show exchange offline dialog for testnet reset (#71)

src/hooks/useSelectedNetwork.ts

@@ -1,6 +1,7 @@
-import { useCallback } from 'react';
+import { useCallback, useEffect } from 'react';
 import { useDispatch, useSelector } from 'react-redux';
 
+import { DialogTypes } from '@/constants/dialogs';
 import { LocalStorageKey } from '@/constants/localStorage';
 import { DEFAULT_APP_ENVIRONMENT, DydxNetwork, ENVIRONMENT_CONFIG_MAP } from '@/constants/networks';
 
@@ -8,6 +9,7 @@ import { useAccounts, useLocalStorage } from '@/hooks';
 
 import { setSelectedNetwork } from '@/state/app';
 import { getSelectedNetwork } from '@/state/appSelectors';
+import { openDialog } from '@/state/dialogs';
 
 import { validateAgainstAvailableEnvironments } from '@/lib/network';
 
@@ -25,6 +27,17 @@ export const useSelectedNetwork = (): {
     validateFn: validateAgainstAvailableEnvironments,
   });
 
+  useEffect(() => {
+    if (
+      import.meta.env.MODE === 'production' &&
+      ENVIRONMENT_CONFIG_MAP[selectedNetwork].dydxChainId === 'dydx-testnet-3'
+    ) {
+      dispatch(
+        openDialog({ type: DialogTypes.ExchangeOffline, dialogProps: { preventClose: true } })
+      );
+    }
+  }, [selectedNetwork]);
+
   const switchNetwork = useCallback(
     (network: DydxNetwork) => {
       disconnect();