Updated on 2026-08-14

2025-07-14 18:01:49 +05:00 · 2025-07-14 18:01:49 +05:00 · bdaa181aec
commit bdaa181aec
parent 5988ef1834
13 changed files with 790 additions and 0 deletions
--- a/libs/crypto/src/main/java/com/tangem/lib/crypto/BlockchainFeeUtils.kt
+++ b/libs/crypto/src/main/java/com/tangem/lib/crypto/BlockchainFeeUtils.kt
@ -0,0 +1,81 @@
+package com.tangem.lib.crypto
+
+import com.tangem.blockchain.common.transaction.Fee
+import com.tangem.blockchain.common.transaction.TransactionFee
+import java.math.BigInteger
+import java.math.RoundingMode
+
+/**
+ * !!!IMPORTANT!!!
+ * Methods for tuning transaction fee of different blockchains
+ *
+ * Temporary solution for domain specific logic for Blockchain.
+ * Instead of creating repositories and unnecessary and overkill use cases
+ */
+object BlockchainFeeUtils {
+
+    private val HUNDRED_PERCENT = BigInteger("100")
+
+    /**
+     * We need to increase gasLimit for Ethereum fees for 2 cases
+     *
+     * DEX: for dex calculated gasLimit for given data might be changed when transaction processing
+     * for that case dex providers recommend to increase gasLimit for few percents to ensure transaction completes
+     *
+     * CEX: for that case we calculate fee for random generated address and gasLimit might be different for it
+     * and result address to send. That's why we should increase gasLimit a little
+     *
+     */
+    fun TransactionFee.patchTransactionFeeForSwap(increaseBy: Int): TransactionFee {
+        return when (this) {
+            is TransactionFee.Choosable -> {
+                this.copy(
+                    minimum = this.minimum.increaseEthGasLimitInNeeded(increaseBy),
+                    normal = this.normal.increaseEthGasLimitInNeeded(increaseBy),
+                    priority = this.priority.increaseEthGasLimitInNeeded(increaseBy),
+                )
+            }
+            is TransactionFee.Single -> this.copy(normal = this.normal.increaseEthGasLimitInNeeded(increaseBy))
+        }
+    }
+
+    private fun Fee.increaseEthGasLimitInNeeded(increaseBy: Int): Fee {
+        return when (this) {
+            is Fee.Ethereum.EIP1559,
+            is Fee.Ethereum.Legacy,
+            -> this.increaseGasLimitBy(increaseBy)
+            is Fee.Alephium,
+            is Fee.Aptos,
+            is Fee.Bitcoin,
+            is Fee.CardanoToken,
+            is Fee.Common,
+            is Fee.Filecoin,
+            is Fee.Hedera,
+            is Fee.Kaspa,
+            is Fee.Sui,
+            is Fee.Tron,
+            is Fee.VeChain,
+            -> this
+        }
+    }
+
+    /**
+     * Increase gasLimit for Fee.Ethereum
+     */
+    private fun Fee.increaseGasLimitBy(percentage: Int): Fee {
+        if (this !is Fee.Ethereum) return this
+        val gasLimit = this.gasLimit
+        val increasedGasPrice = this.amount.value?.movePointRight(this.amount.decimals)
+            ?.divide(gasLimit.toBigDecimal(), RoundingMode.HALF_UP)
+        val increasedGasLimit = gasLimit
+            .multiply(percentage.toBigInteger())
+            .divide(HUNDRED_PERCENT)
+        val increasedAmount = this.amount.copy(
+            value = increasedGasLimit.toBigDecimal().multiply(increasedGasPrice).movePointLeft(this.amount.decimals),
+        )
+        return when (this) {
+            is Fee.Ethereum.EIP1559 -> copy(amount = increasedAmount, gasLimit = increasedGasLimit)
+            is Fee.Ethereum.Legacy -> copy(amount = increasedAmount, gasLimit = increasedGasLimit)
+        }
+    }
+}