export const runtime = "nodejs";

import { NextResponse } from "next/server";
import { requireSession } from "@/lib/auth/require";
import { deliverAgentMessage } from "@/lib/tickets/delivery";
import { getTicketWithMessages } from "@/lib/tickets/service";
import { isTicketVisibleTo } from "@/lib/tickets/visibility";
import { saveAttachment, AttachmentTooLargeError, MAX_ATTACHMENT_BYTES } from "@/lib/attachments/storage";

export async function POST(request: Request, { params }: { params: Promise<{ id: string }> }) {
  const { session, response } = await requireSession();
  if (!session) return response;

  const currentUser = { id: session.user.id, role: session.user.role };
  const { id } = await params;

  const existing = await getTicketWithMessages(id);
  if (!existing || !isTicketVisibleTo(existing.ticket, currentUser)) {
    return NextResponse.json({ error: "Ticket not found" }, { status: 404 });
  }

  const formData = await request.formData().catch(() => null);
  const file = formData?.get("file");
  if (!(file instanceof File)) {
    return NextResponse.json({ error: "Missing file" }, { status: 400 });
  }
  if (file.size > MAX_ATTACHMENT_BYTES) {
    return NextResponse.json({ error: "File too large" }, { status: 413 });
  }

  const captionRaw = formData?.get("caption");
  const caption = typeof captionRaw === "string" ? captionRaw.trim() : "";
  // Internal notes are admin-only — see messages/route.ts for the same rule.
  const visibility = currentUser.role === "admin" && formData?.get("visibility") === "internal" ? "internal" : "public";

  const buffer = Buffer.from(await file.arrayBuffer());
  let saved;
  try {
    saved = await saveAttachment(buffer);
  } catch (err) {
    if (err instanceof AttachmentTooLargeError) {
      return NextResponse.json({ error: "File too large" }, { status: 413 });
    }
    throw err;
  }

  try {
    const result = await deliverAgentMessage({
      ticketId: id,
      agentId: session.user.id,
      agentName: session.user.name,
      body: caption || file.name || "Вложение",
      visibility,
      attachment: {
        filename: file.name || "file",
        mimeType: file.type || "application/octet-stream",
        sizeBytes: saved.sizeBytes,
        storageKey: saved.storageKey,
        buffer,
      },
    });
    return NextResponse.json(result, { status: 201 });
  } catch {
    return NextResponse.json({ error: "Ticket not found" }, { status: 404 });
  }
}