Daily Rewards basic mechanism

readme.md

Daily Rewards Mechanism

This gist is showing how to do a daily rewards like it is usually implemented on some games. For example, if you own a specific item, you are allowed to claim a specific item within a time limit.

daily_rewards.js

const express = require('express');
const { Pool } = require('pg');

const app = express();
const port = 3000;

const pool = new Pool({
  host: 'localhost',
  user: 'project_rewards',
  password: 'project_rewards',
  database: 'project_rewards',
  port: 5432,
});

app.use(express.json());

// DB Schema
// -- Create table for user items
// CREATE TABLE user_items (
//     id SERIAL PRIMARY KEY,
//     user_id SERIAL,
//     item_name TEXT
// );

// Route to claim reward
app.post('/claim', async (req, res) => {
  const userId = req.body.userId;

  try {
    const client = await pool.connect();

    // Check if user owns "Blue Gemstone"
    const checkOwnership = await client.query('SELECT * FROM user_items WHERE user_id = $1 AND item_name = $2', [userId, 'Blue Gemstone']);

    if (checkOwnership.rowCount === 0) {
      res.status(403).send('User does not own the required Blue Gemstone.');
      client.release();
      return;
    }

    // Get the server's current time in GMT+7
    const currentServerTime = new Date();
    currentServerTime.setHours(currentServerTime.getHours() + 7);
    console.log("Server time:", new Date());

    // Zero-out the hours, minutes, seconds, and milliseconds
    currentServerTime.setHours(0, 0, 0, 0);

    // Check if a reward has been claimed today
    const checkLastClaim = await client.query('SELECT * FROM reward_history WHERE user_id = $1 AND reward_name = $2 AND claimed_date >= $3::timestamptz ORDER BY claimed_date DESC',
      [userId, 'Red Gemstone', currentServerTime.toISOString()]
    );

    if (checkLastClaim.rowCount > 0) {
      res.status(403).send('Reward already claimed today. You can claim again at 00:00 GMT+7.');
      client.release();
      return;
    }

    // Insert claim into history
    await client.query('INSERT INTO reward_history (user_id, reward_name, claimed_amount, claimed_date) VALUES ($1, $2, $3, $4)', [userId, 'Red Gemstone', 5, currentServerTime]);

    // Insert 5 Red Gemstones into user inventory (done 5 times for simplicity)
    for (let i = 0; i < 5; i++) {
      await client.query('INSERT INTO user_items (user_id, item_name) VALUES ($1, $2)', [userId, 'Red Gemstone']);
    }

    res.status(200).send('Successfully claimed 5 Red Gemstones.');

    client.release();
  } catch (err) {
    console.error(err);
    res.status(500).send('Internal Server Error');
  }
});

app.listen(port, () => {
  console.log(`Server running at http://localhost:${port}/`);
});

module.exports = app;  // Export the app instance for testing

daily_rewards.test.js

const request = require('supertest');
const app = require('./daily_rewards');
const mockDate = require('jest-date-mock');


describe('Test case for user 1 with date mocking', () => {
    beforeAll(() => {
        mockDate.advanceTo(new Date());
    });

    it('test the date mocking', () => {
        mockDate.advanceTo(new Date(2018, 5, 27, 0, 0, 0)); // reset to date time.

        const now = Date.now();

        mockDate.advanceBy(3000); // advance time 3 seconds
        expect(+new Date() - now).toBe(3000);

        mockDate.advanceBy(-1000); // advance time -1 second
        expect(+new Date() - now).toBe(2000);

        mockDate.clear();
        Date.now(); // will got current timestamp
    });

    it('User 1 claims and succeeds', async () => {
        const response = await request(app).post('/claim').send({ userId: 1 });
        expect(response.status).toBe(200);
        // Further checks like verifying the database state can be added here
    });

    it('User 1 tries to claim again after 3 minutes and fails', async () => {
        // Move time forward by 3 minutes
        mockDate.advanceBy(3 * 60 * 1000);
        const response = await request(app).post('/claim').send({ userId: 1 });
        expect(response.status).toBe(403);
        expect(response.text).toBe('Reward already claimed today. You can claim again at 00:00 GMT+7.');
    });

    it('User 1 tries to claim again the next day and succeeds', async () => {
        // Move time forward by 1 day
        mockDate.advanceBy(24 * 60 * 60 * 1000);
        const response = await request(app).post('/claim').send({ userId: 1 });
        expect(response.status).toBe(200);
    });

    it('User 1 tries to claim again the next day + 1 hour and fails', async () => {
        // Move time forward by 1 hour
        mockDate.advanceBy(1 * 60 * 60 * 1000);
        const response = await request(app).post('/claim').send({ userId: 1 });
        expect(response.status).toBe(403);
        expect(response.text).toBe('Reward already claimed today. You can claim again at 00:00 GMT+7.');
    });

    afterAll(() => {
        // Reset the Date object to the current time
        mockDate.clear();
    });
});

describe('Test case for user 2', () => {
    it("User 2 can't claim because they don't have a Blue Gemstone", async () => {
        const response = await request(app).post('/claim').send({ userId: 2 });
        expect(response.status).toBe(403);
        expect(response.text).toBe('User does not own the required Blue Gemstone.');
    });
});