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#include <Parser.h>

// Base64 Decoder
// see Parser.h for details about sRxData
bool Parser::decode64(sRxData &rx)
{
    int length = rx.str.size();
    unsigned char a,b,c,d;
    unsigned char ptr = 0;
    unsigned char x,y,z;
    int ptrOut[150];

    int ptrIn = 3;
    int max = length;
    int len = length;
    int decLen = 0;

    if (rx.input[ptrIn] == 0) {
        return false;
        //TODO: catch error to show that something went wrong during the decode process
        //throw "Nothing received";
    }

    while(len != 0) {
        a = rx.input[ptrIn++] - '=';
        b = rx.input[ptrIn++] - '=';
        c = rx.input[ptrIn++] - '=';
        d = rx.input[ptrIn++] - '=';

        if(ptrIn > max - 2) break;

        x = (a << 2) | (b >> 4);
        y = ((b & 0x0f) << 4) | (c >> 2);
        z = ((c & 0x03) << 6) | d;

        if(len--) ptrOut[ptr++] = x; else break;
        if(len--) ptrOut[ptr++] = y; else break;
        if(len--) ptrOut[ptr++] = z; else break;
    }

    for (int a=0; a<ptr; a++) {
        if (length == false) {
            int b1, b2, b3;

            b1 = ptrOut[a++];
            b2 = ptrOut[a];

            b3 = (b2 << 8) | b1;

            if (b3 > 32767)
                b3 = b3 - 65536;

            rx.decode[decLen] = b3;
            decLen++;
        } else {
            rx.decode[decLen] = ptrOut[a];
            decLen++;
        }
        rx.decLen = decLen;
    }
    return true;
}

// base64 encoder
string Parser::encode64(char data[150],unsigned int length)
{
    unsigned int pt = 0;
    unsigned char a,b,c;
    unsigned char ptr = 0;

    char tx_buff[150];

    while(length > 0)
    {
        if(length) { a = data[ptr++]; length--;} else a = 0;
        if(length) { b = data[ptr++]; length--;} else b = 0;
        if(length) { c = data[ptr++]; length--;} else c = 0;

        tx_buff[pt++] = '=' + (a >> 2);
        tx_buff[pt++] = '=' + (((a & 0x03) << 4) | ((b & 0xf0) >> 4));
        tx_buff[pt++] = '=' + (((b & 0x0f) << 2) | ((c & 0xc0) >> 6));
        tx_buff[pt++] = '=' + ( c & 0x3f);
    }
    tx_buff[pt] = 0;

    return string(tx_buff);
}

// Datensatz nach 8bit Integer
int Parser::dataToChar(int *data , int start, bool is_signed) {
    int out = (data[start]);

    if ((out > 128) && (is_signed))
      out = out - 256;

    return out;
}

// received char to 8 bit integer
int Parser::charToData(int data) {
    if (data < 0)
        return data + 256;
    return data;
}

// convert data to 16bit Integer
int Parser::dataToInt(int *Data , int Start, bool is_signed)
{
    int Out = (Data[Start+1]<<8) | (Data[Start+0]);

    if ((Out > 32767) && (is_signed))
      Out = Out - 65536;

    return Out;

}

// convert data to 32bit Long
long Parser::dataToLong(int *Data , int Start, bool is_signed)
{
    long Out = (Data[Start+3]<<24) | (Data[Start+2]<<16) | (Data[Start+1]<<8) | (Data[Start+0]);

    if ((Out > 32767) && (is_signed))
      Out = Out;

    return Out;
}

float Parser::getFloat(long value, int count)
{
    long num = pow(10, count);

    float temp = value;

    return temp / num;
}

string Parser::dataToString(int Data[150], int Start, int End)
{
    char String[150];
    for (int a = Start; a < End; a++)
    {
        String[a - Start] = Data[a];
    }
    String[End - Start] = '\0';

    return string(String);
}

// check CRC
bool Parser::check_CRC(string RXstr)
{
    int length = RXstr.size();
    int CRC = 0;
    char *RX = (char *)RXstr.c_str();

    if (RX[1] == 127)
    {
        RX[1] = 0;
    }

    for(int i=0; i < length-2; i++)
    {
            CRC+=RX[i];
    }

    CRC = CRC % 4096;

    if(RX[length - 2] != ('=' + (CRC / 64)))
    {
        return false;
    }

    if(RX[length - 1] != ('=' + CRC % 64))
    {
        return false;
    }

    return true;
}

// add CRC
string Parser::add_CRC(string TX)
{
    int length = TX.size();
    unsigned int tmpCRC = 0;

    char CRC[2];

    for(int i = 0; i < length; i++)
    {
        tmpCRC += TX[i];
    }

    tmpCRC %= 4096;

    CRC[0] = '=' + tmpCRC / 64;
    CRC[1] = '=' + tmpCRC % 64;
    CRC[2] = '\0';

    return string(TX) + string(CRC);
}