Fetch Rewards Coding Exercise - Reward Report System - Ajay Mohandas

Contains the backend logic for rewards calculations

Goal

Users can view their reward balances, spend points and system to record every transaction as per payer, points and timestamp

Rules

• We want the oldest points to be spent first (oldest based on transaction timestamp, not the order they’re received)
• We want no payer's points to go negative

Expectation

• Add transactions for a specific payer and date.
• Spend points using the rules above and return a list for each call
• Return all payer point balances

Problem Statement - https://fetch-hiring.s3.us-east-1.amazonaws.com/points.pdf

Assumptions

No database to persist the data and hence each time you run the application user data would be null

Basic validation are performed by the application, added spring security can be added but is not present in this application

Since its a simple application, apis do not have any header or token for authorization

How to run the project

Pre-requisite

• Install any version above Java 8 but tried and tested in Java 8 and Java 17,
• Install any IDE of your choice VS Code, Intellij
• Postman to test APIs

Run from IDE

• Make sure IDE supports Spring Application, if not add plugins for Spring Application
• If using VS Code, go to marketplace and install plugins for Spring
• Clone the project using GitHub to a local folder using https://github.com/ajaymohandas89/FetchRewardsPointsSystems
• Simply run the PointsApplication.java
• Application will be running on http://localhost:8080
• Test the backend services using API testing tool
• Import API collection in Postman using Import and upload FetchRewards_UserPointsProblem.postman_collection.json or test using below API curl commands

Run Test Case

• From the project run test cases under UserPointServiceTest.java

APIS for testing

1. Check Balance Of User

API

http://localhost:8080/userpoints/v1/balance/{userId}

CURL

curl --location --request GET 'http://localhost:8080/userpoints/v1/balance/1'

RESPONSE

[
    "UNILEVER:0",
    "MILLER COORS:5300",
    "DANNON:1000"
]

2. Fetch All Users Transactions

API

http://localhost:8080/userpoints/v1/transactions

CURL

curl --location --request GET 'http://localhost:8080/userpoints/v1/transactions'

RESPONSE

{
    "1": [
        {
            "transactionId": "4657090f-94f4-4993-8c84-4e2cbf794bd1",
            "payer": "DANNON",
            "points": 1000,
            "timestamp": "2022-12-04T22:07:36.9109449"
        },
        {
            "transactionId": "3445f577-aa00-48ef-b9c3-1b65425bc285",
            "payer": "DANNON",
            "points": 0,
            "timestamp": "2022-12-04T22:08:12.3789424"
        },
        {
            "transactionId": "c258d4a1-085c-42f9-adc1-a83026e6b945",
            "payer": "UNILEVER",
            "points": 0,
            "timestamp": "2022-12-04T22:08:12.3799424"
        },
        {
            "transactionId": "3e1216eb-96ab-4f55-9416-a6e6aee629ef",
            "payer": "MILLER COORS",
            "points": 5300,
            "timestamp": "2022-12-04T22:08:12.3809421"
        }
    ]
}

3. Fetch Each User Transactions

API

http://localhost:8080/userpoints/v1/transactions/{userId}

CURL

curl --location --request GET 'http://localhost:8080/userpoints/v1/transactions/1'

RESPONSE

[
    {
        "transactionId": "4657090f-94f4-4993-8c84-4e2cbf794bd1",
        "payer": "DANNON",
        "points": 1000,
        "timestamp": "2022-12-04T22:07:36.9109449"
    },
    {
        "transactionId": "3445f577-aa00-48ef-b9c3-1b65425bc285",
        "payer": "DANNON",
        "points": 0,
        "timestamp": "2022-12-04T22:08:12.3789424"
    },
    {
        "transactionId": "c258d4a1-085c-42f9-adc1-a83026e6b945",
        "payer": "UNILEVER",
        "points": 0,
        "timestamp": "2022-12-04T22:08:12.3799424"
    },
    {
        "transactionId": "3e1216eb-96ab-4f55-9416-a6e6aee629ef",
        "payer": "MILLER COORS",
        "points": 5300,
        "timestamp": "2022-12-04T22:08:12.3809421"
    }
]

4. Add Point For A User

API

http://localhost:8080/userpoints/v1/addPoints/{userId}

CURL

curl --location --request POST 'http://localhost:8080/userpoints/v1/addPoints/2' \
--header 'Content-Type: application/json' \
--data-raw '{
    "payer": "C", 
    "point": 300

}'

REQUEST

{
    "payer": "C", 
    "point": 300
}

RESPONSE

{
    "payer": "C",
    "points": 300,
    "timestamp": "2022-12-04T17:12:15.2119043"
}

5. Spend Point For A User

API

http://localhost:8080/userpoints/v1/spend

CURL

curl --location --request PUT 'http://localhost:8080/userpoints/v1/spend' \
--header 'Content-Type: application/json' \
--data-raw '{
    "userId": 2, 
    "points": 150
}'

REQUEST

{
    "userId": 1, 
    "points": 5000
}

RESPONSE

[
    {
        "payer": "DANNON",
        "points": "-100"
    },
    {
        "payer": "UNILEVER",
        "points": "-200"
    },
    {
        "payer": "MILLER COORS",
        "points": "-4700"
    }
]