#include <QMutexLocker>
#include <QFile>
#include <QElapsedTimer>

#include "filecopier.h"

FileCopier::FileCopier(QObject *parent) : QThread(parent), mCancel(false), mTotal(0), mCopied(0){}

void FileCopier::addJob(const QString &source, const QString &dest){
    QMutexLocker l(&mAddJobMutex);
    if(!mJobs.contains(source)){
        mJobs[source] = dest;
        ++mTotal;
    }
}

void FileCopier::run(){
    int bufsize = 32 * 1024 * 1024;
    char *buf = new char[bufsize];
    mCancel = false;
    mCopied = 0;
    QElapsedTimer et;
    while(!mJobs.isEmpty()){
        mAddJobMutex.lock();
        auto first = mJobs.constBegin();
        auto source = first.key();
        auto dest = first.value();
        mJobs.remove(source);
        mAddJobMutex.unlock();
        QFile sFile(source);
        QFile dFile(dest);
        bool openSource = sFile.open(QIODevice::ReadOnly);
        bool openDest = dFile.open(QIODevice::WriteOnly);
        if(!openSource || !openDest){
            emit success(false, source);
            goto cleanup;
        }
        emit newFile(source, dest, sFile.size());
        int read = 0;
        qint64 total = 0;
        qint64 elapsed = 0;
        qint64 bytesSinceEl = 0;
        et.start();
        while(!sFile.atEnd()){
            read = sFile.read(buf, bufsize);
            dFile.write(buf, read);
            total += read;
            bytesSinceEl += read;
            elapsed = et.elapsed();
            if(elapsed > 1000){
                mCancelMutex.lock();
                bool cancel = mCancel;
                mCancelMutex.unlock();
                if(cancel){
                    dFile.close();
                    QFile::remove(dest);
                    emit success(false, source);
                    goto cleanup;
                }
                mCountMutex.lock();
                emit bytesReadIntval(bytesSinceEl, elapsed, mTotal, mCopied);
                mCountMutex.unlock();
                elapsed = 0;
                bytesSinceEl = 0;
                et.restart();
            }
            emit bytesRead(total);
        }
        emit success(true, source);
        ++mCopied;
        emit bytesReadIntval(bytesSinceEl, elapsed, mTotal, mCopied);
        et.restart();
    }

    cleanup:
    delete buf;
    mTotal = 0;
    mJobs.clear();
}

void FileCopier::cancel(){
    QMutexLocker l(&mCancelMutex);
    mCancel = true;
}