const express = require("express");
const { Pool } = require("pg");
const os = require("os");
const path = require("path");

const app = express();

// middleware
app.use(express.json());
app.use(express.static(path.join(__dirname)));

let counter = 0;

// DB connection
const pool = new Pool({
  host: "postgres-service",
  user: "postgres",
  password: "postgres",
  database: "testdb",
  port: 5432,
});

// 🔥 Wait for DB
async function waitForDB() {
  let connected = false;
  while (!connected) {
    try {
      await pool.query("SELECT 1");
      connected = true;
      console.log("✅ Database connected");
    } catch (err) {
      console.log("⏳ Waiting for database...");
      await new Promise(res => setTimeout(res, 2000));
    }
  }
}

async function initDB() {
  try {
    await pool.query(`
      CREATE TABLE IF NOT EXISTS messages (
        id SERIAL PRIMARY KEY,
        text VARCHAR(255)
      )
    `);
    console.log("✅ Table ready");
  } catch (err) {
    console.log("TABLE ERROR:", err.message);
  }
}

// 🔹 Status API
app.get("/api/status", async (req, res) => {
  counter++;

  try {
    const result = await pool.query("SELECT NOW()");
    res.json({
      time: result.rows[0].now,
      hostname: os.hostname(),
      requests: counter,
      status: "Connected"
    });
  } catch (err) {
    res.json({
      time: "N/A",
      hostname: os.hostname(),
      requests: counter,
      status: "Database not ready"
    });
  }
});

// 🔹 Insert data
app.post("/api/add", async (req, res) => {
  const { text } = req.body;

  try {
    await pool.query(
      "INSERT INTO messages (text) VALUES ($1)",
      [text]
    );
    res.send("Inserted");
  } catch (err) {
    console.log("INSERT ERROR:", err);
    res.status(500).send("Error inserting data");
  }
});

// 🔹 Get data
app.get("/api/messages", async (req, res) => {
  try {
    const result = await pool.query(
      "SELECT * FROM messages ORDER BY id DESC"
    );
    res.json(result.rows);
  } catch (err) {
    console.log("FETCH ERROR:", err);
    res.status(500).send("Error fetching data");
  }
});

async function startServer() {
  await waitForDB();
  await initDB();

  app.listen(3000, () => {
    console.log("🚀 Server running on port 3000");
  });
}

startServer();