feat: make signatureType optional and add detection function

Author: mmackz

packages/sdk/src/Actions/EventAction.ts

@@ -157,7 +157,7 @@ export interface ActionClaimant {
    *
    * @type {SignatureType}
    */
-  signatureType: SignatureType;
+  signatureType?: SignatureType;
   /**
    * The 4 byte signature of the event or function
    *
@@ -202,7 +202,7 @@ export interface ActionStep {
    *
    * @type {SignatureType}
    */
-  signatureType: SignatureType;
+  signatureType?: SignatureType;
   /**
    * The type of action being performed.
    *
@@ -1366,15 +1366,32 @@ function _fromRawActionStep<T extends RawActionStep | RawActionClaimant>(
 }
 
 /**
- * Typeguard to determine if a user is supplying a simple or raw EventActionPayload
+ * Determines whether a signature is an event or function signature based on its format.
+ * - 32-byte signatures (0x + 64 chars) that don't start with 28 zeros are event signatures
+ * - 4-byte signatures (0x + 8 chars) or 32-byte signatures with 28 leading zeros are function signatures
  *
- * @param {*} opts
- * @returns {opts is EventActionPayloadSimple}
+ * @param {Hex} signature - The signature to check
+ * @returns {SignatureType} The detected signature type
  */
-function _isEventActionPayloadSimple(
-  opts: EventActionPayload,
-): opts is EventActionPayloadSimple {
-  return Array.isArray((opts as EventActionPayloadSimple).actionSteps);
+export function detectSignatureType(signature: Hex): SignatureType {
+  const hexWithoutPrefix = signature.slice(2);
+
+  // 4-byte function selector (8 hex chars)
+  if (hexWithoutPrefix.length === 8) {
+    return SignatureType.FUNC;
+  }
+
+  // I32-byte selectors (64 hex chars)
+  if (hexWithoutPrefix.length === 64) {
+    // Check if it starts with 28 bytes (56 chars) of zeros
+    const leadingPart = hexWithoutPrefix.slice(0, 56);
+    if (leadingPart === '0'.repeat(56)) {
+      return SignatureType.FUNC;
+    }
+    return SignatureType.EVENT;
+  }
+
+  throw new Error('Invalid signature format');
 }
 
 /**
@@ -1502,21 +1519,38 @@ export function prepareEventActionPayload({
     ],
     [
       {
-        actionClaimant: _toRawActionStep(actionClaimant),
+        actionClaimant: {
+          ..._toRawActionStep(actionClaimant),
+          signatureType:
+            actionClaimant.signatureType ??
+            detectSignatureType(actionClaimant.signature),
+        },
         actionStepOne: {
           ..._toRawActionStep(actionStepOne),
+          signatureType:
+            actionStepOne.signatureType ??
+            detectSignatureType(actionStepOne.signature),
           actionType: actionStepOne.actionType || 0,
         },
         actionStepTwo: {
           ..._toRawActionStep(actionStepTwo),
+          signatureType:
+            actionStepTwo.signatureType ??
+            detectSignatureType(actionStepTwo.signature),
           actionType: actionStepTwo.actionType || 0,
         },
         actionStepThree: {
           ..._toRawActionStep(actionStepThree),
+          signatureType:
+            actionStepThree.signatureType ??
+            detectSignatureType(actionStepThree.signature),
           actionType: actionStepThree.actionType || 0,
         },
         actionStepFour: {
           ..._toRawActionStep(actionStepFour),
+          signatureType:
+            actionStepFour.signatureType ??
+            detectSignatureType(actionStepFour.signature),
           actionType: actionStepFour.actionType || 0,
         },
       },