/**
 * @file    reHDD.cpp
 * @brief   app logic
 * @author  hendrik schutter
 * @date    01.05.2020
 */

#include "../include/reHDD.h"

static int fdNewDrivesInformPipe[2];//File descriptor for pipe that informs if new drives are found

static int fdShredInformPipe[2];//File descriptor for pipe that informs if a wipe thread signals

static std::mutex mxDrives;

list <Drive> listNewDrives; //store found drives that are updated every 5sec

static list <Drive> listDrives; //stores all drive data from scann thread

TUI *ui;

static  uint8_t u8SelectedEntry;

static fd_set selectSet;

/**
 * \brief   app constructor
 * \param	void
 * \return  instance of App
 */
reHDD::reHDD(void)
{
    u8SelectedEntry = 0U;
}

/**
 * \brief   app logic
 * \param	void
 * \return  void
 */
void reHDD::app_logic(void)
{
    ui = new TUI();
    ui->initTUI();

    pipe(fdNewDrivesInformPipe);
    pipe(fdShredInformPipe);

    thread thDevices(ThreadScannDevices); //start thread that scanns for drives
    thread thUserInput(ThreadUserInput); //start thread that reads user input
    thread thCheckFrozenDrives(ThreadCheckFrozenDrives); //start thread that checks timeout for drives

    while(1)
        {
            FD_ZERO(&selectSet);
            FD_SET(fdNewDrivesInformPipe[0], &selectSet);
            FD_SET(fdShredInformPipe[0], &selectSet);

            select(FD_SETSIZE, &selectSet, NULL, NULL, NULL);

            if(FD_ISSET(fdNewDrivesInformPipe[0], &selectSet))
                {
                    mxDrives.lock();
                    char dummy;
                    read (fdNewDrivesInformPipe[0],&dummy,1);
                    filterNewDrives(&listDrives, &listNewDrives); //filter and copy to app logic vector
                    printDrives(&listDrives);
                    mxDrives.unlock();
                }
            if(FD_ISSET(fdShredInformPipe[0], &selectSet))
                {
                    char dummy;
                    read (fdShredInformPipe[0],&dummy,1);
                    updateShredMetrics(&listDrives);
#ifdef LOG_LEVEL_HIGH
                    Logger::logThis()->info("got progress signal from a shred task");
#endif




                }
            ui->updateTUI(&listDrives, u8SelectedEntry);
        } //endless loop
    thDevices.join();
    thUserInput.join();
    thCheckFrozenDrives.join();
}

Drive* reHDD::getSelectedDrive()
{
    if(u8SelectedEntry < listDrives.size() )
        {
            list<Drive>::iterator it = listDrives.begin();
            advance(it, u8SelectedEntry);
            return &(*it);
        }
    else
        {
            Logger::logThis()->warning("selected drive not present");
            return {};
        }
}

void reHDD::ThreadScannDevices()
{
    while(true)
        {
            mxDrives.lock();
            listNewDrives.clear();
            searchDrives(&listNewDrives);           //search for new drives and store them in list
            filterIgnoredDrives(&listNewDrives);    //filter out ignored drives
            addSMARTData(&listNewDrives);           //add S.M.A.R.T. Data to the drives
            mxDrives.unlock();
            write(fdNewDrivesInformPipe[1], "A",1);
            sleep(5); //sleep 5 sec
        }
}

void reHDD::ThreadCheckFrozenDrives()
{
    while(true)
        {
            mxDrives.lock();
            for(auto it = begin(listDrives); it != end(listDrives); ++it)
                {
                    if(it->state == Drive::SHRED_ACTIVE)
                        {
                            it->checkFrozenDrive();
                        }
                }
            mxDrives.unlock();
            sleep(13); //sleep 13 sec
        }
}

void reHDD::ThreadUserInput()
{
    while(true)
        {
            // cout << TUI::readUserInput() << endl;
            switch (TUI::readUserInput())
                {
                case TUI::UserInput::DownKey:
                    //cout << "Down" << endl;
                    handleArrowKey(TUI::UserInput::DownKey);
                    ui->updateTUI(&listDrives, u8SelectedEntry);
                    break;
                case TUI::UserInput::UpKey:
                    //cout << "Up" << endl;
                    handleArrowKey(TUI::UserInput::UpKey);
                    ui->updateTUI(&listDrives, u8SelectedEntry);
                    break;
                case TUI::UserInput::Undefined:
                    //cout << "Undefined" << endl;
                    break;
                case TUI::UserInput::Abort:
                    //cout << "Abort" << endl;
                    handleAbort();
                    ui->updateTUI(&listDrives, u8SelectedEntry);
                    break;
                case TUI::UserInput::Delete:
                    //cout << "Delete" << endl;

                    if (getSelectedDrive() != nullptr)
                        {
                            if(getSelectedDrive()->state == Drive::NONE)
                                {
                                    getSelectedDrive()->state = Drive::DELETE_SELECTED;
                                }
                        }

                    ui->updateTUI(&listDrives, u8SelectedEntry);
                    break;
                case TUI::UserInput::Shred:
                    //cout << "Shred" << endl;

                    if (getSelectedDrive() != nullptr)
                        {
                            if(getSelectedDrive()->state == Drive::NONE)
                                {
                                    getSelectedDrive()->state = Drive::SHRED_SELECTED;
                                }
                        }

                    ui->updateTUI(&listDrives, u8SelectedEntry);
                    break;
                case TUI::UserInput::ShredAll:
                    //cout << "ShredAll" << endl;
                    startShredAllDrives(&listDrives);
                    ui->updateTUI(&listDrives, u8SelectedEntry);
                    break;
                case TUI::UserInput::Enter:
                    //cout << "Enter" << endl;
                    handleEnter();
                    ui->updateTUI(&listDrives, u8SelectedEntry);
                    break;
                case TUI::UserInput::ESC:
                    //cout << "ESC" << endl;
                    handleESC();
                    ui->updateTUI(&listDrives, u8SelectedEntry);
                    break;
                default:
                    break;
                }
        }
}

void reHDD::ThreadShred(Drive* const pDrive)
{
    if (pDrive != nullptr)
        {
            pDrive->setActionStartTimestamp(); //save timestamp at start of shredding
            Shred* pShredTask = new Shred(); //create new shred task
            pShredTask->shredDrive(pDrive, &fdShredInformPipe[1]); //start new shred task
            delete pShredTask; //delete shred task
            ui->updateTUI(&listDrives, u8SelectedEntry);
        }
}

void reHDD::ThreadDelete()
{
    if (getSelectedDrive() != nullptr)
        {
            getSelectedDrive()->setActionStartTimestamp(); //save timestamp at start of deleting
            Delete::deleteDrive(getSelectedDrive()); //blocking, no thread
            getSelectedDrive()->state = Drive::TaskState::NONE; //delete finished
            getSelectedDrive()->bWasDeleteted = true;
            Logger::logThis()->info("Finished delete for: " + getSelectedDrive()->getModelName() + "-" +  getSelectedDrive()->getSerial());
            ui->updateTUI(&listDrives, u8SelectedEntry);
        }
}

void reHDD::filterNewDrives(list <Drive>* plistOldDrives, list <Drive>* plistNewDrives)
{
    list <Drive>::iterator itOld; //Iterator for current (old) drive list
    list <Drive>::iterator itNew; //Iterator for new drive list that was created from to scann thread

    //remove offline old drives from previously run
    for (itOld = plistOldDrives->begin(); itOld != plistOldDrives->end();)
        {
            if(itOld->bIsOffline == true)
                {
                    Logger::logThis()->warning("Offline drive found: " + itOld->getPath());
                    itOld = plistOldDrives->erase(itOld);
                    /*
                    if(plistOldDrives->size() > 0){ //This can be a risk if the user starts a task for the selected drive and the selected drive changes
                        u8SelectedEntry = 0U;
                    }
                    */
                }
            else
                {
                    ++itOld;
                }
        }

    //search offline drives and mark them
    for (itOld = plistOldDrives->begin(); itOld != plistOldDrives->end(); ++itOld)
        {
            itOld->bIsOffline = true; //set offline before searching in the new list
            for (itNew = plistNewDrives->begin(); itNew != plistNewDrives->end();)
                {
                    if((itOld->getSerial() == itNew->getSerial()) || (itOld->getPath() == itNew->getPath()))
                        {
                            itOld->bIsOffline = false; //drive is still attached
                            //copy new smart data to existing drive
                            itOld->setDriveSMARTData(itNew->getModelFamily(), itNew->getModelName(), itNew->getSerial(), itNew->getCapacity(), itNew->getErrorCount(), itNew->getPowerOnHours(), itNew->getPowerCycles(), itNew->getTemperature());
#ifdef LOG_LEVEL_HIGH
                            Logger::logThis()->info("Delete new drive, because allready attached: " + itNew->getModelName());
#endif
                            itNew = plistNewDrives->erase(itNew); //This drive is allready attached, remove from new list
                        }
                    else
                        {
                            ++itNew;
                        }
                }
        }

    //mark offline old drives
    for (itOld = plistOldDrives->begin(); itOld != plistOldDrives->end(); ++itOld)
        {
            if(itOld->bIsOffline == true)
                {
                    //cout << "offline drive found: " << itOld->getPath() << endl;
                    Logger::logThis()->warning("Mark offline drive found: " + itOld->getPath());
                    itOld->state = Drive::NONE; //clear state --> shred task will terminate
                }
        }

    //add new drives to drive list
    for (itNew = plistNewDrives->begin(); itNew != plistNewDrives->end(); ++itNew)
        {
            plistOldDrives->push_back(*itNew);
            //Logger::logThis()->info("Add new drive: " + itNew->getModelName());
        }
    plistNewDrives->clear();
}

/**
 * \brief   search attached drives on /dev/sd*
 * \param	pointer of list <Drive>* plistDrives
 * \return  void
 */
void reHDD::searchDrives(list <Drive>* plistDrives)
{
    //Logger::logThis()->info("-->    search drives   <--");
    char * cLine = NULL;
    size_t len = 0;

    FILE* outputfileHwinfo = popen("lsblk -I 8 -d -o NAME", "r");

    if (outputfileHwinfo == NULL)
        {
            Logger::logThis()->error("Unable to scan attached drives");
            exit(EXIT_FAILURE);
        }

    while ((getline(&cLine, &len, outputfileHwinfo)) != -1)
        {
            if (string(cLine).length() == 4)
                {
                    Drive* tmpDrive = new Drive("/dev/" + string(cLine).substr(0, 3));
                    tmpDrive->state = Drive::NONE;
                    tmpDrive->bIsOffline = false;
                    plistDrives->push_back(*tmpDrive);
                    //Logger::logThis()->info("drive found: " + tmpDrive->getPath());
                }
        }
    pclose(outputfileHwinfo);
}

/**
 * \brief   filter out drives that are listed in "ignoreDrives.conf"
 * \param	pointer of list <Drive>* plistDrives
 * \return  void
 */
void reHDD::filterIgnoredDrives(list <Drive>* plistDrives)
{
    list<tuple<string>> vtlIgnoredDevices; //store drives from ingnore file
    ifstream input( "ignoreDrives.conf" ); //read ingnore file

    for(string sLine; getline( input, sLine );)
        {
            //Logger::logThis()->info("read uuid: " + sLine);
            vtlIgnoredDevices.emplace_back(sLine); //add found path and uuid from ignore file to vector
        }
    //loop through found entries in ingnore file
    for(auto row : vtlIgnoredDevices)
        {
            list <Drive>::iterator it;
            for (it = plistDrives->begin(); it != plistDrives->end(); ++it)
                {
                    string sUUID;
                    char * cLine = NULL;
                    size_t len = 0;
                    string sCMD = "blkid ";
                    sCMD.append(it->getPath());
                    //cout << "cmd: " << sCMD << endl;
                    FILE* outputfileBlkid = popen(sCMD.c_str(), "r"); //get UUID from drive
                    if (outputfileBlkid == NULL)
                        {
                            exit(EXIT_FAILURE);
                        }

                    while ((getline(&cLine, &len, outputfileBlkid)) != -1) //parse UUID from blkid
                        {
                            if (string(cLine).find("PTUUID") != string::npos)
                                {
                                    string sBlkidOut = string(cLine);
                                    sBlkidOut.erase(0, 18);
                                    sBlkidOut.erase(8, sBlkidOut.length());
                                    sUUID = sBlkidOut;
                                    //cout << "blkid uuid:" << sUUID << endl;
                                }
                        }
                    pclose(outputfileBlkid);
                    //cout << "blkid uuid:" << sUUID << endl;

                    if (!get<0>(row).compare(sUUID)) //compare uuid from ignore file and uuid from drive
                        {
                            // same uuid found than in ignore file --> ignore this drive
#ifdef LOG_LEVEL_HIGH
                            Logger::logThis()->info("same uuid found than in ignore file --> ignore this drive: " + it->getPath());
#endif
                            it = plistDrives->erase(it);
                            it--;
                        }
                }
        }
}

/**
 * \brief   start shred for all drives
 * \param	pointer of list <Drive>* plistDrives
 * \return  void
 */
void reHDD::startShredAllDrives(list <Drive>* plistDrives)
{
    list <Drive>::iterator it;
    mxDrives.lock();
    for (it = plistDrives->begin(); it != plistDrives->end(); ++it)
        {
            if(it->state == Drive::NONE)
                {
                    Drive* pTmpDrive = iterator_to_pointer<Drive, std::list<Drive>::iterator > (it);
#ifdef LOG_LEVEL_HIGH
                    ostringstream address;
                    address << (void const *)&(*pTmpDrive);
                    Logger::logThis()->info("Started shred (all) for: " + pTmpDrive->getModelName() + "-" +  pTmpDrive->getSerial() + " @" + address.str());
#endif
                    pTmpDrive->state = Drive::TaskState::SHRED_ACTIVE;
                    thread(ThreadShred, pTmpDrive).detach();
                }
        }
    mxDrives.unlock();
}

/**
 * \brief   print drives with all information
 * \param	pointer of list <Drive>* plistDrives
 * \return  void
 */
void reHDD::printDrives(list <Drive>* plistDrives)
{
#ifdef LOG_LEVEL_HIGH
    Logger::logThis()->info("------------DRIVES START------------");
    //cout << "------------DRIVES---------------" << endl;
    list <Drive>::iterator it;
    uint8_t u8Index = 0;
    for (it = plistDrives->begin(); it != plistDrives->end(); ++it)
        {
            /*
               cout << "        Drive: " << distance(pvecDrives->begin(), it) << endl;
               cout << "Path:          " << it->getPath() << endl;
               cout << "ModelFamily:   " << it->getModelFamily() << endl;
               cout << "ModelName:     " << it->getModelName() << endl;
               cout << "Capacity:      " << it->getCapacity() << endl;
               cout << "Serial:        " << it->getSerial() << endl;
               cout << "PowerOnHours:  " << it->getPowerOnHours() << endl;
               cout << "PowerCycle:    " << it->getPowerCycles() << endl;
               cout << "ErrorCount:    " << it->getErrorCount() << endl;
               cout << endl;*/

            ostringstream address;
            address << (void const *)&(*it);
            Logger::logThis()->info(to_string(u8Index++) + ": " + it->getPath() + " - " + it->getModelFamily() + " - " + it->getSerial() + " @" + address.str());
        }
    Logger::logThis()->info("------------DRIVES END--------------");
    //cout << "---------------------------------" << endl;
#endif
}

/**
 * \brief   update shred metrics for all drives
 * \param	pointer of list <Drive>* plistDrives
 * \return  void
 */
void reHDD::updateShredMetrics(list <Drive>* plistDrives)
{
    list <Drive>::iterator it;
    for (it = plistDrives->begin(); it != plistDrives->end(); ++it)
        {
            if(it->state == Drive::SHRED_ACTIVE)
                {
                    Drive* pTmpDrive = iterator_to_pointer<Drive, std::list<Drive>::iterator > (it);
                    //set metrics for calculating shred speed
                    std::chrono::time_point<std::chrono::system_clock> chronoCurrentTimestamp = std::chrono::system_clock::now();
                    time_t u32ShredTimeDelta = (chronoCurrentTimestamp - pTmpDrive->sShredSpeed.chronoShredTimestamp).count();
                    if(u32ShredTimeDelta > METRIC_THRESHOLD)
                        {
                            pTmpDrive->sShredSpeed.u32ShredTimeDelta = u32ShredTimeDelta;
                            pTmpDrive->sShredSpeed.chronoShredTimestamp = std::chrono::system_clock::now();
                            pTmpDrive->sShredSpeed.ulWrittenBytes = pTmpDrive->sShredSpeed.ulSpeedMetricBytesWritten;
                            pTmpDrive->sShredSpeed.ulSpeedMetricBytesWritten = 0U;
                        }
                }
        }
}

/**
 * \brief   add S.M.A.R.T data from SMART
 * \param	pointer of list <Drive>* plistDrives
 * \return  void
 */
void reHDD::addSMARTData(list <Drive>* plistDrives)
{
    list <Drive>::iterator it;
    for (it = plistDrives->begin(); it != plistDrives->end(); ++it)
        {
            Drive* pTmpDrive = iterator_to_pointer<Drive, std::list<Drive>::iterator > (it);
            SMART::readSMARTData(pTmpDrive);
        }
}

void reHDD::handleArrowKey(TUI::UserInput userInput)
{
    int8_t u8EntrySize = (int8_t) listDrives.size();
    switch (userInput)
        {
        case TUI::UserInput::DownKey:
            u8SelectedEntry++;
            if(u8SelectedEntry >= u8EntrySize)
                {
                    u8SelectedEntry = 0;
                }
            break;
        case TUI::UserInput::UpKey:
            if(u8SelectedEntry == 0)
                {
                    u8SelectedEntry = (u8EntrySize-1);
                }
            else
                {
                    u8SelectedEntry--;
                }
            break;
        default:
            u8SelectedEntry = 0;
            break;
        }

    //Logger::logThis()->info("ArrowKey - selected drive: " + to_string(u8SelectedEntry));
}

void reHDD::handleEnter()
{

    if (getSelectedDrive() != nullptr)
        {
            if(getSelectedDrive()->state == Drive::TaskState::SHRED_SELECTED)
                {
                    Logger::logThis()->info("Started shred for: " + getSelectedDrive()->getModelName() + "-" +  getSelectedDrive()->getSerial());
                    getSelectedDrive()->state = Drive::TaskState::SHRED_ACTIVE;
                    //task for drive is running --> don´t show  more task options
                    Drive* pTmpDrive = getSelectedDrive();
                    thread(ThreadShred, pTmpDrive).detach();
                }

            if(getSelectedDrive()->state == Drive::TaskState::DELETE_SELECTED)
                {
                    Logger::logThis()->info("Started delete for: " + getSelectedDrive()->getModelName() + "-" +  getSelectedDrive()->getSerial());
                    getSelectedDrive()->state = Drive::TaskState::DELETE_ACTIVE;
                    //task for drive is running --> don´t show  more task options
                    thread(ThreadDelete).detach();
                }
        }
}

void reHDD::handleESC()
{
    if (getSelectedDrive() != nullptr)
        {
            if(getSelectedDrive()->state == Drive::TaskState::SHRED_SELECTED)
                {
                    getSelectedDrive()->state = Drive::TaskState::NONE;
                    //task for drive is selected --> remove selection
                }

            if(getSelectedDrive()->state == Drive::TaskState::DELETE_SELECTED)
                {
                    getSelectedDrive()->state = Drive::TaskState::NONE;
                    //task for drive is selected --> remove selection
                }
        }
}

void reHDD::handleAbort()
{
    if (getSelectedDrive() != nullptr)
        {
            if(getSelectedDrive()->state == Drive::SHRED_ACTIVE || getSelectedDrive()->state == Drive::DELETE_ACTIVE  )
                {
                    getSelectedDrive()->state = Drive::NONE;
                    Logger::logThis()->info("Abort-Shred-Signal for: " + getSelectedDrive()->getModelName() + "-" +  getSelectedDrive()->getSerial());
                    //task for drive is running --> remove selection
                }
        }
}