Welcome to PowerDale

PowerDale is a small town with around 100 residents. Most houses have a smart meter installed that can save and send information about how much energy a house has used.

There are three major providers of energy in town that charge different amounts for the power they supply.

• Dr Evil's Dark Energy
• The Green Eco
• Power for Everyone

Introducing JOI Energy

JOI Energy is a new start-up in the energy industry. Rather than selling energy they want to differentiate themselves from the market by recording their customers' energy usage from their smart meters and recommending the best supplier to meet their needs.

You have been placed into their development team, whose current goal is to produce an API which their customers and smart meters will interact with.

Unfortunately, two members of the team are on annual leave, and another one has called in sick! You are left with a ThoughtWorker to progress with the current user stories on the story wall. This is your chance to make an impact on the business, improve the code base and deliver value.

Story Wall

At JOI energy the development team use a story wall or Kanban board to keep track of features or "stories" as they are worked on.

The wall you will be working from today has 7 columns:

• Backlog
• Ready for Dev
• In Dev
• Ready for Testing
• In Testing
• Ready for sign off
• Done

Examples can be found here https://leankit.com/learn/kanban/kanban-board/

Users

To trial the new JOI software 5 people from the JOI accounts team have agreed to test the service and share their energy data.

User	Smart Meter ID	Power Supplier
Sarah	smart-meter-0	Dr Evil's Dark Energy
Peter	smart-meter-1	The Green Eco
Charlie	smart-meter-2	Dr Evil's Dark Energy
Andrea	smart-meter-3	Power for Everyone
Alex	smart-meter-4	The Green Eco

These values are used in the code and in the following examples.

Overview

JOI Energy is a new energy company that uses data to ensure customers are able to be on the best price plan for their energy consumption.

API

Below is a list of API endpoints with their respective input and output.

Store Readings

Endpoint

POST /readings/store

Example of body

{
    "smartMeterId": <smartMeterId>,
    "electricityReadings": [
        { "time": <timestamp>, "reading": <reading> },
        { "time": <timestamp>, "reading": <reading> },
        ...
    ]
}

Parameters

Parameter	Description
smartMeterId	One of the smart meters ids listed above
timestamp	The time when the delta is measured
reading	The delta reading since the last reading

Example readings

Date (GMT)	Epoch timestamp	Reading (kW)
2020-11-11 8:00	1605081600	0.0503
2020-11-12 8:00	1605168000	0.0213

In the above example, 0.0213 kW where consumed between 2020-11-11 8:00 and 2020-11-12 8:00.

Posting readings using CURL

$ curl \
  -X POST \
  -H "Content-Type: application/json" \
  "http://localhost:8080/readings/store" \
  -d '{"smartMeterId":"smart-meter-0","electricityReadings":[{"time":1605081600,"reading":0.0503},{"time":1605168000,"reading":0.0213}]}'

The above

Get Stored Readings

Endpoint

GET /readings/read/<smartMeterId>

Parameters

Parameter	Description
smartMeterId	One of the smart meters ids listed above

Retrieving readings using CURL

$ curl "http://localhost:8080/readings/read/smart-meter-0"

Example output

[
  { "time": "2020-11-11T08:00:00.000000Z", "reading": 0.0503 },
  { "time": "2020-11-12T08:00:00.000000Z", "reading": 0.0213 },
  ...
]

View Current Price Plan and Compare Usage Cost Against all Price Plans

Endpoint

GET /price-plans/compare-all/<smartMeterId>

Parameters

Parameter	Description
smartMeterId	One of the smart meters ids listed above

Retrieving readings using CURL

$ curl "http://localhost:8080/price-plans/compare-all/smart-meter-0"

Example output

{
  "pricePlanComparisons": {
    "price-plan-2": 13.824,
    "price-plan-1": 27.648,
    "price-plan-0": 138.24
  },
  "pricePlanId": "price-plan-0"
}

View Recommended Price Plans for Usage

Endpoint

GET /price-plans/recommend/<smartMeterId>[?limit=<limit>]

Parameters

Parameter	Description
smartMeterId	One of the smart meters ids listed above
limit	(Optional) limit the number of plans to be displayed

Retrieving readings using CURL

$ curl "http://localhost:8080/price-plans/recommend/smart-meter-0?limit=2"

Example output

[
  {
    "price-plan-2": 13.824
  },
  {
    "price-plan-1": 27.648
  }
]

Requirements

The project requires Java 1.8 or higher.

The project makes use of Gradle and uses the Gradle wrapper, which means you don't need Gradle installed.

Tasks

List all the tasks that Gradle can do, such as build and test.

$ ./gradlew tasks

Build

Compiles the project, runs the test and then created an executable JAR file

$ ./gradlew build

Run the application using Java and the executable JAR file produced by the Gradle build task. The application will be listening to port 8080.

$ java -jar build/libs/tw-energy.jar

Test

There are two types of tests, the unit tests and the functional tests. These can be executed as follows.

• Run unit tests only

  $ ./gradlew test

• Run functional tests only

  $ ./gradlew functionalTest

• Run both unit and functional tests

  $ ./gradlew check

Run

Run the application which will be listening on port 8080.

$ ./gradlew bootRun