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

#include "QueryResultModel.h"
#include "QueryExplainModel.h"
#include "sqlhighlighter.h"
#include <QTextTable>
#include <QTimer>
#include <windows.h>
#include "json/json.h"
#include "explaintreemodelitem.h"

//#include <thread>

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),
	queryCancel(nullptr)
{
	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("execute");
	connect(action, &QAction::triggered, this, &MainWindow::performQuery);

	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);
}

MainWindow::~MainWindow()
{}

void MainWindow::QueueTask(callable c)
{
	std::lock_guard<std::mutex> lg(m_mutexCallableQueue);
	m_callableQueue.emplace_back(std::move(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()
{
	bool empty;
	callable c;
	{ // narrow scope for lock guard
		std::lock_guard<std::mutex> lg(m_mutexCallableQueue);
		c = m_callableQueue.back();
		m_callableQueue.pop_back();
		empty = m_callableQueue.empty();
	}

	c();

	if (!empty) {
		// This gives other events a chance to be processed to keep the UI snappy.
		QTimer::singleShot(0, this, SLOT(processCallableQueue()));
	}
}

void MainWindow::startConnect()
{
	if (connection == nullptr) {
		connection = std::make_unique<pg::Connection>();
	}
	QString connstr = ui->connectionStringEdit->text();
	bool ok = connection->connectStart(connstr + " application_name=Ivory client_encoding=utf8");
	if (ok && connection->status() != CONNECTION_BAD) {
		// Start polling
		int s = connection->socket();

		connectingState.notifier = std::make_unique<QSocketNotifier>(s, QSocketNotifier::Write);
		connect(connectingState.notifier.get(), &QSocketNotifier::activated, this, &MainWindow::socket_activate_connect);

		connectingState.poll_state = PGRES_POLLING_WRITING;
		statusBar()->showMessage(tr("Connecting"));
	}
	else {
		statusBar()->showMessage(tr("Connecting fail"));
	}

}

void MainWindow::socket_activate_connect(int )
{
	connectingState.poll_state = connection->connectPoll();


	if (connectingState.poll_state == PGRES_POLLING_OK) {
		connection->setNoticeReceiver(
					std::bind(&MainWindow::processNotice, this, std::placeholders::_1));
		statusBar()->showMessage(tr("Connected"));
		connectingState.notifier.reset();
	}
	else if (connectingState.poll_state = PGRES_POLLING_FAILED) {
		statusBar()->showMessage(tr("Connection failed"));
		connectingState.notifier.reset();
	}
	else if (connectingState.poll_state == PGRES_POLLING_READING) {
		statusBar()->showMessage(tr("Connecting.."));
		connectingState.notifier = std::make_unique<QSocketNotifier>(connection->socket(), QSocketNotifier::Read);
		connect(connectingState.notifier.get(), &QSocketNotifier::activated, this, &MainWindow::socket_activate_connect);
	}
	else if (connectingState.poll_state == PGRES_POLLING_WRITING) {
		statusBar()->showMessage(tr("Connecting..."));
		connectingState.notifier = std::make_unique<QSocketNotifier>(connection->socket(), QSocketNotifier::Write);
		connect(connectingState.notifier.get(), &QSocketNotifier::activated, this, &MainWindow::socket_activate_connect);
	}
}


void MainWindow::performQuery()
{
	ui->ResultView->setModel(nullptr);
	resultModel.reset();
	ui->messagesEdit->clear();

	queryCancel = std::move(connection->getCancel());

	QString command = ui->queryEdit->toPlainText();
	std::thread([this,command]()
		{
			auto res = std::make_shared<Pgsql::Result>(connection->query(command));
			QueueTask([this, res]() { query_ready(std::move(*res)); });
		}).detach();
}

void MainWindow::query_ready(Pgsql::Result dbres)
{
	if (dbres) {
		auto st = dbres.resultStatus();
		if (st == PGRES_TUPLES_OK) {
			resultModel.reset(new QueryResultModel(nullptr , std::move(dbres)));
			ui->ResultView->setModel(resultModel.get());
			statusBar()->showMessage(tr("Query ready."));
		}
		else {
			if (st == PGRES_EMPTY_QUERY) {
				statusBar()->showMessage(tr("Empty query."));
			}
			else if (st == PGRES_COMMAND_OK) {
				statusBar()->showMessage(tr("Command OK."));
			}
			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("BEAD 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..."));
			}
			receiveNotice(dbres.diagDetails());
		}
	}
	else {
		statusBar()->showMessage(tr("Query cancelled."));
	}
}

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

	queryCancel = std::move(connection->getCancel());

	QString command = "EXPLAIN (ANALYZE, VERBOSE, BUFFERS, FORMAT JSON) ";
	command += ui->queryEdit->toPlainText();
//	explainFuture = std::async(std::launch::async, [this,command]()-> std::unique_ptr<ExplainRoot>
   std::thread([this,command]()
		{
			std::shared_ptr<ExplainRoot> explain;
			auto res = connection->query(command);
			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)
{
	if (explain) {
		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);
		statusBar()->showMessage(tr("Explain ready."));
	}
	else {
		statusBar()->showMessage(tr("Explain failed."));
	}
}

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

void MainWindow::processNotice(const PGresult *result)
{
	qRegisterMetaType<Pgsql::ErrorDetails>("Pgsql::ErrorDetails");
	pg::ErrorDetails details = pg::ErrorDetails::createErrorDetailsFromPGresult(result);
	QMetaObject::invokeMethod(this, "receiveNotice", Qt::AutoConnection, Q_ARG(Pgsql::ErrorDetails, details)); // queues on main thread
}

void MainWindow::receiveNotice(Pgsql::ErrorDetails notice)
{
	QTextCursor cursor = ui->messagesEdit->textCursor();
	cursor.movePosition(QTextCursor::End, QTextCursor::MoveAnchor);


//	QString msg;
//	cursor.insertText("TEST\r\n");

	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));
	}
}