Spend points api

When a users spends points, they don't know or care which payer the points come from. There are two rules for determining what points to "spend" first:

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

Api routes:

• Add transactions for a specific payer and date.
• Spend points using the rules above and return a list of { "payer": <string>, "points": <integer> } for each call.
• Return all payer point balances.

Usage with pip

1. Go to the project folder

   cd PayersPointsApi

2. Create a virtual environment

   python -m venv venv

3. Activate the created virtual environment:

   • venv\Scripts\activate.bat - for Windows;

   • source venv/bin/activate - for Linux & MacOS.

4. Install dependencies

   pip install -r requirements.txt

5. Go to the folder next to manage.py*

   cd DjangoApp

6. Start a local server Django

   python manage.py runserver

Usage with Docker

1. Go to the project folder

   cd PayersPointsApi

2. Build an image based on Dockerfile

   docker build . -t transactions_api

3. Launch container

   docker run -p -t 8000:8000 transactions_api

Active points

1. /api/transactions/
2. /api/balance/
3. /api/spend-points/

Example

Initial transactions:

• { "payer": "DANNON", "points": 1000, "timestamp": "2020-11-02T14:00:00Z" }
• { "payer": "UNILEVER", "points": 200, "timestamp": "2020-10-31T11:00:00Z" }
• { "payer": "DANNON", "points": -200, "timestamp": "2020-10-31T15:00:00Z" }
• { "payer": "MILLER COORS", "points": 10000, "timestamp": "2020-11-01T14:00:00Z" }
• { "payer": "DANNON", "points": 300, "timestamp": "2020-10-31T10:00:00Z" }

Then you call your spend points route with the following request:

{ "points": 5000 }

The expected response from the spend call would be:

[
    { "payer": "DANNON", "points": -100 },
    { "payer": "UNILEVER", "points": -200 },
    { "payer": "MILLER COORS", "points": -4,700 }
]

A subsequent call to the points balance route, after the spend, should returns the following results:

{
"DANNON": 1000,
"UNILEVER": 0,
"MILLER COORS": 5300
}

P.s. there are ready-made tests in the repository, and if you open the project locally, there will already be a database with transactions from the example