JackpotRandomTicketBuyer

Lightweight helper contract for purchasing randomly-generated tickets. Simplifies the process of buying tickets with random number selections.

State Variables

Variable	Type	Description
jackpot	IJackpot	Immutable reference to Jackpot contract
usdc	IERC20	Immutable USDC token reference
nonce	uint256	Per-call nonce for randomness uniqueness

Events

RandomTicketsBought

event RandomTicketsBought(
    address indexed recipient,
    uint256 indexed drawingId,
    uint256 count,
    uint256 cost,
    uint256[] ticketIds
);

Functions

buyTickets

Purchase a specified number of randomly-generated tickets.

function buyTickets(
    uint256 _count,
    address _recipient,
    address[] memory _referrers,
    uint256[] memory _referralSplitBps,
    bytes32 _source
) external returns (uint256[] memory ticketIds)

Parameters:

Name	Type	Description
_count	uint256	Number of random tickets to purchase
_recipient	address	Address to receive the ticket NFTs
_referrers	address[]	Referrer addresses for fee sharing
_referralSplitBps	uint256[]	PRECISE_UNIT-scaled weights (sum to 1e18)
_source	bytes32	Source identifier for tracking

Returns:

Type	Description
uint256[]	Array of minted ticket IDs

Requirements:

• _count must be > 0

• _recipient must not be zero address

• Caller must have approved sufficient USDC

Example:

// Buy 10 random tickets
uint256 count = 10;
uint256 ticketPrice = jackpot.getDrawingState(jackpot.currentDrawingId()).ticketPrice;
uint256 totalCost = count * ticketPrice;

usdc.approve(address(randomBuyer), totalCost);

uint256[] memory ticketIds = randomBuyer.buyTickets(
    count,
    msg.sender,
    new address[](0),
    new uint256[](0),
    bytes32("my-app")
);

With Referrers

// Buy 5 random tickets with referrer
uint256 count = 5;
uint256 totalCost = count * jackpot.ticketPrice();

usdc.approve(address(randomBuyer), totalCost);

address[] memory referrers = new address[](1);
referrers[0] = referrerAddress;

uint256[] memory splits = new uint256[](1);
splits[0] = 1e18; // 100% to single referrer

uint256[] memory ticketIds = randomBuyer.buyTickets(
    count,
    msg.sender,
    referrers,
    splits,
    bytes32("referral-app")
);

How Randomness Works

The contract uses on-chain entropy sources to generate random ticket numbers:

1. Entropy Sources: Combines prevrandao, previous block hash, and a per-call nonce

2. Unique Generation: Nonce increments each call to prevent same-block collisions

3. Valid Tickets: All generated tickets have valid, unique normal numbers and valid bonusballs

Security Note

The randomness is suitable for ticket generation but not cryptographically secure. The final drawing uses Pyth Network entropy for provably fair winner selection.

Comparison with Other Purchase Methods

Method	Use Case	Ticket Selection
Jackpot.buyTickets	Direct purchase	User chooses numbers
JackpotRandomTicketBuyer	Quick random purchase	Auto-generated
BatchPurchaseFacilitator	Large orders	Mix of static + random
JackpotAutoSubscription	Recurring purchases	Mix of static + random

Integration Example

contract MyLotteryApp {
    IJackpotRandomTicketBuyer public randomBuyer;
    IERC20 public usdc;

    function quickPlay(uint256 ticketCount) external {
        uint256 cost = ticketCount * getTicketPrice();

        // Transfer USDC from user
        usdc.transferFrom(msg.sender, address(this), cost);
        usdc.approve(address(randomBuyer), cost);

        // Buy random tickets
        randomBuyer.buyTickets(
            ticketCount,
            msg.sender,
            new address[](0),
            new uint256[](0),
            bytes32("my-lottery-app")
        );
    }

    function getTicketPrice() public view returns (uint256) {
        uint256 drawingId = IJackpot(randomBuyer.jackpot()).currentDrawingId();
        return IJackpot(randomBuyer.jackpot()).getDrawingState(drawingId).ticketPrice;
    }
}