Add methods for ZKInputs IntermStates generation

- Add L1Tx TxCompressedData method
- Add PoolL2Tx TxCompressedDataV2 method
- Update ProcessTxs logic
- Add ZKInputs Intermediate States & Fee parameters calculation

common/pooll2tx.go

@@ -140,13 +140,64 @@ func (tx *PoolL2Tx) TxCompressedData() (*big.Int, error) {
 		return nil, err
 	}
 	copy(b[19:25], fromIdxBytes[:])
-	copy(b[25:27], []byte{0, 1, 0, 0}) // TODO check js implementation (unexpected behaviour from test vector generated from js)
+	copy(b[25:27], []byte{0, 1}) // TODO this will be generated by the ChainID config parameter
 	copy(b[27:31], sc.Bytes())
 
 	bi := new(big.Int).SetBytes(b[:])
 	return bi, nil
 }
 
+// TxCompressedDataV2 spec:
+// [ 1 bits  ] toBJJSign // 1 byte
+// [ 8 bits  ] userFee // 1 byte
+// [ 40 bits ] nonce // 5 bytes
+// [ 32 bits ] tokenID // 4 bytes
+// [ 16 bits ] amountFloat16 // 2 bytes
+// [ 48 bits ] toIdx // 6 bytes
+// [ 48 bits ] fromIdx // 6 bytes
+// Total bits compressed data:  193 bits // 25 bytes in *big.Int representation
+func (tx *PoolL2Tx) TxCompressedDataV2() (*big.Int, error) {
+	if tx.Amount == nil {
+		tx.Amount = big.NewInt(0)
+	}
+	amountFloat16, err := NewFloat16(tx.Amount)
+	if err != nil {
+		return nil, err
+	}
+	var b [25]byte
+	toBJJSign := byte(0)
+	if tx.ToBJJ != nil && babyjub.PointCoordSign(tx.ToBJJ.X) {
+		toBJJSign = byte(1)
+	}
+	b[0] = toBJJSign
+	b[1] = byte(tx.Fee)
+	nonceBytes, err := tx.Nonce.Bytes()
+	if err != nil {
+		return nil, err
+	}
+	copy(b[2:7], nonceBytes[:])
+	copy(b[7:11], tx.TokenID.Bytes())
+	copy(b[11:13], amountFloat16.Bytes())
+	toIdxBytes, err := tx.ToIdx.Bytes()
+	if err != nil {
+		return nil, err
+	}
+	copy(b[13:19], toIdxBytes[:])
+	fromIdxBytes, err := tx.FromIdx.Bytes()
+	if err != nil {
+		return nil, err
+	}
+	copy(b[19:25], fromIdxBytes[:])
+
+	bi := new(big.Int).SetBytes(b[:])
+	return bi, nil
+}
+
+// RqTxCompressedDataV2 is like the TxCompressedDataV2 but using the 'Rq'
+// parameters. In a future iteration of the hermez-node, the 'Rq' parameters
+// can be inside a struct, which contains the 'Rq' transaction grouped inside,
+// so then computing the 'RqTxCompressedDataV2' would be just calling
+// 'tx.Rq.TxCompressedDataV2()'.
 // RqTxCompressedDataV2 spec:
 // [ 1 bits  ] rqToBJJSign // 1 byte
 // [ 8 bits  ] rqUserFee // 1 byte