import { NextResponse } from "next/server";

const API_BASE_URL = process.env.KIE_API_URL ?? "https://api.kie.ai";
const API_KEY = process.env.KIE_API_KEY ?? "";

function buildErrorResponse(message: string, status = 500) {
  return NextResponse.json({ message }, { status });
}

async function parseResponse(response: Response) {
  const raw = await response.text();

  if (!raw) {
    return {};
  }

  try {
    return JSON.parse(raw);
  } catch {
    return { message: raw };
  }
}

export async function POST(req: Request) {
  if (!API_KEY) {
    return buildErrorResponse("Kie.ai API key is not configured.");
  }

  let body: unknown;

  try {
    body = await req.json();
  } catch {
    return buildErrorResponse("Request body must be valid JSON.", 400);
  }

  if (!body || typeof body !== "object") {
    return buildErrorResponse("Request body must be an object.", 400);
  }

  const { model = "google/nano-banana", callBackUrl, input } = body as {
    model?: string;
    callBackUrl?: string;
    input?: Record<string, unknown>;
  };

  if (!input || typeof input !== "object") {
    return buildErrorResponse("Input payload is required.", 400);
  }

  const prompt = input.prompt;

  if (typeof prompt !== "string" || prompt.trim().length === 0) {
    return buildErrorResponse("Input prompt is required.", 400);
  }

  const payload: Record<string, unknown> = { model, input };

  if (callBackUrl) {
    payload.callBackUrl = callBackUrl;
  }

  const upstreamResponse = await fetch(`${API_BASE_URL}/api/v1/jobs/createTask`, {
    method: "POST",
    headers: {
      "Content-Type": "application/json",
      Authorization: `Bearer ${API_KEY}`
    },
    body: JSON.stringify(payload),
    cache: "no-store"
  });

  const data = await parseResponse(upstreamResponse);

  if (!upstreamResponse.ok) {
    const message = typeof data?.message === "string" ? data.message : "Kie.ai API request failed.";
    return buildErrorResponse(message, upstreamResponse.status);
  }

  return NextResponse.json(data, { status: upstreamResponse.status });
}

export async function GET(req: Request) {
  if (!API_KEY) {
    return buildErrorResponse("Kie.ai API key is not configured.");
  }

  const url = new URL(req.url);
  const taskId = url.searchParams.get("taskId");

  if (!taskId) {
    return buildErrorResponse("taskId query parameter is required.", 400);
  }

  const upstreamResponse = await fetch(
    `${API_BASE_URL}/api/v1/jobs/recordInfo?taskId=${encodeURIComponent(taskId)}`,
    {
      headers: {
        Authorization: `Bearer ${API_KEY}`
      },
      cache: "no-store"
    }
  );

  const data = await parseResponse(upstreamResponse);

  if (!upstreamResponse.ok) {
    const message = typeof data?.message === "string" ? data.message : "Failed to retrieve Kie.ai task status.";
    return buildErrorResponse(message, upstreamResponse.status);
  }

  return NextResponse.json(data, { status: upstreamResponse.status });
}