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

#include <QCloseEvent>
#include <QFileDialog>
#include <QMessageBox>
#include <QStandardPaths>
#include <QUndoStack>
#include <QUndoView>

#include "../../ApplicationConfig.h"
#include "data/settingshandler.h"
#include "dialogs/edititemdialog.h"
#include "dialogs/newitemdialog.h"
#include "genericcore.h"
#include "model/tablemodel.h"

static QStandardPaths::StandardLocation standardLocation = QStandardPaths::HomeLocation;
static QString updateTextClean = "Do you want to update the application now?";
static QString updateTextDirty = "Do you want to save the tasks & update the application now?";

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

  m_core = std::make_unique<GenericCore>();

  setWindowTitle(QCoreApplication::applicationName() + " [*]");

  /// application icon
  const QString iconString = "://feature.png";
#ifdef QT_DEBUG
  QPixmap pixmap       = QPixmap(iconString);
  QTransform transform = QTransform();
  transform.rotate(180);
  QPixmap rotated = pixmap.transformed(transform);
  setWindowIcon(QIcon(rotated));
#else
  setWindowIcon(QIcon(iconString));
#endif

  const QVariantMap settings = SettingsHandler::getSettings("GUI");
  restoreGeometry(settings.value("geometry").toByteArray());
  restoreState(settings.value("windowState").toByteArray());

  m_tableModel = m_core->getModel();
  ui->tableView->setModel(m_tableModel.get());

  createActions();
  createHelpMenu();
  createGuiDialogs();

  connect(m_core.get(), &GenericCore::displayStatusMessage, this,
          &MainWindow::displayStatusMessage);
  connect(this, &MainWindow::displayStatusMessage, this, &MainWindow::showStatusMessage);
  connect(this, &MainWindow::checkForUpdates, this,
          &MainWindow::on_actionCheck_for_update_triggered, Qt::QueuedConnection);

  // connect(ui->tableView->selectionModel(), &QItemSelectionModel::selectionChanged, this,
  //         &MainWindow::onSelectionChanged);
  connect(ui->tableView->selectionModel(), &QItemSelectionModel::currentChanged, this,
          &MainWindow::onCurrentChanged);

  onSelectionChanged(QItemSelection(), QItemSelection());
  onCurrentChanged(QModelIndex(), QModelIndex());
}

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

void MainWindow::closeEvent(QCloseEvent* event) {
  if (isWindowModified()) {
    QMessageBox msgBox;
    msgBox.setWindowTitle(windowTitle() + " - Save dialog");
    msgBox.setText("The document has been modified.");
    msgBox.setInformativeText("Do you want to save your changes?");
    msgBox.setStandardButtons(QMessageBox::Save | QMessageBox::Discard | QMessageBox::Cancel);
    msgBox.setDefaultButton(QMessageBox::Save);
    int ret = msgBox.exec();

    switch (ret) {
      case QMessageBox::Save:
        emit saveItems();
        event->accept();
        break;
      case QMessageBox::Discard:
        event->accept();
        break;
      case QMessageBox::Cancel:
        event->ignore();
        break;
      default:
        /// should never be reached
        qCritical() << "unexpected switch case in closeEvent:" << ret;
        event->ignore();
        break;
    }
  } else {
    event->accept();
  }

  if (event->isAccepted()) {
    qInfo() << "Saving GUI settings...";
    SettingsHandler::saveSettings({{"geometry", saveGeometry()}, {"windowState", saveState()}},
                                  "GUI");
  }
}

void MainWindow::showStatusMessage(const QString text) {
  qInfo() << text;
  ui->statusbar->showMessage(text);
}

void MainWindow::onCurrentChanged(const QModelIndex& current, const QModelIndex& previous) {
  // Q_UNUSED(current);
  Q_UNUSED(previous);

  // QItemSelection localSelection = ui->tableView->selectionModel()->selection();
  if (current == QModelIndex()) {
    // qDebug() << "Nothing selected. Disabling delete action";
    m_deleteItemAct->setEnabled(false);
  } else {
    // qDebug() << "Something selected. Enabling delete action";
    m_deleteItemAct->setEnabled(true);
  }
}

void MainWindow::onSelectionChanged(const QItemSelection& selected,
                                    const QItemSelection& deselected) {
  Q_UNUSED(selected);
  Q_UNUSED(deselected);

  QItemSelection localSelection = ui->tableView->selectionModel()->selection();
  if (localSelection.empty()) {
    // qDebug() << "Nothing selected. Disabling delete action";
    m_deleteItemAct->setEnabled(false);
  } else {
    // qDebug() << "Something selected. Enabling delete action";
    m_deleteItemAct->setEnabled(true);
  }
}

void MainWindow::onAboutClicked() {
  const QString applicationName = APPLICATION_NAME;
  const QString titlePrefix     = tr("About ");
  const QString aboutText =
      tr(QString("<b>%1 v%2</b> is a template for Qt applications."
                 "<br><br><a href=\"https://working-copy.org/\">Working-Copy_Collective website</a>"
                 "<br><br><a href=\"mailto:support@working-copy.org\">Mail to support</a>"
                 "<br><br>It uses the <a href=\"https://qt.io\">Qt Framework</a>.")
             .arg(applicationName)
             .arg(APPLICATION_VERSION)
             .toLatin1());
  QMessageBox::about(this, titlePrefix + applicationName, aboutText);
}

void MainWindow::on_actionCheck_for_update_triggered() {
  showStatusMessage("Checking for update...");
  const bool updateAvailable = m_core->isApplicationUpdateAvailable();
  if (updateAvailable) {
    const QString text = isWindowModified() ? updateTextDirty : updateTextClean;
    const QMessageBox::StandardButton clickedButton = QMessageBox::question(
        this, tr("Update available."), text, QMessageBox::Yes | QMessageBox::No, QMessageBox::Yes);
    if (clickedButton == QMessageBox::Yes) {
      m_core->triggerApplicationUpdate();
      close();
    }
  }
}

void MainWindow::on_pushButton_clicked() {
  const QString prefix("Backend provided by: ");
  ui->label->setText(prefix + m_core->toString());
}

void MainWindow::openNewItemDialog() {
  showStatusMessage(tr("Invoked 'Edit|New Item'"));
  m_newItemDialog->show();
}

void MainWindow::openEditItemDialog() {
  showStatusMessage(tr("Invoked 'Edit|Edit Item'"));
  m_editItemDialog->show();
}

void MainWindow::deleteCurrentItem() {
  showStatusMessage(tr("Invoked 'Edit|Delete Item'"));
  // QItemSelection localSelection  = ui->tableView->selectionModel()->selection();
  const QModelIndex currentIndex = ui->tableView->selectionModel()->currentIndex();
  if (currentIndex == QModelIndex()) {
    qDebug() << "No current item. Nothing to remove.";
  } else {
    m_tableModel->removeRows(currentIndex.row(), 1);
  }
}

void MainWindow::deleteSelectedtItems() {
  showStatusMessage(tr("Invoked 'Edit|Delete Item'"));
  QItemSelection localSelection = ui->tableView->selectionModel()->selection();
  if (localSelection.empty()) {
    qDebug() << "No items selected. Nothing to remove.";
  } else {
    for (QList<QItemSelectionRange>::reverse_iterator iter = localSelection.rbegin(),
                                                      rend = localSelection.rend();
         iter != rend; ++iter) {
      // qInfo() << "iter:" << *iter;
      // const QModelIndex parentIndex = iter->parent();
      const int topRow    = iter->top();
      const int bottomRow = iter->bottom();
      const int nRows     = bottomRow - topRow + 1;
      m_tableModel->removeRows(topRow, nRows);
    }
  }
}

void MainWindow::onCleanStateChanged(bool clean) {
  qInfo() << "Slot onCleanStateChanged triggered: clean:" << clean;
  setWindowModified(!clean);
  if (!clean) {
    ui->statusbar->clearMessage();
  }
}

void MainWindow::onShowUndoViewToggled(bool checked) {
  //  qInfo() << "Slot onShowUndoViewToggled toggled: checked:" << checked;
  //  m_undoView->setVisible(checked);

  /// workaround until m_showUndoViewAction is checkable
  qInfo() << "Slot onShowUndoViewToggled triggered, toggleing undo view...";
  Q_UNUSED(checked);
  if (m_modelUndoView->isVisible()) {
    m_modelUndoView->setVisible(false);

  } else {
    m_modelUndoView->setVisible(true);
  }
}

void MainWindow::saveItems() {
  showStatusMessage(tr("Invoked 'File|Save'"));
  m_core->saveItems();
}

void MainWindow::importCSV() {
  showStatusMessage(tr("Invoked 'File|Import CSV'"));
  const QString csvFilePath = QFileDialog::getOpenFileName(
      this, tr("Import CSV"), QStandardPaths::standardLocations(standardLocation).first(),
      tr("CSV Files (*.csv)"));
  if (QFileInfo::exists(csvFilePath)) {
    m_core->importCSVFile(csvFilePath);
  } else {
    qWarning() << "Selected CSV file path doesn't exist. Doing nothing...";
    showStatusMessage(tr("Could't find CSV file!"));
  }
}
void MainWindow::createActions() {
  // TODO add generic menu actions (file/new, edit/cut, ...)
  createFileActions();
  createUndoActions();
  createEditActions();
}

void MainWindow::createFileActions() {
  m_newFileAct = make_unique<QAction>(tr("&New File"), this);
  m_newFileAct->setShortcut(QKeySequence(Qt::CTRL | Qt::SHIFT | Qt::Key_N));
  m_newFileAct->setStatusTip(tr("Create a new file"));
  // connect(m_newAct, &QAction::triggered, this, &MainWindow::newFile);
  m_newFileAct->setEnabled(false);
  ui->menu_File->addAction(m_newFileAct.get());

  m_openAct = make_unique<QAction>(tr("&Open..."), this);
  m_openAct->setShortcuts(QKeySequence::Open);
  m_openAct->setStatusTip(tr("Open an existing file"));
  // connect(m_openAct, &QAction::triggered, this, &MainWindow::open);
  m_openAct->setEnabled(false);
  ui->menu_File->addAction(m_openAct.get());

  m_saveAct = make_unique<QAction>(tr("&Save"), this);
  m_saveAct->setShortcuts(QKeySequence::Save);
  m_saveAct->setStatusTip(tr("Save the document to disk"));
  connect(m_saveAct.get(), &QAction::triggered, this, &MainWindow::saveItems);
  ui->menu_File->addAction(m_saveAct.get());

  ui->menu_File->addSeparator();

  m_importAct = make_unique<QAction>(tr("&Import CSV..."), this);
  m_importAct->setStatusTip(tr("Import an existing CSV file"));
  connect(m_importAct.get(), &QAction::triggered, this, &MainWindow::importCSV);
  ui->menu_File->addAction(m_importAct.get());

  m_exportAct = make_unique<QAction>(tr("&Export CSV..."), this);
  m_exportAct->setStatusTip(tr("Export content to a CSV document to disk"));
  // connect(m_exportAct, &QAction::triggered, this, &MainWindow::exportCSV);
  m_exportAct->setEnabled(false);
  ui->menu_File->addAction(m_exportAct.get());

  ui->menu_File->addSeparator();

  m_printAct = make_unique<QAction>(tr("&Print..."), this);
  m_printAct->setShortcuts(QKeySequence::Print);
  m_printAct->setStatusTip(tr("Print the document"));
  // connect(m_printAct, &QAction::triggered, this, &MainWindow::print);
  m_printAct->setEnabled(false);
  ui->menu_File->addAction(m_printAct.get());

  ui->menu_File->addSeparator();

  m_exitAct = make_unique<QAction>(tr("E&xit"), this);
  m_exitAct->setShortcuts(QKeySequence::Quit);
  m_exitAct->setStatusTip(tr("Exit the application"));
  connect(m_exitAct.get(), &QAction::triggered, this, &QWidget::close);
  ui->menu_File->addAction(m_exitAct.get());
}

void MainWindow::createUndoActions() {
  if (!m_core) {
    qCritical() << "No core instance set, aborting...";
    return;
  }
  m_modelUndoStack = m_core->getModelUndoStack();

  connect(m_modelUndoStack, &QUndoStack::cleanChanged, this, &MainWindow::onCleanStateChanged);

  m_undoAct.reset(m_modelUndoStack->createUndoAction(this, tr("&Undo")));
  m_undoAct->setShortcuts(QKeySequence::Undo);
  m_undoAct->setStatusTip(tr("Undo the last operation"));
  ui->menu_Edit->addAction(m_undoAct.get());

  m_redoAct.reset(m_modelUndoStack->createRedoAction(this, tr("&Redo")));
  m_redoAct->setShortcuts(QKeySequence::Redo);
  m_redoAct->setStatusTip(tr("Redo the last operation"));
  ui->menu_Edit->addAction(m_redoAct.get());

  m_modelUndoView = make_unique<QUndoView>(m_modelUndoStack);
  m_modelUndoView->setWindowTitle(tr("Undo list"));
  m_modelUndoView->setAttribute(Qt::WA_QuitOnClose, false);
  m_modelUndoView->setMinimumSize(450, 600);
  m_showModelUndoViewAct = make_unique<QAction>(tr("Show undo/redo window"), this);
  m_showModelUndoViewAct->setStatusTip(tr("Opens a window displaying the items on the undo stack"));

  // TODO showUndoViewAction should be checkable
  //  m_showUndoViewAction->setCheckable(true);
  //  connect(m_showUndoViewAction, &QAction::toggled, this, &MainWindow::onShowUndoViewToggled);
  connect(m_showModelUndoViewAct.get(), &QAction::triggered, this,
          &MainWindow::onShowUndoViewToggled);
  ui->menu_View->addAction(m_showModelUndoViewAct.get());
}

void MainWindow::createEditActions() {
  m_cutAct = make_unique<QAction>(tr("Cu&t"), this);
  m_cutAct->setShortcuts(QKeySequence::Cut);
  m_cutAct->setStatusTip(
      tr("Cut the current selection's contents to the "
         "clipboard"));
  // connect(m_cutAct, &QAction::triggered, this, &MainWindow::cut);
  m_cutAct->setEnabled(false);
  ui->menu_Edit->addAction(m_cutAct.get());

  m_copyAct = make_unique<QAction>(tr("&Copy"), this);
  m_copyAct->setShortcuts(QKeySequence::Copy);
  m_copyAct->setStatusTip(
      tr("Copy the current selection's contents to the "
         "clipboard"));
  // connect(m_copyAct, &QAction::triggered, this, &MainWindow::copy);
  m_copyAct->setEnabled(false);
  ui->menu_Edit->addAction(m_copyAct.get());

  m_pasteAct = make_unique<QAction>(tr("&Paste"), this);
  m_pasteAct->setShortcuts(QKeySequence::Paste);
  m_pasteAct->setStatusTip(
      tr("Paste the clipboard's contents into the current "
         "selection"));
  // connect(m_pasteAct, &QAction::triggered, this, &MainWindow::paste);
  m_pasteAct->setEnabled(false);
  ui->menu_Edit->addAction(m_pasteAct.get());

  ui->menu_Edit->addSeparator();

  m_openNewItemDialogAct = make_unique<QAction>(tr("&New item"), this);
  m_openNewItemDialogAct->setShortcut(QKeySequence::New);
  m_openNewItemDialogAct->setStatusTip(tr("Opens a dialog to add a new item"));
  connect(m_openNewItemDialogAct.get(), &QAction::triggered, this, &MainWindow::openNewItemDialog);
  ui->menu_Edit->addAction(m_openNewItemDialogAct.get());

  m_openEditItemDialogAct = make_unique<QAction>(tr("&Edit item"), this);
  m_openEditItemDialogAct->setShortcut(QKeySequence(Qt::CTRL | Qt::Key_E));
  m_openEditItemDialogAct->setStatusTip(tr("Opens a edit dialog for the current item"));
  connect(m_openEditItemDialogAct.get(), &QAction::triggered, this,
          &MainWindow::openEditItemDialog);
  ui->menu_Edit->addAction(m_openEditItemDialogAct.get());

  m_deleteItemAct = make_unique<QAction>(tr("&Delete item(s)"), this);
  m_deleteItemAct->setShortcuts(QKeySequence::Delete);
  m_deleteItemAct->setStatusTip(tr("Delete currently selected item(s)"));
  // connect(m_deleteItemAct.get(), &QAction::triggered, this, &MainWindow::deleteSelectedtItems);
  connect(m_deleteItemAct.get(), &QAction::triggered, this, &MainWindow::deleteCurrentItem);
  ui->menu_Edit->addAction(m_deleteItemAct.get());

  ui->menu_Edit->addSeparator();

  m_findItemAct = make_unique<QAction>(tr("&Find item(s)"), this);
  m_findItemAct->setShortcuts(QKeySequence::Find);
  m_findItemAct->setStatusTip(tr("Opens a dialog to find item(s) by containing text"));
  // connect(m_findItemAct, &QAction::triggered, this, &MainWindow::findItems);
  m_findItemAct->setEnabled(false);
  ui->menu_Edit->addAction(m_findItemAct.get());
}

void MainWindow::createHelpMenu() {
  QMenu* helpMenu = ui->menu_Help;
  helpMenu->addSeparator();
  QAction* aboutAct = helpMenu->addAction(tr("&About"), this, &MainWindow::onAboutClicked);
  aboutAct->setStatusTip(tr("Show the application's About box"));

  QAction* aboutQtAct = helpMenu->addAction(tr("About &Qt"), qApp, &QApplication::aboutQt);
  aboutQtAct->setStatusTip(tr("Show the Qt library's About box"));
}

void MainWindow::createGuiDialogs() {
  /// new item dialog
  m_newItemDialog = make_unique<NewItemDialog>(this);
  m_newItemDialog->createContent();
  connect(m_newItemDialog.get(), &NewItemDialog::addItems, m_tableModel.get(),
          &TableModel::appendItems);
  /// edit item dialog
  m_editItemDialog = make_unique<EditItemDialog>(ui->tableView, this);
  m_editItemDialog->createContent();
}