/*******************************************************************************
 * gui/common/RsCollection.cpp                                                 *
 *                                                                             *
 * Copyright (C) 2011, Retroshare Team <retroshare.project@gmail.com>          *
 *                                                                             *
 * This program is free software: you can redistribute it and/or modify        *
 * it under the terms of the GNU Affero General Public License as              *
 * published by the Free Software Foundation, either version 3 of the          *
 * License, or (at your option) any later version.                             *
 *                                                                             *
 * This program 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 Affero General Public License for more details.                         *
 *                                                                             *
 * You should have received a copy of the GNU Affero General Public License    *
 * along with this program. If not, see <https://www.gnu.org/licenses/>.       *
 *                                                                             *
 *******************************************************************************/

#include <stdexcept>
#include <retroshare/rsfiles.h>

#include "RsCollection.h"
#include "RsCollectionDialog.h"
#include "util/misc.h"

#include <QDir>
#include <QObject>
#include <QTextStream>
#include <QDomElement>
#include <QDomDocument>
#include <QMessageBox>
#include <QIcon>

// #define COLLECTION_DEBUG 1

const QString RsCollection::ExtensionString = QString("rscollection") ;

RsCollection::RsCollection()
{
    mFileTree = std::unique_ptr<RsFileTree>(new RsFileTree());
}
RsCollection::RsCollection(const RsFileTree& ft)
{
    mFileTree = std::unique_ptr<RsFileTree>(new RsFileTree(ft));

    for(uint64_t i=0;i<mFileTree->numFiles();++i)
        mHashes.insert(std::make_pair(mFileTree->fileData(i).hash,i ));
}

RsCollection::RsCollection(const std::vector<DirDetails>& file_infos,FileSearchFlags flags)
    : mFileTree(new RsFileTree)
{
    if(! ( (flags & RS_FILE_HINTS_LOCAL) || (flags & RS_FILE_HINTS_REMOTE)))
    {
        std::cerr << "(EE) Wrong flags passed to RsCollection constructor. Please fix the code!" << std::endl;
        return ;
    }

    for(uint32_t i = 0;i<file_infos.size();++i)
        recursAddElements(mFileTree->root(),file_infos[i],flags) ;

    for(uint64_t i=0;i<mFileTree->numFiles();++i)
        mHashes.insert(std::make_pair(mFileTree->fileData(i).hash,i ));
}

RsCollection::~RsCollection()
{
}

void RsCollection::autoDownloadFiles(ColFileInfo colFileInfo, QString dlDir) const
{
    if (!colFileInfo.filename_has_wrong_characters)
    {
        QString cleanPath = dlDir + colFileInfo.path ;
        std::cout << "making directory " << cleanPath.toStdString() << std::endl;

        if(!QDir(QApplication::applicationDirPath()).mkpath(cleanPath))
            std::cerr << "Unable to make path: " + cleanPath.toStdString() << std::endl;

        if (colFileInfo.type==DIR_TYPE_FILE)
            rsFiles->FileRequest(colFileInfo.name.toUtf8().constData(),
                                 RsFileHash(colFileInfo.hash.toStdString()),
                                 colFileInfo.size,
                                 cleanPath.toUtf8().constData(),
                                 RS_FILE_REQ_ANONYMOUS_ROUTING,
                                 std::list<RsPeerId>());
    }
    foreach(ColFileInfo colFileInfoChild, colFileInfo.children)
    {
        autoDownloadFiles(colFileInfoChild, dlDir);
    }
}

static QString purifyFileName(const QString& input,bool& bad)
{
    static const QString bad_chars = "/\\\"*:?<>|" ;
    bad = false ;
    QString output = input ;

    for(int i=0;i<output.length();++i)
        for(int j=0;j<bad_chars.length();++j)
            if(output[i] == bad_chars[j])
            {
                output[i] = '_' ;
                bad = true ;
            }

    return output ;
}

void RsCollection::merge_in(const QString& fname,uint64_t size,const RsFileHash& hash,RsFileTree::DirIndex parent_index)
{
    mHashes[hash]= mFileTree->addFile(parent_index,fname.toStdString(),hash,size);
}
void RsCollection::merge_in(const RsFileTree& tree, RsFileTree::DirIndex parent_index)
{
    recursMergeTree(mFileTree->root(),tree,tree.directoryData(parent_index)) ;
}

void RsCollection::recursMergeTree(RsFileTree::DirIndex parent,const RsFileTree& tree,const RsFileTree::DirData& dd)
{
    for(uint32_t i=0;i<dd.subfiles.size();++i)
    {
        const RsFileTree::FileData& fd(tree.fileData(dd.subfiles[i]));
        mHashes[fd.hash] = mFileTree->addFile(parent,fd.name,fd.hash,fd.size);
    }
    for(uint32_t i=0;i<dd.subdirs.size();++i)
    {
        const RsFileTree::DirData& ld(tree.directoryData(dd.subdirs[i]));

        auto new_dir_index = mFileTree->addDirectory(parent,ld.name);
        recursMergeTree(new_dir_index,tree,ld);
    }
}

void RsCollection::recursAddElements(RsFileTree::DirIndex parent, const DirDetails& dd, FileSearchFlags flags)
{
    if (dd.type == DIR_TYPE_FILE)
        mHashes[dd.hash] = mFileTree->addFile(parent,dd.name,dd.hash,dd.size);
    else if (dd.type == DIR_TYPE_DIR)
    {
        RsFileTree::DirIndex new_dir_index = mFileTree->addDirectory(parent,dd.name);

        for(uint32_t i=0;i<dd.children.size();++i)
        {
            if (!dd.children[i].ref)
                continue;

            DirDetails subDirDetails;

            if (!rsFiles->RequestDirDetails(dd.children[i].ref, subDirDetails, flags))
                continue;

            recursAddElements(new_dir_index,subDirDetails,flags) ;
        }
    }
}

QString RsCollection::errorString(RsCollectionErrorCode code)
{
    switch(code)
    {
    default: [[fallthrough]] ;
    case RsCollectionErrorCode::UNKNOWN_ERROR:                 return QObject::tr("Unknown error");
    case RsCollectionErrorCode::COLLECTION_NO_ERROR:           return QObject::tr("No error");
    case RsCollectionErrorCode::FILE_READ_ERROR:               return QObject::tr("Error while openning file");
    case RsCollectionErrorCode::FILE_CONTAINS_HARMFUL_STRINGS: return QObject::tr("Collection file contains potentially harmful code");
    case RsCollectionErrorCode::INVALID_ROOT_NODE:             return QObject::tr("Invalid root node. RsCollection node was expected.");
    case RsCollectionErrorCode::XML_PARSING_ERROR:             return QObject::tr("XML parsing error in collection file");
    }
}

RsCollection::RsCollection(const RsCollection& col)
    : mFileTree(new RsFileTree(*col.mFileTree)),mHashes(col.mHashes)
{
}

RsCollection::RsCollection(const QString& fileName, RsCollectionErrorCode& error)
    : mFileTree(new RsFileTree)
{
    if (!checkFile(fileName,error))
        return ;

    QFile file(fileName);

    if (!file.open(QIODevice::ReadOnly))
    {
        std::cerr << "Cannot open file " << fileName.toStdString() << " !!" << std::endl;
        error = RsCollectionErrorCode::FILE_READ_ERROR;
        //showErrorBox(fileName, QApplication::translate("RsCollectionFile", "Cannot open file %1").arg(fileName));
        return ;
    }

    QDomDocument xml_doc;
    bool ok = xml_doc.setContent(&file) ;

    if(!ok)
    {
        error = RsCollectionErrorCode::XML_PARSING_ERROR;
        return;
    }
    file.close();

    QDomNode root = xml_doc.elementsByTagName("RsCollection").at(0).toElement();

    if(root.isNull())
    {
        error = RsCollectionErrorCode::INVALID_ROOT_NODE;
        return;
    }

    if(!recursParseXml(xml_doc,root,0))
        error = RsCollectionErrorCode::XML_PARSING_ERROR;
    else
        error = RsCollectionErrorCode::COLLECTION_NO_ERROR;
}

// check that the file is a valid rscollection file, and not a lol bomb or some shit like this

bool RsCollection::checkFile(const QString& fileName, RsCollectionErrorCode& error)
{
    QFile file(fileName);
    error = RsCollectionErrorCode::COLLECTION_NO_ERROR;

    if (!file.open(QIODevice::ReadOnly))
    {
        std::cerr << "Cannot open file " << fileName.toStdString() << " !!" << std::endl;
        error = RsCollectionErrorCode::FILE_READ_ERROR;

        //showErrorBox(fileName, QApplication::translate("RsCollectionFile", "Cannot open file %1").arg(fileName));
        return false;
    }
    if (file.reset()){
        std::cerr << "Checking this file for bomb elements and various wrong stuff" << std::endl;
        char c ;

        std::vector<std::string> bad_strings ;
        bad_strings.push_back(std::string("<!entity ")) ;
        static const int max_size = 12 ; // should be as large as the largest element in bad_strings
        char current[max_size] = { 0,0,0,0,0,0,0,0,0,0,0,0 } ;
        int n=0 ;

        while( !file.atEnd() || n >= 0)
        {
            if (!file.atEnd())
                file.getChar(&c);
            else
                c=0;

            if(c == '\t' || c == '\n' || c == '\b' || c == '\r')
                continue ;

            if (n == max_size || file.atEnd())
                for(int i=0;i<n-1;++i)
                    current[i] = current[i+1] ;

            if(n == max_size)
                --n ;

            if(c >= 'A' && c <= 'Z') c += 'a' - 'A' ;

            if(!file.atEnd())
                current[n] = c ;
            else
                current[n] = 0 ;

            //std::cerr << "n==" << n <<" Checking string " << std::string(current,n+1)  << " c = " << std::hex << (int)c << std::dec << std::endl;

            for(uint i=0;i<bad_strings.size();++i)
                if(std::string(current,bad_strings[i].length()) == bad_strings[i])
                {
                    //showErrorBox(file.fileName(), QApplication::translate("RsCollectionFile", "This file contains the string \"%1\" and is therefore an invalid collection file. \n\nIf you believe it is correct, remove the corresponding line from the file and re-open it with Retroshare.").arg(bad_strings[i].c_str()));
                    error = RsCollectionErrorCode::FILE_CONTAINS_HARMFUL_STRINGS;
                    file.close();
                    return false ;
                    //std::cerr << "Bad string detected" << std::endl;
                }

            if(file.atEnd())
                n-- ;
            else if(n < max_size)
                ++n ;
        }
        file.close();
        return true;
    }
    error = RsCollectionErrorCode::UNKNOWN_ERROR;
    return false;
}

bool RsCollection::save(const QString& fileName) const
{
    QFile file(fileName);

    if (!file.open(QIODevice::WriteOnly))
    {
        std::cerr << "Cannot write to file " << fileName.toStdString() << " !!" << std::endl;
        return false;
    }

    QDomDocument xml_doc ;
    QDomElement root = xml_doc.createElement("RsCollection");

    const RsFileTree::DirData& root_data(mFileTree->directoryData(mFileTree->root()));

    if(!recursExportToXml(xml_doc,root,root_data))
        return false;

    xml_doc.appendChild(root);

    QTextStream stream(&file) ;
    stream.setCodec("UTF-8") ;

    stream << xml_doc.toString() ;
    file.close();

    return true;
}

bool RsCollection::recursParseXml(QDomDocument& doc,const QDomNode& e,const RsFileTree::DirIndex parent)
{
    mHashes.clear();
    QDomNode n = e.firstChild() ;
#ifdef COLLECTION_DEBUG
    std::cerr << "Parsing element " << e.tagName().toStdString() << std::endl;
#endif

    while(!n.isNull())
    {
        QDomElement ee = n.toElement(); // try to convert the node to an element.

#ifdef COLLECTION_DEBUG
        std::cerr << "  Seeing child " << ee.tagName().toStdString() << std::endl;
#endif

        if(ee.tagName() == QString("File"))
        {
            RsFileHash hash(ee.attribute(QString("sha1")).toStdString()) ;

            bool bad_chars_detected = false;
            std::string name = purifyFileName(ee.attribute(QString("name")), bad_chars_detected).toUtf8().constData() ;
            uint64_t size = ee.attribute(QString("size")).toULongLong() ;

            mHashes[hash] = mFileTree->addFile(parent,name,hash,size);
        }
        else if(ee.tagName() == QString("Directory"))
        {
            bool bad_chars_detected = false ;
            std::string cleanDirName = purifyFileName(ee.attribute(QString("name")),bad_chars_detected).toUtf8().constData() ;

            RsFileTree::DirIndex new_dir_index = mFileTree->addDirectory(parent,cleanDirName);

            recursParseXml(doc,ee,new_dir_index);
        }

        n = n.nextSibling() ;
    }
    return true;
}
bool RsCollection::recursExportToXml(QDomDocument& doc,QDomElement& e,const RsFileTree::DirData& dd) const
{
    for(uint32_t i=0;i<dd.subfiles.size();++i)
    {
        QDomElement f = doc.createElement("File") ;

        const RsFileTree::FileData& fd(mFileTree->fileData(dd.subfiles[i]));

        f.setAttribute(QString("name"),QString::fromUtf8(fd.name.c_str())) ;
        f.setAttribute(QString("sha1"),QString::fromStdString(fd.hash.toStdString())) ;
        f.setAttribute(QString("size"),QString::number(fd.size)) ;

        e.appendChild(f) ;
    }

    for(uint32_t i=0;i<dd.subdirs.size();++i)
    {
        const RsFileTree::DirData& di(mFileTree->directoryData(dd.subdirs[i]));

        QDomElement d = doc.createElement("Directory") ;
        d.setAttribute(QString("name"),QString::fromUtf8(di.name.c_str())) ;

        if(!recursExportToXml(doc,d,di))
            return false;

        e.appendChild(d) ;
    }

    return true;
}

qulonglong RsCollection::count() const
{
    return mFileTree->numFiles();
}
qulonglong RsCollection::size()
{
    return mFileTree->totalFileSize();
}

bool RsCollection::isCollectionFile(const QString &fileName)
{
    QString ext = QFileInfo(fileName).suffix().toLower();

    return (ext == RsCollection::ExtensionString);
}

void RsCollection::updateHashes(const std::map<RsFileHash,RsFileHash>& old_to_new_hashes)
{
    for(auto it:old_to_new_hashes)
    {
        auto fit = mHashes.find(it.first);

        if(fit == mHashes.end())
        {
            RsErr() << "Could not find hash " << it.first << " in RsCollection list of hashes. This is a bug." ;
            return ;
        }
        const auto& fd(mFileTree->fileData(fit->second));

        if(fd.hash != it.first)
        {
            RsErr() << "Mismatch hash for file " << fd.name << " (found " << fd.hash << " instead of " << it.first << ") in RsCollection list of hashes. This is a bug." ;
            return ;
        }
        mFileTree->updateFile(fit->second,fd.name,it.second,fd.size);
    }
}

bool RsCollection::removeFile(RsFileTree::FileIndex index_to_remove,RsFileTree::DirIndex parent_index)
{
    return mFileTree->removeFile(index_to_remove,parent_index);
}
bool RsCollection::removeDirectory(RsFileTree::DirIndex index_to_remove,RsFileTree::DirIndex parent_index)
{
    return mFileTree->removeDirectory(index_to_remove,parent_index);
}

void RsCollection::cleanup()
{
    RsDbg() << "Cleaning up RsCollection with " << mFileTree->numDirs() << " dirs and " << mFileTree->numFiles() << " files." ;

    mFileTree = RsFileTree::fromTreeCleaned(*mFileTree);

    RsDbg() << "Simplified to " << mFileTree->numDirs() << " dirs and " << mFileTree->numFiles() << " files.";
}