// npm install bcryptjs
const bcrypt = require('bcryptjs');

const saltRounds = 10; // Standard practice, higher means more secure but slower

/**
 * Hashes a plain-text password using bcrypt.
 * @param {string} password - The plain-text password.
 * @returns {Promise<string>} A promise that resolves to the hashed password.
 */
async function hashPassword(password) {
  try {
    const hashedPassword = await bcrypt.hash(password, saltRounds);
    return hashedPassword;
  } catch (error) {
    console.error("Error hashing password:", error);
    throw new Error("Password hashing failed.");
  }
}

/**
 * Verifies a plain-text password against a stored hashed password.
 * @param {string} plainPassword - The plain-text password to check.
 * @param {string} hashedPassword - The hashed password stored in the database.
 * @returns {Promise<boolean>} A promise that resolves to true if passwords match, false otherwise.
 */
async function verifyPassword(plainPassword, hashedPassword) {
  try {
    const match = await bcrypt.compare(plainPassword, hashedPassword);
    return match;
  } catch (error) {
    console.error("Error verifying password:", error);
    throw new Error("Password verification failed.");
  }
}

// Example Usage:
(async () => {
  const userPassword = "MySuperSecurePassword123!";

  // 1. Hash the password (e.g., during user registration)
  const storedHash = await hashPassword(userPassword);
  console.log("Original Password:", userPassword);
  console.log("Hashed Password (stored in DB):", storedHash);

  // 2. Verify the password (e.g., during user login)
  const isMatch1 = await verifyPassword(userPassword, storedHash);
  console.log("Verification with correct password:", isMatch1); // Should be true

  const wrongPassword = "WrongPassword!";
  const isMatch2 = await verifyPassword(wrongPassword, storedHash);
  console.log("Verification with incorrect password:", isMatch2); // Should be false
})();