"use server";

import { revalidatePath } from "next/cache";
import { redirect } from "next/navigation";
import { prisma } from "@/lib/prisma";
import { requireAdmin } from "@/lib/rbac";
import { classSchema } from "@/lib/validators";

export type ClassState = { error?: string } | undefined;

function nullable(v: string | undefined | null) {
  const t = (v ?? "").trim();
  return t === "" ? null : t;
}
function parseDate(v: string | undefined | null) {
  const t = (v ?? "").trim();
  if (!t) return null;
  const d = new Date(t);
  return Number.isNaN(d.getTime()) ? null : d;
}

export async function createClassAction(_prev: ClassState, formData: FormData): Promise<ClassState> {
  await requireAdmin();
  const parsed = classSchema.safeParse(Object.fromEntries(formData));
  if (!parsed.success) return { error: parsed.error.issues[0]?.message ?? "Data tidak valid." };
  const d = parsed.data;

  const exists = await prisma.class.findUnique({ where: { code: d.code } });
  if (exists) return { error: `Kode kelas ${d.code} sudah dipakai.` };

  try {
    await prisma.class.create({
      data: {
        name: d.name,
        code: d.code,
        description: nullable(d.description),
        level: d.level,
        teacherId: nullable(d.teacherId),
        totalMeetings: d.totalMeetings,
        packagePrice: d.packagePrice,
        pricePerMeeting: d.pricePerMeeting && d.pricePerMeeting > 0 ? d.pricePerMeeting : null,
        capacity: d.capacity,
        schedule: nullable(d.schedule),
        color: nullable(d.color) ?? "#7C5CFC",
        status: d.status,
        startDate: parseDate(d.startDate),
      },
    });
  } catch (e) {
    return { error: e instanceof Error ? e.message : "Gagal membuat kelas." };
  }
  revalidatePath("/classes");
  redirect("/classes");
}

export async function updateClassAction(_prev: ClassState, formData: FormData): Promise<ClassState> {
  await requireAdmin();
  const id = String(formData.get("id"));
  const parsed = classSchema.safeParse(Object.fromEntries(formData));
  if (!parsed.success) return { error: parsed.error.issues[0]?.message ?? "Data tidak valid." };
  const d = parsed.data;

  try {
    await prisma.class.update({
      where: { id },
      data: {
        name: d.name,
        code: d.code,
        description: nullable(d.description),
        level: d.level,
        teacherId: nullable(d.teacherId),
        totalMeetings: d.totalMeetings,
        packagePrice: d.packagePrice,
        pricePerMeeting: d.pricePerMeeting && d.pricePerMeeting > 0 ? d.pricePerMeeting : null,
        capacity: d.capacity,
        schedule: nullable(d.schedule),
        color: nullable(d.color) ?? "#7C5CFC",
        status: d.status,
        startDate: parseDate(d.startDate),
      },
    });
  } catch (e) {
    return { error: e instanceof Error ? e.message : "Gagal memperbarui kelas." };
  }
  revalidatePath("/classes");
  revalidatePath(`/classes/${id}`);
  redirect("/classes");
}

export async function archiveClassAction(formData: FormData) {
  await requireAdmin();
  const id = String(formData.get("id"));
  await prisma.class.update({ where: { id }, data: { status: "ARCHIVED" } });
  revalidatePath("/classes");
  redirect("/classes");
}

export async function generateSessionsAction(formData: FormData) {
  await requireAdmin();
  const classId = String(formData.get("classId"));
  const cls = await prisma.class.findUnique({ where: { id: classId }, include: { sessions: true } });
  if (!cls) redirect("/classes");

  const existing = new Set(cls.sessions.map((s) => s.meetingNumber));
  const base = cls.startDate ?? new Date();
  const created = [];
  for (let i = 1; i <= cls.totalMeetings; i++) {
    if (existing.has(i)) continue;
    const date = new Date(base);
    date.setDate(date.getDate() + (i - 1) * 7);
    const s = await prisma.session.create({
      data: { classId, meetingNumber: i, date, topic: `Pertemuan ${i}: ${cls.name}`, teacherId: cls.teacherId },
    });
    created.push(s.id);
  }
  revalidatePath(`/classes/${classId}`);
  redirect(`/classes/${classId}`);
}