feat(auth): implement authentication system with register, login, and middleware

Add API endpoints for user registration and login using bcrypt for
password hashing and comparison. Introduce a Pinia store for managing
authentication state, including login, register, and logout actions.
Implement middleware to protect admin routes, redirecting
unauthenticated users to the login page. Integrate Prisma for database
interactions.

middleware/auth.ts

+export default defineNuxtRouteMiddleware((to) => {
+    const isAuthenticated = false; // TODO: check if user is authenticated
+    if (!isAuthenticated && to.path.startsWith('/admin')) {
+        return navigateTo('/login');
+    }
+});
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server/api/auth/login.ts

+import { compare } from 'bcrypt';
+import { prisma } from '~/server/prisma';
+
+export default defineEventHandler(async (event) => {
+    const userExists = await prisma.user.count();
+    if (!userExists) {
+        throw createError({ statusCode: 403, statusMessage: 'No users exist' });
+    }
+
+    const { email, password } = await readBody(event);
+
+    const user = await prisma.user.findUnique({
+        where: { email },
+    });
+
+    if (!user || !(await compare(password, user.password))) {
+        throw createError({ statusCode: 401, statusMessage: 'Invalid credentials' });
+    }
+
+    // Set up session or token logic here
+
+    return { user };
+});
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server/api/auth/register.ts

+import { hash } from 'bcrypt';
+import { prisma } from '~/server/prisma';
+
+export default defineEventHandler(async (event) => {
+    const userExists = await prisma.user.count();
+    if (userExists) {
+        throw createError({ statusCode: 403, statusMessage: 'User already exists' });
+    }
+
+    const { email, name, password } = await readBody(event);
+
+    if (!/[A-Z]/.test(password) || !/[a-z]/.test(password) || !/[0-9]/.test(password) || !/[^A-Za-z0-9]/.test(password)) {
+        return new Response('Password must contain at least one uppercase letter, one lowercase letter, one number, and one special character', {
+            status: 422,
+        });
+    }
+
+    const hashedPassword = await hash(password, 10);
+
+    const user = await prisma.user.create({
+        data: {
+            email,
+            name,
+            password: hashedPassword,
+        },
+    });
+
+    return { user };
+});
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server/api/auth/userExists.ts

+import {prisma} from "~/server/prisma";
+
+export default defineEventHandler(async (event) => {
+    const userCount = await prisma.user.count();
+    return { userExists: userCount > 0 };
+})
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server/prisma.ts

+import { PrismaClient } from '@prisma/client';
+
+const prisma = new PrismaClient();
+
+export { prisma };
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stores/auth.ts

+import { defineStore } from 'pinia';
+import { useRouter } from 'vue-router';
+
+export const useAuthStore = defineStore('auth', {
+    state: () => ({
+        user: null,
+    }),
+
+    actions: {
+        async login(email: string, password: string) {
+            try {
+                const response = await fetch('/api/auth/login', {
+                    method: 'POST',
+                    headers: {
+                        "Content-Type": "application/json",
+                    },
+                    body: JSON.stringify({ email, password }),
+                });
+
+                if (!response.ok) {
+                    // Promise.reject() is used to avoid "'throw' of exception caught locally" warning
+                    // https://stackoverflow.com/a/60725482/12680199
+                    return Promise.reject(Error('Invalid credentials'));
+                }
+
+                this.user = await response.json();
+                const router = useRouter();
+                await router.push('/admin');
+            } catch (error) {
+                console.error(error);
+            }
+        },
+
+        async register(email: string, password: string, name: string) {
+            try {
+                const response = await fetch('/api/auth/register', {
+                    method: 'POST',
+                    headers: {
+                        "Content-Type": "application/json",
+                    },
+                    body: JSON.stringify({ email, password, name }),
+                });
+
+                if (!response.ok) {
+                    // Promise.reject() is used to avoid "'throw' of exception caught locally" warning
+                    // https://stackoverflow.com/a/60725482/12680199
+                    return Promise.reject(Error('Error registering user'));
+                }
+
+                this.user = await response.json();
+                const router = useRouter();
+                await router.push('/admin');
+            } catch (error) {
+                console.error(error);
+            }
+        },
+
+        async logout() {
+            this.user = null;
+            const router = useRouter();
+            await router.push('/');
+        }
+    }
+})
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