const express = require("express");
const axios = require("axios");
const cors = require("cors");

const app = express();

// Middleware
app.use(cors()); // allow all origins
app.use(express.json()); // parse JSON body

app.post("/login", async (req, res) => {
  try {
    const { tgWebAppData } = req.body;
    if (!tgWebAppData) {
      return res.status(400).json({ error: "Missing tgWebAppData in body" });
    }

    // Try decoding multiple times
    let decoded = tgWebAppData;
    let decodes = [decoded];
    try {
      decoded = decodeURIComponent(decoded);
      decodes.push(decoded);
      decoded = decodeURIComponent(decoded);
      decodes.push(decoded);
    } catch (_) {}

    const params = new URLSearchParams(decoded);

    // Extract parameters
    const userRaw = params.get("user");
    const auth_date = params.get("auth_date");
    const chat_instance = params.get("chat_instance");
    const chat_type = params.get("chat_type");
    const signature = params.get("signature");
    const hash = params.get("hash");

    if (!userRaw || !hash) {
      return res.status(400).json({
        error: "Missing required values",
        debug: { decodes, params: Object.fromEntries(params) },
      });
    }

    // Build initData block
    const block =
      `auth_date=${auth_date}\n` +
      `chat_instance=${chat_instance}\n` +
      `chat_type=${chat_type}\n` +
      `signature=${signature}\n` +
      `user=${userRaw}`;

    const initDataString = JSON.stringify([block, hash]);

    // Try calling AnimeKombat
    let response;
    try {
      response = await axios.post(
        "https://be.animekombat.com/api/auth/login",
        { initData: initDataString },
        {
          headers: {
            Accept: "application/json, text/plain, */*",
            "Content-Type": "application/json",
          },
        }
      );
    } catch (err) {
      return res.status(err.response?.status || 500).json({
        error: "AnimeKombat rejected request",
        reason: err.response?.data || err.message,
        debug: {
          initDataString,
          decodes,
          params: Object.fromEntries(params),
        },
      });
    }

    // Success
    res.json({
      token: response.data.access_token,
      type: response.data.token_type,
      expires: response.data.expires_in,
      user: (() => {
        try {
          return JSON.parse(userRaw);
        } catch {
          return userRaw;
        }
      })(),
      debug: { initDataString, decodes },
    });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

app.listen(7860, () =>
  console.log("Server running at http://localhost:3000")
);