From 1f06e850636a9ef3d87f0a0b1aa32d5c71b7bf58 Mon Sep 17 00:00:00 2001
From: abdrasulov <abdrasulov@gmail.com>
Date: Mon, 2 Jun 2025 17:38:31 +0600
Subject: [PATCH] Implement ABI encoding for string

---
 .../contracts/ContractMethodHelper.kt         | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/ethereumkit/src/main/java/io/horizontalsystems/ethereumkit/contracts/ContractMethodHelper.kt b/ethereumkit/src/main/java/io/horizontalsystems/ethereumkit/contracts/ContractMethodHelper.kt
index 0a3519bb..9fa7297a 100644
--- a/ethereumkit/src/main/java/io/horizontalsystems/ethereumkit/contracts/ContractMethodHelper.kt
+++ b/ethereumkit/src/main/java/io/horizontalsystems/ethereumkit/contracts/ContractMethodHelper.kt
@@ -47,6 +47,11 @@ object ContractMethodHelper {
                     data += pad(unsignedBigIntergerToByteArray(BigInteger.valueOf(arguments.size * 32L + arraysData.size)))
                     arraysData += pad(BigInteger.valueOf(argument.size.toLong()).toByteArray()) + argument
                 }
+                is String -> {
+                    data += pad(unsignedBigIntergerToByteArray(BigInteger.valueOf(arguments.size * 32L + arraysData.size)))
+                    arraysData += encode(argument)
+                }
+                else -> throw IllegalArgumentException("encoding for $argument")
             }
         }
         return data + arraysData
@@ -149,4 +154,18 @@ object ContractMethodHelper {
         }
         return data
     }
+
+    fun encode(string: String): ByteArray {
+        val stringData = string.toByteArray(Charsets.UTF_8)
+        val count = stringData.size
+
+        var res = pad(byteArrayOf(count.toByte())) + stringData
+
+        val remainder = count % 32
+        if (remainder > 0) {
+            res += ByteArray(32 - remainder)
+        }
+
+        return res
+    }
 }
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