import { apiError, apiJson } from "@/lib/api-handler";
import { resolveApiAuth } from "@/lib/api-auth";
import { getAssistantPreferences } from "@/lib/assistant-preference";
import { transcribeAudioFile } from "@/lib/llm/transcribe";

export const runtime = "nodejs";
export const maxDuration = 120;

const MAX_AUDIO_BYTES = 25 * 1024 * 1024;

export async function POST(request: Request) {
  const auth = await resolveApiAuth(request);
  if (!auth?.userId) {
    return apiError("Unauthorized", 401);
  }

  const assistant = await getAssistantPreferences(auth.userId);
  if (!assistant.enabled) {
    return apiError("Assistant not enabled", 403);
  }

  let formData: FormData;
  try {
    formData = await request.formData();
  } catch {
    return apiError("Invalid multipart body", 400);
  }

  const file = formData.get("file");
  if (!(file instanceof File)) {
    return apiError("No audio file in request", 400);
  }

  if (!file.type.startsWith("audio/") && file.type !== "video/webm") {
    return apiError("Only audio recordings are allowed", 415);
  }

  if (file.size > MAX_AUDIO_BYTES) {
    return apiError("Recording exceeds 25 MB limit", 413);
  }

  const filename = file.name.trim() || "recording.wav";

  try {
    const text = await transcribeAudioFile(file, filename);
    return apiJson({ text });
  } catch (err) {
    const message = err instanceof Error ? err.message : "Transcription failed";
    return apiError(message, 502);
  }
}