import { NextRequest, NextResponse } from "next/server";
import { headers } from "next/headers";
import { auth } from "@/lib/auth";
import { prisma } from "@/lib/prisma";
import { sendQuestionCreatedEmail, sendQuestionReplyEmail } from "@/lib/email";

interface FileAttachment {
  name: string;
  url: string;
  size: number;
}

export async function POST(
  req: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  const session = await auth.api.getSession({ headers: await headers() });
  if (!session) return NextResponse.json({ error: "Unauthorized" }, { status: 401 });

  const { id } = await params;
  const isStaff = session.user.role === "admin" || session.user.role === "curator";

  const question = await prisma.studentQuestion.findUnique({
    where: { id },
    include: { user: { select: { id: true, name: true, email: true } } },
  });

  if (!question) return NextResponse.json({ error: "Not found" }, { status: 404 });
  if (!isStaff && question.userId !== session.user.id) {
    return NextResponse.json({ error: "Forbidden" }, { status: 403 });
  }

  const body = await req.json();
  const { text, files } = body as { text: string; files?: FileAttachment[] };

  if (!text?.trim()) {
    return NextResponse.json({ error: "text is required" }, { status: 400 });
  }

  const message = await prisma.studentQuestionMessage.create({
    data: {
      questionId: id,
      authorId: session.user.id,
      text: text.trim(),
      files: files?.length ? (files as object[]) : undefined,
    },
    include: { author: { select: { id: true, name: true, role: true } } },
  });

  // Touch question.updatedAt
  await prisma.studentQuestion.update({
    where: { id },
    data: { updatedAt: new Date() },
  });

  // Send notifications
  if (isStaff) {
    await sendQuestionReplyEmail(
      question.user.email,
      question.user.name,
      question.title,
      id,
    );
  } else {
    const staff = await prisma.user.findMany({
      where: { role: { in: ["admin", "curator"] } },
      select: { email: true, name: true },
    });
    await Promise.all(
      staff.map((s) =>
        sendQuestionCreatedEmail(s.email, s.name, session.user.name, question.title)
      )
    );
  }

  return NextResponse.json(message, { status: 201 });
}