// File: contracts/CasinoV1.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;

import "@chainlink/contracts/src/v0.8/VRFConsumerBaseV2.sol";
import "@chainlink/contracts/src/v0.8/interfaces/VRFCoordinatorV2Interface.sol";
import "@chainlink/contracts/src/v0.8/interfaces/KeeperCompatibleInterface.sol";
import "@chainlink/contracts/src/v0.8/interfaces/LinkTokenInterface.sol";

error CasinoV1__PayEnoughEthereum();
error CasinoV1__NotOpen();
error CasinoV1__UpkeepIsFalse(uint256 currentBalance, uint256 playersNumber, uint256 casinoState);
error CasinoV1__TransferFailed();
error CasinoV1__NotOwner();

/**@title Casino Contract
 * @author Agnick
 * @notice This contract is for creating a casino contract
 * @dev Using VRFConsumerBaseV2 and KeeperCompatibleInterface
 */
contract CasinoV1 is VRFConsumerBaseV2, KeeperCompatibleInterface {
    /* Type declarations */
    enum CasinoStates {
        OPEN,
        PROCESSING
    }
    /* State Variables */
    address payable private i_owner;
    // Chainlink vrf
    VRFCoordinatorV2Interface private immutable i_vrfCoordinator;
    uint256 private immutable i_vrfSubFundAmount;
    uint64 private immutable i_subId;
    bytes32 private immutable i_keyHash;
    uint16 private constant MIN_REQUEST_CONFIRMATIONS = 3;
    uint32 private immutable i_callbackGasLimit;
    uint32 private constant NUM_WORDS = 1;
    // Chainlink LINKTOKEN
    LinkTokenInterface private immutable i_linkToken;
    // Lottery variables
    CasinoStates private s_casinoState;
    address payable[] private s_casinoPlayers;
    address payable private s_winner;
    uint256 private immutable i_entranceFee;
    uint256 private immutable i_interval;
    uint256 private s_lastTimeStamp;

    /* Events */
    event Entered(address indexed player, uint256 indexed ticketsAmount);
    event RandomRequested(uint256 indexed requestId);
    event WinnerPicked(address indexed winner, uint256 indexed winnerReward);

    /* Constructor */
    constructor(
        uint256 entranceFee,
        uint256 interval,
        address vrfCoordinator,
        address link,
        uint64 subId,
        bytes32 keyHash,
        uint32 callbackGasLimit,
        uint256 vrfSubFundAmount
    ) VRFConsumerBaseV2(vrfCoordinator) {
        i_owner = payable(msg.sender);
        s_casinoState = CasinoStates.OPEN;
        s_lastTimeStamp = block.timestamp;
        i_entranceFee = entranceFee;
        i_interval = interval;
        i_vrfCoordinator = VRFCoordinatorV2Interface(vrfCoordinator);
        i_linkToken = LinkTokenInterface(link);
        i_subId = subId;
        i_keyHash = keyHash;
        i_callbackGasLimit = callbackGasLimit;
        i_vrfSubFundAmount = vrfSubFundAmount;
    }

    /**
     * @notice Allows players to buy tickets.
     * @dev Reverts if ethereum value isn't equal to entrance multiplied by tickets amount
     * @dev and doesn't allow to enter if casino state isn't open.
     * @dev Pushing player address to casino players array as many times as tickets bought.
     * @dev Emits an event.
     * @param ticketsAmount number of tickets player wants to buy.
     */
    function enter(uint256 ticketsAmount) public payable {
        if (msg.value != i_entranceFee * ticketsAmount) {
            revert CasinoV1__PayEnoughEthereum();
        }
        if (s_casinoState != CasinoStates.OPEN) {
            revert CasinoV1__NotOpen();
        }
        for (uint256 ticket = 0; ticket < ticketsAmount; ticket++) {
            s_casinoPlayers.push(payable(msg.sender));
        }
        emit Entered(msg.sender, ticketsAmount);
    }

    /**
     * @notice This is the function that the Chainlink Keeper nodes call.
     * @notice they look for `upkeepNeeded` to return True.
     * @dev the following should be true for this to return true:
     * @dev 1. The casino is open,
     * @dev 2. The casino has players,
     * @dev 3. The contract has ETH,
     * @dev 4. The time interval has passed between casino runs.
     * @return upkeepNeeded variable.
     */
    function checkUpkeep(
        bytes memory /* checkData */
    )
        public
        view
        override
        returns (
            bool upkeepNeeded,
            bytes memory /* performData */
        )
    {
        bool isOpen = (s_casinoState == CasinoStates.OPEN);
        bool hasPlayers = (s_casinoPlayers.length > 0);
        bool hasBalance = (address(this).balance > 0);
        bool timePassed = ((block.timestamp - s_lastTimeStamp) > i_interval);
        upkeepNeeded = (isOpen && hasPlayers && hasBalance && timePassed);
        return (upkeepNeeded, "0x0");
    }

    /**
     * @notice Once `checkUpkeep` is returning `true`, this function is called.
     * @notice It funds VRF subscription ID with some LINK if needed and requests random number.
     * @dev Changes casino state to the processing.
     * @dev If subscription ID is greater than 1 funds it with some LINK.
     * @dev Kicks off a Chainlink VRF call to get a random winner.
     * @dev Emits an event.
     */
    function performUpkeep(
        bytes calldata /* performData */
    ) external override {
        (bool upkeepNeeded, ) = checkUpkeep("");
        if (!upkeepNeeded) {
            revert CasinoV1__UpkeepIsFalse(
                address(this).balance,
                s_casinoPlayers.length,
                uint256(s_casinoState)
            );
        }
        s_casinoState = CasinoStates.PROCESSING;
        if (i_subId > 1) {
            (uint256 subBalance, , , ) = getSubscription();
            if (
                subBalance < i_vrfSubFundAmount &&
                i_linkToken.balanceOf(address(this)) >= i_vrfSubFundAmount
            ) {
                i_linkToken.transferAndCall(
                    address(i_vrfCoordinator),
                    i_vrfSubFundAmount,
                    abi.encode(i_subId)
                );
            }
        }
        uint256 requestId = i_vrfCoordinator.requestRandomWords(
            i_keyHash,
            i_subId,
            MIN_REQUEST_CONFIRMATIONS,
            i_callbackGasLimit,
            NUM_WORDS
        );
        emit RandomRequested(requestId);
    }

    /**
     * @notice Automatically called if random number was requested.
     * @dev Calculates index of winner by modulo operator, sets winner as a global variable.
     * @dev Drops state variables, calculates owner commission as a 5%.
     * @dev Sends transaction to the winner: (contract balance - owner commission) --> winner address.
     * @dev Send transaction to the owner: owner commission --> owner address.
     * @dev Emits an event.
     * @param randomWords truly random numbers array that were requested from the Chainlink.
     */
    function fulfillRandomWords(
        uint256, /* requestId */
        uint256[] memory randomWords
    ) internal override {
        uint256 winnerIndex = randomWords[0] % s_casinoPlayers.length;
        address payable winner = s_casinoPlayers[winnerIndex];
        s_winner = winner;
        s_casinoState = CasinoStates.OPEN;
        s_casinoPlayers = new address payable[](0);
        s_lastTimeStamp = block.timestamp;
        uint256 ownerCommission = (address(this).balance * 500) / 10000;
        uint256 winnerReward = address(this).balance - ownerCommission;
        // tx to the winner
        (bool winnerTx, ) = winner.call{value: winnerReward}("");
        if (!winnerTx) {
            revert CasinoV1__TransferFailed();
        }
        // tx to the owner
        (bool ownerTX, ) = i_owner.call{value: ownerCommission}("");
        if (!ownerTX) {
            revert CasinoV1__TransferFailed();
        }
        emit WinnerPicked(winner, winnerReward);
    }

    /**
     * @notice Function that returns info about VRF subscription id.
     * @return balance - current LINK balance of the VRF subscription.
     * @return reqCount - requests amount.
     * @return owner - VRF subscription admin address.
     * @return consumers - list of VRF subscription consumers.
     */
    function getSubscription()
        public
        view
        returns (
            uint96 balance,
            uint64 reqCount,
            address owner,
            address[] memory consumers
        )
    {
        (balance, reqCount, owner, consumers) = i_vrfCoordinator.getSubscription(i_subId);
    }

    /* Get functions */
    function getCasinoState() public view returns (CasinoStates) {
        return s_casinoState;
    }

    function getInterval() public view returns (uint256) {
        return i_interval;
    }

    function getEntranceFee() public view returns (uint256) {
        return i_entranceFee;
    }

    function getNumberOfTickets() public view returns (uint256) {
        return s_casinoPlayers.length;
    }

    function getPlayerByTicket(uint256 ticketNumber) public view returns (address) {
        return s_casinoPlayers[ticketNumber];
    }

    function getTicketsAmountByAddress(address player) public view returns (uint256 tickets) {
        for (uint256 i = 0; i < s_casinoPlayers.length; i++) {
            if (s_casinoPlayers[i] == player) {
                tickets += 1;
            }
        }
    }

    function getLastTimeStamp() public view returns (uint256) {
        return s_lastTimeStamp;
    }

    function getRecentWinner() public view returns (address) {
        return s_winner;
    }

    function getContractBalance() public view returns (uint256) {
        return address(this).balance;
    }
}

// File: @chainlink/contracts/src/v0.8/VRFConsumerBaseV2.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;

/** ****************************************************************************
 * @notice Interface for contracts using VRF randomness
 * *****************************************************************************
 * @dev PURPOSE
 *
 * @dev Reggie the Random Oracle (not his real job) wants to provide randomness
 * @dev to Vera the verifier in such a way that Vera can be sure he's not
 * @dev making his output up to suit himself. Reggie provides Vera a public key
 * @dev to which he knows the secret key. Each time Vera provides a seed to
 * @dev Reggie, he gives back a value which is computed completely
 * @dev deterministically from the seed and the secret key.
 *
 * @dev Reggie provides a proof by which Vera can verify that the output was
 * @dev correctly computed once Reggie tells it to her, but without that proof,
 * @dev the output is indistinguishable to her from a uniform random sample
 * @dev from the output space.
 *
 * @dev The purpose of this contract is to make it easy for unrelated contracts
 * @dev to talk to Vera the verifier about the work Reggie is doing, to provide
 * @dev simple access to a verifiable source of randomness. It ensures 2 things:
 * @dev 1. The fulfillment came from the VRFCoordinator
 * @dev 2. The consumer contract implements fulfillRandomWords.
 * *****************************************************************************
 * @dev USAGE
 *
 * @dev Calling contracts must inherit from VRFConsumerBase, and can
 * @dev initialize VRFConsumerBase's attributes in their constructor as
 * @dev shown:
 *
 * @dev   contract VRFConsumer {
 * @dev     constructor(<other arguments>, address _vrfCoordinator, address _link)
 * @dev       VRFConsumerBase(_vrfCoordinator) public {
 * @dev         <initialization with other arguments goes here>
 * @dev       }
 * @dev   }
 *
 * @dev The oracle will have given you an ID for the VRF keypair they have
 * @dev committed to (let's call it keyHash). Create subscription, fund it
 * @dev and your consumer contract as a consumer of it (see VRFCoordinatorInterface
 * @dev subscription management functions).
 * @dev Call requestRandomWords(keyHash, subId, minimumRequestConfirmations,
 * @dev callbackGasLimit, numWords),
 * @dev see (VRFCoordinatorInterface for a description of the arguments).
 *
 * @dev Once the VRFCoordinator has received and validated the oracle's response
 * @dev to your request, it will call your contract's fulfillRandomWords method.
 *
 * @dev The randomness argument to fulfillRandomWords is a set of random words
 * @dev generated from your requestId and the blockHash of the request.
 *
 * @dev If your contract could have concurrent requests open, you can use the
 * @dev requestId returned from requestRandomWords to track which response is associated
 * @dev with which randomness request.
 * @dev See "SECURITY CONSIDERATIONS" for principles to keep in mind,
 * @dev if your contract could have multiple requests in flight simultaneously.
 *
 * @dev Colliding `requestId`s are cryptographically impossible as long as seeds
 * @dev differ.
 *
 * *****************************************************************************
 * @dev SECURITY CONSIDERATIONS
 *
 * @dev A method with the ability to call your fulfillRandomness method directly
 * @dev could spoof a VRF response with any random value, so it's critical that
 * @dev it cannot be directly called by anything other than this base contract
 * @dev (specifically, by the VRFConsumerBase.rawFulfillRandomness method).
 *
 * @dev For your users to trust that your contract's random behavior is free
 * @dev from malicious interference, it's best if you can write it so that all
 * @dev behaviors implied by a VRF response are executed *during* your
 * @dev fulfillRandomness method. If your contract must store the response (or
 * @dev anything derived from it) and use it later, you must ensure that any
 * @dev user-significant behavior which depends on that stored value cannot be
 * @dev manipulated by a subsequent VRF request.
 *
 * @dev Similarly, both miners and the VRF oracle itself have some influence
 * @dev over the order in which VRF responses appear on the blockchain, so if
 * @dev your contract could have multiple VRF requests in flight simultaneously,
 * @dev you must ensure that the order in which the VRF responses arrive cannot
 * @dev be used to manipulate your contract's user-significant behavior.
 *
 * @dev Since the block hash of the block which contains the requestRandomness
 * @dev call is mixed into the input to the VRF *last*, a sufficiently powerful
 * @dev miner could, in principle, fork the blockchain to evict the block
 * @dev containing the request, forcing the request to be included in a
 * @dev different block with a different hash, and therefore a different input
 * @dev to the VRF. However, such an attack would incur a substantial economic
 * @dev cost. This cost scales with the number of blocks the VRF oracle waits
 * @dev until it calls responds to a request. It is for this reason that
 * @dev that you can signal to an oracle you'd like them to wait longer before
 * @dev responding to the request (however this is not enforced in the contract
 * @dev and so remains effective only in the case of unmodified oracle software).
 */
abstract contract VRFConsumerBaseV2 {
  error OnlyCoordinatorCanFulfill(address have, address want);
  address private immutable vrfCoordinator;

  /**
   * @param _vrfCoordinator address of VRFCoordinator contract
   */
  constructor(address _vrfCoordinator) {
    vrfCoordinator = _vrfCoordinator;
  }

  /**
   * @notice fulfillRandomness handles the VRF response. Your contract must
   * @notice implement it. See "SECURITY CONSIDERATIONS" above for important
   * @notice principles to keep in mind when implementing your fulfillRandomness
   * @notice method.
   *
   * @dev VRFConsumerBaseV2 expects its subcontracts to have a method with this
   * @dev signature, and will call it once it has verified the proof
   * @dev associated with the randomness. (It is triggered via a call to
   * @dev rawFulfillRandomness, below.)
   *
   * @param requestId The Id initially returned by requestRandomness
   * @param randomWords the VRF output expanded to the requested number of words
   */
  function fulfillRandomWords(uint256 requestId, uint256[] memory randomWords) internal virtual;

  // rawFulfillRandomness is called by VRFCoordinator when it receives a valid VRF
  // proof. rawFulfillRandomness then calls fulfillRandomness, after validating
  // the origin of the call
  function rawFulfillRandomWords(uint256 requestId, uint256[] memory randomWords) external {
    if (msg.sender != vrfCoordinator) {
      revert OnlyCoordinatorCanFulfill(msg.sender, vrfCoordinator);
    }
    fulfillRandomWords(requestId, randomWords);
  }
}

// File: @chainlink/contracts/src/v0.8/interfaces/VRFCoordinatorV2Interface.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface VRFCoordinatorV2Interface {
  /**
   * @notice Get configuration relevant for making requests
   * @return minimumRequestConfirmations global min for request confirmations
   * @return maxGasLimit global max for request gas limit
   * @return s_provingKeyHashes list of registered key hashes
   */
  function getRequestConfig()
    external
    view
    returns (
      uint16,
      uint32,
      bytes32[] memory
    );

  /**
   * @notice Request a set of random words.
   * @param keyHash - Corresponds to a particular oracle job which uses
   * that key for generating the VRF proof. Different keyHash's have different gas price
   * ceilings, so you can select a specific one to bound your maximum per request cost.
   * @param subId  - The ID of the VRF subscription. Must be funded
   * with the minimum subscription balance required for the selected keyHash.
   * @param minimumRequestConfirmations - How many blocks you'd like the
   * oracle to wait before responding to the request. See SECURITY CONSIDERATIONS
   * for why you may want to request more. The acceptable range is
   * [minimumRequestBlockConfirmations, 200].
   * @param callbackGasLimit - How much gas you'd like to receive in your
   * fulfillRandomWords callback. Note that gasleft() inside fulfillRandomWords
   * may be slightly less than this amount because of gas used calling the function
   * (argument decoding etc.), so you may need to request slightly more than you expect
   * to have inside fulfillRandomWords. The acceptable range is
   * [0, maxGasLimit]
   * @param numWords - The number of uint256 random values you'd like to receive
   * in your fulfillRandomWords callback. Note these numbers are expanded in a
   * secure way by the VRFCoordinator from a single random value supplied by the oracle.
   * @return requestId - A unique identifier of the request. Can be used to match
   * a request to a response in fulfillRandomWords.
   */
  function requestRandomWords(
    bytes32 keyHash,
    uint64 subId,
    uint16 minimumRequestConfirmations,
    uint32 callbackGasLimit,
    uint32 numWords
  ) external returns (uint256 requestId);

  /**
   * @notice Create a VRF subscription.
   * @return subId - A unique subscription id.
   * @dev You can manage the consumer set dynamically with addConsumer/removeConsumer.
   * @dev Note to fund the subscription, use transferAndCall. For example
   * @dev  LINKTOKEN.transferAndCall(
   * @dev    address(COORDINATOR),
   * @dev    amount,
   * @dev    abi.encode(subId));
   */
  function createSubscription() external returns (uint64 subId);

  /**
   * @notice Get a VRF subscription.
   * @param subId - ID of the subscription
   * @return balance - LINK balance of the subscription in juels.
   * @return reqCount - number of requests for this subscription, determines fee tier.
   * @return owner - owner of the subscription.
   * @return consumers - list of consumer address which are able to use this subscription.
   */
  function getSubscription(uint64 subId)
    external
    view
    returns (
      uint96 balance,
      uint64 reqCount,
      address owner,
      address[] memory consumers
    );

  /**
   * @notice Request subscription owner transfer.
   * @param subId - ID of the subscription
   * @param newOwner - proposed new owner of the subscription
   */
  function requestSubscriptionOwnerTransfer(uint64 subId, address newOwner) external;

  /**
   * @notice Request subscription owner transfer.
   * @param subId - ID of the subscription
   * @dev will revert if original owner of subId has
   * not requested that msg.sender become the new owner.
   */
  function acceptSubscriptionOwnerTransfer(uint64 subId) external;

  /**
   * @notice Add a consumer to a VRF subscription.
   * @param subId - ID of the subscription
   * @param consumer - New consumer which can use the subscription
   */
  function addConsumer(uint64 subId, address consumer) external;

  /**
   * @notice Remove a consumer from a VRF subscription.
   * @param subId - ID of the subscription
   * @param consumer - Consumer to remove from the subscription
   */
  function removeConsumer(uint64 subId, address consumer) external;

  /**
   * @notice Cancel a subscription
   * @param subId - ID of the subscription
   * @param to - Where to send the remaining LINK to
   */
  function cancelSubscription(uint64 subId, address to) external;

  /*
   * @notice Check to see if there exists a request commitment consumers
   * for all consumers and keyhashes for a given sub.
   * @param subId - ID of the subscription
   * @return true if there exists at least one unfulfilled request for the subscription, false
   * otherwise.
   */
  function pendingRequestExists(uint64 subId) external view returns (bool);
}

// File: @chainlink/contracts/src/v0.8/interfaces/KeeperCompatibleInterface.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface KeeperCompatibleInterface {
  /**
   * @notice method that is simulated by the keepers to see if any work actually
   * needs to be performed. This method does does not actually need to be
   * executable, and since it is only ever simulated it can consume lots of gas.
   * @dev To ensure that it is never called, you may want to add the
   * cannotExecute modifier from KeeperBase to your implementation of this
   * method.
   * @param checkData specified in the upkeep registration so it is always the
   * same for a registered upkeep. This can easily be broken down into specific
   * arguments using `abi.decode`, so multiple upkeeps can be registered on the
   * same contract and easily differentiated by the contract.
   * @return upkeepNeeded boolean to indicate whether the keeper should call
   * performUpkeep or not.
   * @return performData bytes that the keeper should call performUpkeep with, if
   * upkeep is needed. If you would like to encode data to decode later, try
   * `abi.encode`.
   */
  function checkUpkeep(bytes calldata checkData) external returns (bool upkeepNeeded, bytes memory performData);

  /**
   * @notice method that is actually executed by the keepers, via the registry.
   * The data returned by the checkUpkeep simulation will be passed into
   * this method to actually be executed.
   * @dev The input to this method should not be trusted, and the caller of the
   * method should not even be restricted to any single registry. Anyone should
   * be able call it, and the input should be validated, there is no guarantee
   * that the data passed in is the performData returned from checkUpkeep. This
   * could happen due to malicious keepers, racing keepers, or simply a state
   * change while the performUpkeep transaction is waiting for confirmation.
   * Always validate the data passed in.
   * @param performData is the data which was passed back from the checkData
   * simulation. If it is encoded, it can easily be decoded into other types by
   * calling `abi.decode`. This data should not be trusted, and should be
   * validated against the contract's current state.
   */
  function performUpkeep(bytes calldata performData) external;
}

// File: @chainlink/contracts/src/v0.8/interfaces/LinkTokenInterface.sol



// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

interface LinkTokenInterface {
  function allowance(address owner, address spender) external view returns (uint256 remaining);

  function approve(address spender, uint256 value) external returns (bool success);

  function balanceOf(address owner) external view returns (uint256 balance);

  function decimals() external view returns (uint8 decimalPlaces);

  function decreaseApproval(address spender, uint256 addedValue) external returns (bool success);

  function increaseApproval(address spender, uint256 subtractedValue) external;

  function name() external view returns (string memory tokenName);

  function symbol() external view returns (string memory tokenSymbol);

  function totalSupply() external view returns (uint256 totalTokensIssued);

  function transfer(address to, uint256 value) external returns (bool success);

  function transferAndCall(
    address to,
    uint256 value,
    bytes calldata data
  ) external returns (bool success);

  function transferFrom(
    address from,
    address to,
    uint256 value
  ) external returns (bool success);
}