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

#include <QFileDialog>
#include <QMessageBox>
#include <QJsonDocument>

MainWindow::MainWindow(QWidget *parent)
	: QMainWindow(parent)
	, ui(new Ui::MainWindow)
{
	ui->setupUi(this);
	connect(ui->actionOpen, &QAction::triggered, this, [this](bool){open();});
	connect(ui->nextButton, &QPushButton::clicked, this, [this](bool){setImage(index+1);});
	connect(ui->prevButton, &QPushButton::clicked, this, [this](bool){setImage(index-1);});
	connect(ui->actionSave, &QAction::triggered, this, [this](bool){save();});
	connect(ui->actionQuit, &QAction::triggered, this, [this](bool){close();});
	ui->verticalLayout->addWidget(&status);
	ui->imageLabel->setScaledContents( true );
	ui->imageLabel->setSizePolicy( QSizePolicy::Ignored, QSizePolicy::Ignored );
}

MainWindow::~MainWindow()
{
	delete ui;
}

void MainWindow::open()
{
	QString dirpath = QFileDialog::getExistingDirectory(this, "Choose a directory with images", "", QFlags<QFileDialog::Option>());
	if(dirpath.isEmpty())
		return;

	openDir(dirpath.toStdString());
}

void MainWindow::openDir(const std::filesystem::path& path)
{
	imageMetas.clear();

	QDir dir(path);
	bool hasMetadata = false;
	std::vector<std::filesystem::path> imagePaths;
	for(QString filename : dir.entryList(QDir::Files))
	{
		if(filename == "metadata.jsonl")
			hasMetadata = true;
		else if(filename.endsWith(".jpg") || filename.endsWith(".png"))
			imagePaths.push_back(path/filename.toStdString());
	}

	if(imagePaths.empty())
	{
		QMessageBox::warning(this, "No images found", "No valid images found in this directory");
		return;
	}

	if(hasMetadata)
	{
		if(!loadMetadata(path/"metadata.jsonl"))
			QMessageBox::warning(this, "Could not read",
								 (std::string("Could not read ") + path.string() + std::string("/metadata.jsonl, file contains errors")).c_str());
	}

	for(const std::filesystem::path &path : imagePaths)
	{
		if(imageIsKnown(path))
			continue;
		qDebug()<<path.c_str()<<"not in existing metadata.jsonl";
		imageMetas.push_back(ImageMeta(path));
	}

	this->dir = path;

	ui->textEdit->document()->setPlainText(imageMetas[0].text);
	setImage(0);
}

void MainWindow::setImage(ssize_t index)
{
	if(imageMetas.empty())
		return;
	else if(index > imageMetas.size()-1)
			return;
	else if(index < 0)
		return;

	imageMetas[this->index].text = ui->textEdit->document()->toPlainText();
	this->index = index;
	ui->counterLabel->setText(QString::asprintf("%04zu/%04zu", index, imageMetas.size()-1));
	ui->textEdit->document()->setPlainText(imageMetas[index].text);

	QPixmap image;
	bool ret = image.load(imageMetas[index].path.string().c_str());
	if(!ret)
	{
		ui->imageLabel->setPixmap(QPixmap());
		ui->imageLabel->setText(("Unable to load " + imageMetas[index].path.string()).c_str());
		ui->imageLabel->setText("No image loaded");
	}
	else
	{
		ui->imageLabel->setPixmap(image);
	}

	ui->imageLabel->setText("");
}

bool MainWindow::loadMetadata(const std::filesystem::path& path)
{
	QFile meta(path);
	meta.open(QIODeviceBase::ReadOnly);
	if(!meta.isOpen())
	{
		qWarning()<<("Could not open " + path.string()).c_str();
		return false;
	}

	QByteArray line = meta.readLine();
	while(!line.isEmpty())
	{
		QJsonParseError error;
		QJsonDocument json = QJsonDocument::fromJson(line, &error);
		if(json.isNull())
		{
			qWarning()<<error.errorString();
			return false;
		}

		imageMetas.push_back(ImageMeta(json.object(), path.parent_path()));
		line = meta.readLine();
	}

	return true;
}

bool MainWindow::imageIsKnown(const std::filesystem::path& path)
{
	for(const ImageMeta& meta : imageMetas)
	{
		if(meta.path == path)
			return true;
	}
	return false;
}

void MainWindow::save()
{
	if(imageMetas.empty())
		return;

	QFile file(dir/"metadata.jsonl");
	if(!file.open(QIODeviceBase::WriteOnly | QIODeviceBase::Truncate))
	{
		QMessageBox::warning(this, "Could not save",
							 ("Could not save, can not open " + (dir/"metadata.jsonl").string() + " for writeing").c_str());
		return;
	}

	for(const ImageMeta& meta : imageMetas)
	{
		QJsonObject obj;
		obj["file_name"] = std::filesystem::relative(meta.path, dir).string().c_str();
		obj["text"] = meta.text;
		QJsonDocument document(obj);
		QByteArray json = document.toJson(QJsonDocument::Compact);
		json.removeIf([](char ch){return ch == '\n';});
		json.append('\n');
		file.write(json);
	}
	file.close();
	QMessageBox::information(this, "Saved", ("Saved to " + (dir/"metadata.jsonl").string()).c_str());
}