// This file is part of RSS Guard.
//
// Copyright (C) 2011-2017 by Martin Rotter <rotter.martinos@gmail.com>
//
// RSS Guard is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// RSS Guard is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with RSS Guard. If not, see <http://www.gnu.org/licenses/>.

#include "gui/tabwidget.h"

#include "definitions/definitions.h"
#include "miscellaneous/application.h"
#include "miscellaneous/settings.h"
#include "miscellaneous/textfactory.h"
#include "miscellaneous/iconfactory.h"
#include "gui/tabbar.h"
#include "gui/messagesview.h"
#include "gui/feedsview.h"
#include "gui/feedmessageviewer.h"

#include "gui/plaintoolbutton.h"
#include "gui/dialogs/formmain.h"

#if defined(USE_WEBENGINE)
#include "gui/webbrowser.h"
#else
#include "network-web/webfactory.h"
#include "gui/newspaperpreviewer.h"
#endif

#include <QMenu>
#include <QToolButton>


TabWidget::TabWidget(QWidget *parent) : QTabWidget(parent), m_menuMain(nullptr) {
  setTabBar(new TabBar(this));
  setupMainMenuButton();
  initializeTabs();
  createConnections();
}

TabWidget::~TabWidget() {
  qDebug("Destroying TabWidget instance.");
}

void TabWidget::setupMainMenuButton() {
  m_btnMainMenu = new PlainToolButton(this);
  m_btnMainMenu->setAutoRaise(true);
  m_btnMainMenu->setPadding(3);
  m_btnMainMenu->setToolTip(tr("Displays main menu."));
  m_btnMainMenu->setIcon(qApp->icons()->fromTheme(QSL("start-here")));
  m_btnMainMenu->setPopupMode(QToolButton::InstantPopup);

  connect(m_btnMainMenu, &PlainToolButton::clicked, this, &TabWidget::openMainMenu);
}

void TabWidget::openMainMenu() {
  if (m_menuMain == nullptr) {
    m_menuMain = new QMenu(tr("Main menu"), this);
    m_menuMain->addMenu(qApp->mainForm()->m_ui->m_menuFile);
    m_menuMain->addMenu(qApp->mainForm()->m_ui->m_menuView);
    m_menuMain->addMenu(qApp->mainForm()->m_ui->m_menuAccounts);
    m_menuMain->addMenu(qApp->mainForm()->m_ui->m_menuFeeds);
    m_menuMain->addMenu(qApp->mainForm()->m_ui->m_menuMessages);
    m_menuMain->addMenu(qApp->mainForm()->m_ui->m_menuWebBrowserTabs);
    m_menuMain->addMenu(qApp->mainForm()->m_ui->m_menuTools);
    m_menuMain->addMenu(qApp->mainForm()->m_ui->m_menuHelp);
  }

  QPoint button_position = m_btnMainMenu->pos();
  const QSize target_size = m_btnMainMenu->size() / 2.0;

  button_position.setX(button_position.x() + target_size.width());
  button_position.setY(button_position.y() + target_size.height());

  m_menuMain->exec(mapToGlobal(button_position));
}

void TabWidget::showDownloadManager() {
  for (int i = 0; i < count(); i++) {
    if (widget(i)->metaObject()->className() == QSL("DownloadManager")) {
      setCurrentIndex(i);
      return;
    }
  }

  // Download manager is not opened. Create tab with it.
  qApp->downloadManager()->setParent(this);
  addTab(qApp->downloadManager(), qApp->icons()->fromTheme(QSL("emblem-downloads")), tr("Downloads"), TabBar::DownloadManager);
  setCurrentIndex(count() - 1);
}

void TabWidget::checkTabBarVisibility() {
  const bool should_be_visible = count() > 1 || !qApp->settings()->value(GROUP(GUI), SETTING(GUI::HideTabBarIfOnlyOneTab)).toBool();

  if (should_be_visible) {
    setCornerWidget(m_btnMainMenu, Qt::TopLeftCorner);
    m_btnMainMenu->setVisible(true);
  }
  else {
    setCornerWidget(0, Qt::TopLeftCorner);
    setCornerWidget(0, Qt::TopRightCorner);
    m_btnMainMenu->setVisible(false);
  }

  tabBar()->setVisible(should_be_visible);
}

void TabWidget::tabInserted(int index) {
  QTabWidget::tabInserted(index);
  checkTabBarVisibility();

  const int count_of_tabs = count();

  if (index < count_of_tabs - 1 && count_of_tabs > 1) {
    // New tab was inserted and the tab is not the last one.
    fixContentsAfterMove(index, count_of_tabs - 1);
  }
}

void TabWidget::tabRemoved(int index) {
  QTabWidget::tabRemoved(index);
  checkTabBarVisibility();

  const int count_of_tabs = count();

  if (index < count_of_tabs && count_of_tabs > 1) {
    // Some tab was removed and the tab was not the last one.
    fixContentsAfterMove(index, count_of_tabs - 1);
  }
}

void TabWidget::createConnections() {
  connect(tabBar(), &TabBar::tabCloseRequested, this, &TabWidget::closeTab);
  connect(tabBar(), &TabBar::emptySpaceDoubleClicked, this, &TabWidget::addEmptyBrowser);
  connect(tabBar(), &TabBar::tabMoved, this, &TabWidget::fixContentsAfterMove);

  connect(feedMessageViewer()->messagesView(), &MessagesView::openMessagesInNewspaperView, this, &TabWidget::addNewspaperView);
  connect(feedMessageViewer()->feedsView(), &FeedsView::openMessagesInNewspaperView, this, &TabWidget::addNewspaperView);
}

void TabWidget::initializeTabs() {
  // Create widget for "Feeds" page and add it.
  m_feedMessageViewer = new FeedMessageViewer(this);
  const int index_of_browser = addTab(m_feedMessageViewer, QIcon(), tr("Feeds"), TabBar::FeedReader);
  setTabToolTip(index_of_browser, tr("Browse your feeds and messages"));
}

void TabWidget::setupIcons() {
  // Iterate through all tabs and update icons
  // accordingly.
  for (int index = 0; index < count(); index++) {
    // Index 0 usually contains widget which displays feeds & messages.
    if (tabBar()->tabType(index) == TabBar::FeedReader) {
      setTabIcon(index, qApp->icons()->fromTheme(QSL("application-rss+xml")));
    }
  }
}

bool TabWidget::closeTab(int index) {
  if (tabBar()->tabType(index) == TabBar::Closable) {
    removeTab(index, true);
    return true;
  }
  else if (tabBar()->tabType(index) == TabBar::DownloadManager) {
    removeTab(index, false);
    return true;
  }
  else {
    return false;
  }
}

void TabWidget::closeAllTabsExceptCurrent() {
  // Close tabs after active tab.
  int index_of_active = currentIndex();

  for (int i = count() - 1; i >= 0; i--) {
    if (i != index_of_active) {
      if (i < index_of_active) {
        index_of_active--;
      }

      closeTab(i);
    }
  }
}

void TabWidget::closeAllTabs() {
  for (int i = count() - 1; i >= 0; i--) {
    closeTab(i);
  }
}

int TabWidget::addNewspaperView(RootItem *root, const QList<Message> &messages) {
#if defined(USE_WEBENGINE)
  WebBrowser *prev = new WebBrowser(this);
#else
  NewspaperPreviewer *prev = new NewspaperPreviewer(root, messages, this);
#endif

  int index = addTab(prev, qApp->icons()->fromTheme(QSL("format-justify-fill")), tr("Newspaper view"), TabBar::Closable);

  setCurrentIndex(index);

#if defined(USE_WEBENGINE)
  prev->loadMessages(messages, root);
#endif

  return index;
}

int TabWidget::addEmptyBrowser() {
  return addBrowser(false, true);
}

int TabWidget::addLinkedBrowser(const QUrl &initial_url) {
  return addBrowser(false, false, initial_url);
}

int TabWidget::addLinkedBrowser(const QString &initial_url) {
  return addLinkedBrowser(QUrl(initial_url));
}

int TabWidget::addBrowser(bool move_after_current, bool make_active, const QUrl &initial_url) {
#if defined(USE_WEBENGINE)

  // Create new WebBrowser.
  WebBrowser *browser = new WebBrowser(this);
  int final_index;

#if defined (Q_OS_MACOS)
  const QString browser_tab_name = tr("  Web browser");
#else
  const QString browser_tab_name = tr("Web browser");
#endif

  if (move_after_current) {
    // Insert web browser after current tab.
    final_index = insertTab(currentIndex() + 1, browser, qApp->icons()->fromTheme(QSL("text-html")),
                            browser_tab_name, TabBar::Closable);
  }
  else {
    // Add new browser as the last tab.
    final_index = addTab(browser, qApp->icons()->fromTheme(QSL("text-html")),
                         //: Web browser default tab title.
                         browser_tab_name,
                         TabBar::Closable);
  }

  // Make connections.
  connect(browser, &WebBrowser::titleChanged, this, &TabWidget::changeTitle);
  connect(browser, &WebBrowser::iconChanged, this, &TabWidget::changeIcon);

  // Setup the tab index.
  browser->setIndex(final_index);

  // Load initial web page if desired.
  if (initial_url.isValid()) {
    browser->loadUrl(initial_url);
  }

  // Make new web browser active if desired.
  if (make_active) {
    setCurrentIndex(final_index);
    browser->setFocus(Qt::OtherFocusReason);
  }

  return final_index;
#else
  Q_UNUSED(move_after_current)
  Q_UNUSED(make_active)

  WebFactory::instance()->openUrlInExternalBrowser(initial_url.toString());

  return -1;
#endif
}

void TabWidget::indentTabText(int index){
#if defined (Q_OS_MACOS)
  if (tabBar()->tabType(index) != TabBar::FeedReader && !tabIcon(index).isNull()) {
    // We have closable tab with some icon, fix the title.
    const QString text = tabText(index);

    if (!text.startsWith(QSL("  "))) {
      setTabText(index, QSL("  ") + text);
    }
  }
#else
  Q_UNUSED(index)
#endif
}

void TabWidget::removeTab(int index, bool clear_from_memory) {
  if (clear_from_memory) {
    widget(index)->deleteLater();
  }

  QTabWidget::removeTab(index);
}

int TabWidget::addTab(TabContent *widget, const QIcon &icon, const QString &label, const TabBar::TabType &type) {
  const int index = QTabWidget::addTab(widget, icon, label);
  tabBar()->setTabType(index, type);
  indentTabText(index);

  return index;
}

int TabWidget::addTab(TabContent *widget, const QString &label, const TabBar::TabType &type) {
  const int index = QTabWidget::addTab(widget, label);
  tabBar()->setTabType(index, type);
  indentTabText(index);

  return index;
}

int TabWidget::insertTab(int index, QWidget *widget, const QIcon &icon, const QString &label, const TabBar::TabType &type) {
  const int tab_index = QTabWidget::insertTab(index, widget, icon, label);
  tabBar()->setTabType(tab_index, type);
  indentTabText(index);

  return tab_index;
}

int TabWidget::insertTab(int index, QWidget *widget, const QString &label, const TabBar::TabType &type) {
  const int tab_index = QTabWidget::insertTab(index, widget, label);
  tabBar()->setTabType(tab_index, type);
  indentTabText(index);

  return tab_index;
}

void TabWidget::changeIcon(int index, const QIcon &new_icon) {
  setTabIcon(index, new_icon);
  indentTabText(index);
}

void TabWidget::changeTitle(int index, const QString &new_title) {
  setTabText(index, TextFactory::shorten(new_title));
  setTabToolTip(index, new_title);
  indentTabText(index);
}

void TabWidget::fixContentsAfterMove(int from, int to) {
  from = qMin(from, to);
  to = qMax(from, to);

  for ( ; from <= to; from++) {
    TabContent *content = static_cast<TabContent*>(widget(from));
    content->setIndex(from);
  }
}