add placeholder for "no cards"

amnet-native/app/CardManager.tsx

@@ -1,11 +1,14 @@
 import * as Clipboard from 'expo-clipboard';
-import {useCallback, useMemo} from "react";
 import {FlatList, View} from "react-native";
+import React, {useCallback, useMemo} from "react";
 
 import {AMCard} from "../models/AMCard";
 import {AimeCard} from "../components/AimeCard";
 import RealmContext from "../models/RealmContext";
 import ContextMenu from "react-native-context-menu-view";
+import {EmptyStatePlaceholder} from "../components/EmptyStatePlaceholder";
+import {CreditCard, Plus} from "lucide-react-native";
+import {Button, useTheme} from "react-native-paper";
 
 const {useQuery, useRealm} = RealmContext;
 
@@ -37,9 +40,20 @@ function CardEntry(props: { card: AMCard }) {
     );
 }
 
-export default function CardManager() {
+export default function CardManager({navigation}) {
     const query = useQuery(AMCard);
     const cards = useMemo(() => query.sorted("added", true), [query]);
+    
+    const theme = useTheme();
+    
+    if (!cards.length) {
+        return (
+            <View style={{flex: 1, gap: 10, justifyContent: "center", alignItems: "center"}}>
+                <EmptyStatePlaceholder message="No cards added yet" icon={<CreditCard color="gray"/>}/>
+                <Button mode="text" onPress={() => navigation.navigate('add-card')} icon={() => <Plus size={18} color={theme.colors.primary}/>}>Add Card</Button>
+            </View>
+        )
+    }
 
     return (
         <FlatList contentInsetAdjustmentBehavior="always"

amnet-native/components/EmptyStatePlaceholder.tsx

@@ -0,0 +1,13 @@
+import {View} from "react-native";
+import {Paragraph} from "react-native-paper";
+
+export function EmptyStatePlaceholder(props: { message: string, icon: React.ReactNode }) {
+    return (
+        <View style={{display: "flex", gap: 5, alignItems: "center"}}>
+            {props.icon}
+            <Paragraph style={{color: "gray", fontSize: 14}}>
+                {props.message}
+            </Paragraph>
+        </View>
+    )
+}