/* Copyright (C) 2015
 * swift Project Community / Contributors
 *
 * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
 * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
 * including this file, may be copied, modified, propagated, or distributed except according to the terms
 * contained in the LICENSE file.
 */

#include "blackmisc/logmessage.h"
#include "blackmisc/simulation/fscommon/vpilotmodelrule.h"
#include "blackmisc/simulation/fscommon/vpilotrulesreader.h"
#include "blackmisc/statusmessage.h"
#include "blackmisc/worker.h"

#include <QByteArray>
#include <QDateTime>
#include <QDir>
#include <QDomDocument>
#include <QDomNamedNodeMap>
#include <QDomNode>
#include <QDomNodeList>
#include <QFile>
#include <QFileInfo>
#include <QFileInfoList>
#include <QFlags>
#include <QIODevice>
#include <QReadLocker>
#include <QStandardPaths>
#include <QTimer>
#include <QWriteLocker>
#include <QtGlobal>

using namespace BlackMisc;
using namespace BlackMisc::Network;

namespace BlackMisc
{
    namespace Simulation
    {
        namespace FsCommon
        {
            CVPilotRulesReader::CVPilotRulesReader(bool standardDirectory, QObject *parent) :
                QObject(parent)
            {
                if (standardDirectory) { this->addDirectory(CVPilotRulesReader::standardMappingsDirectory()); }
            }

            CVPilotRulesReader::~CVPilotRulesReader()
            {
                gracefulShutdown();
            }

            QStringList CVPilotRulesReader::getFiles() const
            {
                QReadLocker l(&m_lockData);
                return m_fileList;
            }

            bool CVPilotRulesReader::hasFiles() const
            {
                QReadLocker l(&m_lockData);
                return !m_fileList.isEmpty();
            }

            void CVPilotRulesReader::addFilename(const QString &fileName)
            {
                QWriteLocker l(&m_lockData);
                if (this->m_fileList.contains(fileName)) { return; }
                this->m_fileList.append(fileName);
            }

            void CVPilotRulesReader::addDirectory(const QString &directory)
            {
                QDir dir(directory);
                if (!dir.exists()) { return; }
                QStringList nameFilters({"*.vmr"});
                QFileInfoList entries = dir.entryInfoList(nameFilters, QDir::Files | QDir::Readable);
                for (const QFileInfo &file : entries)
                {
                    this->addFilename(file.absoluteFilePath());
                }
            }

            int CVPilotRulesReader::countFilesLoaded() const
            {
                QReadLocker l(&m_lockData);
                return m_loadedFiles;
            }

            CVPilotModelRuleSet CVPilotRulesReader::getRules() const
            {
                QReadLocker l(&m_lockData);
                return m_rules;
            }

            int CVPilotRulesReader::getModelsCount() const
            {
                return this->m_cachedVPilotModels.getThreadLocal().size();
            }

            CAircraftModelList CVPilotRulesReader::getAsModels()
            {
                // already cached?
                CAircraftModelList vPilotModels(this->m_cachedVPilotModels.get());
                if (!vPilotModels.isEmpty() || m_rules.isEmpty()) { return vPilotModels; }

                // important: that can take a while and should normally
                // run in background
                const CVPilotModelRuleSet rules(getRules()); // thread safe copy
                vPilotModels = rules.toAircraftModels(); // long lasting operation
                this->ps_setCache(vPilotModels);
                return vPilotModels;
            }

            CAircraftModelList CVPilotRulesReader::getAsModelsFromCache() const
            {
                return this->m_cachedVPilotModels.get();
            }

            int CVPilotRulesReader::countRulesLoaded() const
            {
                QReadLocker l(&m_lockData);
                return m_rules.size();
            }

            void CVPilotRulesReader::gracefulShutdown()
            {
                QWriteLocker l(&m_lockData);
                m_shutdown = true;
            }

            const QString &CVPilotRulesReader::standardMappingsDirectory()
            {
                static QString directory;
                if (directory.isEmpty())
                {
                    directory = QStandardPaths::standardLocations(QStandardPaths::DocumentsLocation).first();
                    if (!directory.endsWith('/')) { directory.append('/'); }
                    directory.append("vPilot Files/Model Matching Rule Sets");
                }
                return directory;
            }

            bool CVPilotRulesReader::read(bool convertToModels)
            {
                int loadedFiles = 0;
                QStringList filesWithProblems;
                CVPilotModelRuleSet rules;
                const QStringList fileList(getFiles());
                for (const QString &fn : fileList)
                {
                    if (m_shutdown) { return false; }
                    loadedFiles++;
                    bool s = this->loadFile(fn, rules);
                    if (!s) { this->m_fileListWithProblems.append(fn); }
                }

                {
                    QWriteLocker l(&m_lockData);
                    this->m_loadedFiles = loadedFiles;
                    this->m_fileListWithProblems = filesWithProblems;
                    this->m_rules = rules;
                    if (m_shutdown) { return false; }
                }

                const bool success = loadedFiles > 0;
                if (convertToModels)
                {
                    const CAircraftModelList vPilotModels(rules.toAircraftModels()); // long lasting operation
                    this->ps_setCache(vPilotModels);
                }

                emit readFinished(success);
                return success;
            }

            CWorker *CVPilotRulesReader::readInBackground(bool convertToModels)
            {
                // set a thread safe flag
                {
                    QWriteLocker l(&m_lockData);
                    if (m_asyncLoadInProgress || m_shutdown) { return nullptr; }
                    m_asyncLoadInProgress = true;
                }
                BlackMisc::CWorker *worker = BlackMisc::CWorker::fromTask(this, "CVPilotRulesReader", [this, convertToModels]()
                {
                    this->read(convertToModels);
                });
                worker->then(this, &CVPilotRulesReader::ps_readInBackgroundFinished);
                return worker;
            }

            void CVPilotRulesReader::ps_readInBackgroundFinished()
            {
                QWriteLocker l(&m_lockData);
                m_asyncLoadInProgress = false;
            }

            void CVPilotRulesReader::ps_onVPilotCacheChanged()
            {
                // void
            }

            void CVPilotRulesReader::ps_setCache(const CAircraftModelList &models)
            {
                if (this->m_cachedVPilotModels.isOwnerThread())
                {
                    CStatusMessage m;
                    {
                        QWriteLocker l(&m_lockData);
                        m = this->m_cachedVPilotModels.set(models);
                    }
                    if (m.isFailure())
                    {
                        CLogMessage::preformatted(m);
                    }
                }
                else
                {
                    QTimer::singleShot(0, this, [this, models]() { this->ps_setCache(models); });
                }
            }

            bool CVPilotRulesReader::loadFile(const QString &fileName, CVPilotModelRuleSet &ruleSet)
            {
                QFile f(fileName);
                if (!f.exists()) { return  false; }
                if (!f.open(QFile::ReadOnly | QFile::Text)) { return false; }
                QByteArray fc = f.readAll();
                if (fc.isEmpty()) { return false; }
                QDomDocument doc;
                if (!doc.setContent(fc)) { return false; }
                QDomNodeList rules = doc.elementsByTagName("ModelMatchRule");
                if (rules.isEmpty()) { return false; }

                QDomNodeList mmRuleSet = doc.elementsByTagName("ModelMatchRuleSet");
                if (mmRuleSet.size() < 1) { return true; }

                const QDomNamedNodeMap attributes = mmRuleSet.at(0).attributes();
                QString folder = attributes.namedItem("Folder").nodeValue().trimmed();
                if (folder.isEmpty())
                {
                    folder = QFileInfo(fileName).fileName().replace(".vmr", "");
                }

                // "2/1/2014 12:00:00 AM", "5/26/2014 2:00:00 PM"
                const QString updated = attributes.namedItem("UpdatedOn").nodeValue();
                QDateTime qt = QDateTime::fromString(updated, "M/d/yyyy h:mm:ss AP");
                qint64 updatedTimestamp = qt.toMSecsSinceEpoch();

                int rulesSize = rules.size();
                for (int i = 0; i < rulesSize; i++)
                {
                    const QDomNamedNodeMap ruleAttributes = rules.at(i).attributes();
                    const QString typeCode = ruleAttributes.namedItem("TypeCode").nodeValue();
                    const QString modelName = ruleAttributes.namedItem("ModelName").nodeValue();
                    // remark, callsign prefix is airline ICAO code
                    const QString callsignPrefix = ruleAttributes.namedItem("CallsignPrefix").nodeValue();
                    if (modelName.isEmpty()) { continue; }

                    // split if we have multiple models
                    if (modelName.contains("//"))
                    {
                        // multiple models
                        const QStringList models = modelName.split("//");
                        for (const QString &model : models)
                        {
                            if (model.isEmpty()) { continue; }
                            CVPilotModelRule rule(model, folder, typeCode, callsignPrefix, updatedTimestamp);
                            ruleSet.push_back(rule);
                        }
                    }
                    else
                    {
                        // single model
                        CVPilotModelRule rule(modelName, folder, typeCode, callsignPrefix, updatedTimestamp);
                        ruleSet.push_back(rule);
                    }
                }
                return true;
            }

        } // namespace
    } // namespace
} // namespace