transfer FT: user pay for storage cost

web-frontend/src/custom/smart-contract/useFTTransfer.tsx

@@ -1,4 +1,4 @@
-import { useEffect, useState } from 'react';
+import { useCallback, useEffect, useState } from 'react';
 
 import {
   Client,
@@ -8,6 +8,8 @@ import {
   Args,
   ClientFactory,
   MAINNET_CHAIN_ID,
+  strToBytes,
+  STORAGE_BYTE_COST,
 } from '@massalabs/massa-web3';
 import { ToastContent, parseAmount, toast } from '@massalabs/react-ui-kit';
 import { providers } from '@massalabs/wallet-provider';
@@ -57,31 +59,36 @@ export function useFTTransfer(nickname: string) {
     callSmartContract,
   } = useWriteSmartContract(client, isMainnet);
 
-  const transfer = (
-    recipient: string,
-    tokenAddress: string,
-    amount: string,
-    decimals: number,
-  ) => {
-    if (!client) {
-      throw new Error('Massa client not found');
-    }
+  const transfer = useCallback(
+    (
+      recipient: string,
+      tokenAddress: string,
+      amount: string,
+      decimals: number,
+    ) => {
+      if (!client) {
+        throw new Error('Massa client not found');
+      }
 
-    const rawAmount = parseAmount(amount, decimals);
-    const args = new Args().addString(recipient).addU256(rawAmount);
-
-    callSmartContract(
-      'transfer',
-      tokenAddress,
-      args.serialize(),
-      {
-        pending: Intl.t('send-coins.steps.ft-transfer-pending'),
-        success: Intl.t('send-coins.steps.ft-transfer-success'),
-        error: Intl.t('send-coins.steps.ft-transfer-failed'),
-      },
-      BigInt(0),
-    );
-  };
+      const rawAmount = parseAmount(amount, decimals);
+      const args = new Args().addString(recipient).addU256(rawAmount);
+
+      estimateCoinsCost(client, tokenAddress, recipient).then((coins) => {
+        callSmartContract(
+          'transfer',
+          tokenAddress,
+          args.serialize(),
+          {
+            pending: Intl.t('send-coins.steps.ft-transfer-pending'),
+            success: Intl.t('send-coins.steps.ft-transfer-success'),
+            error: Intl.t('send-coins.steps.ft-transfer-failed'),
+          },
+          coins,
+        );
+      });
+    },
+    [client, callSmartContract],
+  );
 
   return {
     opId,
@@ -249,3 +256,32 @@ function useWriteSmartContract(client?: Client, isMainnet?: boolean) {
     callSmartContract,
   };
 }
+async function estimateCoinsCost(
+  client: Client,
+  tokenAddress: string,
+  recipient: string,
+): Promise<bigint> {
+  const addrInfo = await client.publicApi().getAddresses([tokenAddress]);
+  const allKeys = addrInfo[0].candidate_datastore_keys;
+  const key = balanceKey(recipient);
+  const foundKey = allKeys.find((k) => {
+    return JSON.stringify(k) === JSON.stringify(key);
+  });
+
+  if (foundKey) {
+    return 0n;
+  }
+
+  const storage =
+    4n + // space of a key/value in the datastore
+    BigInt(key.length) + // key length
+    32n; // length of the value of the balance
+
+  return STORAGE_BYTE_COST * storage;
+}
+
+function balanceKey(address: string): number[] {
+  const BALANCE_KEY_PREFIX = 'BALANCE';
+
+  return Array.from(strToBytes(BALANCE_KEY_PREFIX + address));
+}