Final project, Raffle system using varifiable random function, Skoltech 2023

This code was written to create a lottery system in which users could send money and a winner would be chosen at random. Which owner can set a period for selling in a lottery, and if users want to play after the period has expired, the system will reject them. After the closed period, a random winner will be selected by owner. Randomness was implement by VRF on Oracle chainlink.

• Using Remix-Ethereum platform by using 0.8.0+complier

• Using Sepolia Chain Link VRF
  VRFConsumerBase(0x8103B0A8A00be2DDC778e6e7eaa21791Cd364625, >> coordinator
  0x779877A7B0D9E8603169DdbD7836e478b4624789) >> link
  {keyHash = 0x474e34a077df58807dbe9c96d3c009b23b3c6d0cce433e59bbf5b34f823bc56c;
  fee = 0.25 * 10 ** 18 ;
  admin = msg.sender;}
  in this part you can change to others testnet i.e. Goerli, BNB \

1. Ower create lottery by click on createLottery button

   • input ticket price(lottery price)
   • input second(time period for lottery in seconds)

2. Owner and users can enquiry data about lottery
   getLotteryCount: Input lotteryID, to see how many participants are playing in lotteryID
   getLottery: Input lotteryID, to see data in tuple
   - uint256: lotteryId
   - address[]: participants
   - uint256: prize
   - uint256: ticketPrice
   - address: winner
   - boolean: isFinished
   - uint256: endDate

   

3. Users play by click on participate button

   • input lotteryID

4. Owner can get the winner by click on declareWinner

   • input lotteryID and see details of the winner in getLottery

Reference:

1. https://docs.chain.link/vrf/v2/subscription/supported-networks