const http = require("http");
const axios = require("axios");

// Configuration
const host = process.env.HOST || "0.0.0.0";
const port = process.env.PORT || 8080;
const GIPHY_API_KEY = process.env.GIPHY_API_KEY;
const PROXY_SECRET = process.env.PROXY_SECRET || "gif";

function catchError(res, error) {
  console.error("An error occurred:", error.message);
  res.writeHead(500);
  res.end(JSON.stringify({ error: "Internal Server Error" }));
}

const requestListener = function (clientReq, clientRes) {
  const parts = clientReq.url?.split("/").filter(Boolean) || [];
  
  const providedSecret = parts[0];
  const tag = parts[1] || "";

  if (providedSecret !== PROXY_SECRET) {
    console.warn(`Unauthorized access: Invalid secret`);
    clientRes.writeHead(403);
    clientRes.end();
    return;
  }

  if (!GIPHY_API_KEY) {
    console.error("GIPHY_API_KEY is not configured.");
    clientRes.writeHead(500);
    clientRes.end();
    return;
  }

  const apiUrl = `https://api.giphy.com/v1/gifs/random?api_key=${GIPHY_API_KEY}&rating=pg-13${tag ? `&tag=${tag}` : ""}`;

  axios
    .get(apiUrl)
    .then((apiRes) => {
      const gifUrl = apiRes?.data?.data?.images?.original?.url;
      
      if (gifUrl) {
        console.log(`Success: Found GIF for '${tag}'`);
        clientRes.setHeader("Content-Type", "application/json");
        clientRes.writeHead(200);
        clientRes.end(JSON.stringify({ url: gifUrl }));
      } else {
        console.log(`Notice: No GIF found for topic '${tag}'`);
        clientRes.writeHead(404);
        clientRes.end(JSON.stringify({ error: "No GIF found" }));
      }
    })
    .catch((error) => {
      catchError(clientRes, error);
    });
};

const server = http.createServer(requestListener);
server.listen(port, host, () => {
  console.log(`Server is running on http://${host}:${port}`);
});