1. Deployment

1.1 Local Deployment

Requirements

Truffle v5.1.47 (core: 5.1.47)
Solidity v0.5.16 (solc-js)
Node v12.16.3
Web3.js v1.2.1
Ganache v2.5.4
npm

Initial Setup

cd into project directory
Run npm install
Create a .secret file and add your Metamask's seed phrase in the file

Set Up Ganache

Create a new project on Ganache
Add truffle-config.js from project folder
In the Chain section, ensure Gas Limit is 6721975
Start Ganache Server
cd into project directory
Run truffle migrate --reset --network development in console

Set Up Accounts

Open up Metamask and add a new Custom RPC

The RPC URL can be found on Ganache

Import the first account on Ganache to your Metamask. The private key of that account can be found by clicking on the 'key' icon on Ganache
You can add all the accounts in Ganache to simulate multiple users.
Only the first account is the owner account which deployed all the contracts. This will be the account that will have the initial supply of SCSE, MAE and EEE tokens.
If you do not see the ETH being reflected in your Metamask wallet, change to another network and change back to Ganache

Set Up Website

cd into '.Something Funky Is Nice/dex-exchange'
Run npm install
Run npm run start in console
If all token balances are 0 in the website, make sure your Metamask account is connected to the website

2. Plan

For this assignment, we will have an Owner who will be deploying all of our contracts. This Owner will be allocated the initial supply of tokens for SCSE, MAE and EEE. Thus, 1 million of each tokens will be allocated to the Owner.

The Owner will sell these tokens on the exchange at an affordable price.

Users who wish to obtain these tokens will have to trade their ETH for these tokens. Before doing so, they have to first swap their ETH to the base token, WETH. Only by doing so, can they trade on the exchange using the trading pairs available.

3. Funky Crypto Exchange Architecture

In our Exchange, we have a structure holding onto these coins, SCSE, EEE and MAE. In each of these coins, it holds a Buy and Sell book.

3.1 Token's Order Book (Buy / Sell)

In the Token's Order Book, it is used to store the Limit Orders that users had made in the exchange. A limit order has a price and amount. In order to easily insert new Limit Orders, we shall do the following:

In each Order Book, it stores multiple Price which are linked together using a linked list. This Price are inserted in ascending order.
We used a linked list as this allows for easier insertion of new prices.
Deletion of Price when there are no more Amount nodes in it is achieved by connecting it's sibling nodes to each other instead of that Price node.
In each Price, there may be one or more Amount.
We also used a linked list to connect these Amount but it is not used to insert the Amount in an order. The linked list is to allow for easier deletion of Amount when an order has been fully filled or when an order is deleted by the user.
Deletion of Amount node is the same as Price.
The nodes in Amount are inserted based on a Queue system. The oldest orders have a higher priority than the newer orders. New orders are place behind older orders.

3.2 Buy Limit Order

3.3 Sell Limit Order

3.4 Buy Market Order

For a Buy Market Order, it is similar to the Buy Limit Order, with the only difference being there is no price indication. The order will take whatever is inside the Sell Order Book and trade the amount that the user wants from the cheapest price order to the most expensive price order. This continues until the amount is fully filled, the user ran out of WETH to trade or there is no more orders in the Sell Order Book.

3.4 Sell Market Order

For a Sell Market Order, it is the opposite of a Buy Market Order. It searches the Buy Order Book from the most expensive orders to the least expensive orders.

4. Features

4.1 Metamask Integration

In order to use the functionality of the website, users MUST install Metamask.

4.2 ETH/WETH Token Swap

In order to facilitate a smooth trading experience, we will use Wrapped Ethereum as our base token to trade. Users are able to swap their ETH to WETH in our exchange and vice versa.