feat(db): integrate Drizzle ORM with SQLite

.gitignore

@@ -39,3 +39,8 @@ yarn-error.log*
 # typescript
 *.tsbuildinfo
 next-env.d.ts
+
+# SQLite Datenbanken
+*.db
+*.db-journal
+/db/migrations/

README.md

@@ -7,14 +7,14 @@ A modern, high-performance Kanban & Workflow web application designed to help yo
 ![TypeScript](https://img.shields.io/badge/TypeScript-5-blue?style=flat-square&logo=typescript)
 ![Tailwind CSS](https://img.shields.io/badge/Tailwind-v4-38bdf8?style=flat-square&logo=tailwind-css)
 ![Auth.js](https://img.shields.io/badge/Auth.js-v5-purple?style=flat-square)
-![PostgreSQL](https://img.shields.io/badge/PostgreSQL-16-4169E1?style=flat-square&logo=postgresql)
+![Drizzle ORM](https://img.shields.io/badge/Drizzle-ORM-C5F74F?style=flat-square&logo=drizzle)
 
 ## 🛠️ Tech Stack
 
 - **Framework:** [Next.js 16](https://nextjs.org/) (App Router, Route Groups)
 - **UI & Styling:** [React 19](https://react.dev/), [Tailwind CSS v4](https://tailwindcss.com/)
-- **Authentication:** [Auth.js v5 (NextAuth)](https://authjs.dev/) with Credentials Provider
-- **Database & State:** PostgreSQL / Prisma (in progress)
+- **Authentication:** [Auth.js v5 (NextAuth)](https://authjs.dev/) with Credentials Provider & bcrypt hashing
+- **Database & ORM:** [Drizzle ORM](https://orm.drizzle.team/) & Drizzle Kit
 
 ## 📂 Architecture & Structure
 
@@ -22,8 +22,9 @@ The project uses Next.js Route Groups to separate public and protected applicati
 
 - `app/(auth)/` — Public authentication routes (Login, Register)
 - `app/(app)/` — Protected workspace & dashboard routes (Sidebar, Header, Kanban Board)
-- `app/api/` — Backend API endpoints & Auth handlers
+- `app/api/` — Backend API endpoints & Auth handlers (`/api/auth/register`, `[...nextauth]`)
+- `db/` — Database schema definitions, migrations, and Drizzle configuration (`drizzle.config.ts`)
 
 ## 🎯 Current Status
 
-_In Progress_ — Core layout structure, responsive navigation, and authentication (Auth.js v5) are fully set up. Next up: Kanban board columns and task management features.
+_In Progress_ — Core layout structure, responsive navigation, and authentication (Auth.js v5) are implemented. Next up: Migration from SQLite to PostgreSQL via Drizzle ORM.

app/(auth)/login/page.tsx

@@ -111,7 +111,7 @@ export default function LoginPage() {
           <button
             type="submit"
             disabled={loading}
-            className="w-full py-2 text-sm font-medium rounded-lg bg-foreground text-background hover:opacity-70 transition-opacity disabled:opacity-20 cursor-pointer"
+            className="w-full py-2 text-sm font-medium rounded-lg bg-foreground text-background hover:opacity-70 transition-opacity disabled:opacity-20 cursor-pointer disabled:cursor-auto"
           >
             {loading ? "Logging in..." : "Sign In"}
           </button>

auth.ts

@@ -1,26 +1,88 @@
+/**
+ * @file auth.ts
+ * @description NextAuth configuration file setting up credentials authentication, database lookups via Drizzle, JWT sessions, and custom pages.
+ */
+
 import NextAuth from "next-auth";
 import Credentials from "next-auth/providers/credentials";
+import { db } from "@/db";
+import { usersTable } from "@/db/schema";
+import { eq } from "drizzle-orm";
+import bcrypt from "bcryptjs";
 
+/**
+ * Exports NextAuth configuration handlers, authentication state checkers, and auth methods.
+ */
 export const { handlers, auth, signIn, signOut } = NextAuth({
   providers: [
     Credentials({
-      name: "Credentials",
       credentials: {
         email: { label: "Email", type: "email" },
         password: { label: "Password", type: "password" },
       },
+      /**
+       * Authorizes a user by verifying their email and comparing hashed passwords from the database.
+       *
+       * @async
+       * @param {Record<string, any>} [credentials] - The user credentials submitted via the sign-in form.
+       * @returns {Promise<{ id: string; email: string } | null>} The authenticated user object or null if authorization fails.
+       */
       async authorize(credentials) {
-        if (
-          credentials?.email === "test@flowstate.io" &&
-          credentials?.password === "password"
-        ) {
-          return { id: "1", name: "Charlotte W.", email: "test@flowstate.io" };
-        }
-        return null;
+        if (!credentials?.email || !credentials?.password) return null;
+
+        const email = credentials.email as string;
+        const password = credentials.password as string;
+
+        const user = await db.query.usersTable.findFirst({
+          where: eq(usersTable.email, email),
+        });
+
+        if (!user || !user.password) return null;
+
+        const passwordsMatch = await bcrypt.compare(password, user.password);
+
+        if (!passwordsMatch) return null;
+
+        return { id: String(user.id), email: user.email };
       },
     }),
   ],
   pages: {
     signIn: "/login",
   },
+  session: {
+    strategy: "jwt",
+  },
+  callbacks: {
+    /**
+     * Adds the user ID to the JWT token upon initial sign-in.
+     *
+     * @async
+     * @param {Object} params - The JWT callback parameters.
+     * @param {import("next-auth/jwt").JWT} params.token - The current JWT token.
+     * @param {import("next-auth").User} [params.user] - The authenticated user object.
+     * @returns {Promise<import("next-auth/jwt").JWT>} The updated JWT token.
+     */
+    async jwt({ token, user }) {
+      if (user) {
+        token.id = user.id;
+      }
+      return token;
+    },
+    /**
+     * Injects the user ID from the JWT token into the client session object.
+     *
+     * @async
+     * @param {Object} params - The session callback parameters.
+     * @param {import("next-auth").Session} params.session - The current session object.
+     * @param {import("next-auth/jwt").JWT} params.token - The decoded JWT token.
+     * @returns {Promise<import("next-auth").Session>} The updated session object.
+     */
+    async session({ session, token }) {
+      if (token && session.user) {
+        session.user.id = token.id as string;
+      }
+      return session;
+    },
+  },
 });

db/index.ts

@@ -0,0 +1,15 @@
+/**
+ * @file db/index.ts (oder ähnlich)
+ * @description Initializes the SQLite database connection using better-sqlite3 and sets up the Drizzle ORM instance with the provided schema.
+ */
+
+import { drizzle } from "drizzle-orm/better-sqlite3";
+import Database from "better-sqlite3";
+import * as schema from "./schema";
+
+const sqlite = new Database("./sqlite.db");
+
+/**
+ * The Drizzle ORM database instance configured for SQLite with type definitions from the schema.
+ */
+export const db = drizzle(sqlite, { schema });

db/schema.ts

@@ -0,0 +1,28 @@
+/**
+ * @file db/schema.ts (oder ähnlich)
+ * @description Defines the SQLite database schema for users and exports related TypeScript types using Drizzle ORM.
+ */
+
+import { sqliteTable, text, integer } from "drizzle-orm/sqlite-core";
+
+/**
+ * Database table definition for application users.
+ */
+export const usersTable = sqliteTable("users", {
+  id: integer("id").primaryKey({ autoIncrement: true }),
+  email: text("email").notNull().unique(),
+  password: text("password").notNull(),
+  createdAt: integer("created_at", { mode: "timestamp" })
+    .$defaultFn(() => new Date())
+    .notNull(),
+});
+
+/**
+ * Represents a user record selected from the database.
+ */
+export type User = typeof usersTable.$inferSelect;
+
+/**
+ * Represents a new user object required for insertion into the database.
+ */
+export type NewUser = typeof usersTable.$inferInsert;

drizzle.config.ts

@@ -0,0 +1,18 @@
+/**
+ * @file drizzle.config.ts
+ * @description Drizzle Kit configuration file specifying schema locations, migration output directories, and database connection credentials for SQLite.
+ */
+
+import { defineConfig } from "drizzle-kit";
+
+/**
+ * Configuration object for Drizzle Kit CLI commands (migrations, introspection, studio).
+ */
+export default defineConfig({
+  schema: "./db/schema.ts",
+  out: "./db/migrations",
+  dialect: "sqlite",
+  dbCredentials: {
+    url: "./sqlite.db",
+  },
+});

package.json

@@ -9,6 +9,9 @@
     "lint": "eslint"
   },
   "dependencies": {
+    "bcryptjs": "^3.0.3",
+    "better-sqlite3": "^13.0.2",
+    "drizzle-orm": "^0.45.2",
     "lucide-react": "^1.28.0",
     "next": "16.2.12",
     "next-auth": "^5.0.0-beta.32",
@@ -17,9 +20,11 @@
   },
   "devDependencies": {
     "@tailwindcss/postcss": "^4",
+    "@types/better-sqlite3": "^9.6.0",
     "@types/node": "^20",
     "@types/react": "^19",
     "@types/react-dom": "^19",
+    "drizzle-kit": "^0.31.10",
     "eslint": "^9",
     "eslint-config-next": "16.2.12",
     "tailwindcss": "^4",