const express = require("express");
const fs = require("fs");
const path = require("path");
const { exec } = require("child_process");
const bcrypt = require("bcrypt");

const app = express();
app.use(express.json());
app.use(express.static(path.join(__dirname, "public")));

const usersFile = path.join(__dirname, "users.json");
const usersDir = path.join(__dirname, "users");

// Ensure `users.json` and `users/` exist
if (!fs.existsSync(usersFile)) fs.writeFileSync(usersFile, JSON.stringify([]));
if (!fs.existsSync(usersDir)) fs.mkdirSync(usersDir);

// Helper to write logs
function appendLog(username, log) {
  const userDir = path.join(usersDir, username);
  const logFile = path.join(userDir, "logs.txt");

  try {
    // Ensure the user directory exists
    if (!fs.existsSync(userDir)) {
      fs.mkdirSync(userDir, { recursive: true });
    }

    // Append the log to logs.txt
    fs.appendFileSync(logFile, log + "\n");
  } catch (error) {
    console.error(`Error appending log for user ${username}:`, error);
  }
}

// Endpoint to handle user sign-up
app.post("/signup", async (req, res) => {
    const { username, password } = req.body;

    if (!username || !password) {
        return res.status(400).send("Username and password are required.");
    }

    try {
        // Ensure the users file exists
        if (!fs.existsSync(usersFile)) {
            fs.writeFileSync(usersFile, JSON.stringify([]));
        }

        const usersData = JSON.parse(fs.readFileSync(usersFile));
        if (usersData.some((user) => user.username === username)) {
            return res.status(400).send("User already exists.");
        }

        // Hash the password
        const hashedPassword = await bcrypt.hash(password, 10);

        // Add new user
        usersData.push({ username, password: hashedPassword });
        fs.writeFileSync(usersFile, JSON.stringify(usersData, null, 2));

        // Create user directory and logs file
        const userDir = path.join(usersDir, username);
        if (!fs.existsSync(userDir)) {
            fs.mkdirSync(userDir, { recursive: true });
        }
        fs.writeFileSync(path.join(userDir, "logs.txt"), "");

        res.status(200).json({ message: "User signed up successfully." });
    } catch (error) {
        console.error("Error during signup:", error);
        res.status(500).send("Internal server error.");
  }
});

// Endpoint to handle terminal commands
app.post("/execute", (req, res) => {
    const { username, command } = req.body;

    const userDir = path.join(usersDir, username);
    if (!fs.existsSync(userDir)) {
        return res.status(400).send("User not found.");
    }

    const logFile = path.join(userDir, "logs.txt");
    const commandParts = command.split(" ");
    const mainCommand = commandParts[0];
    const args = commandParts.slice(1);

    // Spawn a child process to execute the command
    const child = spawn(mainCommand, args, { cwd: userDir, shell: true });

    child.stdout.on("data", (data) => {
        const output = data.toString().trim();
        appendLog(username, output);
    });

    child.stderr.on("data", (data) => {
        const errorOutput = data.toString().trim();
        appendLog(username, errorOutput);
    });

    child.on("close", (code) => {
        appendLog(username, `Process exited with code ${code}`);
    });

    res.send("Command executed.");
});

// Endpoint to get user logs
app.get("/logs", async (req, res) => {
    const { username } = req.query;

    if (!username) {
        return res.status(400).send("Username is required.");
    }

    const userDir = path.join(usersDir, username);
    const logsFile = path.join(userDir, "logs.txt");

    try {
        const logs = await fs.readFile(logsFile, "utf8");
        res.send(logs);
    } catch (error) {
        console.error("Error fetching logs:", error);
        res.status(404).send("Logs not found.");
    }
});

// Endpoint for "Deploy Kaizen"
app.post("/deploy", (req, res) => {
  const { username, repoUrl } = req.body;

  const userDir = path.join(usersDir, username);
  if (!fs.existsSync(userDir)) fs.mkdirSync(userDir, { recursive: true });

  // Clear the user's directory before deployment
  fs.rmdirSync(userDir, { recursive: true });
  fs.mkdirSync(userDir);

  const cloneCommand = `git clone ${repoUrl} .`;

  const child = exec(cloneCommand, { cwd: userDir });

  child.stdout.on("data", (data) => {
    appendLog(username, data.trim());
  });

  child.stderr.on("data", (data) => {
    appendLog(username, data.trim());
  });

  child.on("close", async (code) => {
    appendLog(username, `Clone process exited with code ${code}`);
    if (code !== 0) {
      res.status(500).send("Error cloning repository.");
      return;
    }

    // Ensure package.json exists
    if (!fs.existsSync(path.join(userDir, "package.json"))) {
      appendLog(username, "No package.json found. Initializing a default one.");
      execSync("yarn init -y", { cwd: userDir });
    }

    // Run yarn install and start
    const installStartCommand = `yarn install && yarn start`;
    const installChild = exec(installStartCommand, { cwd: userDir });

    installChild.stdout.on("data", (data) => {
      appendLog(username, data.trim());
    });

    installChild.stderr.on("data", (data) => {
      appendLog(username, data.trim());
    });

    installChild.on("close", (installCode) => {
      appendLog(username, `Install/Start process exited with code ${installCode}`);
      if (installCode === 0) {
        res.send("Deployment completed successfully.");
      } else {
        res.status(500).send("Error during deployment.");
      }
    });
  });
});

// Start the server
app.listen(7860, () => {
  console.log("Server running on http://localhost:3000");
});