thank you suahard

src/app/(BottomTabNavigation)/Cases/QRCodeScanner/AddCase/index.tsx

@@ -1,22 +1,47 @@
 import { useLocalSearchParams, useRouter } from 'expo-router';
+import { useEffect, useState } from 'react';
 import { Image, Text, TouchableOpacity, View } from 'react-native';
-import { uploadCase } from '../../../../../supabase/queries/cases';
-import { CaseUid } from '../../../../../types/types';
+
 import styles from './styles';
+import {
+  containsDuplicateCase,
+  uploadCase,
+} from '../../../../../supabase/queries/cases';
+import { CaseUid } from '../../../../../types/types';
 
 function AddCase() {
-  const { id, title, summary, image } = useLocalSearchParams<{
+  const { id, title, image, summary } = useLocalSearchParams() as {
     id: CaseUid;
     title: string;
-    summary: string;
     image: string;
-  }>();
+    summary: string;
+  };
   const router = useRouter();
+  const [loading, setLoading] = useState<boolean>(true);
+
+  useEffect(() => {
+    const validateCaseUniqueness = async () => {
+      const duplicate = await containsDuplicateCase(id);
+      if (duplicate) {
+        console.log('DUPLICATES NOT ALLOWED!');
+        router.back();
+      }
+    };
+    validateCaseUniqueness();
+    setLoading(false);
+  }, []);
 
   const addToCases = async () => {
     uploadCase(id);
     router.push('/Cases');
   };
+  if (loading) {
+    return (
+      <View>
+        <Text>LOADING... LOL</Text>
+      </View>
+    );
+  }
   return (
     <View style={styles.container}>
       <Text style={styles.title}>{title}</Text>

src/app/(BottomTabNavigation)/Cases/QRCodeScanner/index.tsx

@@ -1,13 +1,10 @@
 import { BarCodeScanner, BarCodeScannerResult } from 'expo-barcode-scanner';
-import { router } from 'expo-router';
+import { router, useNavigation } from 'expo-router';
 import React, { useEffect, useState } from 'react';
 import { Text, TouchableOpacity, View } from 'react-native';
-import supabase from '../../../../supabase/createClient';
-import {
-  containsDuplicateCase,
-  getCaseById,
-} from '../../../../supabase/queries/cases';
+
 import styles from './styles';
+import { getCaseById, isValidCase } from '../../../../supabase/queries/cases';
 
 enum permissions {
   UNDETERMINED,
@@ -17,8 +14,15 @@ enum permissions {
 
 function QRCodeScannerScreen() {
   const [hasPermission, setHasPermission] = useState(permissions.UNDETERMINED);
-  const [message, setMessage] = useState('');
-  const [scanned, setScanned] = useState(false);
+  const [scanned, setScanned] = useState<boolean>(false);
+  const navigation = useNavigation();
+
+  useEffect(() => {
+    const unsubscribe = navigation.addListener('blur', async () => {
+      setScanned(false);
+    });
+    return unsubscribe;
+  }, [navigation]);
 
   useEffect(() => {
     const getBarCodeScannerPermissions = async () => {
@@ -30,23 +34,22 @@ function QRCodeScannerScreen() {
     getBarCodeScannerPermissions();
   }, []);
 
-  const isValidBarcode = (caseId: string) => true;
-
   const handleBarCodeScanned = async (result: BarCodeScannerResult) => {
     const caseId = result.data;
-    if (isValidBarcode(caseId)) {
-      const { id, title, summary, image } = await getCaseById(caseId);
-      const duplicate = await containsDuplicateCase(id);
-      if (duplicate) {
-        console.log('YOU ALREADY HAVE THIS CASE!');
-      } else {
-        router.push({
-          pathname: '/Cases/QRCodeScanner/AddCase',
-          params: { id, title, summary, image },
-        });
+    if (!scanned) {
+      setScanned(true);
+      const valid = await isValidCase(caseId);
+      if (!valid) {
+        // TODO: Display error toast message
+        return;
       }
-    } else {
-      setMessage('INVALID QR CODE!');
+      const data = await getCaseById(caseId);
+
+      const { id, title, image, summary } = data;
+      router.push({
+        pathname: '/Cases/QRCodeScanner/AddCase',
+        params: { id, title, image, summary },
+      });
     }
   };
 
@@ -61,7 +64,6 @@ function QRCodeScannerScreen() {
         onBarCodeScanned={handleBarCodeScanned}
         style={[styles.scanner]}
       />
-      <Text>Current Scanning: {message}</Text>
       <TouchableOpacity onPress={() => router.back()} style={styles.button}>
         <Text>Go Back</Text>
       </TouchableOpacity>

src/supabase/createClient.ts

@@ -2,12 +2,15 @@ import AsyncStorage from '@react-native-async-storage/async-storage';
 import { createClient } from '@supabase/supabase-js';
 import 'react-native-url-polyfill/auto';
 
-if (!process.env.SUPABASE_URL || !process.env.SUPABASE_ANON_KEY) {
+if (
+  !process.env.EXPO_PUBLIC_SUPABASE_URL ||
+  !process.env.EXPO_PUBLIC_SUPABASE_ANON_KEY
+) {
   throw new Error('Supabase environment variables are not defined.');
 }
 const supabase = createClient(
-  process.env.SUPABASE_URL,
-  process.env.SUPABASE_ANON_KEY,
+  process.env.EXPO_PUBLIC_SUPABASE_URL,
+  process.env.EXPO_PUBLIC_SUPABASE_ANON_KEY,
   {
     auth: {
       storage: AsyncStorage,

src/supabase/queries/cases.ts

@@ -44,6 +44,14 @@ export async function getCaseById(caseId: CaseUid): Promise<Case> {
   }
 }
 
+export async function isValidCase(caseId: CaseUid): Promise<boolean> {
+  const { data } = await supabase.from('cases').select().eq('caseId', caseId);
+  if (!data) {
+    return false;
+  }
+  return data.length !== 0;
+}
+
 /**
  * Fetch an array of Case objects contained in an array of `CaseId`s. Fetches cases from `cases` table.
  *
@@ -93,7 +101,7 @@ export async function containsDuplicateCase(caseId: CaseUid) {
       .select()
       .eq('userId', userId)
       .eq('caseId', caseId);
-    return data?.length === 0;
+    return data?.length !== 0;
   } catch (error) {
     throw error;
   }