# Directory Structure

## Django apps

EvalAI is a Django-based application, hence it leverages the concept of Django apps to properly namespace the functionalities. All the apps can be found in the `apps` directory situated in the root folder.

Some important apps along with their main uses are:

- **Challenges**

This app handles all the workflow related to creating, modifying, and deleting challenges.

- **Hosts**

This app is responsible for providing functionalities to the challenge hosts/organizers.

- **Participants**

This app serves users who want to take part in any challenge. It contains code for creating a Participant Team, through which they can participate in any challenge.

- **Jobs**

One of the most important apps, responsible for processing and evaluating submissions made by participants. It contains code for creating a submission, changing the visibility of the submission and populating the leaderboard for any challenge.

- **Web**

This app serves some basic functionalities like providing support for contact us or adding a new contributor to the team, etc.

- **Accounts**

As the name indicates, this app deals with storing and managing data related to user accounts.

- **Base**

A placeholder app which contains the code that is used across various other apps.

## Settings

Settings are used across the backend codebase by Django to provide config values on a per-environment basis. Currently, the following settings are available:

- **dev**

Used in development environment

- **testing**

Used whenever test cases are run

- **staging**

Used on staging server

- **production**

Used on production server

## URLs

The base URLs for the project are present in `evalai/urls.py`. This file includes URLs of various applications, which are also namespaced by the app name. So URLs for the `challenges` app will have its app namespace in the URL as `challenges`. This actually helps us separate our API based on the app.

## Frontend

The whole codebase for the frontend resides in a folder named `frontend` in the root directory

## Scripts

Scripts contain various helper scripts, utilities, python workers. It contains the following folders:

- **migration**

Contains some of the scripts which are used for one-time migration or formatting of data.

- **tools**

A folder for storing helper scripts, e.g. a script to fetch pull request

- **workers**

One of the main directories, which contains the code for submission worker. Submission worker is a normal python worker which is responsible for processing and evaluating submission of a user. The command to start a worker is:

```
python scripts/workers/submission_worker.py
```

## Test Suite

All of the codebase related to testing resides in `tests` folder in the root directory. In this directory, tests are namespaced according to the app, e.g. tests for `challenges` app lives in a folder named `challenges`.

## Management Commands

To perform certain actions like seeding the database, we use Django management commands. Since the management commands are common throughout the project, they are present in `base` application directory. At the moment, the only management command is `seed`, which is used to populate the database with some random values. The command can be invoked by calling

```
python manage.py seed
```