#include "SqlDocument.h"
#include "util/SqlSyntaxHighlighter.h"
#include <QFile>
#include <QFileDialog>
#include <QFileInfo>
#include <QStandardPaths>
#include <QStringConverter>
#include <QPlainTextDocumentLayout>
#include <QTextDocument>
#include <QTextStream>

SqlDocument::SqlDocument(QObject *parent)
	: QObject(parent)
	, m_document(new QTextDocument(this))
	, m_highlighter(new SqlSyntaxHighlighter(m_document))
{
	// QPlainTextEdit only accepts documents that use a QPlainTextDocumentLayout
	m_document->setDocumentLayout(new QPlainTextDocumentLayout(m_document));
	connect(m_document, &QTextDocument::modificationChanged, this, &SqlDocument::modifiedChanged);
	setFileName(tr("new"));
}

SqlDocument::~SqlDocument() = default;

bool SqlDocument::isModified() const
{
	return m_document->isModified();
}

void SqlDocument::setModified(bool modified)
{
	m_document->setModified(modified);
}

void SqlDocument::clear()
{
	m_document->clear();
	setFileName(tr("new"));
	m_new = true;
	setModified(false);
}

bool SqlDocument::load(const QString &filename)
{
	bool result = false;
	QFile file(filename);
	if (file.open(QIODevice::ReadOnly)) {
		QByteArray ba = file.readAll();
		auto toUtf16 = QStringDecoder(QStringDecoder::Utf8);
		QString text = toUtf16(ba);
		if (toUtf16.hasError()) {
			file.reset();
			QTextStream stream(&file);
			text = stream.readAll();
		}

		m_document->setPlainText(text);
		setModified(false);
		setFileName(filename);
		m_new = false;
		result = true;
	}
	return result;
}

bool SqlDocument::save(QWidget *parent)
{
	bool result;
	if (m_fileName.isEmpty() || m_new) {
		result = saveAs(parent);
	}
	else {
		result = saveSqlTo(m_fileName);
	}
	return result;
}

bool SqlDocument::saveAs(QWidget *parent)
{
	bool result = false;
	QString filename = promptUserForSaveSqlFilename(parent);
	if (!filename.isEmpty()) {
		result = saveSqlTo(filename);
		if (result) {
			setFileName(filename);
			m_new = false;
		}
	}
	return result;
}

bool SqlDocument::saveCopyAs(QWidget *parent)
{
	bool result = false;
	QString filename = promptUserForSaveSqlFilename(parent);
	if (!filename.isEmpty()) {
		result = saveSqlTo(filename);
	}
	return result;
}

void SqlDocument::addEditor(QWidget *editor)
{
	if (!m_editors.contains(editor))
		m_editors.append(editor);
}

void SqlDocument::removeEditor(QWidget *editor)
{
	m_editors.removeAll(editor);
}

void SqlDocument::setFileName(const QString &filename)
{
	m_fileName = filename;
	emit fileNameChanged();
}

bool SqlDocument::saveSqlTo(const QString &filename)
{
	bool result = false;

	QFile file(filename);
	if (file.open(QIODevice::WriteOnly)) {
		QTextStream stream(&file);
		stream.setEncoding(QStringConverter::Utf8);
		QString text = m_document->toPlainText();
		stream << text;

		stream.flush();
		if (stream.status() == QTextStream::Ok) {
			setModified(false);
			result = true;
		}
	}
	return result;
}

QString SqlDocument::promptUserForSaveSqlFilename(QWidget *parent)
{
	QString home_dir = QStandardPaths::locate(QStandardPaths::HomeLocation, "", QStandardPaths::LocateDirectory);
	return QFileDialog::getSaveFileName(parent, tr("Save query"), home_dir, tr("SQL file (*.sql)"));
}