feat: introduced Authentification Context

app/contexts/AuthContext.tsx

@@ -0,0 +1,137 @@
+import { createContext, useContext, useEffect, useState } from "react";
+import { Platform } from "react-native";
+import * as SecureStore from 'expo-secure-store'
+
+interface AuthProps {
+  authState?: {email: string | null; authenticated: boolean | null; session: string | null};
+  onRegister?: (email: string, password: string) => Promise<any>;
+  onLogin?: (email: string, password: string) => Promise<any>
+  onLogout?: () => void
+}
+
+const SESSION_KEY = 'my_session'
+const USER_KEY = "email"
+const AuthContext = createContext<AuthProps>({})
+
+export const useAuth = ()=>{
+  return useContext(AuthContext)
+}
+
+async function setStorageItemAsync(key: string, value: string | null){
+  if (Platform.OS === 'web') {
+    try {
+      if (value === null) {
+        localStorage.removeItem(key);
+      } else {
+        localStorage.setItem(key, value);
+      }
+    } catch (e) {
+      console.error('Local storage is unavailable:', e);
+    }
+  } else {
+    if (value == null) {
+      await SecureStore.deleteItemAsync(key);
+    } else {
+      await SecureStore.setItemAsync(key, value);
+    }
+  }
+}
+
+async function getStorageItemAsync(key: string) : Promise<string|null> {
+   if(Platform.OS === 'web'){
+    return localStorage.getItem(key)
+   }else{
+    return SecureStore.getItemAsync(key)
+   }
+}
+
+export const AuthProvider = ({children}: any) => {
+  const [authState, setAuthState] = useState<{
+    email: string | null;
+    authenticated: boolean | null;
+    session : string | null;
+    isLoading: boolean;
+  }>({
+    email: null, authenticated: null, session: null, isLoading: false
+  });
+
+  useEffect(() => {
+    const loadSession = async () => {
+      setAuthState((prev) => {
+        return {
+          ...prev,
+          isLoading: true
+        }
+      })
+
+
+      const session = await getStorageItemAsync(SESSION_KEY)
+      const email = await getStorageItemAsync(USER_KEY)
+
+      if(session && email){
+        setAuthState({
+          email: email,
+          authenticated: true,
+          session: session,
+          isLoading: false
+        })
+      }
+      setAuthState((prev) => {
+        return {
+          ...prev,
+          isLoading: false
+        }
+      })
+    }
+    loadSession()
+  },[])
+
+
+  const register = async (email: string, password: string) => {
+    //registration Logic goes here
+  }
+
+  const login = async (email: string, password: string) => {
+
+  //login functionality goes here
+    console.log("login called")
+    setAuthState((prev) => {
+      return{
+        ...prev,
+        isLoading: true
+      }
+    })
+
+    setAuthState({
+      email: email,
+      authenticated: true,
+      session: "super duper session token das wir vlt mal brauchen",
+      isLoading: false
+
+    })
+
+    await setStorageItemAsync(SESSION_KEY, "super duper session token das wir vlt mal brauchen")
+    await setStorageItemAsync(USER_KEY, email)
+  }
+
+  const logout = async () => {
+    await setStorageItemAsync(SESSION_KEY, null)
+    await setStorageItemAsync(USER_KEY, null)
+    
+    setAuthState({
+      email: null,
+      authenticated: false,
+      session: null,
+      isLoading: false
+    });
+  };
+
+
+  const value = {
+    onRegister: register,
+    onLogin: login,
+    onLogout: logout,
+    authState
+  }
+  return <AuthContext.Provider value={value}>{children}</AuthContext.Provider>
+}