/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** 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 The Qt Company. For licensing terms
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** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 as published by the Free Software
** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
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****************************************************************************/

#include "session.h"

#include "buildconfiguration.h"
#include "deployconfiguration.h"
#include "editorconfiguration.h"
#include "foldernavigationwidget.h"
#include "kit.h"
#include "project.h"
#include "projectexplorer.h"
#include "projectnodes.h"
#include "target.h"

#include <coreplugin/coreconstants.h>
#include <coreplugin/editormanager/editormanager.h>
#include <coreplugin/icore.h>
#include <coreplugin/idocument.h>
#include <coreplugin/imode.h>
#include <coreplugin/modemanager.h>
#include <coreplugin/progressmanager/progressmanager.h>

#include <texteditor/texteditor.h>

#include <utils/algorithm.h>
#include <utils/stylehelper.h>

#include <QDebug>
#include <QDir>
#include <QFileInfo>

#include <QMessageBox>
#include <QPushButton>

#ifdef WITH_TESTS
#include <QTemporaryFile>
#include <QTest>
#include <vector>
#endif

using namespace Core;
using namespace Utils;
using namespace ProjectExplorer::Internal;

namespace ProjectExplorer {

/*!
     \class ProjectExplorer::SessionManager

     \brief The SessionManager class manages sessions.

     TODO the interface of this class is not really great.
     The implementation suffers from that all the functions from the
     public interface just wrap around functions which do the actual work.
     This could be improved.
*/

class SessionManagerPrivate
{
public:
    void restoreValues(const PersistentSettingsReader &reader);
    void restoreDependencies(const PersistentSettingsReader &reader);
    void restoreStartupProject(const PersistentSettingsReader &reader);
    void restoreEditors(const PersistentSettingsReader &reader);
    void restoreProjects(const QStringList &fileList);
    void askUserAboutFailedProjects();
    void sessionLoadingProgress();

    bool recursiveDependencyCheck(const QString &newDep, const QString &checkDep) const;
    QStringList dependencies(const QString &proName) const;
    QStringList dependenciesOrder() const;
    void dependencies(const QString &proName, QStringList &result) const;

    static QString windowTitleAddition(const QString &filePath);
    static QString sessionTitle(const QString &filePath);

    bool hasProjects() const { return !m_projects.isEmpty(); }

    QString m_sessionName = QLatin1String("default");
    bool m_virginSession = true;
    bool m_loadingSession = false;
    bool m_casadeSetActive = false;

    mutable QStringList m_sessions;
    mutable QHash<QString, QDateTime> m_sessionDateTimes;

    Project *m_startupProject = nullptr;
    QList<Project *> m_projects;
    QStringList m_failedProjects;
    QMap<QString, QStringList> m_depMap;
    QMap<QString, QVariant> m_values;
    QFutureInterface<void> m_future;
    PersistentSettingsWriter *m_writer = nullptr;

private:
    static QString locationInProject(const QString &filePath);
};

static SessionManager *m_instance = nullptr;
static SessionManagerPrivate *d = nullptr;

static QString projectFolderId(Project *pro)
{
    return pro->projectFilePath().toString();
}

const int PROJECT_SORT_VALUE = 100;

SessionManager::SessionManager(QObject *parent) : QObject(parent)
{
    m_instance = this;
    d = new SessionManagerPrivate;

    connect(ModeManager::instance(), &ModeManager::currentModeChanged,
            this, &SessionManager::saveActiveMode);

    connect(EditorManager::instance(), &EditorManager::editorCreated,
            this, &SessionManager::configureEditor);
    connect(this, &SessionManager::projectAdded,
            EditorManager::instance(), &EditorManager::updateWindowTitles);
    connect(this, &SessionManager::projectRemoved,
            EditorManager::instance(), &EditorManager::updateWindowTitles);
    connect(this, &SessionManager::projectDisplayNameChanged,
            EditorManager::instance(), &EditorManager::updateWindowTitles);
    connect(EditorManager::instance(), &EditorManager::editorOpened,
            this, &SessionManager::markSessionFileDirty);
    connect(EditorManager::instance(), &EditorManager::editorsClosed,
            this, &SessionManager::markSessionFileDirty);

    EditorManager::setWindowTitleAdditionHandler(&SessionManagerPrivate::windowTitleAddition);
    EditorManager::setSessionTitleHandler(&SessionManagerPrivate::sessionTitle);
}

SessionManager::~SessionManager()
{
    EditorManager::setWindowTitleAdditionHandler({});
    EditorManager::setSessionTitleHandler({});
    emit m_instance->aboutToUnloadSession(d->m_sessionName);
    delete d->m_writer;
    delete d;
    d = nullptr;
}

SessionManager *SessionManager::instance()
{
   return m_instance;
}

bool SessionManager::isDefaultVirgin()
{
    return isDefaultSession(d->m_sessionName) && d->m_virginSession;
}

bool SessionManager::isDefaultSession(const QString &session)
{
    return session == QLatin1String("default");
}

void SessionManager::saveActiveMode(Id mode)
{
    if (mode != Core::Constants::MODE_WELCOME)
        setValue(QLatin1String("ActiveMode"), mode.toString());
}

bool SessionManagerPrivate::recursiveDependencyCheck(const QString &newDep, const QString &checkDep) const
{
    if (newDep == checkDep)
        return false;

    foreach (const QString &dependency, m_depMap.value(checkDep)) {
        if (!recursiveDependencyCheck(newDep, dependency))
            return false;
    }

    return true;
}

/*
 * The dependency management exposes an interface based on projects, but
 * is internally purely string based. This is suboptimal. Probably it would be
 * nicer to map the filenames to projects on load and only map it back to
 * filenames when saving.
 */

QList<Project *> SessionManager::dependencies(const Project *project)
{
    const QString proName = project->projectFilePath().toString();
    const QStringList proDeps = d->m_depMap.value(proName);

    QList<Project *> projects;
    foreach (const QString &dep, proDeps) {
        const Utils::FilePath fn = Utils::FilePath::fromString(dep);
        Project *pro = Utils::findOrDefault(d->m_projects, [&fn](Project *p) { return p->projectFilePath() == fn; });
        if (pro)
            projects += pro;
    }

    return projects;
}

bool SessionManager::hasDependency(const Project *project, const Project *depProject)
{
    const QString proName = project->projectFilePath().toString();
    const QString depName = depProject->projectFilePath().toString();

    const QStringList proDeps = d->m_depMap.value(proName);
    return proDeps.contains(depName);
}

bool SessionManager::canAddDependency(const Project *project, const Project *depProject)
{
    const QString newDep = project->projectFilePath().toString();
    const QString checkDep = depProject->projectFilePath().toString();

    return d->recursiveDependencyCheck(newDep, checkDep);
}

bool SessionManager::addDependency(Project *project, Project *depProject)
{
    const QString proName = project->projectFilePath().toString();
    const QString depName = depProject->projectFilePath().toString();

    // check if this dependency is valid
    if (!d->recursiveDependencyCheck(proName, depName))
        return false;

    QStringList proDeps = d->m_depMap.value(proName);
    if (!proDeps.contains(depName)) {
        proDeps.append(depName);
        d->m_depMap[proName] = proDeps;
    }
    emit m_instance->dependencyChanged(project, depProject);

    return true;
}

void SessionManager::removeDependency(Project *project, Project *depProject)
{
    const QString proName = project->projectFilePath().toString();
    const QString depName = depProject->projectFilePath().toString();

    QStringList proDeps = d->m_depMap.value(proName);
    proDeps.removeAll(depName);
    if (proDeps.isEmpty())
        d->m_depMap.remove(proName);
    else
        d->m_depMap[proName] = proDeps;
    emit m_instance->dependencyChanged(project, depProject);
}

bool SessionManager::isProjectConfigurationCascading()
{
    return d->m_casadeSetActive;
}

void SessionManager::setProjectConfigurationCascading(bool b)
{
    d->m_casadeSetActive = b;
    markSessionFileDirty();
}

void SessionManager::setActiveTarget(Project *project, Target *target, SetActive cascade)
{
    QTC_ASSERT(project, return);

    if (project->isShuttingDown())
        return;

    project->setActiveTarget(target);

    if (!target) // never cascade setting no target
        return;

    if (cascade != SetActive::Cascade || !d->m_casadeSetActive)
        return;

    Utils::Id kitId = target->kit()->id();
    for (Project *otherProject : SessionManager::projects()) {
        if (otherProject == project)
            continue;
        if (Target *otherTarget = Utils::findOrDefault(otherProject->targets(),
                                                       [kitId](Target *t) { return t->kit()->id() == kitId; }))
            otherProject->setActiveTarget(otherTarget);
    }
}

void SessionManager::setActiveBuildConfiguration(Target *target, BuildConfiguration *bc, SetActive cascade)
{
    QTC_ASSERT(target, return);
    QTC_ASSERT(target->project(), return);

    if (target->project()->isShuttingDown() || target->isShuttingDown())
        return;

    target->setActiveBuildConfiguration(bc);

    if (!bc)
        return;
    if (cascade != SetActive::Cascade || !d->m_casadeSetActive)
        return;

    Utils::Id kitId = target->kit()->id();
    QString name = bc->displayName(); // We match on displayname
    for (Project *otherProject : SessionManager::projects()) {
        if (otherProject == target->project())
            continue;
        Target *otherTarget = otherProject->activeTarget();
        if (!otherTarget || otherTarget->kit()->id() != kitId)
            continue;

        for (BuildConfiguration *otherBc : otherTarget->buildConfigurations()) {
            if (otherBc->displayName() == name) {
                otherTarget->setActiveBuildConfiguration(otherBc);
                break;
            }
        }
    }
}

void SessionManager::setActiveDeployConfiguration(Target *target, DeployConfiguration *dc, SetActive cascade)
{
    QTC_ASSERT(target, return);
    QTC_ASSERT(target->project(), return);

    if (target->project()->isShuttingDown() || target->isShuttingDown())
        return;

    target->setActiveDeployConfiguration(dc);

    if (!dc)
        return;
    if (cascade != SetActive::Cascade || !d->m_casadeSetActive)
        return;

    Utils::Id kitId = target->kit()->id();
    QString name = dc->displayName(); // We match on displayname
    for (Project *otherProject : SessionManager::projects()) {
        if (otherProject == target->project())
            continue;
        Target *otherTarget = otherProject->activeTarget();
        if (!otherTarget || otherTarget->kit()->id() != kitId)
            continue;

        for (DeployConfiguration *otherDc : otherTarget->deployConfigurations()) {
            if (otherDc->displayName() == name) {
                otherTarget->setActiveDeployConfiguration(otherDc);
                break;
            }
        }
    }
}

void SessionManager::setStartupProject(Project *startupProject)
{
    QTC_ASSERT((!startupProject && d->m_projects.isEmpty())
               || (startupProject && d->m_projects.contains(startupProject)), return);

    if (d->m_startupProject == startupProject)
        return;

    d->m_startupProject = startupProject;
    if (d->m_startupProject && d->m_startupProject->needsConfiguration()) {
        ModeManager::activateMode(Constants::MODE_SESSION);
        ModeManager::setFocusToCurrentMode();
    }
    emit m_instance->startupProjectChanged(startupProject);
}

Project *SessionManager::startupProject()
{
    return d->m_startupProject;
}

Target *SessionManager::startupTarget()
{
    return d->m_startupProject ? d->m_startupProject->activeTarget() : nullptr;
}

BuildSystem *SessionManager::startupBuildSystem()
{
    Target *t = startupTarget();
    return t ? t->buildSystem() : nullptr;
}

/*!
 * Returns the RunConfiguration of the currently active target
 * of the startup project, if such exists, or \c nullptr otherwise.
 */


RunConfiguration *SessionManager::startupRunConfiguration()
{
    Target *t = startupTarget();
    return t ? t->activeRunConfiguration() : nullptr;
}

void SessionManager::addProject(Project *pro)
{
    QTC_ASSERT(pro, return);
    QTC_CHECK(!pro->displayName().isEmpty());
    QTC_CHECK(pro->id().isValid());

    d->m_virginSession = false;
    QTC_ASSERT(!d->m_projects.contains(pro), return);

    d->m_projects.append(pro);

    connect(pro, &Project::displayNameChanged,
            m_instance, [pro]() { emit m_instance->projectDisplayNameChanged(pro); });

    emit m_instance->projectAdded(pro);
    const auto updateFolderNavigation = [pro] {
        // destructing projects might trigger changes, so check if the project is actually there
        if (QTC_GUARD(d->m_projects.contains(pro))) {
            const QIcon icon = pro->rootProjectNode() ? pro->rootProjectNode()->icon() : QIcon();
            FolderNavigationWidgetFactory::insertRootDirectory({projectFolderId(pro),
                                                                PROJECT_SORT_VALUE,
                                                                pro->displayName(),
                                                                pro->projectFilePath().parentDir(),
                                                                icon});
        }
    };
    updateFolderNavigation();
    configureEditors(pro);
    connect(pro, &Project::fileListChanged, m_instance, [pro, updateFolderNavigation]() {
        configureEditors(pro);
        updateFolderNavigation(); // update icon
    });
    connect(pro, &Project::displayNameChanged, m_instance, updateFolderNavigation);

    if (!startupProject())
        setStartupProject(pro);
}

void SessionManager::removeProject(Project *project)
{
    d->m_virginSession = false;
    QTC_ASSERT(project, return);
    removeProjects({project});
}

bool SessionManager::loadingSession()
{
    return d->m_loadingSession;
}

bool SessionManager::save()
{
    emit m_instance->aboutToSaveSession();

    const FilePath filePath = sessionNameToFileName(d->m_sessionName);
    QVariantMap data;

    // See the explanation at loadSession() for how we handle the implicit default session.
    if (isDefaultVirgin()) {
        if (filePath.exists()) {
            PersistentSettingsReader reader;
            if (!reader.load(filePath)) {
                QMessageBox::warning(ICore::dialogParent(), tr("Error while saving session"),
                                     tr("Could not save session %1").arg(filePath.toUserOutput()));
                return false;
            }
            data = reader.restoreValues();
        }
    } else {
        // save the startup project
        if (d->m_startupProject) {
            data.insert(QLatin1String("StartupProject"),
                        d->m_startupProject->projectFilePath().toString());
        }

        const QColor c = StyleHelper::requestedBaseColor();
        if (c.isValid()) {
            QString tmp = QString::fromLatin1("#%1%2%3")
                    .arg(c.red(), 2, 16, QLatin1Char('0'))
                    .arg(c.green(), 2, 16, QLatin1Char('0'))
                    .arg(c.blue(), 2, 16, QLatin1Char('0'));
            data.insert(QLatin1String("Color"), tmp);
        }

        QStringList projectFiles = Utils::transform(projects(), [](Project *p) {
                return p->projectFilePath().toString();
        });
        // Restore information on projects that failed to load:
        // don't read projects to the list, which the user loaded
        foreach (const QString &failed, d->m_failedProjects) {
            if (!projectFiles.contains(failed))
                projectFiles << failed;
        }

        data.insert(QLatin1String("ProjectList"), projectFiles);
        data.insert(QLatin1String("CascadeSetActive"), d->m_casadeSetActive);

        QVariantMap depMap;
        auto i = d->m_depMap.constBegin();
        while (i != d->m_depMap.constEnd()) {
            QString key = i.key();
            QStringList values;
            foreach (const QString &value, i.value())
                values << value;
            depMap.insert(key, values);
            ++i;
        }
        data.insert(QLatin1String("ProjectDependencies"), QVariant(depMap));
        data.insert(QLatin1String("EditorSettings"), EditorManager::saveState().toBase64());
    }

    const auto end = d->m_values.constEnd();
    QStringList keys;
    for (auto it = d->m_values.constBegin(); it != end; ++it) {
        data.insert(QLatin1String("value-") + it.key(), it.value());
        keys << it.key();
    }
    data.insert(QLatin1String("valueKeys"), keys);

    if (!d->m_writer || d->m_writer->fileName() != filePath) {
        delete d->m_writer;
        d->m_writer = new PersistentSettingsWriter(filePath, "QtCreatorSession");
    }
    const bool result = d->m_writer->save(data, ICore::dialogParent());
    if (result) {
        if (!isDefaultVirgin())
            d->m_sessionDateTimes.insert(activeSession(), QDateTime::currentDateTime());
    } else {
        QMessageBox::warning(ICore::dialogParent(), tr("Error while saving session"),
            tr("Could not save session to file %1").arg(d->m_writer->fileName().toUserOutput()));
    }

    return result;
}

/*!
  Closes all projects
  */
void SessionManager::closeAllProjects()
{
    removeProjects(projects());
}

const QList<Project *> SessionManager::projects()
{
    return d->m_projects;
}

bool SessionManager::hasProjects()
{
    return d->hasProjects();
}

bool SessionManager::hasProject(Project *p)
{
    return d->m_projects.contains(p);
}

QStringList SessionManagerPrivate::dependencies(const QString &proName) const
{
    QStringList result;
    dependencies(proName, result);
    return result;
}

void SessionManagerPrivate::dependencies(const QString &proName, QStringList &result) const
{
    QStringList depends = m_depMap.value(proName);

    foreach (const QString &dep, depends)
        dependencies(dep, result);

    if (!result.contains(proName))
        result.append(proName);
}

QString SessionManagerPrivate::sessionTitle(const QString &filePath)
{
    if (SessionManager::isDefaultSession(d->m_sessionName)) {
        if (filePath.isEmpty()) {
            // use single project's name if there is only one loaded.
            const QList<Project *> projects = SessionManager::projects();
            if (projects.size() == 1)
                return projects.first()->displayName();
        }
    } else {
        QString sessionName = d->m_sessionName;
        if (sessionName.isEmpty())
            sessionName = SessionManager::tr("Untitled");
        return sessionName;
    }
    return QString();
}

QString SessionManagerPrivate::locationInProject(const QString &filePath) {
    const Project *project = SessionManager::projectForFile(Utils::FilePath::fromString(filePath));
    if (!project)
        return QString();

    const Utils::FilePath file = Utils::FilePath::fromString(filePath);
    const Utils::FilePath parentDir = file.parentDir();
    if (parentDir == project->projectDirectory())
        return "@ " + project->displayName();

    if (file.isChildOf(project->projectDirectory())) {
        const Utils::FilePath dirInProject = parentDir.relativeChildPath(project->projectDirectory());
        return "(" + dirInProject.toUserOutput() + " @ " + project->displayName() + ")";
    }

    // For a file that is "outside" the project it belongs to, we display its
    // dir's full path because it is easier to read than a series of  "../../.".
    // Example: /home/hugo/GenericProject/App.files lists /home/hugo/lib/Bar.cpp
   return "(" + parentDir.toUserOutput() + " @ " + project->displayName() + ")";
}

QString SessionManagerPrivate::windowTitleAddition(const QString &filePath)
{
    return locationInProject(filePath);
}

QStringList SessionManagerPrivate::dependenciesOrder() const
{
    QList<QPair<QString, QStringList> > unordered;
    QStringList ordered;

    // copy the map to a temporary list
    for (const Project *pro : m_projects) {
        const QString proName = pro->projectFilePath().toString();
        const QStringList depList = filtered(m_depMap.value(proName),
                                             [this](const QString &proPath) {
            return contains(m_projects, [proPath](const Project *p) {
                return p->projectFilePath().toString() == proPath;
            });
        });
        unordered << qMakePair(proName, depList);
    }

    while (!unordered.isEmpty()) {
        for (int i = (unordered.count() - 1); i >= 0; --i) {
            if (unordered.at(i).second.isEmpty()) {
                ordered << unordered.at(i).first;
                unordered.removeAt(i);
            }
        }

        // remove the handled projects from the dependency lists
        // of the remaining unordered projects
        for (int i = 0; i < unordered.count(); ++i) {
            foreach (const QString &pro, ordered) {
                QStringList depList = unordered.at(i).second;
                depList.removeAll(pro);
                unordered[i].second = depList;
            }
        }
    }

    return ordered;
}

QList<Project *> SessionManager::projectOrder(const Project *project)
{
    QList<Project *> result;

    QStringList pros;
    if (project)
        pros = d->dependencies(project->projectFilePath().toString());
    else
        pros = d->dependenciesOrder();

    foreach (const QString &proFile, pros) {
        for (Project *pro : projects()) {
            if (pro->projectFilePath().toString() == proFile) {
                result << pro;
                break;
            }
        }
    }

    return result;
}

Project *SessionManager::projectForFile(const Utils::FilePath &fileName)
{
    return Utils::findOrDefault(SessionManager::projects(),
                                [&fileName](const Project *p) { return p->isKnownFile(fileName); });
}

void SessionManager::configureEditor(IEditor *editor, const QString &fileName)
{
    if (auto textEditor = qobject_cast<TextEditor::BaseTextEditor*>(editor)) {
        Project *project = projectForFile(Utils::FilePath::fromString(fileName));
        // Global settings are the default.
        if (project)
            project->editorConfiguration()->configureEditor(textEditor);
    }
}

void SessionManager::configureEditors(Project *project)
{
    foreach (IDocument *document, DocumentModel::openedDocuments()) {
        if (project->isKnownFile(document->filePath())) {
            foreach (IEditor *editor, DocumentModel::editorsForDocument(document)) {
                if (auto textEditor = qobject_cast<TextEditor::BaseTextEditor*>(editor)) {
                        project->editorConfiguration()->configureEditor(textEditor);
                }
            }
        }
    }
}

void SessionManager::removeProjects(const QList<Project *> &remove)
{
    for (Project *pro : remove)
        emit m_instance->aboutToRemoveProject(pro);

    bool changeStartupProject = false;

    // Delete projects
    for (Project *pro : remove) {
        pro->saveSettings();
        pro->markAsShuttingDown();

        // Remove the project node:
        d->m_projects.removeOne(pro);

        if (pro == d->m_startupProject)
            changeStartupProject = true;

        FolderNavigationWidgetFactory::removeRootDirectory(projectFolderId(pro));
        disconnect(pro, nullptr, m_instance, nullptr);
        emit m_instance->projectRemoved(pro);
    }

    if (changeStartupProject)
        setStartupProject(hasProjects() ? projects().first() : nullptr);

     qDeleteAll(remove);
}

/*!
    Lets other plugins store persistent values within the session file.
*/

void SessionManager::setValue(const QString &name, const QVariant &value)
{
    if (d->m_values.value(name) == value)
        return;
    d->m_values.insert(name, value);
}

QVariant SessionManager::value(const QString &name)
{
    auto it = d->m_values.constFind(name);
    return (it == d->m_values.constEnd()) ? QVariant() : *it;
}

QString SessionManager::activeSession()
{
    return d->m_sessionName;
}

QStringList SessionManager::sessions()
{
    if (d->m_sessions.isEmpty()) {
        // We are not initialized yet, so do that now
        QDir sessionDir(ICore::userResourcePath().toDir());
        QFileInfoList sessionFiles = sessionDir.entryInfoList(QStringList() << QLatin1String("*.qws"), QDir::NoFilter, QDir::Time);
        foreach (const QFileInfo &fileInfo, sessionFiles) {
            const QString &name = fileInfo.completeBaseName();
            d->m_sessionDateTimes.insert(name, fileInfo.lastModified());
            if (name != QLatin1String("default"))
                d->m_sessions << name;
        }
        d->m_sessions.prepend(QLatin1String("default"));
    }
    return d->m_sessions;
}

QDateTime SessionManager::sessionDateTime(const QString &session)
{
    return d->m_sessionDateTimes.value(session);
}

FilePath SessionManager::sessionNameToFileName(const QString &session)
{
    return ICore::userResourcePath(session + ".qws");
}

/*!
    Creates \a session, but does not actually create the file.
*/

bool SessionManager::createSession(const QString &session)
{
    if (sessions().contains(session))
        return false;
    Q_ASSERT(d->m_sessions.size() > 0);
    d->m_sessions.insert(1, session);
    return true;
}

bool SessionManager::renameSession(const QString &original, const QString &newName)
{
    if (!cloneSession(original, newName))
        return false;
    if (original == activeSession())
        loadSession(newName);
    return deleteSession(original);
}


/*!
    \brief Shows a dialog asking the user to confirm deleting the session \p session
*/
bool SessionManager::confirmSessionDelete(const QStringList &sessions)
{
    const QString title = sessions.size() == 1 ? tr("Delete Session") : tr("Delete Sessions");
    const QString question = sessions.size() == 1
            ? tr("Delete session %1?").arg(sessions.first())
            : tr("Delete these sessions?\n    %1").arg(sessions.join("\n    "));
    return QMessageBox::question(ICore::dialogParent(),
                                 title,
                                 question,
                                 QMessageBox::Yes | QMessageBox::No) == QMessageBox::Yes;
}

/*!
     Deletes \a session name from session list and the file from disk.
*/
bool SessionManager::deleteSession(const QString &session)
{
    if (!d->m_sessions.contains(session))
        return false;
    d->m_sessions.removeOne(session);
    QFile fi(sessionNameToFileName(session).toString());
    if (fi.exists())
        return fi.remove();
    return false;
}

void SessionManager::deleteSessions(const QStringList &sessions)
{
    for (const QString &session : sessions)
        deleteSession(session);
}

bool SessionManager::cloneSession(const QString &original, const QString &clone)
{
    if (!d->m_sessions.contains(original))
        return false;

    QFile fi(sessionNameToFileName(original).toString());
    // If the file does not exist, we can still clone
    if (!fi.exists() || fi.copy(sessionNameToFileName(clone).toString())) {
        d->m_sessions.insert(1, clone);
        d->m_sessionDateTimes.insert(clone, sessionNameToFileName(clone).toFileInfo().lastModified());
        return true;
    }
    return false;
}

void SessionManagerPrivate::restoreValues(const PersistentSettingsReader &reader)
{
    const QStringList keys = reader.restoreValue(QLatin1String("valueKeys")).toStringList();
    foreach (const QString &key, keys) {
        QVariant value = reader.restoreValue(QLatin1String("value-") + key);
        m_values.insert(key, value);
    }
}

void SessionManagerPrivate::restoreDependencies(const PersistentSettingsReader &reader)
{
    QMap<QString, QVariant> depMap = reader.restoreValue(QLatin1String("ProjectDependencies")).toMap();
    auto i = depMap.constBegin();
    while (i != depMap.constEnd()) {
        const QString &key = i.key();
        QStringList values;
        foreach (const QString &value, i.value().toStringList())
            values << value;
        m_depMap.insert(key, values);
        ++i;
    }
}

void SessionManagerPrivate::askUserAboutFailedProjects()
{
    QStringList failedProjects = m_failedProjects;
    if (!failedProjects.isEmpty()) {
        QString fileList =
            QDir::toNativeSeparators(failedProjects.join(QLatin1String("<br>")));
        QMessageBox box(QMessageBox::Warning,
                                   SessionManager::tr("Failed to restore project files"),
                                   SessionManager::tr("Could not restore the following project files:<br><b>%1</b>").
                                   arg(fileList));
        auto keepButton = new QPushButton(SessionManager::tr("Keep projects in Session"), &box);
        auto removeButton = new QPushButton(SessionManager::tr("Remove projects from Session"), &box);
        box.addButton(keepButton, QMessageBox::AcceptRole);
        box.addButton(removeButton, QMessageBox::DestructiveRole);

        box.exec();

        if (box.clickedButton() == removeButton)
            m_failedProjects.clear();
    }
}

void SessionManagerPrivate::restoreStartupProject(const PersistentSettingsReader &reader)
{
    const QString startupProject = reader.restoreValue(QLatin1String("StartupProject")).toString();
    if (!startupProject.isEmpty()) {
        for (Project *pro : qAsConst(m_projects)) {
            if (pro->projectFilePath().toString() == startupProject) {
                m_instance->setStartupProject(pro);
                break;
            }
        }
    }
    if (!m_startupProject) {
        if (!startupProject.isEmpty())
            qWarning() << "Could not find startup project" << startupProject;
        if (hasProjects())
            m_instance->setStartupProject(m_projects.first());
    }
}

void SessionManagerPrivate::restoreEditors(const PersistentSettingsReader &reader)
{
    const QVariant editorsettings = reader.restoreValue(QLatin1String("EditorSettings"));
    if (editorsettings.isValid()) {
        EditorManager::restoreState(QByteArray::fromBase64(editorsettings.toByteArray()));
        sessionLoadingProgress();
    }
}

/*!
     Loads a session, takes a session name (not filename).
*/
void SessionManagerPrivate::restoreProjects(const QStringList &fileList)
{
    // indirectly adds projects to session
    // Keep projects that failed to load in the session!
    m_failedProjects = fileList;
    if (!fileList.isEmpty()) {
        ProjectExplorerPlugin::OpenProjectResult result = ProjectExplorerPlugin::openProjects(fileList);
        if (!result)
            ProjectExplorerPlugin::showOpenProjectError(result);
        foreach (Project *p, result.projects())
            m_failedProjects.removeAll(p->projectFilePath().toString());
    }
}

/*
 * ========== Notes on storing and loading the default session ==========
 * The default session comes in two flavors: implicit and explicit. The implicit one,
 * also referred to as "default virgin" in the code base, is the one that is active
 * at start-up, if no session has been explicitly loaded due to command-line arguments
 * or the "restore last session" setting in the session manager.
 * The implicit default session silently turns into the explicit default session
 * by loading a project or a file or changing settings in the Dependencies panel. The explicit
 * default session can also be loaded by the user via the Welcome Screen.
 * This mechanism somewhat complicates the handling of session-specific settings such as
 * the ones in the task pane: Users expect that changes they make there become persistent, even
 * when they are in the implicit default session. However, we can't just blindly store
 * the implicit default session, because then we'd overwrite the project list of the explicit
 * default session. Therefore, we use the following logic:
 *     - Upon start-up, if no session is to be explicitly loaded, we restore the parts of the
 *       explicit default session that are not related to projects, editors etc; the
 *       "general settings" of the session, so to speak.
 *     - When storing the implicit default session, we overwrite only these "general settings"
 *       of the explicit default session and keep the others as they are.
 *     - When switching from the implicit to the explicit default session, we keep the
 *       "general settings" and load everything else from the session file.
 * This guarantees that user changes are properly transferred and nothing gets lost from
 * either the implicit or the explicit default session.
 *
 */
bool SessionManager::loadSession(const QString &session, bool initial)
{
    const bool loadImplicitDefault = session.isEmpty();
    const bool switchFromImplicitToExplicitDefault = session == "default"
            && d->m_sessionName == "default" && !initial;

    // Do nothing if we have that session already loaded,
    // exception if the session is the default virgin session
    // we still want to be able to load the default session
    if (session == d->m_sessionName && !isDefaultVirgin())
        return true;

    if (!loadImplicitDefault && !sessions().contains(session))
        return false;

    QStringList fileList;
    // Try loading the file
    FilePath fileName = sessionNameToFileName(loadImplicitDefault ? "default" : session);
    PersistentSettingsReader reader;
    if (fileName.exists()) {
        if (!reader.load(fileName)) {
            QMessageBox::warning(ICore::dialogParent(), tr("Error while restoring session"),
                                 tr("Could not restore session %1").arg(fileName.toUserOutput()));

            return false;
        }

        if (loadImplicitDefault) {
            d->restoreValues(reader);
            emit m_instance->sessionLoaded("default");
            return true;
        }

        fileList = reader.restoreValue(QLatin1String("ProjectList")).toStringList();
    } else if (loadImplicitDefault) {
        return true;
    }

    d->m_loadingSession = true;

    // Allow everyone to set something in the session and before saving
    emit m_instance->aboutToUnloadSession(d->m_sessionName);

    if (!save()) {
        d->m_loadingSession = false;
        return false;
    }

    // Clean up
    if (!EditorManager::closeAllEditors()) {
        d->m_loadingSession = false;
        return false;
    }

    // find a list of projects to close later
    const QList<Project *> projectsToRemove = Utils::filtered(projects(), [&fileList](Project *p) {
        return !fileList.contains(p->projectFilePath().toString());
    });
    const QList<Project *> openProjects = projects();
    const QStringList projectPathsToLoad = Utils::filtered(fileList, [&openProjects](const QString &path) {
        return !Utils::contains(openProjects, [&path](Project *p) {
            return p->projectFilePath().toString() == path;
        });
    });
    d->m_failedProjects.clear();
    d->m_depMap.clear();
    if (!switchFromImplicitToExplicitDefault)
        d->m_values.clear();
    d->m_casadeSetActive = false;

    d->m_sessionName = session;
    delete d->m_writer;
    d->m_writer = nullptr;
    EditorManager::updateWindowTitles();

    if (fileName.exists()) {
        d->m_virginSession = false;

        ProgressManager::addTask(d->m_future.future(), tr("Loading Session"),
           "ProjectExplorer.SessionFile.Load");

        d->m_future.setProgressRange(0, 1);
        d->m_future.setProgressValue(0);

        if (!switchFromImplicitToExplicitDefault)
            d->restoreValues(reader);
        emit m_instance->aboutToLoadSession(session);

        // retrieve all values before the following code could change them again
        Id modeId = Id::fromSetting(value(QLatin1String("ActiveMode")));
        if (!modeId.isValid())
            modeId = Id(Core::Constants::MODE_EDIT);

        QColor c = QColor(reader.restoreValue(QLatin1String("Color")).toString());
        if (c.isValid())
            StyleHelper::setBaseColor(c);

        d->m_future.setProgressRange(0, projectPathsToLoad.count() + 1/*initialization above*/ + 1/*editors*/);
        d->m_future.setProgressValue(1);
        QCoreApplication::processEvents(QEventLoop::ExcludeUserInputEvents);

        d->restoreProjects(projectPathsToLoad);
        d->sessionLoadingProgress();
        d->restoreDependencies(reader);
        d->restoreStartupProject(reader);

        removeProjects(projectsToRemove); // only remove old projects now that the startup project is set!

        d->restoreEditors(reader);

        d->m_future.reportFinished();
        d->m_future = QFutureInterface<void>();

        // Fall back to Project mode if the startup project is unconfigured and
        // use the mode saved in the session otherwise
        if (d->m_startupProject && d->m_startupProject->needsConfiguration())
            modeId = Id(Constants::MODE_SESSION);

        ModeManager::activateMode(modeId);
        ModeManager::setFocusToCurrentMode();
    } else {
        removeProjects(projects());
        ModeManager::activateMode(Id(Core::Constants::MODE_EDIT));
        ModeManager::setFocusToCurrentMode();
    }

    d->m_casadeSetActive = reader.restoreValue(QLatin1String("CascadeSetActive"), false).toBool();

    emit m_instance->sessionLoaded(session);

    // Starts a event loop, better do that at the very end
    d->askUserAboutFailedProjects();
    d->m_loadingSession = false;
    return true;
}

/*!
    Returns the last session that was opened by the user.
*/
QString SessionManager::lastSession()
{
    return ICore::settings()->value(Constants::LASTSESSION_KEY).toString();
}

/*!
    Returns the session that was active when Qt Creator was last closed, if any.
*/
QString SessionManager::startupSession()
{
    return ICore::settings()->value(Constants::STARTUPSESSION_KEY).toString();
}

void SessionManager::reportProjectLoadingProgress()
{
    d->sessionLoadingProgress();
}

void SessionManager::markSessionFileDirty()
{
    d->m_virginSession = false;
}

void SessionManagerPrivate::sessionLoadingProgress()
{
    m_future.setProgressValue(m_future.progressValue() + 1);
    QCoreApplication::processEvents(QEventLoop::ExcludeUserInputEvents);
}

QStringList SessionManager::projectsForSessionName(const QString &session)
{
    const FilePath fileName = sessionNameToFileName(session);
    PersistentSettingsReader reader;
    if (fileName.exists()) {
        if (!reader.load(fileName)) {
            qWarning() << "Could not restore session" << fileName.toUserOutput();
            return QStringList();
        }
    }
    return reader.restoreValue(QLatin1String("ProjectList")).toStringList();
}

#ifdef WITH_TESTS

void ProjectExplorerPlugin::testSessionSwitch()
{
    QVERIFY(SessionManager::createSession("session1"));
    QVERIFY(SessionManager::createSession("session2"));
    QTemporaryFile cppFile("main.cpp");
    QVERIFY(cppFile.open());
    cppFile.close();
    QTemporaryFile projectFile1("XXXXXX.pro");
    QTemporaryFile projectFile2("XXXXXX.pro");
    struct SessionSpec {
        SessionSpec(const QString &n, QTemporaryFile &f) : name(n), projectFile(f) {}
        const QString name;
        QTemporaryFile &projectFile;
    };
    std::vector<SessionSpec> sessionSpecs{SessionSpec("session1", projectFile1),
                SessionSpec("session2", projectFile2)};
    for (const SessionSpec &sessionSpec : sessionSpecs) {
        static const QByteArray proFileContents
                = "TEMPLATE = app\n"
                  "CONFIG -= qt\n"
                  "SOURCES = " + cppFile.fileName().toLocal8Bit();
        QVERIFY(sessionSpec.projectFile.open());
        sessionSpec.projectFile.write(proFileContents);
        sessionSpec.projectFile.close();
        QVERIFY(SessionManager::loadSession(sessionSpec.name));
        const OpenProjectResult openResult
                = ProjectExplorerPlugin::openProject(sessionSpec.projectFile.fileName());
        if (openResult.errorMessage().contains("text/plain"))
            QSKIP("This test requires the presence of QmakeProjectManager to be fully functional");
        QVERIFY(openResult);
        QCOMPARE(openResult.projects().count(), 1);
        QVERIFY(openResult.project());
        QCOMPARE(SessionManager::projects().count(), 1);
    }
    for (int i = 0; i < 30; ++i) {
        QVERIFY(SessionManager::loadSession("session1"));
        QCOMPARE(SessionManager::activeSession(), "session1");
        QCOMPARE(SessionManager::projects().count(), 1);
        QVERIFY(SessionManager::loadSession("session2"));
        QCOMPARE(SessionManager::activeSession(), "session2");
        QCOMPARE(SessionManager::projects().count(), 1);
    }
    QVERIFY(SessionManager::loadSession("session1"));
    SessionManager::closeAllProjects();
    QVERIFY(SessionManager::loadSession("session2"));
    SessionManager::closeAllProjects();
    QVERIFY(SessionManager::deleteSession("session1"));
    QVERIFY(SessionManager::deleteSession("session2"));
}

#endif // WITH_TESTS

} // namespace ProjectExplorer