/****************************************************************************
**
** Copyright (C) 2016 Dmitry Savchenko
** Copyright (C) 2016 Vasiliy Sorokin
** 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
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**
** 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 "todoitemsprovider.h"
#include "constants.h"
#include "cpptodoitemsscanner.h"
#include "qmljstodoitemsscanner.h"
#include "todoitemsmodel.h"
#include "todoitemsscanner.h"

#include <coreplugin/editormanager/editormanager.h>
#include <coreplugin/idocument.h>

#include <projectexplorer/projectexplorer.h>
#include <projectexplorer/projectnodes.h>
#include <projectexplorer/projecttree.h>
#include <projectexplorer/session.h>

#include <utils/algorithm.h>

#include <QRegularExpression>
#include <QTimer>

using namespace ProjectExplorer;
using namespace Utils;

namespace Todo {
namespace Internal {

TodoItemsProvider::TodoItemsProvider(Settings settings, QObject *parent) :
    QObject(parent),
    m_settings(settings)
{
    setupItemsModel();
    setupStartupProjectBinding();
    setupCurrentEditorBinding();
    setupUpdateListTimer();
    createScanners();
}

TodoItemsModel *TodoItemsProvider::todoItemsModel()
{
    return m_itemsModel;
}

void TodoItemsProvider::settingsChanged(const Settings &newSettings)
{
    if (newSettings.keywords != m_settings.keywords) {
        foreach (TodoItemsScanner *scanner, m_scanners)
            scanner->setParams(newSettings.keywords);
    }

    m_settings = newSettings;

    updateList();
}

void TodoItemsProvider::projectSettingsChanged(Project *project)
{
    Q_UNUSED(project)
    updateList();
}

void TodoItemsProvider::updateList()
{
    m_itemsList.clear();

    // Show only items of the current file if any
    if (m_settings.scanningScope == ScanningScopeCurrentFile) {
        if (m_currentEditor)
            m_itemsList = m_itemsHash.value(m_currentEditor->document()->filePath());
    // Show only items of the current sub-project
    } else if (m_settings.scanningScope == ScanningScopeSubProject) {
        if (m_startupProject)
            setItemsListWithinSubproject();
    // Show only items of the startup project if any
    } else if (m_startupProject) {
        setItemsListWithinStartupProject();
    }

    m_itemsModel->todoItemsListUpdated();
}

void TodoItemsProvider::createScanners()
{
    qRegisterMetaType<QList<TodoItem> >("QList<TodoItem>");

    if (CppTools::CppModelManager::instance())
        m_scanners << new CppTodoItemsScanner(m_settings.keywords, this);

    if (QmlJS::ModelManagerInterface::instance())
        m_scanners << new QmlJsTodoItemsScanner(m_settings.keywords, this);

    foreach (TodoItemsScanner *scanner, m_scanners) {
        connect(scanner, &TodoItemsScanner::itemsFetched, this,
            &TodoItemsProvider::itemsFetched, Qt::QueuedConnection);
    }
}

void TodoItemsProvider::setItemsListWithinStartupProject()
{
    const auto filePaths = Utils::toSet(m_startupProject->files(Project::SourceFiles));

    QVariantMap settings = m_startupProject->namedSettings(Constants::SETTINGS_NAME_KEY).toMap();

    for (auto it = m_itemsHash.cbegin(), end = m_itemsHash.cend(); it != end; ++it) {
        const FilePath filePath = it.key();
        if (filePaths.contains(filePath)) {
            bool skip = false;
            for (const QVariant &pattern : settings[Constants::EXCLUDES_LIST_KEY].toList()) {
                QRegularExpression re(pattern.toString());
                if (filePath.toString().indexOf(re) != -1) {
                    skip = true;
                    break;
                }
            }
            if (!skip)
                m_itemsList << it.value();
        }
    }
}

void TodoItemsProvider::setItemsListWithinSubproject()
{
    // TODO prefer current editor as source of sub-project
    const Node *node = ProjectTree::currentNode();
    if (node) {
        ProjectNode *projectNode = node->parentProjectNode();
        if (projectNode) {
            // FIXME: The name doesn't match the implementation that lists all files.
            QSet<FilePath> subprojectFileNames;
            projectNode->forEachGenericNode([&](Node *node) {
                 subprojectFileNames.insert(node->filePath());
            });

            // files must be both in the current subproject and the startup-project.
            const auto fileNames = Utils::toSet(m_startupProject->files(Project::SourceFiles));
            for (auto it = m_itemsHash.cbegin(), end = m_itemsHash.cend(); it != end; ++it) {
                if (subprojectFileNames.contains(it.key()) && fileNames.contains(it.key()))
                    m_itemsList << it.value();
            }
        }
    }
}

void TodoItemsProvider::itemsFetched(const QString &fileName, const QList<TodoItem> &items)
{
    // Replace old items with new ones
    m_itemsHash.insert(FilePath::fromString(fileName), items);

    m_shouldUpdateList = true;
}

void TodoItemsProvider::startupProjectChanged(Project *project)
{
    m_startupProject = project;
    updateList();
}

void TodoItemsProvider::projectsFilesChanged()
{
    updateList();
}

void TodoItemsProvider::currentEditorChanged(Core::IEditor *editor)
{
    m_currentEditor = editor;
    if (m_settings.scanningScope == ScanningScopeCurrentFile
            || m_settings.scanningScope == ScanningScopeSubProject) {
        updateList();
    }
}

void TodoItemsProvider::updateListTimeoutElapsed()
{
    if (m_shouldUpdateList) {
        m_shouldUpdateList = false;
        updateList();
    }
}

void TodoItemsProvider::setupStartupProjectBinding()
{
    m_startupProject = SessionManager::startupProject();
    connect(SessionManager::instance(), &SessionManager::startupProjectChanged,
        this, &TodoItemsProvider::startupProjectChanged);
    connect(ProjectExplorerPlugin::instance(), &ProjectExplorerPlugin::fileListChanged,
            this, &TodoItemsProvider::projectsFilesChanged);
}

void TodoItemsProvider::setupCurrentEditorBinding()
{
    m_currentEditor = Core::EditorManager::currentEditor();
    connect(Core::EditorManager::instance(), &Core::EditorManager::currentEditorChanged,
        this, &TodoItemsProvider::currentEditorChanged);
}

void TodoItemsProvider::setupUpdateListTimer()
{
    m_shouldUpdateList = false;
    QTimer *timer = new QTimer(this);
    connect(timer, &QTimer::timeout, this, &TodoItemsProvider::updateListTimeoutElapsed);
    timer->start(Constants::OUTPUT_PANE_UPDATE_INTERVAL);
}

void TodoItemsProvider::setupItemsModel()
{
    m_itemsModel = new TodoItemsModel(this);
    m_itemsModel->setTodoItemsList(&m_itemsList);
}

}
}