(4, 80);
		ui->explainTreeView->setColumnWidth(5, 80);
		ui->explainTreeView->setColumnWidth(6, 600);
		ui->tabWidget->setCurrentWidget(ui->explainTab);
		statusBar()->showMessage(tr("Explain ready."));
	}
	else {
		addLog("Explain no result");
		ui->tabWidget->setCurrentWidget(ui->messageTab);
		statusBar()->showMessage(tr("Explain failed."));
	}
}

void MainWindow::cancel_query()
{
	m_dbConnection.cancel();
}

void MainWindow::receiveNotice(Pgsql::ErrorDetails notice)
{
	ui->messagesEdit->append(QString::fromStdString(notice.errorMessage));

	ui->messagesEdit->append(QString::fromStdString(notice.severity));
	ui->messagesEdit->append(QString("At position: %1").arg(notice.statementPosition));
	ui->messagesEdit->append(QString::fromStdString("State: " + notice.state));
	ui->messagesEdit->append(QString::fromStdString("Primary: " + notice.messagePrimary));
	ui->messagesEdit->append(QString::fromStdString("Detail: " + notice.messageDetail));
	ui->messagesEdit->append(QString::fromStdString("Hint: " + notice.messageHint));
	ui->messagesEdit->append(QString::fromStdString("Context: " + notice.context));
//	std::string state; ///< PG_DIAG_SQLSTATE Error code as listed in	https://www.postgresql.org/docs/9.5/static/errcodes-appendix.html
//	std::string severity;
//	std::string messagePrimary;
//	std::string messageDetail;
//	std::string messageHint;
//	int statementPosition; ///< First character is one, measured in characters not bytes!
	//	std::string context;

//	int internalPosition;
//	std::string internalQuery;
//	std::string schemaName;
//	std::string tableName;
//	std::string columnName;
//	std::string datatypeName;
//	std::string constraintName;
//	std::string sourceFile;
//	std::string sourceLine;
//	std::string sourceFunction;

//	QTextCursor cursor = ui->messagesEdit->textCursor();
//	cursor.movePosition(QTextCursor::End, QTextCursor::MoveAnchor);

//	QTextTable *table = cursor.insertTable(4, 2);
//	if (table) {
//		table->cellAt(1, 0).firstCursorPosition().insertText("State");
//		table->cellAt(1, 1).firstCursorPosition().insertText(QString::fromStdString(notice.state));
//		table->cellAt(2, 0).firstCursorPosition().insertText("Primary");
//		table->cellAt(2, 1).firstCursorPosition().insertText(QString::fromStdString(notice.messagePrimary));
//		table->cellAt(3, 0).firstCursorPosition().insertText("Detail");
//		table->cellAt(3, 1).firstCursorPosition().insertText(QString::fromStdString(notice.messageDetail));
//	}

	// syntax error at or near "limit
	// statementPosition
}

void MainWindow::addLog(QString s)
{
	QTextCursor text_cursor = QTextCursor(ui->edtLog->document());
	text_cursor.movePosition(QTextCursor::End);
	text_cursor.insertText(s + "\r\n");
}

void MainWindow::startTimer()
{
	m_startTime = std::chrono::steady_clock::now();
	m_timer = std::make_unique<QTimer>(nullptr);
	m_timer->setTimerType(Qt::CoarseTimer);
	connect(m_timer.get(), SIGNAL(timeout()), this, SLOT(updateTimer()));
	m_timer->start(18);
}

void MainWindow::updateTimer()
{
	auto nu = std::chrono::steady_clock::now();
	std::chrono::duration<float, std::milli> diff = nu - m_startTime;
	elapsedTime = diff;
	m_timeElapsedLabel->setText(msfloatToHumanReadableString(diff.count()));


	if (m_timer) {
		int ms = diff.count();
		int interval = 18;
		if (ms >= 10000) {
			int rem = ms % 1000;
			interval = 1000 - rem;
		}
		else if (ms >= 1000) {
			interval = 100;
		}

		m_timer->start(interval);
	}
}

void MainWindow::endTimer()
{
	if (m_timer) {
		m_timer.reset();
		updateTimer();
	}
}

bool MainWindow::continueWithoutSaving()
{
	QMessageBox msgBox;
	msgBox.setText("The document has been modified.");
	msgBox.setInformativeText("The current query has unsaved changes, do you want to continue without saving those changes?");
	msgBox.setStandardButtons(QMessageBox::Yes | QMessageBox::No);
	msgBox.setDefaultButton(QMessageBox::No);
	int ret = msgBox.exec();
	return ret == QMessageBox::Yes;
}

void MainWindow::on_actionLoad_SQL_triggered()
{
	//
	if (m_queryTextChanged && !continueWithoutSaving()) {
		return;
	}

	QString home_dir = QStandardPaths::locate(QStandardPaths::HomeLocation, "", QStandardPaths::LocateDirectory);
	QString file_name = QFileDialog::getOpenFileName(this,
		tr("Open sql query"), home_dir, tr("SQL files (*.sql *.txt)"));
	if ( ! file_name.isEmpty()) {
		QFile file(file_name);
		if (file.open(QIODevice::ReadWrite)) {
			QTextStream stream(&file);
			ui->queryEdit->clear();
			while (!stream.atEnd()){
				QString line = stream.readLine();
				ui->queryEdit->appendPlainText(line);
			}
			m_queryTextChanged = false;
			m_fileName = file_name;
		}
	}
}

void MainWindow::saveSqlTo(const QString &filename)
{
	QFile file(filename);
	if (file.open(QIODevice::ReadWrite)) {
		QTextStream stream(&file);
		QString text = ui->queryEdit->toPlainText();
		stream << text;
		m_queryTextChanged = false;
	}
}

void MainWindow::on_actionSave_SQL_triggered()
{
	if (m_fileName.isEmpty()) {
		on_actionSave_SQL_as_triggered();
	}
	else {
		saveSqlTo(m_fileName);
	}
}

void MainWindow::on_actionSave_SQL_as_triggered()
{
	QString home_dir = QStandardPaths::locate(QStandardPaths::HomeLocation, "", QStandardPaths::LocateDirectory);
	QString file_name = QFileDialog::getSaveFileName(this,
		tr("Save query"), home_dir, tr("SQL file (*.sql)"));
	if ( ! file_name.isEmpty()) {
		saveSqlTo(file_name);
		m_fileName = file_name;
	}
}

void MainWindow::on_actionExport_data_triggered()
{
	QString home_dir = QStandardPaths::locate(QStandardPaths::HomeLocation, "", QStandardPaths::LocateDirectory);
	QString file_name = QFileDialog::getSaveFileName(this,
		tr("Export data"), home_dir, tr("CSV file (*.csv)"));

}

void MainWindow::on_actionClose_triggered()
{
	close();
}

void MainWindow::on_actionAbout_triggered()
{
	//
}

#if false

void Copy(		)
{
	QString selected_text;
	// You need a pair of indexes to find the row changes
	QModelIndex previous = indexes.first();
	indexes.removeFirst();
	foreach(current, indexes)
	{
		QVariant data = model->data(current);
		QString text = data.toString();
		// At this point `text` contains the text in one cell
		selected_text.append(text);
		// If you are at the start of the row the row number of the previous index
		// isn't the same.  Text is followed by a row separator, which is a newline.
		if (current.row() != previous.row())
		{
			selected_text.append('\n');
		}
		// Otherwise it's the same row, so append a column separator, which is a tab.
		else
		{
			selected_text.append('\t');
		}
		previous = current;
	}
	QApplication.clipboard().setText(selected_text);
}
#endif

void MainWindow::on_actionExecute_SQL_triggered()
{
	performQuery();
}

void MainWindow::on_actionExplain_Analyze_triggered()
{
	performExplain();
}

void MainWindow::on_actionCancel_triggered()
{
	cancel_query();
}

void MainWindow::queryTextChanged()
{
	m_queryTextChanged = true;
}

void MainWindow::closeEvent(QCloseEvent *event)
{
	if (!m_queryTextChanged  || continueWithoutSaving()) {
		event->accept();
	}
	else {
		event->ignore();
	}
}

void MainWindow::showEvent(QShowEvent *event)
{
	if (!event->spontaneous()) {
		m_queryTextChanged = false;
	}
	event->accept();
}