/**
 * Copyright (c) 2026 Niolla
 * All rights reserved.
 *
 * This source code is proprietary and confidential.
 * Unauthorized copying, modification, distribution, or use
 * of this file, via any medium, is strictly prohibited.
 */

// app/utils/passwordReset.util.js

const crypto = require("crypto");
const redis = require("../config/redisClient");
const emailService = require("../services/email/email.service");

const PASSWORD_RESET_TTL =
  Number(process.env.PASSWORD_RESET_TTL_SECONDS) || 900;

const generatePasswordResetToken = () => {
  return crypto.randomBytes(32).toString("hex");
};

const hashPasswordResetToken = (token) => {
  return crypto.createHash("sha256").update(token).digest("hex");
};

const createPasswordReset = async (userId) => {
  // 1. Generate RAW token
  const token = generatePasswordResetToken();

  // 2. Hash RAW token
  const tokenHash = hashPasswordResetToken(token);

  // 3. Create Redis key
  const redisKey = `password-reset:${tokenHash}`;

  // 4. Save user ID with 15 minute TTL
  await redis.set(redisKey, userId, "EX", PASSWORD_RESET_TTL);

  // Send only RAW token to user
  return token;
};

const verifyPasswordResetToken = async (token) => {
  if (!token || typeof token !== "string") {
    return null;
  }

  // Hash token received from user
  const tokenHash = hashPasswordResetToken(token);

  // Create same Redis key
  const redisKey = `password-reset:${tokenHash}`;

  // Search Redis
  const userId = await redis.get(redisKey);

  if (!userId) {
    return null;
  }

  return {
    userId,
    redisKey,
  };
};

const deletePasswordReset = async (redisKey) => {
  await redis.del(redisKey);
};

const consumePasswordResetToken = async (token) => {
  if (!token || typeof token !== "string") return null;
  return redis.getdel(`password-reset:${hashPasswordResetToken(token)}`);
};

const sendPasswordResetEmail =
  async (email, firstName, resetToken) => {

    const resetLink =
      `${process.env.FRONTEND_URL}/reset-password?token=${resetToken}`;


    await emailService.send({
      recipient: email, templateKey: "passwordReset",
      variables: {
        firstName: firstName,
        resetLink: resetLink,
        expiryTime: "15 minutes",
      }, eventId: `reset-${hashPasswordResetToken(resetToken)}`,
    });
  };

  const sendPasswordChangedEmail = async (
  email,
  firstName
) => {

  const changedAt =
    new Date().toLocaleString();

  await emailService.send({
    recipient: email, templateKey: "passwordChanged",
    variables: {
      customer_name:
        firstName,

      changed_at:
        changedAt,
    },
  });
};

module.exports = {
  createPasswordReset,
  verifyPasswordResetToken,
  deletePasswordReset,
  consumePasswordResetToken,
  hashPasswordResetToken,
  sendPasswordResetEmail,
  sendPasswordChangedEmail,
};