Lottery v2

Contract info

Contract name: PancakeSwapLottery Contract address: 0x5aF6D33DE2ccEC94efb1bDF8f92Bd58085432d2c Random number generator address: 0x8c6375Aab6e5B26a30bF241EBBf29AD6e6c503c2 (Random number generator contract must be deployed first)

View PancakeSwapLottery.sol on BscScan.

View the PancakeSwap: Lottery contract on BscScan.

Audits

The PancakeSwap Lottery V2 has been audited twice so far. View the results below:

Peckshield's Lottery V2 Audit

Slowmist's Lottery V2 Audit

Lottery Status states

The lottery has four Status states, Pending, Open, Close, and Claimable, that determine which actions can and cannot be taken at a given time.

Read/View functions

viewCurrentLotteryId

function viewCurrentLotteryId() external view override returns (uint256);

Returns the Id# of the current Lottery round as an integer. Round Id#s correlate to round number, and are incremental, e.g. the ninth round of Lottery will be 9.

viewLottery

function viewLottery(uint256 _lotteryId) external view returns (Lottery memory);

Returns information on specified Lottery round as tuple (see Lottery structure below).

        uint256 startTime;
        uint256 endTime;
        uint256 priceTicketInCake;
        uint256 discountDivisor;
        uint256[6] rewardsBreakdown; // 0: 1 matching number // 5: 6 matching numbers
        uint256 treasuryFee; // 500: 5% // 200: 2% // 50: 0.5%
        uint256[6] cakePerBracket;
        uint256[6] countWinnersPerBracket;
        uint256 firstTicketId;
        uint256 firstTicketIdNextLottery;
        uint256 amountCollectedInCake;
        uint32 finalNumber;

Name	Type	Description
startTime	uint256	Starting block for Lottery round.
endTime	uint256	Ending block for Lottery round (approximately 12 hours after a round begins).
priceTicketInCake	uint256	The price of a ticket in CAKE (approximately $5 USD).
discountDivisor	uint256	The divisor used to calculate bulk ticket discount.
rewardsBreakdown	uint256[6]	The division of rewards across brackets (total must add up to 10,000).
treasuryFee	uint256	Amount taken from funds raised per round that's moved to treasury address (maximum 3000).
cakePerBracket	uint256[6]	The amount of CAKE to distribute to winners of each bracket.
countWinnersPerBracket	uint256[6]	Moves through brackets, starting from the highest, accounting for winners when value > 0.
firstTicketId	uint256	Id of the first ticket, set with the opening of the Lottery round, that determines the range of eligible tickets for the current round.
firstTicketIdNextLottery	uint256	Id of the first ticket, set at the closing of current round, that determines the range of eligible tickets for the current round.
amountCollectedInCake	uint256	The amount of CAKE collected through ticket sales for the Lottery round.
finalNumber	uint32	The final number determined by randomResult obtained from the number generator contract (RandomNumberGenerator.sol) using Chainlink VRF.

viewNumbersAndStatusesForTicketIds

function viewNumbersAndStatusesForTicketIds(uint256[] calldata _ticketIds)
    external
    view
    returns (uint32[] memory, bool[] memory);

Returns the corresponding numbers and the statuses of ticketIds array of tickets defined by their ticketId.

viewRewardsForTicketId

function viewRewardsForTicketId(
    uint256 _lotteryId,
    uint256 _ticketId,
    uint32 _bracket;

Calculates rewards for a ticket after draw given the lotteryId, ticketId, and bracket. Filling and querying will provide a link to detailed price information on BscScan.

Name	Type	Description
lotteryId	uint256	The id of the Lottery.
ticketId	uint256	The id of the ticket.
bracket	uint32	Bracket for the ticketId to verify the claim and calculate rewards.

viewUserInfoForLotteryId

    function viewUserInfoForLottery(
        address _user,
        uint256 _lotteryId,
        uint256 _cursor,
        uint256 _size
    )
        external
        view
        returns (
            uint256[] memory,
            uint32[] memory,
            bool[] memory,
            uint256
        )

Returns user lotteryTicketIds, ticketNumbers, and ticketStatuses of a user for a given Lottery (defined by lotteryID).

Name	Type	Description
user	address	The address of the user.
lotteryId	uint256	The id of the Lottery.
cursor	uint256	Cursor to start where to retrieve the tickets.
size	uint256	The number of tickets to retrieve.

calculateRewardsForTicketId

    function _calculateRewardsForTicketId(
        uint256 _lotteryId,
        uint256 _ticketId,
        uint32 _bracket
    ) internal view returns (uint256);

Calculates rewards for a ticket after draw given the lotteryId, ticketId, and bracket.

Name	Type	Description
lotteryId	uint256	The id of the Lottery.
ticketId	uint256	The id of the ticket.
bracket	uint32	Bracket for the ticketId to verify the claim and calculate rewards.

calculateTotalPriceForBulkTickets

    function calculateTotalPriceForBulkTickets(
        uint256 _discountDivisor,
        uint256 _priceTicket,
        uint256 _numberTickets
    ) external pure returns (uint256);

Calculates the price for a set of tickets accounting for bulk discount.

discountDivisor:

$totalPriceForBulkTickets = priceSingleTicket \cdot numberTickets \cdot \frac{(discountDivisor + 1 - numberTickets)}{discountDivisor}$

Filling and querying will provide a link to detailed price information on BscScan.

Name	Type	Description
discountDivisor	uint256	The divisor for the discount.
priceTickets	uint256	The price of a ticket in CAKE.
numberTickets	uint256	The number of tickets to buy.

Write functions (users)

buyTickets

function buyTickets(uint256 _lotteryId, uint32[] calldata _ticketNumbers) external override notContract nonReentrant;

Buy tickets for the current Open Lottery round (between 1 and 100 per purchase). Calculates the price per ticket using calculateTotalPriceForBulkTickets.

Name	Type	Description
lotteryId	uint256	The id of the lottery.
ticketNumbers	uint32	Array of ticket numbers between 1,000,000 and 1,999,999.

claimTickets

    function claimTickets(
        uint256 _lotteryId,
        uint256[] calldata _ticketIds,
        uint32[] calldata _brackets
    ) external override notContract nonReentrant;

Claim a set of winning tickets for a Claimable Lottery round. Checks lotteryId to determine if round is claimable, ownership of ticketId, eligibility of ticket (ticketId falls between firstTicketId and firstTicketIdNextLottery), and whether ticketId falls within eligible prize bracket (between 0 and 5).

Name	Type	Description
lotteryId	uint256	The id of the Lottery.
ticketIds	uint32	Array of ticketIds.
brackets	uint32	Array of brackets for the ticket ids.

Write functions (operator/admin)

closeLottery

function closeLottery(uint256 _lotteryId) external override onlyOperator;

Closes the Open Lottery to Close state. Emits LotteryClose event.

Name	Type	Description
lotteryId	uint256	The id of the Lottery.

drawFinalNumberAndMakeLotteryClaimable

    function drawFinalNumberAndMakeLotteryClaimable(uint256 _lotteryId, bool _autoInjection) external override onlyOperator nonReentrant;

Lottery must be in Close state. Draws the final Lottery number for results from randomResult, calculates the rewards for brackets after accounting for treasury fee, makes Lottery state Claimable, and transfers treasury fee to treasury address.

Name	Type	Description
lotteryId	uint256	The id of the Lottery.
autoInjection	bool	Automatic injection status.

changeRandomNumberGenerator

    function changeRandomGenerator(address _randomGeneratorAddress) external onlyOwner;

Changes the random number generator contract address. Lottery must be Claimable.

Name	Type	Description
randomGeneratorAddress	address	The random generator address.

injectFunds

function injectFunds(uint256 _lotteryId, uint256 _amount) external override onlyOwner;

Inject funds into a Lottery. Lottery must be Open.

Name	Type	Description
lotteryId	uint256	The id of the Lottery.
amount	uint256	Amount, in CAKE token, to inject.

startLottery

    function startLottery(
        uint256 _endTime,
        uint256 _priceTicketInCake,
        uint256 _discountDivisor,
        uint256[6] calldata _rewardsBreakdown,
        uint256 _treasuryFee
    ) external override onlyOperator;

Starts the Lottery, setting it to Open state. Status must be Claimable.

Name	Type	Description
endTime	uint256	End time of the Lottery.
priceTicketInCake	uint256	Price of a ticket in CAKE.
discountDivisor	uint256	The divisor to calculate the discount magnitude for bulks.
rewardsBreakdown	uint256[6]	Breakdown of rewards per bracket (must sum to 10,000).
trasuryFee	uint256	Treasury fee (10,000 = 100%, 100 = 1%).

recoverWrongTokens

function recoverWrongTokens(address _tokenAddress, uint256 _tokenAmount) external onlyOwner;

Allows admin to recover incorrect tokens sent to address mistakenly. Cannot be CAKE tokens.

Name	Type	Description
tokenAddress	address	The address of the token to withdraw.
tokenAmount	uint256	The number of tokens to withdraw.

setMinAndMaxTicketPriceInCake

function recoverWrongTokens(address _tokenAddress, uint256 _tokenAmount) external onlyOwner;

Allows admin to set upper and lower limit of ticket price in CAKE value. Minimum price must be lower than maximum price.

Name	Type	Description
minPriceTicketInCake	uint256	The minimum price in CAKE.
maxPriceTicketInCake	uint256	The maximum price in CAKE.

setMaxNumberTicketsPerBuy

function setMaxNumberTicketsPerBuy(uint256 _maxNumberTicketsPerBuy) external onlyOwner;

Set max number of tickets purchasable at a time (presently 100). Max number of tickets must be higher than 0.

Name	Type	Description
maxNumberTicketsPerBuy	uint256	Max number of tickets in one purchase.

setOperatorAndTreasuryAndInjectorAddress

function setOperatorAndTreasuryAddresses(address _operatorAddress, address _treasuryAddress) external onlyOwner;

Sets the address of the Lottery operator.

Name	Type	Description
operatorAddress	address	The address of the operator.
treasuryAddress	address	The address of the treasury.
injectorAddress	address	The address of the injector.

Events (User)

TicketsPurchase

TicketsPurchase(address indexed buyer, uint256 indexed lotteryId, uint256 numberTickets);

Lottery tickets are purchased.

Emitter: buyTickets go to buyTickets

TicketsClaim

TicketsClaim(address indexed claimer, uint256 amount, uint256 indexed lotteryId, uint256 numberTickets);

Lottery tickets are claimed post-draw.

Emitter: claimTickets go to claimTickets

Events (admin)

AdminTokenRecovery

AdminTokenRecovery(address token, uint256 amount);

Admin recovers incorrect tokens from Lottery address.

Emitter: recoverWrongTokens go to recoverWrongTokens

LotteryClose

LotteryClose(uint256 indexed lotteryId, uint256 firstTicketIdNextLottery);

The Lottery is closed. lotteryId is indexed and firstTicketIdNextLottery is determined by currentTicketId.

Emitter: closeLottery go to closeLottery

LotteryInjection

LotteryInjection(uint256 indexed lotteryId, uint256 amount);

Funds are injected into Lottery.

Emitter: injectFunds go to injectFunds

LotteryOpen

LotteryOpen(
        uint256 indexed lotteryId,
        uint256 startTime,
        uint256 endTime,
        uint256 priceTicketInCake,
        uint256 firstTicketId
    );

The Lottery is opened. firstTicketId is set from currentTicketId,

Emitter: startLottery go to startLottery

LotteryNumberDrawn

LotteryNumberDrawn(uint256 indexed lotteryId, uint256 finalNumber, uint256 countWinningTickets);

Lottery numbers are drawn for Lottery round.

Emitter: drawFinalNumberAndMakeLotteryClaimable go to drawFinalNumberAndMakeLotteryClaimable

NewOperatorAndTreasuryAndInjectorAddresses

NewOperatorAndTreasuryAndInjectorAddresses(address operator, address treasury);

New operator address is set.

Emitter: setOperatorAndTreasuryAndInjectorAddresses go to setOperatorAndTreasuryAndInjectorAddresses

NewRandomNumberGenerator

NewRandomGenerator(address indexed randomGenerator);

New random number generator address is set.

Emitter: changeRandomGenerator go to changeRandomGenerator