import { prisma } from "@/lib/prisma";

export async function listPublishedCourses() {
  return prisma.course.findMany({
    where: { published: true },
    orderBy: { updatedAt: "desc" },
    include: {
      categories: { include: { category: true } },
      modules: {
        orderBy: { sortOrder: "asc" },
        include: {
          lessons: {
            where: { published: true },
            orderBy: { sortOrder: "asc" },
            select: { slug: true },
          },
        },
      },
    },
  });
}

export async function getCourseBySlug(slug: string) {
  return prisma.course.findFirst({
    where: { slug, published: true },
    include: {
      categories: { include: { category: true } },
      modules: {
        orderBy: { sortOrder: "asc" },
        include: {
          lessons: { where: { published: true }, orderBy: { sortOrder: "asc" } },
        },
      },
    },
  });
}

export async function getLessonContext(courseSlug: string, lessonSlug: string) {
  const course = await prisma.course.findFirst({
    where: { slug: courseSlug, published: true },
    include: {
      modules: {
        orderBy: { sortOrder: "asc" },
        include: {
          lessons: { where: { published: true }, orderBy: { sortOrder: "asc" } },
        },
      },
    },
  });
  if (!course) return null;

  for (const mod of course.modules) {
    const lesson = mod.lessons.find((l) => l.slug === lessonSlug);
    if (lesson) return { course, module: mod, lesson };
  }
  return null;
}

export function firstLessonPath(course: {
  slug: string;
  modules: { lessons: { slug: string }[] }[];
}): string | null {
  for (const m of course.modules) {
    const first = m.lessons[0];
    if (first) return `/kurse/${course.slug}/lektionen/${first.slug}`;
  }
  return null;
}