#include "my_chacha_hls.hpp"


void chachaCore(stream<axiWord> &ps2ipIntFifo, stream<chachaOut> &masterOut)
{
	static enum inStates 	{
								IN_STATE_IDLE = 0
							} curState;

	axiWord newInWord = {0,0};
	//static stream<chachaOut> chacha2ps("chacha2ps");
	//#pragma HLS STREAM variable=chacha2ps depth=10 dim=1

	uint32 instate[16],state[16],tmp;
	#pragma HLS array_partition variable=instate complete
	#pragma HLS array_partition variable=state complete
	uint64 nonce,startoffset = 0,endoffset = 0,repeat,initmp;
	keepstate ks;
	uint256 key = 0;
	uint5 i = 0;

	switch(curState) {

			case IN_STATE_IDLE: 
			{
			  if (!ps2ipIntFifo.empty()) {

				ps2ipIntFifo.read(newInWord);

				key = newInWord.data(255,0);
				nonce = newInWord.data(319,256);
				startoffset = newInWord.data(383,320);
				endoffset = newInWord.data(447,384);

				instate[0] = 0x61707865; 								/* "expa" */
				instate[1] = 0x3320646e; 								/* "nd 3" */
				instate[2] = 0x79622d32; 								/* "2-by" */
				instate[3] = 0x6b206574; 								/* "te k" */

				LOOP_KEY:for(i = 4; i < 12; ++i)
				{
				#pragma HLS pipeline
					instate[i] = LITTLE_INT32(key.range(255,224));		/* We use specific range with shift operation -> less LUT */
					key <<= 32;											/* Shift left in order to take the next 32 bit */
				}	/*End of LOOP_KEY */

				/* instate 12 & 13 is the counter every time */
				instate[14] = LITTLE_INT32(nonce.range(63,32));
				instate[15] = LITTLE_INT32(nonce.range(31,0));


				//initmp = startoffset;
				LOOP_CHACHA: for(repeat = 0; repeat <= 1000000; ++repeat)
				{
				#pragma HLS pipeline
					if ( repeat < endoffset)
					{
						//#pragma HLS loop_tripcount min=1 max=1000000			/* Estimate latency no impact on Synthesize only Reporting */
						chachaOut newOutStream = {0,0};
						instate[12] = startoffset.range(31,0);
						instate[13] = startoffset.range(63,32);

						LOOP_INIT:for(i = 0; i < 16; ++i)
						{
							state[i] = instate[i];
						}	/*End of LOOP_INIT */

						LOOP_QR: for(i = 0; i < ROUNDS; i +=2)
						{
							/* Odd round */
							ks = QR(state[0], state[4], state[8], state[12]);	/* column 0 */
							state[0] = ks.stat[0];
							state[4] = ks.stat[1];
							state[8] = ks.stat[2];
							state[12] = ks.stat[3];
							ks = QR(state[1], state[5], state[9], state[13]); 	/* column 1 */
							state[1] = ks.stat[0];
							state[5] = ks.stat[1];
							state[9] = ks.stat[2];
							state[13] = ks.stat[3];
							ks = QR(state[2], state[6], state[10], state[14]); 	/* column 2 */
							state[2] = ks.stat[0];
							state[6] = ks.stat[1];
							state[10] = ks.stat[2];
							state[14] = ks.stat[3];
							ks = QR(state[3], state[7], state[11], state[15]); 	/* column 3 */
							state[3] = ks.stat[0];
							state[7] = ks.stat[1];
							state[11] = ks.stat[2];
							state[15] = ks.stat[3];
							/* Even round */
							ks = QR(state[0], state[5], state[10], state[15]); 	/* diagonal 1 (main diagonal) */
							state[0] = ks.stat[0];
							state[5] = ks.stat[1];
							state[10] = ks.stat[2];
							state[15] = ks.stat[3];
							ks = QR(state[1], state[6], state[11], state[12]); 	/* diagonal 2 */
							state[1] = ks.stat[0];
							state[6] = ks.stat[1];
							state[11] = ks.stat[2];
							state[12] = ks.stat[3];
							ks = QR(state[2], state[7], state[8], state[13]); 	/* diagonal 3 */
							state[2] = ks.stat[0];
							state[7] = ks.stat[1];
							state[8] = ks.stat[2];
							state[13] = ks.stat[3];
							ks = QR(state[3], state[4], state[9], state[14]); 	/* diagonal 4 */
							state[3] = ks.stat[0];
							state[4] = ks.stat[1];
							state[9] = ks.stat[2];
							state[14] = ks.stat[3];
						} 	/*End of LOOP_QR */

						LOOP_OUT:for(i = 0; i < 16; ++i)
						{
							tmp = MOD_Ov(instate[i] + state[i]);
							newOutStream.datstream <<= 32;
							newOutStream.datstream.range(31,0) = LITTLE_INT32(tmp);
						}	/*End of LOOP_OUT */



						if(startoffset == endoffset){
							newOutStream.last = newInWord.last;
						}

						startoffset ++;
						masterOut.write(newOutStream);
					}else{
						break;
					}
				} 		/*End of LOOP_CHACHA */
			}

			curState = IN_STATE_IDLE;
			break;
		}				/*End of case IN_STATE_IDLE */
	};
	
	return;
}