feat: Add PancakeSwap exchange for SWBT/WBTC support (#23)

client/spot_prices.go

@@ -8,6 +8,7 @@ import (
 	"github.com/ethereum/go-ethereum/common"
 	balancerpool "github.com/ojo-network/ethereum-api/abi/balancer/pool"
 	"github.com/ojo-network/ethereum-api/abi/camelot"
+	"github.com/ojo-network/ethereum-api/abi/pancake"
 	"github.com/ojo-network/ethereum-api/abi/uniswap"
 	"github.com/ojo-network/ethereum-api/pool"
 	"github.com/ojo-network/indexer/indexer"
@@ -27,15 +28,19 @@ func (c *Client) PollSpotPrices(pools []pool.Pool) {
 					switch c.poolContract {
 					case pool.PoolUniswap:
 						spotPrice = c.QueryUniswapSpotPrice(p, blockNum)
-						c.logger.Info().Interface("spotPrice", spotPrice).Msg("spot price received")
+						c.logger.Info().Interface("Uniswap spotPrice", spotPrice).Msg("spot price received")
 						c.indexer.AddPrice(spotPrice)
 					case pool.PoolAlgebra:
 						spotPrice = c.QueryAlgebraSpotPrice(p, blockNum)
-						c.logger.Info().Interface("spotPrice", spotPrice).Msg("spot price received")
+						c.logger.Info().Interface("Alegbra spotPrice", spotPrice).Msg("spot price received")
 						c.indexer.AddPrice(spotPrice)
 					case pool.PoolBalancer:
 						spotPrice = c.QueryBalancerSpotPrice(p, blockNum)
-						c.logger.Info().Interface("spotPrice", spotPrice).Msg("spot price received")
+						c.logger.Info().Interface("Balancer spotPrice", spotPrice).Msg("spot price received")
+						c.indexer.AddPrice(spotPrice)
+					case pool.PoolPancake:
+						spotPrice = c.QueryPancakeSpotPrice(p, blockNum)
+						c.logger.Info().Interface("Pancake spotPrice", spotPrice).Msg("spot price received")
 						c.indexer.AddPrice(spotPrice)
 					}
 				}
@@ -104,3 +109,23 @@ func (c *Client) QueryBalancerSpotPrice(p pool.Pool, blockNum uint64) indexer.Sp
 		Price:        sdkmath.LegacyNewDecFromBigIntWithPrec(poolRate, 18),
 	}
 }
+
+// QueryPancakeSpotPrice queries the spot price of a pancake pool
+func (c *Client) QueryPancakeSpotPrice(p pool.Pool, blockNum uint64) indexer.SpotPrice {
+	pancakeCaller, err := pancake.NewPancakeCaller(common.HexToAddress(p.Address), c.ethClient)
+	if err != nil {
+		c.reportError(fmt.Errorf("error initializing %s pool caller: %w", p.ExchangePair(), err))
+		return indexer.SpotPrice{}
+	}
+	slot0, err := pancakeCaller.Slot0(nil)
+	if err != nil {
+		c.reportError(fmt.Errorf("error getting %s pool balance: %w", p.ExchangePair(), err))
+		return indexer.SpotPrice{}
+	}
+	return indexer.SpotPrice{
+		BlockNum:     indexer.BlockNum(blockNum),
+		Timestamp:    utils.CurrentUnixTime(),
+		ExchangePair: p.ExchangePair(),
+		Price:        p.SqrtPriceX96ToDec(slot0.SqrtPriceX96),
+	}
+}

client/swaps.go

@@ -8,6 +8,7 @@ import (
 	balancerpool "github.com/ojo-network/ethereum-api/abi/balancer/pool"
 	"github.com/ojo-network/ethereum-api/abi/balancer/vault"
 	"github.com/ojo-network/ethereum-api/abi/camelot"
+	"github.com/ojo-network/ethereum-api/abi/pancake"
 	"github.com/ojo-network/ethereum-api/abi/uniswap"
 	"github.com/ojo-network/ethereum-api/pool"
 )
@@ -36,6 +37,11 @@ func (c *Client) WatchSwapsAndRestart(p pool.Pool) {
 					if err != nil {
 						c.reportError(fmt.Errorf("error watching %s swap events", p.ExchangePair()))
 					}
+				case pool.PoolPancake:
+					err := c.WatchPancakeSwapEvent(p)
+					if err != nil {
+						c.reportError(fmt.Errorf("error watching %s swap events", p.ExchangePair()))
+					}
 				}
 			}
 		}
@@ -131,7 +137,7 @@ func (c *Client) WatchBalancerSwapEvent(p pool.Pool) error {
 	tokenInParam := make([]common.Address, 1)
 	tokenInParam[0] = common.HexToAddress(p.BaseAddress)
 	tokenOutParam := []common.Address{}
-	for _, tokenAddress := range p.QuoteAddresses{
+	for _, tokenAddress := range p.QuoteAddresses {
 		tokenOutParam = append(tokenOutParam, common.HexToAddress(tokenAddress))
 	}
 
@@ -171,3 +177,36 @@ func (c *Client) WatchBalancerSwapEvent(p pool.Pool) error {
 		}
 	}
 }
+
+// WatchPancakeSwapEvent watches for swap events on a pancake pool
+func (c *Client) WatchPancakeSwapEvent(p pool.Pool) error {
+	pancakeFilterer, err := pancake.NewPancakeFilterer(common.HexToAddress(p.Address), c.ethClient)
+	if err != nil {
+		return err
+	}
+
+	eventSink := make(chan *pancake.PancakeSwap)
+	opts := &bind.WatchOpts{Start: nil, Context: c.ctx}
+	c.logger.Info().Msgf("subscribing to %s swap events", p.ExchangePair())
+	subscription, err := pancakeFilterer.WatchSwap(opts, eventSink, nil, nil)
+	if err != nil {
+		return err
+	}
+
+	for {
+		select {
+		case <-c.ctx.Done():
+			c.logger.Info().Msgf("unsubscribing from %s swap events", p.ExchangePair())
+			subscription.Unsubscribe()
+			return nil
+		case err := <-subscription.Err():
+			return err
+		case event := <-eventSink:
+			swap := p.ConvertPancakeEventToSwap(event)
+			spotPrice := p.ConvertPancakeEventToSpotPrice(event)
+			c.logger.Info().Interface("pancake swap", swap).Msg("pancake swap event received")
+			c.indexer.AddSwap(swap)
+			c.indexer.AddPrice(spotPrice)
+		}
+	}
+}

pool/pool.go

@@ -7,6 +7,7 @@ import (
 
 	"github.com/ojo-network/ethereum-api/abi/balancer/vault"
 	"github.com/ojo-network/ethereum-api/abi/camelot"
+	"github.com/ojo-network/ethereum-api/abi/pancake"
 	"github.com/ojo-network/ethereum-api/abi/uniswap"
 	"github.com/ojo-network/indexer/indexer"
 	"github.com/ojo-network/indexer/utils"
@@ -84,6 +85,25 @@ func (p *Pool) ConvertBalancerEventToSwap(event *vault.PoolSwap, price *big.Int)
 	}
 }
 
+func (p *Pool) ConvertPancakeEventToSpotPrice(event *pancake.PancakeSwap) indexer.SpotPrice {
+	return indexer.SpotPrice{
+		BlockNum:     indexer.BlockNum(event.Raw.BlockNumber),
+		Timestamp:    utils.CurrentUnixTime(),
+		ExchangePair: p.ExchangePair(),
+		Price:        p.SqrtPriceX96ToDec(event.SqrtPriceX96),
+	}
+}
+
+func (p *Pool) ConvertPancakeEventToSwap(event *pancake.PancakeSwap) indexer.Swap {
+	return indexer.Swap{
+		BlockNum:     indexer.BlockNum(event.Raw.BlockNumber),
+		Timestamp:    utils.CurrentUnixTime(),
+		ExchangePair: p.ExchangePair(),
+		Price:        p.SqrtPriceX96ToDec(event.SqrtPriceX96),
+		Volume:       p.swapPancakeVolume(event),
+	}
+}
+
 func (p *Pool) SqrtPriceX96ToDec(sqrtPriceX96 *big.Int) sdkmath.LegacyDec {
 	sdkValue := sdkmath.LegacyNewDecFromBigInt(sqrtPriceX96)
 
@@ -138,3 +158,13 @@ func (p *Pool) swapBalancerVolume(event *vault.PoolSwap) sdkmath.LegacyDec {
 		return volume.Quo(sdkmath.LegacyNewDec(10).Power(uint64(p.BaseDecimal)))
 	}
 }
+
+func (p *Pool) swapPancakeVolume(event *pancake.PancakeSwap) sdkmath.LegacyDec {
+	if p.InvertPrice {
+		volume := sdkmath.LegacyNewDecFromBigInt(event.Amount1).Abs()
+		return volume.Quo(sdkmath.LegacyNewDec(10).Power(uint64(p.QuoteDecimal)))
+	} else {
+		volume := sdkmath.LegacyNewDecFromBigInt(event.Amount0).Abs()
+		return volume.Quo(sdkmath.LegacyNewDec(10).Power(uint64(p.BaseDecimal)))
+	}
+}

pool/supported_exchanges.go

@@ -6,13 +6,16 @@ type PoolContract string
 const ExchangeUniswap ExchangeName = "uniswap"
 const ExchangeCamelot ExchangeName = "camelot"
 const ExchangeBalancer ExchangeName = "balancer"
+const ExchangePancake ExchangeName = "pancake"
 const PoolUniswap PoolContract = "uniswappool"
 const PoolAlgebra PoolContract = "algebrapool"
 const PoolBalancer PoolContract = "balancerpool"
+const PoolPancake PoolContract = "pancakepool"
 
 // maps exchange to pool contract of that exchange
 var SupportedExchanges = map[ExchangeName]PoolContract{
 	ExchangeUniswap:  PoolUniswap,
 	ExchangeCamelot:  PoolAlgebra,
 	ExchangeBalancer: PoolBalancer,
+	ExchangePancake:  PoolPancake,
 }

sample-config.yaml

@@ -115,6 +115,16 @@ exchanges:
         base_decimal: 18
         quote_decimal: 18
         invert_price: false
+  - name: "pancake"
+    node_urls:
+      - "wss://mainnet.infura.io/ws/v3/6849a09aeeb044b592d46bcdce07ccef"
+    pools:
+      - address: "0x365EA9E5Cec960390f35b6509548e84073168A8B"
+        base: "SWBTC"
+        quote: "WBTC"
+        base_decimal: 18
+        quote_decimal: 18
+        invert_price: false
 
 server:
   listen_addr: "0.0.0.0:5005"