trenddapp / lottery

Decentralized Lottery by TrendDapp 💰

Trenddapp

Develop dapps for friends!

Auction . Lottery . NFT . Wordle

Lottery

A decentralized lottery app running on the Ethereum network, where you can easily participate by connecting your crypto wallet and buying tickets. After the specified lottery duration, a winner is chosen with a random number generated by Chainlink.

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Building a DAPP(Decentralized Application) on Ethereum includes two major steps:

1. Writing a smart contract and deploying it to Ethereum.
2. Interacting with the data and smart contract on Ethereum.

Interacting with the data and smart contract on Ethereum:

No matter what programming language you are using, in order to make a request to the Ethereum network, you'll need:

Name	Description
RPC Provider	A node(server) that is connected to the Ethereum network, and listens to the incoming RPC requests.
Smart Contract ABI	An interface that defines all methods with arguments available in the smart contract.
Smart Contract Address	An address that is used to find the smart contract runner nodes in the Ethereum network.
User's Private Key	A private key that is used to sign/verify the write requests(transactions).

Conventions

Here is a list of conventions used:

• Conventional commits

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change. Please make sure to update tests as appropriate.

License

MIT

lottery's Issues

invalid prizePool value for historical lotteries

I think the problem is in the claimReward function that calls _transferPrize function. In the _transferPrize function, the _winnerPrize is reduced from prizePool and then it's added to the historical lotteries.

    function claimReward()
        external
        ifCompleted
        randomNumberGenerated
        onlyWinnerOrOwner
    {
        uint256 winnerPrize = prizePool * (winnerPercentage / 100);
        _transferPrize(winnerPrize);
        _addLottery();
        _reset();
        emit ClaimedReward(lotteryID);
    }

    function _transferPrize(uint256 _winnerPrize) private {
        prizePool -= _winnerPrize;
        winner.transfer(_winnerPrize); // transfer the winnerPrize to the winner
        payable(owner()).transfer(prizePool); // transfer the rest of the prizePool to the owner
    }

    function _addLottery() private {
        allLotteries[lotteryID++] = LotteryInfo(
            lotteryID,
            prizePool,
            costPerTicket,
            startingTimestamp,
            closingTimestamp,
            winner,
            randomResult
        );
    }

And please make the startingTimestamp, winnerPercentage and lotteryDuration public :D