// hubsan x4 tx frame decoder
// input: data.txt = saleae logic spi decoder exported output.
// output: dataout.txt = transmission data frames

#include <QtCore/QCoreApplication>
#include <qfile.h>
#include <qstringlist.h>
/*
Ex1: 20 00 00 00 80 00 7d 00 84 02 64 db 04 26 79 7b
Ex2: 20 00 00 00 80 00 7d 00 84 02 64 db 04 26 79 7b
     aa bb cc dd ee ff gg hh ii jj kk ll mm nn oo pp
cc : throttle observed range: 0x00 - 0xff (smaller is down)
ee : rudder observed range: 0x34 - 0xcc (smaller is right)
gg : elevator observed range: 0x3e - 0xbc (smaller is up)
ii : aileron observed range: 0x45 - 0xc3 (smaller is right)
llmmnnoo: Transmiter ID(?)
pp : checksum
Checksums:
The checksum is calculated as 256 - ((sum of the 1st 15 bytes) modulo 256)
*/
int main(int argc, char *argv[])
{
    // 1st phase, convert text output to data binary file
    QFile in("data.txt");
    QFile::remove("data.bin");
    QFile out("data.bin");

    //int test = 256-((0xff + 0x4a + 0x36 + 0x32 + 0xfe + 0xba + 0x5e + 0x03 + 0xdc + 0x28)%256);
    //QString hh = QString::number(test,16);

    in.open(QIODevice::ReadOnly);
    out.open(QIODevice::WriteOnly);
    QString line = in.readLine(); // skip first line
    while(!in.atEnd())
    {
        line = in.readLine();
        QString data = line.split("0x")[1].left(2);
        bool ok;
        unsigned char byte = data.toInt(&ok,16);
        out.write((const char*)&byte,1);
    }
    out.close();
    in.close();

    // 2nd phase, detect data packets and dump them to text file
    out.open(QIODevice::ReadOnly);
    QByteArray buffer = out.readAll();
    out.close();
    QFile::remove("E:\\Users\\goebish\\Desktop\\dataout.txt");
    QFile out2("E:\\Users\\goebish\\Desktop\\dataout.txt");
    out2.open(QIODevice::WriteOnly);
    int pos=0;

    int line_size = 16; //16;
    int offset = 3; //3;

    out2.write("    aa bb cc dd ee ff gg hh ii jj kk ll mm nn oo pp\n");
    while(pos<buffer.size()-line_size)
    {
        if( buffer.at(pos)   == (char)0xA0 // start of TX packet ?
        ||
        buffer.at(pos)   == (char)0x18  // start of RX packet ?
        )
        {
            out2.write("\n");
            if(buffer.at(pos) == (char)0xA0)
                out2.write("Tx: ");
            else if(buffer.at(pos) == (char)0x18)
                out2.write("Rx: ");

            int pos2 = pos+offset; // start of data;
            int dumped=0;
            while(pos2 < buffer.size() && dumped < line_size)
            {
                unsigned char data = buffer.at(pos2);
                QString hex = QString::number(data,16)+' ';
                if(data < 16)
                    out2.write("0");
                out2.write(hex.toAscii());
                pos2++;
                dumped++;
            }
        }
        pos++;
    }
    out2.close();
}