feat: setup database-driven admin user management

app/actions/auth.ts

@@ -2,29 +2,65 @@
 
 import { cookies } from "next/headers";
 import { redirect } from "next/navigation";
+import prisma from "@/lib/prisma";
+import bcrypt from "bcryptjs";
 
 export type ActionState = { error: string } | null;
 
 export async function login(prevState: ActionState, formData: FormData): Promise<ActionState> {
-  const username = formData.get("username");
-  const password = formData.get("password");
+  const username = formData.get("username") as string;
+  const password = formData.get("password") as string;
 
-  if (
-    username === process.env.ADMIN_USERNAME &&
-    password === process.env.ADMIN_PASSWORD
-  ) {
-    const cookieStore = await cookies();
-    cookieStore.set("admin_session", "true", {
-      httpOnly: true,
-      secure: process.env.NODE_ENV === "production",
-      maxAge: 60 * 60 * 24 * 7, // 1 week
-      path: "/",
-    });
-  } else {
-    return { error: "Geçersiz kullanıcı adı veya şifre" };
+  if (!username || !password) {
+    return { error: "Kullanıcı adı ve şifre gereklidir" };
   }
 
-  redirect("/admin");
+  // Fallback to initial .env credentials if no users exist
+  const userCount = await prisma.user.count();
+  if (userCount === 0) {
+    if (
+      username === process.env.ADMIN_USERNAME &&
+      password === process.env.ADMIN_PASSWORD
+    ) {
+      // Create the first admin user
+      const hashedPassword = await bcrypt.hash(password, 10);
+      await prisma.user.create({
+        data: {
+          username,
+          password: hashedPassword,
+        },
+      });
+      await setSessionCookie();
+      redirect("/admin");
+    } else {
+      return { error: "Geçersiz kullanıcı adı veya şifre" };
+    }
+  } else {
+    // Normal DB login
+    const user = await prisma.user.findUnique({
+      where: { username },
+    });
+
+    if (user && await bcrypt.compare(password, user.password)) {
+      await setSessionCookie();
+      redirect("/admin");
+    } else {
+      return { error: "Geçersiz kullanıcı adı veya şifre" };
+    }
+  }
+  
+  // This redirect is inside if blocks but typescript requires a return here.
+  return { error: "Bilinmeyen bir hata oluştu" };
+}
+
+async function setSessionCookie() {
+  const cookieStore = await cookies();
+  cookieStore.set("admin_session", "true", {
+    httpOnly: true,
+    secure: process.env.NODE_ENV === "production",
+    maxAge: 60 * 60 * 24 * 7, // 1 week
+    path: "/",
+  });
 }
 
 export async function logout() {