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/l1tx.go

@@ -146,6 +146,43 @@ func (tx L1Tx) Tx() Tx {
 	return genericTx
 }
 
+// TxCompressedData spec:
+// [ 1 bits  ] empty (toBJJSign) // 1 byte
+// [ 8 bits  ] empty (userFee) // 1 byte
+// [ 40 bits ] empty (nonce) // 5 bytes
+// [ 32 bits ] tokenID // 4 bytes
+// [ 16 bits ] amountFloat16 // 2 bytes
+// [ 48 bits ] toIdx // 6 bytes
+// [ 48 bits ] fromIdx // 6 bytes
+// [ 16 bits ] chainId // 2 bytes
+// [ 32 bits ] empty (signatureConstant) // 4 bytes
+// Total bits compressed data:  241 bits // 31 bytes in *big.Int representation
+func (tx L1Tx) TxCompressedData() (*big.Int, error) {
+	amountFloat16, err := NewFloat16(tx.Amount)
+	if err != nil {
+		return nil, err
+	}
+	var b [31]byte
+	// b[0:7] empty: no fee neither nonce
+	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[:])
+	copy(b[25:27], []byte{0, 1}) // TODO this will be generated by the ChainID config parameter
+	// b[27:] empty: no signature
+
+	bi := new(big.Int).SetBytes(b[:])
+	return bi, nil
+}
+
 // BytesGeneric returns the generic representation of a L1Tx. This method is
 // used to compute the []byte representation of a L1UserTx, and also to compute
 // the L1TxData for the ZKInputs (at the HashGlobalInputs), using this method