#include "UdtSocket.h"
#include <stdio.h>
#include <stdlib.h>
#include <QApplication>
#include <QtEndian>
#include <QDir>
#include <QDate>
#include "file_ui.h"
#include "communication.h"

#ifndef WIN32
   #include <arpa/inet.h>
#else
   #include <winsock2.h>
   #include <ws2tcpip.h>
#endif

using namespace std;

UdtSocket::UdtSocket(UDTSOCKET file_socket,UDTSOCKET com_socket,QString name): QObject() {
    this->file_socket=file_socket;
    this->com_socket=com_socket;
    this->name=name;
    stop=false;
    file_dialog=new file_ui();

    bool blocking = true;
    UDT::setsockopt(file_socket, 0, UDT_RCVSYN, &blocking, sizeof(bool));

    heartbeat_timer = new QTimer(this);
    connect(heartbeat_timer, SIGNAL(timeout()), this, SLOT(heartbeat()));
    heartbeat_timer->start(200);
}

UdtSocket::~UdtSocket() {
    heartbeat_timer->stop();

    UDT::close(file_socket);
    UDT::close(com_socket);

    file_dialog->deleteLater();
}

//send signal to uav, to check connectivity through a watchdog
//this is necessary because we use udt (udp based), and we cannot check disconnection of ground station
void UdtSocket::heartbeat(void) {
    char data=WATCHDOG_HEADER;
    write(&data,1);
}

void UdtSocket::kill(void) {
    printf("disconnected\n");
    stop=true;
    deleteLater();
}

void UdtSocket::handleConnections(void) {
    while(!stop) {
        int eid = UDT::epoll_create();
        if(eid<0) {
            printf("epoll_create error: %s\n",UDT::getlasterror().getErrorMessage());
        }

        if(UDT::epoll_add_usock(eid,file_socket)<0) {
            if(UDT::getlasterror().getErrorCode()==5004) {
                printf("epoll_add_usock\n");
                break;
            } else {
                printf("epoll_add_usock error: %s\n",UDT::getlasterror().getErrorMessage());
            }
        }
        if(UDT::epoll_add_usock(eid,com_socket)<0) {
            if(UDT::getlasterror().getErrorCode()==5004) {
                printf("epoll_add_usock\n");
                break;
            } else {
                printf("epoll_add_usock error: %s\n",UDT::getlasterror().getErrorMessage());
            }
        }

        set<UDTSOCKET> readfds;

        int rv=UDT::epoll_wait(eid, &readfds,NULL, 10) ;

        if(rv == -1) {
            if(UDT::getlasterror().getErrorCode()!=6003) printf("prob %i\n",UDT::getlasterror().getErrorCode());
            //printf("wait\n");
        } else if(rv == 0) {
            printf("timeout\n"); // a timeout occured
        } else {
            /*
            if(UDT::getlasterror().getErrorCode()==2001) {
                UDT::epoll_release(eid);
            }*/
            for (set<UDTSOCKET>::iterator i = readfds.begin(); i != readfds.end(); i++) {
                //printf("a\n");
                if(*i==file_socket) receiveFile();
                if(*i==com_socket) receiveData();
            }
        }

        UDT::epoll_remove_usock(eid,file_socket);
        UDT::epoll_remove_usock(eid,com_socket);
        UDT::epoll_release(eid);

        QCoreApplication::processEvents();
    }
    kill();
}

void UdtSocket::receiveFile(void) {
    char* recv_buf;
    int bytesRead;
    static bool flag_new_seq=true;
    static QString folder_name;

    //receive file info
    recv_buf= (char*)malloc(1024);
    bytesRead = UDT::recvmsg(file_socket,recv_buf,1024);

    if(bytesRead<=0) {
        free(recv_buf);
        return;
    }

    int size;
    memcpy(&size,&recv_buf[1],sizeof(int));
    if(recv_buf[0]==FILE_INFO_BIG_ENDIAN) size=qFromBigEndian(size);

    //printf("file_ui recu %i %x\n",bytesRead,recv_buf[0]);
    if((recv_buf[0]==FILE_INFO_LITTLE_ENDIAN || recv_buf[0]==FILE_INFO_BIG_ENDIAN) && size>0) {
        if(flag_new_seq==true) {
            //create directory for storage
            QDateTime dateTime = QDateTime::currentDateTime();
            folder_name = dateTime.toString("yyyyMMdd_hhmm")+ "_" + name;
            if(QDir().exists(folder_name)==true) {
                folder_name = dateTime.toString("yyyyMMdd_hhmm_ss")+ "_" + name;
            }
            QDir().mkdir(folder_name);

            flag_new_seq=false;
            file_dialog->log("Creating directory " +folder_name);
        }

        QString file_name= QString::fromAscii((const char*)&recv_buf[5],bytesRead-5);
        QString file_path=folder_name + "/" + file_name;
        file_dialog->log(QString("receiving %1 (%2 bytes)").arg(file_name).arg(size));
        QFile fichier(file_path);

        if(!fichier.open(QIODevice::WriteOnly)) {
            file_dialog->log("      could not write to file!");
        } else {
            //receive file
            recv_buf= (char*)realloc((void*)recv_buf,size);
            bytesRead = UDT::recvmsg(file_socket,recv_buf,size);
            if(bytesRead!=size) {
                file_dialog->log(QString("      error receiving file! (%1/%2)").arg(bytesRead).arg(size));
                free(recv_buf);
                return;
            } else {
                file_dialog->log("      ok");
            }

            QDataStream stream(&fichier);
            stream.writeRawData(recv_buf,size);
            fichier.close();

            file_dialog->addFile(file_path);
        }

        free(recv_buf);
    } else if(recv_buf[0]==END) {
        file_dialog->endOfFiles();
        flag_new_seq=true;
    }
}

void UdtSocket::receiveData(void) {
    while(1) {
        int buf_size;
        int opt_size;
        UDT::getsockopt(com_socket,0,UDT_RCVBUF,&buf_size,&opt_size);

        char* buf=(char*)malloc(buf_size);
        int size;
        size = UDT::recvmsg(com_socket,buf, buf_size);
        buf=(char*)realloc(buf,size+1);

        if(size>0) {
            buf[size]=0;
            emit dataReady(buf,size+1);
        } else {
            //if(UDT::getlasterror().getErrorCode()!=6002) printf("udt socket: %s\n",UDT::getlasterror().getErrorMessage());
            free(buf);
            break;
        }
    }
}

void UdtSocket::write(const char* buf, qint64 size) {
    //printf("write\n%s\n",buf);
    qint64 sent=UDT::sendmsg(com_socket,buf,size, -1, true);
    if(sent!=size) {
        printf("erreur envoi: %s\n",UDT::getlasterror().getErrorMessage());
        if(UDT::getlasterror().getErrorCode()==2001) {
           stop=true;
        }
    }
}