#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <unistd.h>

#include "../inc/m17.h"
#include "golay.h"
#include "crc.h"

//#define FN60_DEBUG

struct LSF
{
	uint8_t dst[6];
	uint8_t src[6];
	uint8_t type[2];
	uint8_t meta[112/8];
	uint8_t crc[2];
} lsf, next_lsf;

uint8_t lich[6];                    //48 bits packed raw, unencoded LICH
uint8_t lich_encoded[12];           //96 bits packed, encoded LICH
uint8_t enc_bits[SYM_PER_PLD*2];    //type-2 bits, unpacked
uint8_t rf_bits[SYM_PER_PLD*2];     //type-4 bits, unpacked

uint8_t data[16], next_data[16];    //raw payload, packed bits
uint16_t fn=0;                      //16-bit Frame Number (for the stream mode)
uint8_t lich_cnt=0;                 //0..5 LICH counter
uint8_t got_lsf=0;                  //have we filled the LSF struct yet?
uint8_t finished=0;

void send_Preamble(const uint8_t type)
{
    float symb;

    if(type) //pre-BERT
    {
        for(uint16_t i=0; i<192/2; i++) //40ms * 4800 = 192
        {
            symb=-3.0;
            write(STDOUT_FILENO, (uint8_t*)&symb,  sizeof(float));
            symb=+3.0;
            write(STDOUT_FILENO, (uint8_t*)&symb,  sizeof(float));
        }
    }
    else //pre-LSF
    {
        for(uint16_t i=0; i<192/2; i++) //40ms * 4800 = 192
        {
            symb=+3.0;
            write(STDOUT_FILENO, (uint8_t*)&symb,  sizeof(float));
            symb=-3.0;
            write(STDOUT_FILENO, (uint8_t*)&symb,  sizeof(float));
        }
    }
}

void send_Syncword(const uint16_t sword)
{
    float symb;

    for(uint8_t i=0; i<16; i+=2)
    {
        symb=symbol_map[(sword>>(14-i))&3];
        write(STDOUT_FILENO, (uint8_t*)&symb,  sizeof(float));
    }
}

//send the data (can be used for both LSF and frames)
void send_data(uint8_t* in)
{
	float s=0.0;
	for(uint16_t i=0; i<SYM_PER_PLD; i++) //40ms * 4800 - 8 (syncword)
	{
		s=symbol_map[in[2*i]*2+in[2*i+1]];
		write(STDOUT_FILENO, (uint8_t*)&s, sizeof(float));
	}
}

void send_EoT()
{
    float symb=+3.0;
    for(uint16_t i=0; i<192; i++) //40ms * 4800 = 192
    {
        write(STDOUT_FILENO, (uint8_t*)&symb,  sizeof(float));
    }
}

//out - unpacked bits
//in - packed raw bits
//fn - frame number
void conv_Encode_Frame(uint8_t* out, uint8_t* in, uint16_t fn)
{
	uint8_t pp_len = sizeof(P_2);
	uint8_t p=0;			//puncturing pattern index
	uint16_t pb=0;			//pushed punctured bits
	uint8_t ud[144+4+4];	//unpacked data

	memset(ud, 0, 144+4+4);

	//unpack frame number
	for(uint8_t i=0; i<16; i++)
	{
		ud[4+i]=(fn>>(15-i))&1;
	}

	//unpack data
	for(uint8_t i=0; i<16; i++)
	{
		for(uint8_t j=0; j<8; j++)
		{
			ud[4+16+i*8+j]=(in[i]>>(7-j))&1;
		}
	}

	//encode
	for(uint8_t i=0; i<144+4; i++)
	{
		uint8_t G1=(ud[i+4]                +ud[i+1]+ud[i+0])%2;
        uint8_t G2=(ud[i+4]+ud[i+3]+ud[i+2]        +ud[i+0])%2;

		//printf("%d%d", G1, G2);

		if(P_2[p])
		{
			out[pb]=G1;
			pb++;
		}

		p++;
		p%=pp_len;

		if(P_2[p])
		{
			out[pb]=G2;
			pb++;
		}

		p++;
		p%=pp_len;
	}

	//printf("pb=%d\n", pb);
}

//out - unpacked bits
//in - packed raw bits (LSF struct)
void conv_Encode_LSF(uint8_t* out, struct LSF *in)
{
	uint8_t pp_len = sizeof(P_1);
	uint8_t p=0;			//puncturing pattern index
	uint16_t pb=0;			//pushed punctured bits
	uint8_t ud[240+4+4];	//unpacked data

	memset(ud, 0, 240+4+4);

	//unpack DST
	for(uint8_t i=0; i<8; i++)
	{
		ud[4+i]   =((in->dst[0])>>(7-i))&1;
		ud[4+i+8] =((in->dst[1])>>(7-i))&1;
		ud[4+i+16]=((in->dst[2])>>(7-i))&1;
		ud[4+i+24]=((in->dst[3])>>(7-i))&1;
		ud[4+i+32]=((in->dst[4])>>(7-i))&1;
		ud[4+i+40]=((in->dst[5])>>(7-i))&1;
	}

	//unpack SRC
	for(uint8_t i=0; i<8; i++)
	{
		ud[4+i+48]=((in->src[0])>>(7-i))&1;
		ud[4+i+56]=((in->src[1])>>(7-i))&1;
		ud[4+i+64]=((in->src[2])>>(7-i))&1;
		ud[4+i+72]=((in->src[3])>>(7-i))&1;
		ud[4+i+80]=((in->src[4])>>(7-i))&1;
		ud[4+i+88]=((in->src[5])>>(7-i))&1;
	}

	//unpack TYPE
	for(uint8_t i=0; i<8; i++)
	{
		ud[4+i+96] =((in->type[0])>>(7-i))&1;
		ud[4+i+104]=((in->type[1])>>(7-i))&1;
	}

	//unpack META
	for(uint8_t i=0; i<8; i++)
	{
		ud[4+i+112]=((in->meta[0])>>(7-i))&1;
		ud[4+i+120]=((in->meta[1])>>(7-i))&1;
		ud[4+i+128]=((in->meta[2])>>(7-i))&1;
		ud[4+i+136]=((in->meta[3])>>(7-i))&1;
		ud[4+i+144]=((in->meta[4])>>(7-i))&1;
		ud[4+i+152]=((in->meta[5])>>(7-i))&1;
		ud[4+i+160]=((in->meta[6])>>(7-i))&1;
		ud[4+i+168]=((in->meta[7])>>(7-i))&1;
		ud[4+i+176]=((in->meta[8])>>(7-i))&1;
		ud[4+i+184]=((in->meta[9])>>(7-i))&1;
		ud[4+i+192]=((in->meta[10])>>(7-i))&1;
		ud[4+i+200]=((in->meta[11])>>(7-i))&1;
		ud[4+i+208]=((in->meta[12])>>(7-i))&1;
		ud[4+i+216]=((in->meta[13])>>(7-i))&1;
	}

	//unpack CRC
	for(uint8_t i=0; i<8; i++)
	{
		ud[4+i+224]=((in->crc[0])>>(7-i))&1;
		ud[4+i+232]=((in->crc[1])>>(7-i))&1;
	}

	//encode
	for(uint8_t i=0; i<240+4; i++)
	{
		uint8_t G1=(ud[i+4]                +ud[i+1]+ud[i+0])%2;
        uint8_t G2=(ud[i+4]+ud[i+3]+ud[i+2]        +ud[i+0])%2;

		//printf("%d%d", G1, G2);

		if(P_1[p])
		{
			out[pb]=G1;
			pb++;
		}

		p++;
		p%=pp_len;

		if(P_1[p])
		{
			out[pb]=G2;
			pb++;
		}

		p++;
		p%=pp_len;
	}

	//printf("pb=%d\n", pb);
}

uint16_t LSF_CRC(struct LSF *in)
{
    uint8_t d[28];

    memcpy(&d[0], in->dst, 6);
    memcpy(&d[6], in->src, 6);
    memcpy(&d[12], in->type, 2);
    memcpy(&d[14], in->meta, 14);

    return CRC_M17(d, 28);
}

//main routine
int main(void)
{
    //debug
    //printf("%06X\n", golay24_encode(1)); //golay encoder codeword test
    //printf("%d -> %d -> %d\n", 1, intrl_seq[1], intrl_seq[intrl_seq[1]]); //interleaver bijective reciprocality test, f(f(x))=x
    //return 0;

    if(fread(&(next_lsf.dst), 6, 1, stdin)<1) finished=1;
    if(fread(&(next_lsf.src), 6, 1, stdin)<1) finished=1;
    if(fread(&(next_lsf.type), 2, 1, stdin)<1) finished=1;
    if(fread(&(next_lsf.meta), 14, 1, stdin)<1) finished=1;
    if(fread(next_data, 16, 1, stdin)<1) finished=1;

    while(!finished)
    {
        lsf = next_lsf;

        //calculate LSF CRC
        uint16_t ccrc=LSF_CRC(&lsf);
        lsf.crc[0]=ccrc>>8;
        lsf.crc[1]=ccrc&0xFF;

        memcpy(data, next_data, sizeof(data));

        //we could discard the data we already have
        if(fread(&(next_lsf.dst), 6, 1, stdin)<1) finished=1;
        if(fread(&(next_lsf.src), 6, 1, stdin)<1) finished=1;
        if(fread(&(next_lsf.type), 2, 1, stdin)<1) finished=1;
        if(fread(&(next_lsf.meta), 14, 1, stdin)<1) finished=1;
        if(fread(next_data, 16, 1, stdin)<1) finished=1;

        if(got_lsf) //stream frames
        {
            //send stream frame syncword
            send_Syncword(SYNC_STR);

            //extract LICH from the whole LSF
            switch(lich_cnt)
            {
                case 0:
                    lich[0]=lsf.dst[0];
                    lich[1]=lsf.dst[1];
                    lich[2]=lsf.dst[2];
                    lich[3]=lsf.dst[3];
                    lich[4]=lsf.dst[4];
                break;

                case 1:
                    lich[0]=lsf.dst[5];
                    lich[1]=lsf.src[0];
                    lich[2]=lsf.src[1];
                    lich[3]=lsf.src[2];
                    lich[4]=lsf.src[3];
                break;

                case 2:
                    lich[0]=lsf.src[4];
                    lich[1]=lsf.src[5];
                    lich[2]=lsf.type[0];
                    lich[3]=lsf.type[1];
                    lich[4]=lsf.meta[0];
                break;

                case 3:
                    lich[0]=lsf.meta[1];
                    lich[1]=lsf.meta[2];
                    lich[2]=lsf.meta[3];
                    lich[3]=lsf.meta[4];
                    lich[4]=lsf.meta[5];
                break;

                case 4:
                    lich[0]=lsf.meta[6];
                    lich[1]=lsf.meta[7];
                    lich[2]=lsf.meta[8];
                    lich[3]=lsf.meta[9];
                    lich[4]=lsf.meta[10];
                break;

                case 5:
                    lich[0]=lsf.meta[11];
                    lich[1]=lsf.meta[12];
                    lich[2]=lsf.meta[13];
                    lich[3]=lsf.crc[0];
                    lich[4]=lsf.crc[1];
                break;

                default:
                    ;
                break;
            }
            lich[5]=lich_cnt<<5;

            //encode the LICH
            uint32_t val;

            val=golay24_encode((lich[0]<<4)|(lich[1]>>4));
            lich_encoded[0]=(val>>16)&0xFF;
            lich_encoded[1]=(val>>8)&0xFF;
            lich_encoded[2]=(val>>0)&0xFF;
            val=golay24_encode(((lich[1]&0x0F)<<8)|lich[2]);
            lich_encoded[3]=(val>>16)&0xFF;
            lich_encoded[4]=(val>>8)&0xFF;
            lich_encoded[5]=(val>>0)&0xFF;
            val=golay24_encode((lich[3]<<4)|(lich[4]>>4));
            lich_encoded[6]=(val>>16)&0xFF;
            lich_encoded[7]=(val>>8)&0xFF;
            lich_encoded[8]=(val>>0)&0xFF;
            val=golay24_encode(((lich[4]&0x0F)<<8)|lich[5]);
            lich_encoded[9]=(val>>16)&0xFF;
            lich_encoded[10]=(val>>8)&0xFF;
            lich_encoded[11]=(val>>0)&0xFF;

            //unpack LICH (12 bytes)
            memset(enc_bits, 0, SYM_PER_PLD*2);
            for(uint8_t i=0; i<12; i++)
            {
                for(uint8_t j=0; j<8; j++)
                    enc_bits[i*8+j]=(lich_encoded[i]>>(7-j))&1;
            }

            //encode the rest of the frame
            conv_Encode_Frame(&enc_bits[96], data, finished ? (fn | 0x8000) : fn);

            //reorder bits
            for(uint16_t i=0; i<SYM_PER_PLD*2; i++)
                rf_bits[i]=enc_bits[intrl_seq[i]];

            //randomize
            for(uint16_t i=0; i<SYM_PER_PLD*2; i++)
            {
                if((rand_seq[i/8]>>(7-(i%8)))&1) //flip bit if '1'
                {
                    if(rf_bits[i])
                        rf_bits[i]=0;
                    else
                        rf_bits[i]=1;
                }
            }

            //send dummy symbols (debug)
            /*float s=0.0;
            for(uint8_t i=0; i<SYM_PER_PLD; i++) //40ms * 4800 - 8 (syncword)
                write(STDOUT_FILENO, (uint8_t*)&s, sizeof(float));*/

			//send frame data
			send_data(rf_bits);

            /*printf("\tDATA: ");
            for(uint8_t i=0; i<16; i++)
                printf("%02X", data[i]);
            printf("\n");*/

            //increment the Frame Number
            fn = (fn + 1) % 0x8000;

            //increment the LICH counter
            lich_cnt = (lich_cnt + 1) % 6;

            //debug-only
			#ifdef FN60_DEBUG
            if(fn==6*10)
                return 0;
			#endif
        }
        else //LSF
        {
            got_lsf=1;

            //encode LSF data
            conv_Encode_LSF(enc_bits, &lsf);

            //send out the preamble and LSF
			send_Preamble(0); //0 - LSF preamble, as opposed to 1 - BERT preamble

            //send LSF syncword
			send_Syncword(SYNC_LSF);

            //reorder bits
            for(uint16_t i=0; i<SYM_PER_PLD*2; i++)
                rf_bits[i]=enc_bits[intrl_seq[i]];

            //randomize
            for(uint16_t i=0; i<SYM_PER_PLD*2; i++)
            {
                if((rand_seq[i/8]>>(7-(i%8)))&1) //flip bit if '1'
                {
                    if(rf_bits[i])
                        rf_bits[i]=0;
                    else
                        rf_bits[i]=1;
                }
            }

			//send LSF data
			send_data(rf_bits);

            //send dummy symbols (debug)
            /*float s=0.0;
            for(uint8_t i=0; i<184; i++) //40ms * 4800 - 8 (syncword)
                write(STDOUT_FILENO, (uint8_t*)&s, sizeof(float));*/

            /*printf("DST: ");
            for(uint8_t i=0; i<6; i++)
                printf("%02X", lsf.dst[i]);
            printf(" SRC: ");
            for(uint8_t i=0; i<6; i++)
                printf("%02X", lsf.src[i]);
            printf(" TYPE: ");
            for(uint8_t i=0; i<2; i++)
                printf("%02X", lsf.type[i]);
            printf(" META: ");
            for(uint8_t i=0; i<14; i++)
                printf("%02X", lsf.meta[i]);
            printf(" CRC: ");
            for(uint8_t i=0; i<2; i++)
                printf("%02X", lsf.crc[i]);
			printf("\n");*/
		}

        if (finished)
            send_EoT();
	}

	return 0;
}