Honeycomb-Chainlink Workshop Sample Project

This is a sample project to build a dApp that calls a Honeycomb marketplace API endpoint through a Chainlink node over the Ropsten testnet.

Based on the Chainlink truffle box, react-box and the Honeycomb use-case demos done at Web3 Summit.

Before installation

$ npm install -g truffle

Install the Metamask add-on to your browser and create a wallet. Note down the mnemonics. Fund it with Ropsten ETH and Ropsten LINK.
Create an Infura account, get an endpoint URL for the Ropsten testnet and note it down.
(Optional) Install Visual Studio Code

$ git clone https://github.com/bbenligiray/honeycomb-chainlink-workshop.git

$ cd honeycomb-chainlink-workshop

$ npm install

$ cp wallet.json.example wallet.json

Open the newly created wallet.json file and enter the mnemonics and the endpoint URL you have noted down earlier.
Go to the front-end project directory

$ cd client

$ npm install

Go to Honeycomb marketplace and log in. Go to the API listings and click the API named Data Sports Group - Premium Sports Content. Find the endpoint with the path /soccer/get_matches and click the Connect button. Select Ropsten as the network and bytes32 as the data format. Note down the oracle address, JobID and LINK price.
Using the Test button and the API endpoints, find the ID of the match that will be bet on. For example, you can call /soccer/get_matches_day with the parameters {"day":"2019-10-20"} to get a list of matches that will be played on that day. You can work your way through the API documentation to find alternative ways of getting a list of matches to be played. Note down the match ID.
Enter the values you have noted down in honeycomb-chainlink-workshop/migrations/2_deploy_contracts.js
Go to the main project directory (honeycomb-chainlink-workshop). Deploy the contract on Ropsten:

$ npm run deploy-ropsten

The contract address is going to get printed on the terminal. Fund it with Ropsten LINK. Each Honeycomb Ropsten call costs 0.1 LINK, so you don't need much.
Go to the front-end project directory (honeycomb-chainlink-workshop/client) and run the front-end project locally, which is going to fire up your browser and connect to your smart contract using your Metamask add-on:

$ npm run start

Rerun the npm run deploy-ropsten command for the changes you have made to the smart contract to take effect.
If you are getting the events.js:183 throw er; error, see this.
You may want to test your smart contract locally. To do that, install ganache-cli and run it on a separate terminal. Note that smart contracts running on a local network would not be able to make calls to an oracle on the Ropsten network, so you would have to simulate the oracle.

Close off betting when the match starts (or ends?), not when the oracle result is received
Implement an ETH deposit requirement to call checkResult(). Otherwise people can keep calling it to drain your contract of LINK.
Protect your contract against bugs and vulnerabilities.
Improve the UX. For example, the Withdraw button should not be clickable before the match result been delivered.
Allow the contract creator to withdraw funds after some point.
Make oracle requests at deployment that get the team names (so the user doesn't need to trust the developer to enter the names correctly).
You shouldn't have to deploy a contract for each match, make this contract reusable for different matches (make sure to listen for the ChainlinkFulfilled event with the correct requestId).
Write an aggregator to use multiple oracles.
Deploy the contract on the mainnet and host your front-end somewhere other people can reach!