#include "filesplitter.h"

FileSplitter::FileSplitter(QString fileName,QString fileID,int unit)
{
    this->fileName = fileName;
    this->unit = unit;
    this->outputDir = QDir::tempPath()+"/sncsplit";
    this->fileID = fileID;
}

QStringList FileSplitter::getSplitResult()
{
    QStringList results;
    if(!prepare())
        return results;
    QDir dir(this->outputDir);
    QFileInfoList list = dir.entryInfoList(QDir::Files,QDir::Name);
    for(int i=0;i<list.size();i++)
    {
        if(list.at(i).isFile())
        {
            results<<list.at(i).absoluteFilePath();
        }
    }
    if(results.size()==0)
    {
        results = split();
    }
    return results;
}

QStringList FileSplitter::split()
{
    QStringList results;
    int size = this->rawData.length();
    int pos = 0;
    int len = this->unit;
    int index = 0;
    QString packkey = getRandPackKey();

    QFileInfo fileinfo(this->fileName);
    QString basename = fileinfo.fileName();
    int count = (size % this->unit==0)? (size / this->unit) : size / this->unit + 1;
    while(1)
    {
        index++;
        QByteArray packData = this->rawData.mid(pos,len);
        QString outname =   QString("%1/%2.%3_%4_%5_%6")
                            .arg(this->outputDir)
                            .arg(basename)
                            .arg(packkey)
                            .arg(QString::number(count))
                            .arg(QString("000000000"+QString::number(index)).right(10))
                            .arg(this->checksum);

        QFile packFile(outname);
        if(packFile.open(QIODevice::WriteOnly))
        {
            if(packFile.write(packData)==packData.size())
            {
                results<<outname;
            }
            packFile.close();
        }
        pos = pos + len;
        if(pos >= size)
            break;
    }
    if(results.size()!=index)
    {
        for(int i=0;i<results.size();i++)
        {
            QFile::remove(results.at(i));
        }
        results.clear();
    }
    return results;
}
QString FileSplitter::merge(QString curdir)
{
    QDir dir(curdir);
    if(!dir.exists())
    {
        dir.mkpath(curdir);
    }
    QByteArray mergeData;
    QFileInfoList list = dir.entryInfoList(QDir::Files,QDir::Name);
    for(int i=0;i<list.size();i++)
    {
        if(list.at(i).isFile())
        {
            QFile pack(list.at(i).absoluteFilePath());
            pack.open(QIODevice::ReadOnly);
            mergeData.append(pack.readAll());
            pack.close();
        }
    }
    QFile output(curdir + "/merge.dat");
    if(!output.open(QIODevice::WriteOnly))
    {
        return "";
    }
    output.write(mergeData);
    output.close();
    return curdir + "/merge.dat";
}
bool FileSplitter::prepare()
{
    QFile file(this->fileName);
    if(!file.open(QIODevice::ReadOnly))
    {
        return false;
    }
    this->rawData = file.readAll();
    this->checksum = QCryptographicHash::hash ( this->rawData, QCryptographicHash::Md5 ).toHex();
    file.close();
    QDir dir;
    if(!dir.exists(this->outputDir + "/" + this->checksum + "_" + this->fileID))
    {
        if(!dir.mkpath(this->outputDir + "/" + this->checksum + "_" + this->fileID))
        {
            return false;
        }
    }
    this->outputDir += "/" + this->checksum + "_" + this->fileID;
    return true;
}

QString FileSplitter::getRandPackKey()
{
    QTime time;
    time = QTime::currentTime();
    qsrand(time.msec()+time.second()*10000);
    int v = 100000 + qrand()%899999;
    return QString::number(v);
}

void FileSplitter::cleanup()
{
    qDebug()<<QDateTime::currentDateTime().toString("yyyy-MM-dd HH:mm:ss")\
           <<"FileSplitter cleanup called."<<this->outputDir;
    if(this->checksum.isEmpty())
        return ;
    QDir dir(this->outputDir);
    QFileInfoList list = dir.entryInfoList(QDir::Files,QDir::Name);
    for(int i=0;i<list.size();i++)
    {
        if(list.at(i).isFile())
        {
            QFile::remove(list.at(i).absoluteFilePath());
        }
    }
    dir.rmdir(this->outputDir);
}