import { NextRequest, NextResponse } from "next/server";
import { geminiGenerate } from "@/lib/gemini";

export const dynamic = "force-dynamic";

/**
 * AI assistant. The UI sends a user prompt plus optional message context
 * (e.g. a copied message to summarize / draft a reply to). The Gemini key
 * never leaves the server.
 */
export async function POST(req: NextRequest) {
  const body = await req.json().catch(() => ({}));
  const prompt: string = (body.prompt ?? "").toString().trim();
  const context: string | undefined = body.context ? String(body.context) : undefined;

  if (!prompt && !context) {
    return NextResponse.json({ ok: false, error: "Nothing to ask." }, { status: 400 });
  }

  const parts: string[] = [];
  if (context) parts.push(`Here is a chat message for context:\n"""\n${context}\n"""`);
  parts.push(prompt || "Summarize the message above.");

  const result = await geminiGenerate(parts.join("\n\n"), {
    system:
      "You are a concise, helpful assistant embedded in a team-messaging app. " +
      "Answer directly in a professional but friendly tone. When drafting a reply, write it in first person, ready to send. Keep responses tight.",
    temperature: 0.5,
  });

  if (!result.ok) {
    return NextResponse.json({ ok: false, error: result.error, retryable: result.retryable }, { status: result.status || 502 });
  }
  return NextResponse.json({ ok: true, text: result.text });
}