brunomsilvaf / challenge-call-center

Interview challenge

Calls Web Service

A service to manage call resources, each representing a phone call between two numbers. Calls Web Service is a Java Spring-boot application, with a view layer served by Thymeleaf. The web service exposes some operations (create, read, delete) via a REST controller. Additionally, the service can be run in a docker container alongside with a MariaDB container.

Running the application via gradle

Building and running unit tests:

gradlew clean build

To run the application, in the project root folder run the command below. A local mariaDB instance should be first configured.

gradlew run

Running the application via docker

Building the docker image using the Jib gradle plugin.

gradlew jibDockerBuild --image=call-center-server

Spinning up the docker containers. In the project root folder (default location of the docker-compose.yml file) run:

docker-compose up

To remove the data volume:

docker volume rm challenge-call-center_db_data

Usage and Configuration

By default, the application will run on port 9000. The different operations are mapped to:

• /call-center/calls/create
• /call-center/calls/createMany
• /call-center/calls/delete/{id}
• /call-center/calls/list
• /call-center/calls/statistics

The HTML pages are mapped as below. Generate and clear are dev tools, allowing the user to easily generate and clear all data.

• /
• /createForm
• /create
• /createMany
• /delete/{id}
• /list
• /statistics
• /clear
• /generate

For the create operations, an object (or list of objects for the createMany) is expected with the following format:

{
    "callerNumber": "[phone]",
    "calleeNumber": "[phone]",
    "type": "Inbound",
    "startTime": 1615116875,
    "endTime": 1615117554
}

The prices of the calls can be configured via the following properties:

challenge.call-center.call.first-five-minutes-cost=0.10
challenge.call-center.call.cost-per-minute-after-five-minutes=0.05

Testing and Generating data

The web service can be tested via any API client like Postman or Insomnia. A file 'Insomnia_Tests.json' is already provided with this project with a sample test case for each operation.

Testing data can be easily generated via a JSON generator. The example below works for https://www.json-generator.com/

[
  '{{repeat(1000)}}',
    {
      callerNumber: '+351 {{phone("9192932xx")}}',
      calleeNumber: '+351 {{phone("9192931xx")}}',
      type: '{{random("Inbound", "Outbound")}}',
      startTime:  '{{Math.round(date(new Date(2020, 0, 1), new Date()).getTime()/1000)}}',
      endTime(tags) {
        return this.startTime + tags.integer(0,999);
      }
    }
]