/
sell.go
191 lines (165 loc) · 5.21 KB
/
sell.go
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package examples
import (
"context"
"encoding/hex"
"fmt"
"math"
"github.com/btcsuite/btcd/txscript"
"github.com/google/uuid"
tdexv2 "github.com/tdex-network/tdex-daemon/api-spec/protobuf/gen/tdex/v2"
"github.com/tdex-network/tdex-daemon/pkg/explorer"
"github.com/vulpemventures/go-elements/elementsutil"
"github.com/vulpemventures/go-elements/psetv2"
)
func SellExample(daemonAddr, explorerAddr string) error {
fmt.Printf("---------- SELL LBTC FOR USDt ----------\n\n")
traderAmount := 0.001
client, explorer, err := initServices(daemonAddr, explorerAddr)
if err != nil {
return err
}
traderWallet := newKeyPair()
fmt.Printf("Trader wallet:\n%s\n\n", traderWallet)
fmt.Printf("Sending LBTCs to trader...\n\n")
utxos, err := faucet(explorer, traderWallet, lbtc, traderAmount)
if err != nil {
return fmt.Errorf("failed to send LBTC funds to trader: %s", err)
}
fmt.Printf("Fetching market from provider...\n\n")
markets, err := fetchMarkets(client)
if err != nil {
return fmt.Errorf("failed to fetch provider markets: %s", err)
}
if len(markets) == 0 {
return fmt.Errorf("provider has no tradable markets")
}
targetMarket := markets[0].GetMarket()
fmt.Printf("Market: %s\n\n", targetMarket)
usdt := targetMarket.GetQuoteAsset()
fmt.Printf("Making trade preview...\n\n")
swapRequest, feeAsset, feeAmount, err := makeTradeSellPreview(
client, targetMarket, lbtc, usdt, traderAmount, traderWallet, utxos,
)
if err != nil {
return fmt.Errorf("failed to make trade preview: %s", err)
}
fmt.Printf("Making trade proposal...\n\n")
swapAccept, err := makeTradeSellProposal(
client, targetMarket, swapRequest, feeAsset, feeAmount,
)
if err != nil {
return fmt.Errorf("failed to make trade proposal: %s", err)
}
fmt.Printf("Signing and completing trade...\n\n")
txid, err := signAndCompleteTrade(client, traderWallet, swapAccept)
if err != nil {
return fmt.Errorf("failed to complete trade: %s", err)
}
fmt.Printf("Completed trade with txid: %s\n\n", txid)
swapRequest.Transaction = ""
swapRequest.UnblindedInputs = swapAccept.GetUnblindedInputs()
fmt.Printf("Swap info: %s\n\n", swapRequest)
return nil
}
func makeTradeSellPreview(
client tdexv2.TradeServiceClient,
market *tdexv2.Market, asset, feeAsset string, amount float64,
w wallet, utxos []explorer.Utxo,
) (*tdexv2.SwapRequest, string, uint64, error) {
satsAmount := uint64(amount * math.Pow10(8))
res, err := client.PreviewTrade(context.Background(), &tdexv2.PreviewTradeRequest{
Market: market,
Type: tdexv2.TradeType_TRADE_TYPE_SELL,
Amount: satsAmount,
Asset: asset,
FeeAsset: feeAsset,
})
if err != nil {
return nil, "", 0, err
}
preview := res.GetPreviews()[0]
feesToAdd := feeAsset == market.GetBaseAsset()
inAmount := satsAmount
if feesToAdd {
inAmount += preview.GetFeeAmount()
}
selectedUtxos, change, err := explorer.SelectUnspents(utxos, inAmount, asset)
if err != nil {
return nil, "", 0, err
}
unblindedIns := make([]*tdexv2.UnblindedInput, 0, len(selectedUtxos))
ins := make([]psetv2.InputArgs, 0, len(selectedUtxos))
for i, u := range selectedUtxos {
ins = append(ins, psetv2.InputArgs{
Txid: u.Hash(),
TxIndex: u.Index(),
})
unblindedIns = append(unblindedIns, &tdexv2.UnblindedInput{
Index: uint32(i),
Asset: u.Asset(),
Amount: u.Value(),
AssetBlinder: hex.EncodeToString(elementsutil.ReverseBytes(u.AssetBlinder())),
AmountBlinder: hex.EncodeToString(elementsutil.ReverseBytes(u.ValueBlinder())),
})
}
outAmount := preview.GetAmount()
if !feesToAdd {
outAmount -= preview.GetFeeAmount()
}
outs := []psetv2.OutputArgs{
{
Asset: preview.GetAsset(),
Amount: outAmount,
Script: w.outputScript,
BlindingKey: w.blindPubkey.SerializeCompressed(),
BlinderIndex: 0,
},
}
if change > 0 {
outs = append(outs, psetv2.OutputArgs{
Asset: asset,
Amount: change,
Script: w.outputScript,
BlindingKey: w.blindPubkey.SerializeCompressed(),
BlinderIndex: 0,
})
}
pset, _ := psetv2.New(ins, outs, nil)
updater, _ := psetv2.NewUpdater(pset)
for i, u := range selectedUtxos {
_, prevout, _ := u.Parse()
updater.AddInWitnessUtxo(i, prevout)
updater.AddInUtxoRangeProof(i, u.RangeProof())
updater.AddInSighashType(i, txscript.SigHashAll)
}
psetBase64, _ := pset.ToBase64()
return &tdexv2.SwapRequest{
Id: uuid.NewString(),
AmountP: satsAmount,
AssetP: asset,
AmountR: preview.GetAmount(),
AssetR: preview.GetAsset(),
Transaction: psetBase64,
UnblindedInputs: unblindedIns,
}, preview.GetFeeAsset(), preview.GetFeeAmount(), nil
}
func makeTradeSellProposal(
client tdexv2.TradeServiceClient,
market *tdexv2.Market, swapRequest *tdexv2.SwapRequest,
feeAsset string, feeAmount uint64,
) (*tdexv2.SwapAccept, error) {
res, err := client.ProposeTrade(context.Background(), &tdexv2.ProposeTradeRequest{
Market: market,
Type: tdexv2.TradeType_TRADE_TYPE_SELL,
SwapRequest: swapRequest,
FeeAsset: feeAsset,
FeeAmount: feeAmount,
})
if err != nil {
return nil, err
}
if res.GetSwapFail() != nil {
return nil, fmt.Errorf(res.GetSwapFail().GetFailureMessage())
}
return res.GetSwapAccept(), nil
}