Strip signature params (#118)

### TL;DR

Added functionality to strip and normalize Solidity function and event signatures.

### What changed?

- Introduced a new `StripPayload` function in `utils.go` to remove parameter names, 'indexed' keywords, and extra whitespaces from Solidity function or event signatures.
- Implemented helper functions `parseParameters`, `cleanType`, and `isType` to support the signature stripping process.
- Updated `GetLogsByContractAndSignature` and `GetTransactionsByContractAndSignature` handlers to use the new `StripPayload` function before processing requests.

### How to test?

1. Call the API endpoints for getting logs or transactions by contract and signature.
2. Use various Solidity function and event signatures, including those with parameter names, `indexed` keywords, and extra whitespaces.
3. Verify that the API correctly handles and matches these signatures, regardless of the extra information included.

### Why make this change?

This change improves the flexibility and user-friendliness of the API. It allows users to query logs and transactions using more verbose Solidity signatures without requiring exact matches. This normalization process ensures that signatures with different formatting or additional information (like parameter names) are still correctly recognized and processed by the system.

internal/common/utils.go

@@ -1,6 +1,11 @@
 package common
 
-import "math/big"
+import (
+	"fmt"
+	"math/big"
+	"strings"
+	"unicode"
+)
 
 func BigIntSliceToChunks(values []*big.Int, chunkSize int) [][]*big.Int {
 	if chunkSize >= len(values) || chunkSize <= 0 {
@@ -16,3 +21,151 @@ func BigIntSliceToChunks(values []*big.Int, chunkSize int) [][]*big.Int {
 	}
 	return chunks
 }
+
+// StripPayload removes parameter names, 'indexed' keywords,
+// and extra whitespaces from a Solidity function or event signature.
+func StripPayload(signature string) string {
+	// Find the index of the first '(' and last ')'
+	start := strings.Index(signature, "(")
+	end := strings.LastIndex(signature, ")")
+	if start == -1 || end == -1 || end <= start {
+		// Return the original signature if it doesn't match the expected pattern
+		return signature
+	}
+
+	functionName := strings.TrimSpace(signature[:start])
+	paramsStr := signature[start+1 : end]
+
+	// Parse parameters
+	strippedParams := parseParameters(paramsStr)
+
+	// Reconstruct the cleaned-up signature
+	strippedSignature := fmt.Sprintf("%s(%s)", functionName, strings.Join(strippedParams, ","))
+	return strippedSignature
+}
+
+// parseParameters parses the parameter string and returns a slice of cleaned-up parameter types
+func parseParameters(paramsStr string) []string {
+	var params []string
+	var currentParam strings.Builder
+	bracketDepth := 0
+	var inType bool // Indicates if we are currently parsing a type
+
+	runes := []rune(paramsStr)
+	i := 0
+	for i < len(runes) {
+		char := runes[i]
+		switch char {
+		case '(', '[', '{':
+			bracketDepth++
+			inType = true
+			currentParam.WriteRune(char)
+			i++
+		case ')', ']', '}':
+			bracketDepth--
+			currentParam.WriteRune(char)
+			i++
+		case ',':
+			if bracketDepth == 0 {
+				// End of current parameter
+				paramType := cleanType(currentParam.String())
+				if paramType != "" {
+					params = append(params, paramType)
+				}
+				currentParam.Reset()
+				inType = false
+				i++
+			} else {
+				currentParam.WriteRune(char)
+				i++
+			}
+		case ' ':
+			if inType {
+				currentParam.WriteRune(char)
+			}
+			i++
+		default:
+			// Check if the word is a keyword to ignore
+			if unicode.IsLetter(char) {
+				wordStart := i
+				for i < len(runes) && (unicode.IsLetter(runes[i]) || unicode.IsDigit(runes[i])) {
+					i++
+				}
+				word := string(runes[wordStart:i])
+
+				// Ignore 'indexed' and parameter names
+				if isType(word) {
+					inType = true
+					currentParam.WriteString(word)
+				} else if word == "indexed" {
+					// Skip 'indexed'
+					inType = false
+				} else {
+					// Ignore parameter names
+					if inType {
+						// If we are in the middle of parsing a type and encounter a parameter name, skip it
+						inType = false
+					}
+				}
+			} else {
+				if inType {
+					currentParam.WriteRune(char)
+				}
+				i++
+			}
+		}
+	}
+
+	// Add the last parameter
+	if currentParam.Len() > 0 {
+		paramType := cleanType(currentParam.String())
+		if paramType != "" {
+			params = append(params, paramType)
+		}
+	}
+
+	return params
+}
+
+// cleanType cleans up a parameter type string by removing extra spaces and 'tuple' keyword
+func cleanType(param string) string {
+	// Remove 'tuple' keyword
+	param = strings.ReplaceAll(param, "tuple", "")
+	// Remove 'indexed' keyword
+	param = strings.ReplaceAll(param, "indexed", "")
+	// Remove any parameter names (already handled in parsing)
+	param = strings.TrimSpace(param)
+	// Remove extra whitespaces
+	param = strings.Join(strings.Fields(param), "")
+	return param
+}
+
+// isType checks if a word is a Solidity type
+func isType(word string) bool {
+	types := map[string]bool{
+		"uint":     true,
+		"int":      true,
+		"uint8":    true,
+		"int8":     true,
+		"uint16":   true,
+		"int16":    true,
+		"uint32":   true,
+		"int32":    true,
+		"uint64":   true,
+		"int64":    true,
+		"uint128":  true,
+		"int128":   true,
+		"uint256":  true,
+		"int256":   true,
+		"address":  true,
+		"bool":     true,
+		"string":   true,
+		"bytes":    true,
+		"fixed":    true,
+		"ufixed":   true,
+		"function": true,
+		// Add other types as needed
+	}
+
+	return types[word]
+}

internal/handlers/logs_handlers.go

@@ -9,6 +9,7 @@ import (
 	"github.com/rs/zerolog/log"
 	"github.com/thirdweb-dev/indexer/api"
 	config "github.com/thirdweb-dev/indexer/configs"
+	"github.com/thirdweb-dev/indexer/internal/common"
 	"github.com/thirdweb-dev/indexer/internal/storage"
 )
 
@@ -105,7 +106,8 @@ func GetLogsByContract(c *gin.Context) {
 func GetLogsByContractAndSignature(c *gin.Context) {
 	contractAddress := c.Param("contract")
 	eventSignature := c.Param("signature")
-	handleLogsRequest(c, contractAddress, eventSignature)
+	strippedSignature := common.StripPayload(eventSignature)
+	handleLogsRequest(c, contractAddress, strippedSignature)
 }
 
 func handleLogsRequest(c *gin.Context, contractAddress, signature string) {

internal/handlers/transactions_handlers.go

@@ -7,6 +7,7 @@ import (
 	"github.com/gin-gonic/gin"
 	"github.com/rs/zerolog/log"
 	"github.com/thirdweb-dev/indexer/api"
+	"github.com/thirdweb-dev/indexer/internal/common"
 	"github.com/thirdweb-dev/indexer/internal/rpc"
 	"github.com/thirdweb-dev/indexer/internal/storage"
 )
@@ -107,7 +108,8 @@ func GetTransactionsByContract(c *gin.Context) {
 func GetTransactionsByContractAndSignature(c *gin.Context) {
 	to := c.Param("to")
 	signature := c.Param("signature")
-	handleTransactionsRequest(c, to, signature)
+	strippedSignature := common.StripPayload(signature)
+	handleTransactionsRequest(c, to, strippedSignature)
 }
 
 func handleTransactionsRequest(c *gin.Context, contractAddress, signature string) {