userSchema.js

const mongoose = require("mongoose");
const bcrypt = require("bcrypt");

const UserSchema = new mongoose.Schema({
  username: {
    type: String,
    unique: true,
    required: true,
    trim: true
  },
  password: {
    type: String,
    required: true
  }
}, { autoIndex: false });

// hashes the password
UserSchema.pre("save", function (next) {
  bcrypt.hash(this.password, 10, (err, hash) => {
    if (err) {
      return next(err);
    }
    this.password = hash;
    next();
  });
});

// used for authentication
UserSchema.statics.authenticate = async (email, password) => {
  const user = await mongoose.model("User").findOne({ email: email });
  if (user) {
    return new Promise((resolve, reject) => {
      bcrypt.compare(password, user.password, (err, result) => {
        if (err) reject(err);
        resolve(result === true ? user : null);
      });
    });
    return user;
  }

  return null;
};

module.exports = UserSchema;