"use server";

import { prisma } from "@/lib/prisma";
import { headers } from "next/headers";
import { auth } from "@/lib/auth";
import { sendCourseAccessEmail } from "@/lib/email";
import { revalidatePath } from "next/cache";

async function requireAdmin() {
  const session = await auth.api.getSession({ headers: await headers() });
  if (!session || session.user.role !== "admin") throw new Error("Forbidden");
  return session;
}

export async function grantCourseAccess(
  userId: string,
  courseId: string,
  expiresAt: Date | null
): Promise<{ ok: true } | { error: string }> {
  try {
    const session = await requireAdmin();

    const [user, course] = await Promise.all([
      prisma.user.findUnique({ where: { id: userId }, select: { email: true, name: true } }),
      prisma.course.findUnique({ where: { id: courseId }, select: { title: true } }),
    ]);

    if (!user) return { error: "Пользователь не найден" };
    if (!course) return { error: "Курс не найден" };

    const existing = await prisma.courseEnrollment.findUnique({
      where: { userId_courseId: { userId, courseId } },
    });

    await prisma.courseEnrollment.upsert({
      where: { userId_courseId: { userId, courseId } },
      update: { expiresAt },
      create: { userId, courseId, expiresAt },
    });

    await prisma.accessLog.create({
      data: {
        courseId,
        userId,
        action: "granted",
        method: "quick",
        grantedById: session.user.id,
      },
    });

    // Send email only on new enrollment (not on update)
    if (!existing) {
      await sendCourseAccessEmail(user.email, user.name ?? user.email, course.title).catch(
        (e) => console.error("[enroll-action] sendCourseAccessEmail:", e)
      );
    }

    revalidatePath("/admin/users");
    revalidatePath(`/admin/users/${userId}`);

    return { ok: true };
  } catch (e) {
    console.error("[enroll-action] grantCourseAccess:", e);
    return { error: "Произошла ошибка. Попробуйте ещё раз." };
  }
}

export async function getPublishedCourses(): Promise<{ id: string; title: string }[]> {
  await requireAdmin();
  return prisma.course.findMany({
    where: { published: true },
    select: { id: true, title: true },
    orderBy: { title: "asc" },
  });
}