Raffle Lottery Smart Contract

This repository contains a Solidity smart contract for a raffle lottery implemented on the Ethereum blockchain. The contract utilizes Chainlink VRF (Verifiable Random Function) for secure and transparent randomization of lottery winners.

Overview

The Raffle Lottery Smart Contract provides functionality for users to participate in a lottery by entering with a specific amount of Ether. The lottery runs for a defined interval, and after the interval, a winner is randomly selected from the pool of participants.

Smart Contract Details

The smart contract is written in Solidity and implements various features including lottery state management, entrance fee, random winner selection, event logging, and more.

Cloning the Repository

To clone this repository, use the following command:

git clone https://github.com/shrutic11/raffle-lottery-f23.git
cd raffle-lottery-f23

Smart Contract Details

The smart contract is written in Solidity and implements the following main features:

1. Lottery State Management: The contract defines the lottery state, including OPEN, PICKING_WINNER, and CLOSED states.

2. Entrance Fee: Participants are required to pay a specific entrance fee in Ether to enter the lottery.

3. Random Winner Selection: The contract uses Chainlink VRF to select a random winner from the participants at the end of the lottery interval.

4. Event Logging: Various events are logged during different stages of the lottery, including participant entry, winner announcement, and the start of a new lottery.

5. Fallback Function: The contract includes a fallback function to handle ETH sent to the contract.

How to Use

To participate in the lottery, users can call the enterRaffle function by sending the required Ether.

Constructor

• Parameters:
  • lotteryOpenInterval: The time interval during which the lottery is open for participants.
  • vrfCoordinator: The address of the Chainlink VRF Coordinator contract.
  • gasLane: The gas lane for Chainlink VRF request.
  • subscriptionId: The Chainlink VRF subscription ID.
  • callbackGasLimit: The gas limit for the Chainlink VRF callback.

Functions

• enterRaffle: Allows users to enter the lottery by paying the entrance fee.

• checkUpkeep: Checks if upkeep is needed for the lottery based on specific conditions.

• performUpkeep: Initiates the process to select a winner and distribute prizes.

• fulfillRandomWords: Handles the callback from Chainlink VRF and determines the lottery winner.

Getters

• getEntranceFee: Returns the entrance fee required to enter the lottery.

• getLotteryOpenInterval: Returns the time interval during which the lottery is open.

• getOwner: Returns the owner's address who deployed the contract.

• getLotteryStartTime: Returns the start time of the current lottery.

• getParticipants: Returns an array of addresses representing the participants in the current lottery.

• getLotteryState: Returns the current state of the lottery.

License

This project is licensed under the terms of the MIT license.

---

For more information and to access the smart contract code, visit the GitHub repository.