Chainlink VRF

function fulfillRandomWords(
  uint256, /* requestId */
  uint256[] memory randomWords
) internal override {
  // Assuming only one random word was requested.
  s_randomRange = (randomWords[0] % 50) + 1;
}

mapping(uint256 => uint256[]) public s_requestIdToRandomWords;
mapping(uint256 => address) public s_requestIdToAddress;
uint256 public s_requestId;
 
function requestRandomWords() external onlyOwner returns (uint256) {
  uint256 requestId = s_vrfCoordinator.requestRandomWords(
      VRFV2PlusClient.RandomWordsRequest({
          keyHash: keyHash,
          subId: s_vrfSubscriptionId,
          requestConfirmations: requestConfirmations,
          callbackGasLimit: callbackGasLimit,
          numWords: numWords,
          extraArgs: VRFV2PlusClient._argsToBytes(VRFV2PlusClient.ExtraArgsV1({nativePayment: true})) // new parameter
      })
  );
  s_requestIdToAddress[requestId] = msg.sender;
 
  // Store the latest requestId for this example.
  s_requestId = requestId;
 
  // Return the requestId to the requester.
  return requestId;
}
 
function fulfillRandomWords(
    uint256 requestId,
    uint256[] memory randomWords
  ) internal override {
  // You can return the value to the requester,
  // but this example simply stores it.
  s_requestIdToRandomWords[requestId] = randomWords;
}

// SPDX-License-Identifier: MIT
// An example of a consumer contract that relies on a subscription for funding.
// It shows how to setup multiple execution paths for handling a response.
pragma solidity 0.8.19;
 
import {LinkTokenInterface} from "@chainlink/contracts/src/v0.8/shared/interfaces/LinkTokenInterface.sol";
import {IVRFCoordinatorV2Plus} from "@chainlink/contracts/src/v0.8/vrf/dev/interfaces/IVRFCoordinatorV2Plus.sol";
import {VRFConsumerBaseV2Plus} from "@chainlink/contracts/src/v0.8/vrf/dev/VRFConsumerBaseV2Plus.sol";
import {VRFV2PlusClient} from "@chainlink/contracts/src/v0.8/vrf/dev/libraries/VRFV2PlusClient.sol";
 
/**
 * THIS IS AN EXAMPLE CONTRACT THAT USES HARDCODED VALUES FOR CLARITY.
 * THIS IS AN EXAMPLE CONTRACT THAT USES UN-AUDITED CODE.
 * DO NOT USE THIS CODE IN PRODUCTION.
 */
 
contract VRFv2MultiplePaths is VRFConsumerBaseV2Plus {
 
    // Your subscription ID.
    uint256 s_subscriptionId;
 
    // Avalanche Primary Network coordinator.
    address vrfCoordinatorV2Plus = 0xE40895D055bccd2053dD0638C9695E326152b1A4;
 
    // The gas lane to use, which specifies the maximum gas price to bump to.
    // For a list of available gas lanes on each network,
    // see https://docs.chain.link/docs/vrf/v2-5/supported-networks
    bytes32 keyHash =
        0x787d74caea10b2b357790d5b5247c2f63d1d91572a9846f780606e4d953677ae;
 
    uint32 callbackGasLimit = 100000;
 
    // The default is 3, but you can set this higher.
    uint16 requestConfirmations = 3;
 
    // For this example, retrieve 1 random value in one request.
    // Cannot exceed VRFCoordinatorV2_5.MAX_NUM_WORDS.
    uint32 numWords = 1;
 
    enum Variable {
        A,
        B,
        C
    }
 
    uint256 public variableA;
    uint256 public variableB;
    uint256 public variableC;
 
    mapping(uint256 => Variable) public requests;
 
    // events
    event FulfilledA(uint256 requestId, uint256 value);
    event FulfilledB(uint256 requestId, uint256 value);
    event FulfilledC(uint256 requestId, uint256 value);
 
    constructor(uint256 subscriptionId) VRFConsumerBaseV2Plus(vrfCoordinatorV2Plus) {
        s_vrfCoordinator = IVRFCoordinatorV2Plus(vrfCoordinatorV2Plus);
        s_subscriptionId = subscriptionId;
    }
 
    function updateVariable(uint256 input) public {
      uint256 requestId = s_vrfCoordinator.requestRandomWords(VRFV2PlusClient.RandomWordsRequest({
            keyHash: keyHash,
            subId: s_subscriptionId,
            requestConfirmations: requestConfirmations,
            callbackGasLimit: callbackGasLimit,
            numWords: numWords,
            extraArgs: VRFV2PlusClient._argsToBytes(VRFV2PlusClient.ExtraArgsV1({nativePayment: true}))
          })
        );
 
        if (input % 2 == 0) {
            requests[requestId] = Variable.A;
        } else if (input % 3 == 0) {
            requests[requestId] = Variable.B;
        } else {
            requests[requestId] = Variable.C;
        }
    }
 
    function fulfillRandomWords(
        uint256 requestId,
        uint256[] memory randomWords
    ) internal override {
        Variable variable = requests[requestId];
        if (variable == Variable.A) {
            fulfillA(requestId, randomWords[0]);
        } else if (variable == Variable.B) {
            fulfillB(requestId, randomWords[0]);
        } else if (variable == Variable.C) {
            fulfillC(requestId, randomWords[0]);
        }
    }
 
    function fulfillA(uint256 requestId, uint256 randomWord) private {
        // execution path A
        variableA = randomWord;
        emit FulfilledA(requestId, randomWord);
    }
 
    function fulfillB(uint256 requestId, uint256 randomWord) private {
        // execution path B
        variableB = randomWord;
        emit FulfilledB(requestId, randomWord);
    }
 
    function fulfillC(uint256 requestId, uint256 randomWord) private {
        // execution path C
        variableC = randomWord;
        emit FulfilledC(requestId, randomWord);
    }
}