import { NextRequest, NextResponse } from "next/server";
import { db } from "@/lib/db";
import { invitations, users } from "@/lib/db/schema";
import { auth } from "@/lib/auth";
import { eq } from "drizzle-orm";
import { z } from "zod";
import { nanoid } from "nanoid";

const AcceptSchema = z.object({
  token: z.string().min(1),
  name: z.string().min(2).max(100),
  password: z.string().min(8).max(128),
});

export async function POST(req: NextRequest) {
  let body: z.infer<typeof AcceptSchema>;
  try {
    body = AcceptSchema.parse(await req.json());
  } catch {
    return NextResponse.json({ error: "Invalid request" }, { status: 400 });
  }

  const invitation = await db
    .select()
    .from(invitations)
    .where(eq(invitations.token, body.token))
    .get();

  if (!invitation) {
    return NextResponse.json({ error: "Invalid invitation token" }, { status: 404 });
  }
  if (invitation.acceptedAt) {
    return NextResponse.json({ error: "Invitation already used" }, { status: 409 });
  }
  if (Number(invitation.expiresAt) < Date.now()) {
    return NextResponse.json({ error: "Invitation has expired" }, { status: 410 });
  }

  // Check if email already registered
  const existing = await db.select().from(users).where(eq(users.email, invitation.email)).get();
  if (existing) {
    return NextResponse.json({ error: "Email already registered" }, { status: 409 });
  }

  // Create user via Better Auth
  try {
    await auth.api.signUpEmail({
      body: {
        email: invitation.email,
        password: body.password,
        name: body.name,
      },
    });
  } catch (err) {
    const message = err instanceof Error ? err.message : "Failed to create account";
    return NextResponse.json({ error: message }, { status: 500 });
  }

  // Mark invitation as accepted and set role
  await db
    .update(invitations)
    .set({ acceptedAt: Date.now() })
    .where(eq(invitations.token, body.token));

  await db
    .update(users)
    .set({ role: invitation.role })
    .where(eq(users.email, invitation.email));

  return NextResponse.json({ success: true });
}