EnergyWeb Origin

<h1 align="center">
  <br>
  <a href="https://www.energyweb.org/"><img src="https://www.energyweb.org/wp-content/uploads/2019/04/logo-brand.png" alt="EnergyWeb" width="150"></a>
  <br>
  EnergyWeb Origin
  <br>
  <h2 align="center">Exchange</h2>
  <br>
</h1>

**Exchange** package provides the order book based exchange functionality for the certificates issued by `issuer` package. The major difference between classic (asset, time, price) order book system is the **product** based matching engine, providing the ability to create custom matching rules.

## Main features

-   Order book matching engine for time, price and product matching
-   ERC 1155 / ERC 1888 compatible
-   Supply / Demand modules

## Trading product concept

### Definition

`Product` defines the characteristics of the given producing device as well as buyers preferences . Currently it's represented as:

```
export class Product {
    public deviceType?: string[];

    public location?: string[];

    public deviceVintage?: number;
}
```

Where

-   `deviceType` - describes the type of the device for e.g. using I-REC types
-   `location` - describes the location of the the device for e.g. can be multi-level like Country->Region->Province
-   `deviceVintage` - describes the vintage of the device for e.g. the start year of the device operation

For a producing device all fields are mandatory.

## Development

Exchange project is currently not meant to be run as a separate nest application. In order to run exchange project please refer to https://github.com/energywebfoundation/origin/tree/master/packages/origin-backend-app

Default TypeOrm configuration requires running PostgreSQL database. The detailed config with .env parameters is:

```
DB_HOST      - default 'localhost'
DB_PORT      - default 5432
DB_USERNAME  - default 'postgres',
DB_PASSWORD  - default 'postgres',
DB_DATABASE  - default 'origin',
```

or

```
DATABASE_URL  - postgres://{user}:{password}@{host}:{port}/{database}
```

### Using TypeORM migrations

Exchange project uses TypeORM mechanism to perform SQL data migrations. For detailed information please refer to https://github.com/typeorm/typeorm/blob/master/docs/migrations.md

-   `yarn typeorm:run` to update DB to latest exchange tables schema
-   `yarn typeorm:migrate SampleMigrationName` to create new migration file based on the changes in the code entities

Development flow:

-   run `yarn typeorm:run` - to apply latest migrations
-   apply changes in the entities, like change the variable name or type
-   run `yarn typeorm:migrate LastestChanges...`
-   inspect newly created migration in /migrations folder
-   run `yarn typeorm:run` to apply newly created migration

**Warning:**

**Existing migration files from `/migration` folder should never be edited after being committed.**

### PostgreSQL installation using Docker

```
docker pull postgres
docker run --name origin-postgres -e POSTGRES_PASSWORD=postgres -d -p 5432:5432 postgres
```

#### pgAdmin

```
docker pull dpage/pgadmin4
docker run -p 80:80 \
    -e 'PGADMIN_DEFAULT_EMAIL=user@domain.com' \
    -e 'PGADMIN_DEFAULT_PASSWORD=SuperSecret' \
    -d dpage/pgadmin4
```

#### SQL dump

`example/example.sql` contains a dump of database filled in with the example data:

1. User with `id=1` as a buyer (owner of the bid orders)
2. User with `id=2` as a seller (owner of the ask orders), with confirmed deposit of 100MWh (100000000)
3. 3 open bids with prices 90,85,75 for `{"deviceType":["Solar;Photovoltaic;Classic silicon"],"location":["Thailand;Central;Nakhon Pathom"],"deviceVintage":{"year":2016}}`
4. 3 open asks with prices 110,120,130 for `{"deviceType":["Solar;Photovoltaic;Classic silicon"],"location":["Thailand;Central;Nakhon Pathom"],"deviceVintage":{"year":2016}}`
5. 3 open bids with prices 79,78,77 for `{"deviceType":["Wind"],"location":["Thailand;Northeast"]`
6. 3 open asks with prices 80,85,86 for `{"deviceType":["Wind;Onshore"],"location":["Thailand;Northeast;Nakhon Ratchasima"],"deviceVintage":{"year":2014}}`
7. 1 filled ask
8. 1 partially filled bid
9. 1 trade

In order to deploy the data please use pgadmin or psql or similar tools to import \*.sql tool.

_Notice_ that you might need to remove previously imported data in case of PK violations. Use

```
TRUNCATE "account","asset","demand","order","trade","transfer" CASCADE
```

with caution.

This can be used for fast integrations and testing

### Swagger

Swagger endpoint can be found at

`http://localhost:3033/api`