server/asset/eth: refactor coins

Separate swapCoin from redeemCoin. Switch (*rpcclient).swap method to
return a *dexeth.SwapState.

client/asset/eth/contractor.go

@@ -112,7 +112,7 @@ func (c *contractorV0) initiate(txOpts *bind.TransactOpts, contracts []*asset.Co
 			RefundTimestamp: big.NewInt(int64(contract.LockTime)),
 			SecretHash:      secretHash,
 			Participant:     common.HexToAddress(contract.Address),
-			Value:           new(big.Int).Mul(bigVal, dexeth.BigGweiFactor),
+			Value:           new(big.Int).Mul(bigVal, big.NewInt(dexeth.GweiFactor)),
 		})
 	}
 

client/asset/eth/eth_test.go

@@ -1639,7 +1639,7 @@ func packInitiateDataV0(initiations []*dexeth.Initiation) ([]byte, error) {
 			RefundTimestamp: big.NewInt(init.LockTime.Unix()),
 			SecretHash:      init.SecretHash,
 			Participant:     init.Participant,
-			Value:           new(big.Int).Mul(bigVal, dexeth.BigGweiFactor),
+			Value:           new(big.Int).Mul(bigVal, big.NewInt(dexeth.GweiFactor)),
 		})
 	}
 	return (*dexeth.ABIs[0]).Pack("initiate", abiInitiations)
@@ -2411,7 +2411,7 @@ func ethToGwei(v uint64) uint64 {
 
 func ethToWei(v uint64) *big.Int {
 	bigV := new(big.Int).SetUint64(ethToGwei(v))
-	return new(big.Int).Mul(bigV, dexeth.BigGweiFactor)
+	return new(big.Int).Mul(bigV, big.NewInt(dexeth.GweiFactor))
 }
 
 func TestPayFee(t *testing.T) {

dex/networks/eth/common.go

@@ -8,7 +8,6 @@ package eth
 
 import (
 	"fmt"
-	"math/big"
 
 	"github.com/ethereum/go-ethereum/common"
 )
@@ -29,24 +28,3 @@ func DecodeCoinID(coinID []byte) (common.Hash, error) {
 // SecretHashSize is the byte-length of the hash of the secret key used in
 // swaps.
 const SecretHashSize = 32
-
-// ToGwei converts a *big.Int in wei (1e18 unit) to gwei (1e9 unit) as a uint64.
-// Errors if the amount of gwei is too big to fit fully into a uint64.
-func ToGwei(wei *big.Int) (uint64, error) {
-	if wei.Cmp(new(big.Int)) == -1 {
-		return 0, fmt.Errorf("wei must be non-negative")
-	}
-	gweiFactorBig := big.NewInt(GweiFactor)
-	gwei := new(big.Int).Div(wei, gweiFactorBig)
-	if !gwei.IsUint64() {
-		return 0, fmt.Errorf("suggest gas price %v gwei is too big for a uint64", wei)
-	}
-	return gwei.Uint64(), nil
-}
-
-// ToWei converts a uint64 in gwei (1e9 unit) to wei (1e18 unit) as a *big.Int.
-func ToWei(gwei uint64) *big.Int {
-	bigGwei := new(big.Int).SetUint64(gwei)
-	gweiFactorBig := big.NewInt(GweiFactor)
-	return new(big.Int).Mul(bigGwei, gweiFactorBig)
-}

dex/networks/eth/params.go

@@ -15,6 +15,7 @@ import (
 	"time"
 
 	"decred.org/dcrdex/dex"
+	v0 "decred.org/dcrdex/dex/networks/eth/contracts/v0"
 	"github.com/ethereum/go-ethereum/common"
 )
 
@@ -36,9 +37,6 @@ var (
 		},
 	}
 
-	// BigGweiFactor is the *big.Int form of the GweiFactor.
-	BigGweiFactor = big.NewInt(GweiFactor)
-
 	VersionedGases = map[uint32]*dex.Gases{
 		0: v0Gases,
 	}
@@ -115,12 +113,31 @@ func RefundGas(contractVer uint32) uint64 {
 
 // GweiToWei converts uint64 Gwei to *big.Int Wei.
 func GweiToWei(v uint64) *big.Int {
-	return new(big.Int).Mul(big.NewInt(int64(v)), BigGweiFactor)
+	return new(big.Int).Mul(big.NewInt(int64(v)), big.NewInt(GweiFactor))
 }
 
-// GweiToWei converts *big.Int Wei to uint64 Gwei.
+// WeiToGwei converts *big.Int Wei to uint64 Gwei. If v is determined to be
+// unsuitable for a uint64, zero is returned.
 func WeiToGwei(v *big.Int) uint64 {
-	return new(big.Int).Div(v, BigGweiFactor).Uint64()
+	vGwei := new(big.Int).Div(v, big.NewInt(GweiFactor))
+	if vGwei.IsUint64() {
+		return vGwei.Uint64()
+	}
+	return 0
+}
+
+// WeiToGweiUint64 converts a *big.Int in wei (1e18 unit) to gwei (1e9 unit) as
+// a uint64. Errors if the amount of gwei is too big to fit fully into a uint64.
+func WeiToGweiUint64(wei *big.Int) (uint64, error) {
+	if wei.Cmp(new(big.Int)) == -1 {
+		return 0, fmt.Errorf("wei must be non-negative")
+	}
+	gweiFactorBig := big.NewInt(GweiFactor)
+	gwei := new(big.Int).Div(wei, gweiFactorBig)
+	if !gwei.IsUint64() {
+		return 0, fmt.Errorf("suggest gas price %v gwei is too big for a uint64", wei)
+	}
+	return gwei.Uint64(), nil
 }
 
 // SwapStep is the state of a swap and corresponds to values in the Solidity
@@ -249,3 +266,20 @@ func VersionedNetworkToken(assetID uint32, contractVer uint32, net dex.Network)
 	}
 	return token, addrs.Address, contractAddr, nil
 }
+
+// SwapStateFromV0 converts a v0.ETHSwapSwap to a *SwapState.
+func SwapStateFromV0(state *v0.ETHSwapSwap) *SwapState {
+	var blockTime int64
+	if state.RefundBlockTimestamp.IsInt64() {
+		blockTime = state.RefundBlockTimestamp.Int64()
+	}
+	return &SwapState{
+		BlockHeight: state.InitBlockNumber.Uint64(),
+		LockTime:    time.Unix(blockTime, 0),
+		Secret:      state.Secret,
+		Initiator:   state.Initiator,
+		Participant: state.Participant,
+		Value:       WeiToGwei(state.Value),
+		State:       SwapStep(state.State),
+	}
+}

dex/networks/eth/txdata.go

@@ -128,7 +128,7 @@ func (t *txDataHandlerV0) parseInitiateData(calldata []byte) (map[[SecretHashSiz
 
 	toReturn := make(map[[SecretHashSize]byte]*Initiation, len(initiations))
 	for _, init := range initiations {
-		gweiValue, err := ToGwei(init.Value)
+		gweiValue, err := WeiToGweiUint64(init.Value)
 		if err != nil {
 			return nil, fmt.Errorf("cannot convert wei to gwei: %w", err)
 		}

dex/networks/eth/txdata_test.go

@@ -22,7 +22,7 @@ func packInitiateDataV0(initiations []*Initiation) ([]byte, error) {
 			RefundTimestamp: big.NewInt(init.LockTime.Unix()),
 			SecretHash:      init.SecretHash,
 			Participant:     init.Participant,
-			Value:           new(big.Int).Mul(bigVal, BigGweiFactor),
+			Value:           new(big.Int).Mul(bigVal, big.NewInt(GweiFactor)),
 		})
 	}
 	return (*ABIs[0]).Pack("initiate", abiInitiations)