unstake Prevents UnstakeAmountTooLarge ZeroAmount Disabled

src/i18n/en-US/index.ts

@@ -670,9 +670,13 @@ export default {
   },
   stakingV3: {
     title: 'dApp Staking v3',
-    amountGreater0: 'Staking amount must be greater than 0.',
+    amountGreater0: 'Amount must be greater than 0.',
     periodEndsNextEra: 'Period ends in the next era.',
     stakerRewardsExpired: 'Staker rewards expired.',
+    disabled: 'Pallet is disabled/in maintenance mode.',
+    unstakeFromPastPeriod:
+      'Unstaking is rejected since the period in which past stake was active has passed.',
+    unstakeAmountTooLarge: 'Unstake amount is greater than the staked amount.',
     unclaimedRewardsFromPastPeriods:
       'There are unclaimed rewards remaining from past periods. They should be claimed before staking again.',
     tooManyStakedContracts:

src/staking-v3/hooks/useDappStaking.ts

@@ -47,6 +47,11 @@ export function useDappStaking() {
   };
 
   const unstake = async (dappAddress: string, amount: number): Promise<void> => {
+    const [result, error] = await canUnStake(amount);
+    if (!result) {
+      throw error;
+    }
+
     const stakingService = container.get<IDappStakingService>(Symbols.DappStakingServiceV3);
     await stakingService.unstakeAndUnlock(dappAddress, amount, currentAccount.value, 'success');
   };
@@ -126,6 +131,9 @@ export function useDappStaking() {
       // Prevents UnclaimedRewardsFromPastPeriods
       // May want to auto claim rewards here
       return [false, t('stakingV3.unclaimedRewardsFromPastPeriods')];
+    } else if (protocolState.value?.maintenance) {
+      // Prevents Disabled
+      return [false, t('stakingV3.disabled')];
     } else if (stakeAmount.gt(balance.value)) {
       // Prevents UnavailableStakeFunds
       return [false, t('stakingV3.unavailableStakeFunds')];
@@ -140,6 +148,27 @@ export function useDappStaking() {
     return [true, ''];
   };
 
+  const canUnStake = async (amount: number): Promise<[boolean, string]> => {
+    const stakeAmount = new BN(ethers.utils.parseEther(amount.toString()).toString());
+    const stakedAmount = new BN(ledger.value?.locked?.toString() ?? 0);
+
+    if (amount <= 0) {
+      // Prevents ZeroAmount
+      return [false, t('stakingV3.amountGreater0')];
+    } else if (stakeAmount.gt(stakedAmount)) {
+      // Prevents UnstakeAmountTooLarge
+      return [false, t('stakingV3.unstakeAmountTooLarge')];
+    } else if (protocolState.value?.maintenance) {
+      // Prevents Disabled
+      return [false, t('stakingV3.disabled')];
+    } else if (!amount) {
+      // Prevents UnstakeFromPastPeriod
+      return [false, t('stakingV3.unstakeFromPastPeriod')];
+    }
+
+    return [true, ''];
+  };
+
   watch(
     currentNetworkIdx,
     async () => {
@@ -160,6 +189,7 @@ export function useDappStaking() {
     unstake,
     claimStakerRewards,
     canStake,
+    canUnStake,
     claimDappRewards,
     claimBonusRewards,
     getAllRewards,