/****************************************************************************
**
** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of Qt Creator.
**
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Digia gives you certain additional
** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
****************************************************************************/

#include "projectwindow.h"

#include "doubletabwidget.h"

#include "kitmanager.h"
#include "project.h"
#include "projectexplorer.h"
#include "session.h"
#include "iprojectproperties.h"
#include "targetsettingspanel.h"
#include "target.h"

#include <coreplugin/idocument.h>
#include <extensionsystem/pluginmanager.h>
#include <utils/algorithm.h>
#include <utils/qtcassert.h>
#include <utils/stylehelper.h>

#include <QGridLayout>
#include <QLabel>
#include <QPainter>
#include <QStackedWidget>

using namespace ProjectExplorer;
using namespace ProjectExplorer::Internal;

namespace {
const int ICON_SIZE(64);

const int ABOVE_HEADING_MARGIN(10);
const int ABOVE_CONTENTS_MARGIN(4);
const int BELOW_CONTENTS_MARGIN(16);

} // anonymous namespace

///
// OnePixelBlackLine
///

class OnePixelBlackLine : public QWidget
{
public:
    OnePixelBlackLine(QWidget *parent)
        : QWidget(parent)
    {
        setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
        setMinimumHeight(1);
        setMaximumHeight(1);
    }
    void paintEvent(QPaintEvent *e)
    {
        Q_UNUSED(e);
        QPainter p(this);
        QColor fillColor = Utils::StyleHelper::mergedColors(
                    palette().button().color(), Qt::black, 80);
        p.fillRect(contentsRect(), fillColor);
    }
};

class RootWidget : public QWidget
{
public:
    RootWidget(QWidget *parent) : QWidget(parent) {
        setFocusPolicy(Qt::NoFocus);
    }
    void paintEvent(QPaintEvent *);
};

void RootWidget::paintEvent(QPaintEvent *e)
{
    QWidget::paintEvent(e);

    QPainter painter(this);
    QColor light = Utils::StyleHelper::mergedColors(
                palette().button().color(), Qt::white, 30);
    QColor dark = Utils::StyleHelper::mergedColors(
                palette().button().color(), Qt::black, 85);

    painter.setPen(light);
    painter.drawLine(rect().topRight(), rect().bottomRight());
    painter.setPen(dark);
    painter.drawLine(rect().topRight() - QPoint(1,0), rect().bottomRight() - QPoint(1,0));
}

///
// PanelsWidget
///

PanelsWidget::PanelsWidget(QWidget *parent) :
    QScrollArea(parent),
    m_root(new RootWidget(this))
{
    // We want a 900px wide widget with and the scrollbar at the
    // side of the screen.
    m_root->setMaximumWidth(900);
    m_root->setContentsMargins(0, 0, 40, 0);

    QPalette pal;
    QColor background = Utils::StyleHelper::mergedColors(
                palette().window().color(), Qt::white, 85);
    pal.setColor(QPalette::All, QPalette::Window, background.darker(102));
    setPalette(pal);
    pal.setColor(QPalette::All, QPalette::Window, background);
    m_root->setPalette(pal);

    // The layout holding the individual panels:
    QVBoxLayout *topLayout = new QVBoxLayout(m_root);
    topLayout->setMargin(0);
    topLayout->setSpacing(0);

    m_layout = new QGridLayout;
    m_layout->setColumnMinimumWidth(0, ICON_SIZE + 4);
    m_layout->setSpacing(0);
    topLayout->addLayout(m_layout);
    topLayout->addStretch(100);

    setWidget(m_root);
    setFrameStyle(QFrame::NoFrame);
    setWidgetResizable(true);
    setFocusPolicy(Qt::NoFocus);
}

PanelsWidget::~PanelsWidget()
{
    qDeleteAll(m_panels);
}

/*
 * Add a widget with heading information into the grid
 * layout of the PanelsWidget.
 *
 *     ...
 * +--------+-------------------------------------------+ ABOVE_HEADING_MARGIN
 * | icon   | name                                      |
 * +        +-------------------------------------------+
 * |        | line                                      |
 * +        +-------------------------------------------+ ABOVE_CONTENTS_MARGIN
 * |        | widget (with contentsmargins adjusted!)   |
 * +--------+-------------------------------------------+ BELOW_CONTENTS_MARGIN
 */
void PanelsWidget::addPropertiesPanel(PropertiesPanel *panel)
{
    QTC_ASSERT(panel, return);

    const int headerRow = m_layout->rowCount();

    // icon:
    if (!panel->icon().isNull()) {
        QLabel *iconLabel = new QLabel(m_root);
        iconLabel->setPixmap(panel->icon().pixmap(ICON_SIZE, ICON_SIZE));
        iconLabel->setContentsMargins(0, ABOVE_HEADING_MARGIN, 0, 0);
        m_layout->addWidget(iconLabel, headerRow, 0, 3, 1, Qt::AlignTop | Qt::AlignHCenter);
    }

    // name:
    QLabel *nameLabel = new QLabel(m_root);
    nameLabel->setText(panel->displayName());
    QPalette palette = nameLabel->palette();
    for (int i = QPalette::Active; i < QPalette::NColorGroups; ++i ) {
        QColor foregroundColor = palette.color(QPalette::ColorGroup(i), QPalette::Foreground);
        foregroundColor.setAlpha(110);
        palette.setBrush(QPalette::ColorGroup(i), QPalette::Foreground, foregroundColor);
    }
    nameLabel->setPalette(palette);
    nameLabel->setContentsMargins(0, ABOVE_HEADING_MARGIN, 0, 0);
    QFont f = nameLabel->font();
    f.setBold(true);
    f.setPointSizeF(f.pointSizeF() * 1.6);
    nameLabel->setFont(f);
    m_layout->addWidget(nameLabel, headerRow, 1, 1, 1, Qt::AlignVCenter | Qt::AlignLeft);

    // line:
    const int lineRow(headerRow + 1);
    QWidget *line = new OnePixelBlackLine(m_root);
    m_layout->addWidget(line, lineRow, 1, 1, -1, Qt::AlignTop);

    // add the widget:
    const int widgetRow(lineRow + 1);
    addPanelWidget(panel, widgetRow);
}

void PanelsWidget::addPanelWidget(PropertiesPanel *panel, int row)
{
    QWidget *widget = panel->widget();
    widget->setContentsMargins(Constants::PANEL_LEFT_MARGIN,
                               ABOVE_CONTENTS_MARGIN, 0,
                               BELOW_CONTENTS_MARGIN);
    widget->setParent(m_root);
    m_layout->addWidget(widget, row, 0, 1, 2);

    m_panels.append(panel);
}

///
// ProjectWindow
///

ProjectWindow::ProjectWindow(QWidget *parent)
    : QWidget(parent),
      m_currentWidget(0),
      m_previousTargetSubIndex(-1)
{
    // Setup overall layout:
    QVBoxLayout *viewLayout = new QVBoxLayout(this);
    viewLayout->setMargin(0);
    viewLayout->setSpacing(0);

    m_tabWidget = new DoubleTabWidget(this);
    viewLayout->addWidget(m_tabWidget);

    // Setup our container for the contents:
    m_centralWidget = new QStackedWidget(this);
    viewLayout->addWidget(m_centralWidget);

    // Connections
    connect(m_tabWidget, SIGNAL(currentIndexChanged(int,int)),
            this, SLOT(showProperties(int,int)));

    QObject *sessionManager = SessionManager::instance();
    connect(sessionManager, SIGNAL(projectAdded(ProjectExplorer::Project*)),
            this, SLOT(registerProject(ProjectExplorer::Project*)));
    connect(sessionManager, SIGNAL(aboutToRemoveProject(ProjectExplorer::Project*)),
            this, SLOT(deregisterProject(ProjectExplorer::Project*)));

    connect(sessionManager, SIGNAL(startupProjectChanged(ProjectExplorer::Project*)),
            this, SLOT(startupProjectChanged(ProjectExplorer::Project*)));

    connect(sessionManager, SIGNAL(projectDisplayNameChanged(ProjectExplorer::Project*)),
            this, SLOT(projectUpdated(ProjectExplorer::Project*)));

    // Update properties to empty project for now:
    showProperties(-1, -1);
}

ProjectWindow::~ProjectWindow()
{
}

void ProjectWindow::extensionsInitialized()
{
    connect(KitManager::instance(), SIGNAL(kitsChanged()), this, SLOT(handleKitChanges()));
}

void ProjectWindow::aboutToShutdown()
{
    showProperties(-1, -1); // that's a bit stupid, but otherwise stuff is still
                            // connected to the session
    disconnect(KitManager::instance(), 0, this, 0);
    disconnect(SessionManager::instance(), 0, this, 0);
}

void ProjectWindow::removedTarget(Target *)
{
    Project *p = qobject_cast<Project *>(sender());
    QTC_ASSERT(p, return);
    if (p->targets().isEmpty())
        projectUpdated(p);
}

void ProjectWindow::projectUpdated(Project *p)
{
    // Called after a project was configured
    int index = m_tabWidget->currentIndex();
    if (deregisterProject(p)) // might return false if the project is unloading
        registerProject(p);
    m_tabWidget->setCurrentIndex(index);
}

void ProjectWindow::handleKitChanges()
{
    bool changed = false;
    int index = m_tabWidget->currentIndex();
    QList<Project *> projects = m_tabIndexToProject;
    foreach (ProjectExplorer::Project *project, projects) {
        if (m_hasTarget.value(project) != hasTarget(project)) {
            changed = true;
            if (deregisterProject(project))
                registerProject(project);
        }
    }
    if (changed)
        m_tabWidget->setCurrentIndex(index);
}

bool ProjectWindow::hasTarget(ProjectExplorer::Project *project)
{
    return !project->targets().isEmpty();
}

void ProjectWindow::registerProject(ProjectExplorer::Project *project)
{
    if (!project || m_tabIndexToProject.contains(project))
        return;

    // find index to insert:
    int index = -1;
    for (int i = 0; i <= m_tabIndexToProject.count(); ++i) {
        if (i == m_tabIndexToProject.count() ||
            m_tabIndexToProject.at(i)->displayName() > project->displayName()) {
            index = i;
            break;
        }
    }

    QStringList subtabs;

    bool projectHasTarget = hasTarget(project);
    m_hasTarget.insert(project, projectHasTarget);

    if (projectHasTarget) // Use the Targets page
        subtabs << QCoreApplication::translate("TargetSettingsPanelFactory", "Build & Run");

    // Add the project specific pages
    QList<IProjectPanelFactory *> factories = ExtensionSystem::PluginManager::getObjects<IProjectPanelFactory>();
    Utils::sort(factories, &IPanelFactory::prioritySort);
    foreach (IProjectPanelFactory *panelFactory, factories) {
        if (panelFactory->supports(project))
            subtabs << panelFactory->displayName();
    }

    m_tabIndexToProject.insert(index, project);
    m_tabWidget->insertTab(index, project->displayName(), project->projectFilePath().toString(), subtabs);

    connect(project, SIGNAL(removedTarget(ProjectExplorer::Target*)),
            this, SLOT(removedTarget(ProjectExplorer::Target*)));
}

bool ProjectWindow::deregisterProject(ProjectExplorer::Project *project)
{
    int index = m_tabIndexToProject.indexOf(project);
    if (index < 0)
        return false;

    m_tabIndexToProject.removeAt(index);
    m_tabWidget->removeTab(index);
    disconnect(project, SIGNAL(removedTarget(ProjectExplorer::Target*)),
            this, SLOT(removedTarget(ProjectExplorer::Target*)));
    return true;
}

void ProjectWindow::startupProjectChanged(ProjectExplorer::Project *p)
{
    int index = m_tabIndexToProject.indexOf(p);
    if (index != -1)
        m_tabWidget->setCurrentIndex(index);
}

void ProjectWindow::showProperties(int index, int subIndex)
{
    if (index < 0 || index >= m_tabIndexToProject.count()) {
        removeCurrentWidget();
        return;
    }

    Project *project = m_tabIndexToProject.at(index);

    // Set up custom panels again:
    int pos = 0;
    IPanelFactory *fac = 0;
    // remember previous sub index state of target settings page
    if (TargetSettingsPanelWidget *previousPanelWidget
            = qobject_cast<TargetSettingsPanelWidget*>(m_currentWidget)) {
        m_previousTargetSubIndex = previousPanelWidget->currentSubIndex();
    }

    if (m_hasTarget.value(project) || !project->supportsNoTargetPanel()) {
        if (subIndex == 0) {
            // Targets page
            removeCurrentWidget();
            TargetSettingsPanelWidget *panelWidget = new TargetSettingsPanelWidget(project);
            if (m_previousTargetSubIndex >= 0)
                panelWidget->setCurrentSubIndex(m_previousTargetSubIndex);
            m_currentWidget = panelWidget;
            m_centralWidget->addWidget(m_currentWidget);
            m_centralWidget->setCurrentWidget(m_currentWidget);
        }
        ++pos;
    }

    QList<IProjectPanelFactory *> factories = ExtensionSystem::PluginManager::getObjects<IProjectPanelFactory>();
    Utils::sort(factories, &IPanelFactory::prioritySort);
    foreach (IProjectPanelFactory *panelFactory, factories) {
        if (panelFactory->supports(project)) {
            if (subIndex == pos) {
                fac = panelFactory;
                break;
            }
            ++pos;
        }
    }

    if (fac) {
        removeCurrentWidget();

        PropertiesPanel *panel = 0;
        if (ITargetPanelFactory *ipf = qobject_cast<ITargetPanelFactory *>(fac))
            panel = ipf->createPanel(project->activeTarget());
        else if (IProjectPanelFactory *ipf = qobject_cast<IProjectPanelFactory *>(fac))
            panel = ipf->createPanel(project);
        Q_ASSERT(panel);

        PanelsWidget *panelsWidget = new PanelsWidget(m_centralWidget);
        panelsWidget->addPropertiesPanel(panel);
        m_currentWidget = panelsWidget;
        m_centralWidget->addWidget(m_currentWidget);
        m_centralWidget->setCurrentWidget(m_currentWidget);

    }

    SessionManager::setStartupProject(project);
}

void ProjectWindow::removeCurrentWidget()
{
    if (m_currentWidget) {
        m_centralWidget->removeWidget(m_currentWidget);
        if (m_currentWidget) {
            delete m_currentWidget;
            m_currentWidget = 0;
        }
    }
}