refactor: Decouple router and handlers (#31)

* refactor: decouple router to allow adding custom log and input data handlers

* feat: refactor handlers

* devops: update service build args

* chore: cleanup unecessary files/code

internal/handler/token_burn.go

@@ -0,0 +1,72 @@
+package handler
+
+import (
+	"context"
+	"math/big"
+
+	"github.com/celo-org/celo-blockchain/common"
+	"github.com/grassrootseconomics/celo-tracker/pkg/event"
+	"github.com/grassrootseconomics/celo-tracker/pkg/router"
+	"github.com/grassrootseconomics/w3-celo"
+)
+
+const burnEventName = "TOKEN_BURN"
+
+var (
+	tokenBurnEvent = w3.MustNewEvent("Burn(address indexed _tokenBurner, uint256 _value)")
+	tokenBurnToSig = w3.MustNewFunc("burn(uint256)", "bool")
+)
+
+func HandleTokenBurnLog() router.LogHandlerFunc {
+	return func(ctx context.Context, lp router.LogPayload, c router.Callback) error {
+		var (
+			tokenBurner common.Address
+			value       big.Int
+		)
+
+		if err := tokenBurnEvent.DecodeArgs(lp.Log, &tokenBurner, &value); err != nil {
+			return err
+		}
+
+		tokenBurnEvent := event.Event{
+			Index:           lp.Log.Index,
+			Block:           lp.Log.BlockNumber,
+			ContractAddress: lp.Log.Address.Hex(),
+			Success:         true,
+			Timestamp:       lp.Timestamp,
+			TxHash:          lp.Log.TxHash.Hex(),
+			TxType:          burnEventName,
+			Payload: map[string]any{
+				"tokenBurner": tokenBurner.Hex(),
+				"value":       value.String(),
+			},
+		}
+
+		return c(ctx, tokenBurnEvent)
+	}
+}
+
+func HandleTokenBurnInputData() router.InputDataHandlerFunc {
+	return func(ctx context.Context, idp router.InputDataPayload, c router.Callback) error {
+		var value big.Int
+
+		if err := tokenBurnToSig.DecodeArgs(w3.B(idp.InputData), &value); err != nil {
+			return err
+		}
+
+		tokenBurnEvent := event.Event{
+			Block:           idp.Block,
+			ContractAddress: idp.ContractAddress,
+			Success:         false,
+			Timestamp:       idp.Timestamp,
+			TxHash:          idp.TxHash,
+			TxType:          burnEventName,
+			Payload: map[string]any{
+				"tokenBurner": idp.From,
+				"value":       value.String(),
+			},
+		}
+
+		return c(ctx, tokenBurnEvent)
+	}
+}