// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

/******************************************/
/* KeeperCompatibleInterface starts here  */
/******************************************/

interface KeeperCompatibleInterface {

  /**
   * @notice checks if the contract requires work to be done.
   * @param checkData data passed to the contract when checking for upkeep.
   * @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.
   */
  function checkUpkeep(
    bytes calldata checkData
  )
    external
    returns (
      bool upkeepNeeded,
      bytes memory performData
    );

  /**
   * @notice Performs work on the contract. Executed by the keepers, via the registry.
   * @param performData is the data which was passed back from the checkData
   * simulation.
   */
  function performUpkeep(
    bytes calldata performData
  ) external;
}

/******************************************/
/* ChainlinkRequestInterface starts here  */
/******************************************/

interface ChainlinkRequestInterface {
  function oracleRequest(
    address sender,
    uint256 requestPrice,
    bytes32 serviceAgreementID,
    address callbackAddress,
    bytes4 callbackFunctionId,
    uint256 nonce,
    uint256 dataVersion,
    bytes calldata data
  ) external;

  function cancelOracleRequest(
    bytes32 requestId,
    uint256 payment,
    bytes4 callbackFunctionId,
    uint256 expiration
  ) external;
}

/******************************************/
/*       OracleInterface starts here      */
/******************************************/

interface OracleInterface {
  function fulfillOracleRequest(
    bytes32 requestId,
    uint256 payment,
    address callbackAddress,
    bytes4 callbackFunctionId,
    uint256 expiration,
    bytes32 data
  )
    external
    returns (
      bool
    );

  function isAuthorizedSender(
    address node
  )
    external
    view
    returns (
      bool
    );

  function withdraw(
    address recipient,
    uint256 amount
  ) external;

  function withdrawable()
    external
    view
    returns (
      uint256
    );
}

/******************************************/
/*      OperatorInterface starts here     */
/******************************************/

interface OperatorInterface is OracleInterface, ChainlinkRequestInterface {

  function requestOracleData(
    address sender,
    uint256 payment,
    bytes32 specId,
    address callbackAddress,
    bytes4 callbackFunctionId,
    uint256 nonce,
    uint256 dataVersion,
    bytes calldata data
  )
    external;

  function fulfillOracleRequest2(
    bytes32 requestId,
    uint256 payment,
    address callbackAddress,
    bytes4 callbackFunctionId,
    uint256 expiration,
    bytes calldata data
  )
    external
    returns (
      bool
    );

  function ownerTransferAndCall(
    address to,
    uint256 value,
    bytes calldata data
  )
    external
    returns (
      bool success
    );

  function distributeFunds(
    address payable[] calldata receivers,
    uint[] calldata amounts
  )
    external
    payable;

  function getAuthorizedSenders()
    external
    returns (
      address[] memory
    );

  function setAuthorizedSenders(
    address[] calldata senders
  ) external;

  function getForwarder()
    external
    returns (
      address
    );
}

/******************************************/
/*      PointerInterface starts here      */
/******************************************/

interface PointerInterface {
  
  function getAddress()
    external
    view
    returns (
      address
    );
}

/******************************************/
/*     LinkTokenInterface starts here     */
/******************************************/

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
    );

}

/******************************************/
/*         ENSResolver starts here        */
/******************************************/

abstract contract ENSResolver_Chainlink {
  function addr(
    bytes32 node
  )
    public
    view
    virtual
    returns (
      address
    );
}

/******************************************/
/*         ENSInterface starts here       */
/******************************************/

interface ENSInterface {

  // Logged when the owner of a node assigns a new owner to a subnode.
  event NewOwner(
    bytes32 indexed node,
    bytes32 indexed label,
    address owner
  );

  // Logged when the owner of a node transfers ownership to a new account.
  event Transfer(
    bytes32 indexed node,
    address owner
  );

  // Logged when the resolver for a node changes.
  event NewResolver(
    bytes32 indexed node,
    address resolver
  );

  // Logged when the TTL of a node changes
  event NewTTL(
    bytes32 indexed node,
    uint64 ttl
  );


  function setSubnodeOwner(
    bytes32 node,
    bytes32 label,
    address owner
  ) external;

  function setResolver(
    bytes32 node,
    address resolver
  ) external;

  function setOwner(
    bytes32 node,
    address owner
  ) external;

  function setTTL(
    bytes32 node,
    uint64 ttl
  ) external;

  function owner(
    bytes32 node
  )
    external
    view
    returns (
      address
    );

  function resolver(
    bytes32 node
  )
    external
    view
    returns (
      address
    );

  function ttl(
    bytes32 node
  )
    external
    view
    returns (
      uint64
    );

}

/******************************************/
/*       BufferChainlink starts here      */
/******************************************/

/**
* @dev A library for working with mutable byte buffers in Solidity.
*
* Byte buffers are mutable and expandable, and provide a variety of primitives
* for writing to them. At any time you can fetch a bytes object containing the
* current contents of the buffer. The bytes object should not be stored between
* operations, as it may change due to resizing of the buffer.
*/
library BufferChainlink {
  /**
  * @dev Represents a mutable buffer. Buffers have a current value (buf) and
  *      a capacity. The capacity may be longer than the current value, in
  *      which case it can be extended without the need to allocate more memory.
  */
  struct buffer {
    bytes buf;
    uint capacity;
  }

  /**
  * @dev Initializes a buffer with an initial capacity.
  * @param buf The buffer to initialize.
  * @param capacity The number of bytes of space to allocate the buffer.
  * @return The buffer, for chaining.
  */
  function init(
    buffer memory buf,
    uint capacity
  )
    internal
    pure
    returns(
      buffer memory
    )
  {
    if (capacity % 32 != 0) {
      capacity += 32 - (capacity % 32);
    }
    // Allocate space for the buffer data
    buf.capacity = capacity;
    assembly {
      let ptr := mload(0x40)
      mstore(buf, ptr)
      mstore(ptr, 0)
      mstore(0x40, add(32, add(ptr, capacity)))
    }
    return buf;
  }

  /**
  * @dev Initializes a new buffer from an existing bytes object.
  *      Changes to the buffer may mutate the original value.
  * @param b The bytes object to initialize the buffer with.
  * @return A new buffer.
  */
  function fromBytes(
    bytes memory b
  )
    internal
    pure
    returns(
      buffer memory
    )
  {
    buffer memory buf;
    buf.buf = b;
    buf.capacity = b.length;
    return buf;
  }

  function resize(
    buffer memory buf,
    uint capacity
  )
    private
    pure
  {
    bytes memory oldbuf = buf.buf;
    init(buf, capacity);
    append(buf, oldbuf);
  }

  function max(
    uint a,
    uint b
  )
    private
    pure
    returns(
      uint
    )
  {
    if (a > b) {
      return a;
    }
    return b;
  }

  /**
  * @dev Sets buffer length to 0.
  * @param buf The buffer to truncate.
  * @return The original buffer, for chaining..
  */
  function truncate(
    buffer memory buf
  )
    internal
    pure
    returns (
      buffer memory
    )
  {
    assembly {
      let bufptr := mload(buf)
      mstore(bufptr, 0)
    }
    return buf;
  }

  /**
  * @dev Writes a byte string to a buffer. Resizes if doing so would exceed
  *      the capacity of the buffer.
  * @param buf The buffer to append to.
  * @param off The start offset to write to.
  * @param data The data to append.
  * @param len The number of bytes to copy.
  * @return The original buffer, for chaining.
  */
  function write(
    buffer memory buf,
    uint off,
    bytes memory data,
    uint len
  )
    internal
    pure
    returns(
      buffer memory
    )
  {
    require(len <= data.length);

    if (off + len > buf.capacity) {
      resize(buf, max(buf.capacity, len + off) * 2);
    }

    uint dest;
    uint src;
    assembly {
      // Memory address of the buffer data
      let bufptr := mload(buf)
      // Length of existing buffer data
      let buflen := mload(bufptr)
      // Start address = buffer address + offset + sizeof(buffer length)
      dest := add(add(bufptr, 32), off)
      // Update buffer length if we're extending it
      if gt(add(len, off), buflen) {
        mstore(bufptr, add(len, off))
      }
      src := add(data, 32)
    }

    // Copy word-length chunks while possible
    for (; len >= 32; len -= 32) {
      assembly {
        mstore(dest, mload(src))
      }
      dest += 32;
      src += 32;
    }

    // Copy remaining bytes
    uint mask = 256 ** (32 - len) - 1;
    assembly {
      let srcpart := and(mload(src), not(mask))
      let destpart := and(mload(dest), mask)
      mstore(dest, or(destpart, srcpart))
    }

    return buf;
  }

  /**
  * @dev Appends a byte string to a buffer. Resizes if doing so would exceed
  *      the capacity of the buffer.
  * @param buf The buffer to append to.
  * @param data The data to append.
  * @param len The number of bytes to copy.
  * @return The original buffer, for chaining.
  */
  function append(
    buffer memory buf,
    bytes memory data,
    uint len
  )
    internal
    pure
    returns (
      buffer memory
    )
  {
    return write(buf, buf.buf.length, data, len);
  }

  /**
  * @dev Appends a byte string to a buffer. Resizes if doing so would exceed
  *      the capacity of the buffer.
  * @param buf The buffer to append to.
  * @param data The data to append.
  * @return The original buffer, for chaining.
  */
  function append(
    buffer memory buf,
    bytes memory data
  )
    internal
    pure
    returns (
      buffer memory
    )
  {
    return write(buf, buf.buf.length, data, data.length);
  }

  /**
  * @dev Writes a byte to the buffer. Resizes if doing so would exceed the
  *      capacity of the buffer.
  * @param buf The buffer to append to.
  * @param off The offset to write the byte at.
  * @param data The data to append.
  * @return The original buffer, for chaining.
  */
  function writeUint8(
    buffer memory buf,
    uint off,
    uint8 data
  )
    internal
    pure
    returns(
      buffer memory
    )
  {
    if (off >= buf.capacity) {
      resize(buf, buf.capacity * 2);
    }

    assembly {
      // Memory address of the buffer data
      let bufptr := mload(buf)
      // Length of existing buffer data
      let buflen := mload(bufptr)
      // Address = buffer address + sizeof(buffer length) + off
      let dest := add(add(bufptr, off), 32)
      mstore8(dest, data)
      // Update buffer length if we extended it
      if eq(off, buflen) {
        mstore(bufptr, add(buflen, 1))
      }
    }
    return buf;
  }

  /**
  * @dev Appends a byte to the buffer. Resizes if doing so would exceed the
  *      capacity of the buffer.
  * @param buf The buffer to append to.
  * @param data The data to append.
  * @return The original buffer, for chaining.
  */
  function appendUint8(
    buffer memory buf,
    uint8 data
  )
    internal
    pure
    returns(
      buffer memory
    )
  {
    return writeUint8(buf, buf.buf.length, data);
  }

  /**
  * @dev Writes up to 32 bytes to the buffer. Resizes if doing so would
  *      exceed the capacity of the buffer.
  * @param buf The buffer to append to.
  * @param off The offset to write at.
  * @param data The data to append.
  * @param len The number of bytes to write (left-aligned).
  * @return The original buffer, for chaining.
  */
  function write(
    buffer memory buf,
    uint off,
    bytes32 data,
    uint len
  )
    private
    pure
    returns(
      buffer memory
    )
  {
    if (len + off > buf.capacity) {
      resize(buf, (len + off) * 2);
    }

    uint mask = 256 ** len - 1;
    // Right-align data
    data = data >> (8 * (32 - len));
    assembly {
      // Memory address of the buffer data
      let bufptr := mload(buf)
      // Address = buffer address + sizeof(buffer length) + off + len
      let dest := add(add(bufptr, off), len)
      mstore(dest, or(and(mload(dest), not(mask)), data))
      // Update buffer length if we extended it
      if gt(add(off, len), mload(bufptr)) {
        mstore(bufptr, add(off, len))
      }
    }
    return buf;
  }

  /**
  * @dev Writes a bytes20 to the buffer. Resizes if doing so would exceed the
  *      capacity of the buffer.
  * @param buf The buffer to append to.
  * @param off The offset to write at.
  * @param data The data to append.
  * @return The original buffer, for chaining.
  */
  function writeBytes20(
    buffer memory buf,
    uint off,
    bytes20 data
  )
    internal
    pure
    returns (
      buffer memory
    )
  {
    return write(buf, off, bytes32(data), 20);
  }

  /**
  * @dev Appends a bytes20 to the buffer. Resizes if doing so would exceed
  *      the capacity of the buffer.
  * @param buf The buffer to append to.
  * @param data The data to append.
  * @return The original buffer, for chhaining.
  */
  function appendBytes20(
    buffer memory buf,
    bytes20 data
  )
    internal
    pure
    returns (
      buffer memory
    )
  {
    return write(buf, buf.buf.length, bytes32(data), 20);
  }

  /**
  * @dev Appends a bytes32 to the buffer. Resizes if doing so would exceed
  *      the capacity of the buffer.
  * @param buf The buffer to append to.
  * @param data The data to append.
  * @return The original buffer, for chaining.
  */
  function appendBytes32(
    buffer memory buf,
    bytes32 data
  )
    internal
    pure
    returns (
      buffer memory
    )
  {
    return write(buf, buf.buf.length, data, 32);
  }

  /**
  * @dev Writes an integer to the buffer. Resizes if doing so would exceed
  *      the capacity of the buffer.
  * @param buf The buffer to append to.
  * @param off The offset to write at.
  * @param data The data to append.
  * @param len The number of bytes to write (right-aligned).
  * @return The original buffer, for chaining.
  */
  function writeInt(
    buffer memory buf,
    uint off,
    uint data,
    uint len
  )
    private
    pure
    returns(
      buffer memory
    )
  {
    if (len + off > buf.capacity) {
      resize(buf, (len + off) * 2);
    }

    uint mask = 256 ** len - 1;
    assembly {
      // Memory address of the buffer data
      let bufptr := mload(buf)
      // Address = buffer address + off + sizeof(buffer length) + len
      let dest := add(add(bufptr, off), len)
      mstore(dest, or(and(mload(dest), not(mask)), data))
      // Update buffer length if we extended it
      if gt(add(off, len), mload(bufptr)) {
        mstore(bufptr, add(off, len))
      }
    }
    return buf;
  }

  /**
    * @dev Appends a byte to the end of the buffer. Resizes if doing so would
    * exceed the capacity of the buffer.
    * @param buf The buffer to append to.
    * @param data The data to append.
    * @return The original buffer.
    */
  function appendInt(
    buffer memory buf,
    uint data,
    uint len
  )
    internal
    pure
    returns(
      buffer memory
    )
  {
    return writeInt(buf, buf.buf.length, data, len);
  }
}

/******************************************/
/*        CBORChainlink starts here       */
/******************************************/

library CBORChainlink {
  using BufferChainlink for BufferChainlink.buffer;

  uint8 private constant MAJOR_TYPE_INT = 0;
  uint8 private constant MAJOR_TYPE_NEGATIVE_INT = 1;
  uint8 private constant MAJOR_TYPE_BYTES = 2;
  uint8 private constant MAJOR_TYPE_STRING = 3;
  uint8 private constant MAJOR_TYPE_ARRAY = 4;
  uint8 private constant MAJOR_TYPE_MAP = 5;
  uint8 private constant MAJOR_TYPE_TAG = 6;
  uint8 private constant MAJOR_TYPE_CONTENT_FREE = 7;

  uint8 private constant TAG_TYPE_BIGNUM = 2;
  uint8 private constant TAG_TYPE_NEGATIVE_BIGNUM = 3;

  function encodeType(
    BufferChainlink.buffer memory buf,
    uint8 major,
    uint value
  )
    private
    pure
  {
    if(value <= 23) {
      buf.appendUint8(uint8((major << 5) | value));
    } else if(value <= 0xFF) {
      buf.appendUint8(uint8((major << 5) | 24));
      buf.appendInt(value, 1);
    } else if(value <= 0xFFFF) {
      buf.appendUint8(uint8((major << 5) | 25));
      buf.appendInt(value, 2);
    } else if(value <= 0xFFFFFFFF) {
      buf.appendUint8(uint8((major << 5) | 26));
      buf.appendInt(value, 4);
    } else if(value <= 0xFFFFFFFFFFFFFFFF) {
      buf.appendUint8(uint8((major << 5) | 27));
      buf.appendInt(value, 8);
    }
  }

  function encodeIndefiniteLengthType(
    BufferChainlink.buffer memory buf,
    uint8 major
  )
    private
    pure
  {
    buf.appendUint8(uint8((major << 5) | 31));
  }

  function encodeUInt(
    BufferChainlink.buffer memory buf,
    uint value
  )
    internal
    pure
  {
    encodeType(buf, MAJOR_TYPE_INT, value);
  }

  function encodeInt(
    BufferChainlink.buffer memory buf,
    int value
  )
    internal
    pure
  {
    if(value < -0x10000000000000000) {
      encodeSignedBigNum(buf, value);
    } else if(value > 0xFFFFFFFFFFFFFFFF) {
      encodeBigNum(buf, value);
    } else if(value >= 0) {
      encodeType(buf, MAJOR_TYPE_INT, uint(value));
    } else {
      encodeType(buf, MAJOR_TYPE_NEGATIVE_INT, uint(-1 - value));
    }
  }

  function encodeBytes(
    BufferChainlink.buffer memory buf,
    bytes memory value
  )
    internal
    pure
  {
    encodeType(buf, MAJOR_TYPE_BYTES, value.length);
    buf.append(value);
  }

  function encodeBigNum(
    BufferChainlink.buffer memory buf,
    int value
  )
    internal
    pure
  {
    buf.appendUint8(uint8((MAJOR_TYPE_TAG << 5) | TAG_TYPE_BIGNUM));
    encodeBytes(buf, abi.encode(uint(value)));
  }

  function encodeSignedBigNum(
    BufferChainlink.buffer memory buf,
    int input
  )
    internal
    pure
  {
    buf.appendUint8(uint8((MAJOR_TYPE_TAG << 5) | TAG_TYPE_NEGATIVE_BIGNUM));
    encodeBytes(buf, abi.encode(uint(-1 - input)));
  }

  function encodeString(
    BufferChainlink.buffer memory buf,
    string memory value
  )
    internal
    pure
  {
    encodeType(buf, MAJOR_TYPE_STRING, bytes(value).length);
    buf.append(bytes(value));
  }

  function startArray(
    BufferChainlink.buffer memory buf
  )
    internal
    pure
  {
    encodeIndefiniteLengthType(buf, MAJOR_TYPE_ARRAY);
  }

  function startMap(
    BufferChainlink.buffer memory buf
  )
    internal
    pure
  {
    encodeIndefiniteLengthType(buf, MAJOR_TYPE_MAP);
  }

  function endSequence(
    BufferChainlink.buffer memory buf
  )
    internal
    pure
  {
    encodeIndefiniteLengthType(buf, MAJOR_TYPE_CONTENT_FREE);
  }
}

/******************************************/
/*          Chainlink starts here         */
/******************************************/

/**
 * @title Library for common Chainlink functions
 * @dev Uses imported CBOR library for encoding to buffer
 */
library Chainlink {
  uint256 internal constant defaultBufferSize = 256; // solhint-disable-line const-name-snakecase

  using CBORChainlink for BufferChainlink.buffer;

  struct Request {
    bytes32 id;
    address callbackAddress;
    bytes4 callbackFunctionId;
    uint256 nonce;
    BufferChainlink.buffer buf;
  }

  /**
   * @notice Initializes a Chainlink request
   * @dev Sets the ID, callback address, and callback function signature on the request
   * @param self The uninitialized request
   * @param jobId The Job Specification ID
   * @param callbackAddr The callback address
   * @param callbackFunc The callback function signature
   * @return The initialized request
   */
  function initialize(
    Request memory self,
    bytes32 jobId,
    address callbackAddr,
    bytes4 callbackFunc
  )
    internal
    pure
    returns (
      Chainlink.Request memory
    )
  {
    BufferChainlink.init(self.buf, defaultBufferSize);
    self.id = jobId;
    self.callbackAddress = callbackAddr;
    self.callbackFunctionId = callbackFunc;
    return self;
  }

  /**
   * @notice Sets the data for the buffer without encoding CBOR on-chain
   * @dev CBOR can be closed with curly-brackets {} or they can be left off
   * @param self The initialized request
   * @param data The CBOR data
   */
  function setBuffer(
    Request memory self,
    bytes memory data
  )
    internal
    pure
  {
    BufferChainlink.init(self.buf, data.length);
    BufferChainlink.append(self.buf, data);
  }

  /**
   * @notice Adds a string value to the request with a given key name
   * @param self The initialized request
   * @param key The name of the key
   * @param value The string value to add
   */
  function add(
    Request memory self,
    string memory key,
    string memory value
  )
    internal
    pure
  {
    self.buf.encodeString(key);
    self.buf.encodeString(value);
  }

  /**
   * @notice Adds a bytes value to the request with a given key name
   * @param self The initialized request
   * @param key The name of the key
   * @param value The bytes value to add
   */
  function addBytes(
    Request memory self,
    string memory key,
    bytes memory value
  )
    internal
    pure
  {
    self.buf.encodeString(key);
    self.buf.encodeBytes(value);
  }

  /**
   * @notice Adds a int256 value to the request with a given key name
   * @param self The initialized request
   * @param key The name of the key
   * @param value The int256 value to add
   */
  function addInt(
    Request memory self,
    string memory key,
    int256 value
  )
    internal
    pure
  {
    self.buf.encodeString(key);
    self.buf.encodeInt(value);
  }

  /**
   * @notice Adds a uint256 value to the request with a given key name
   * @param self The initialized request
   * @param key The name of the key
   * @param value The uint256 value to add
   */
  function addUint(
    Request memory self,
    string memory key,
    uint256 value
  )
    internal
    pure
  {
    self.buf.encodeString(key);
    self.buf.encodeUInt(value);
  }

  /**
   * @notice Adds an array of strings to the request with a given key name
   * @param self The initialized request
   * @param key The name of the key
   * @param values The array of string values to add
   */
  function addStringArray(
    Request memory self,
    string memory key,
    string[] memory values
  )
    internal
    pure
  {
    self.buf.encodeString(key);
    self.buf.startArray();
    for (uint256 i = 0; i < values.length; i++) {
      self.buf.encodeString(values[i]);
    }
    self.buf.endSequence();
  }
}

/******************************************/
/*       ChainlinkClient starts here      */
/******************************************/

/**
 * @title The ChainlinkClient contract
 * @notice Contract writers can inherit this contract in order to create requests for the
 * Chainlink network
 */
abstract contract ChainlinkClient {
  using Chainlink for Chainlink.Request;

  uint256 constant internal LINK_DIVISIBILITY = 10**18;
  uint256 constant private AMOUNT_OVERRIDE = 0;
  address constant private SENDER_OVERRIDE = address(0);
  uint256 constant private ORACLE_ARGS_VERSION = 1;
  uint256 constant private OPERATOR_ARGS_VERSION = 2;
  bytes32 constant private ENS_TOKEN_SUBNAME = keccak256("link");
  bytes32 constant private ENS_ORACLE_SUBNAME = keccak256("oracle");
  address constant private LINK_TOKEN_POINTER = 0xC89bD4E1632D3A43CB03AAAd5262cbe4038Bc571;

  ENSInterface private ens;
  bytes32 private ensNode;
  LinkTokenInterface private link;
  OperatorInterface private oracle;
  uint256 private requestCount = 1;
  mapping(bytes32 => address) private pendingRequests;

  event ChainlinkRequested(
    bytes32 indexed id
  );
  event ChainlinkFulfilled(
    bytes32 indexed id
  );
  event ChainlinkCancelled(
    bytes32 indexed id
  );

  /**
   * @notice Creates a request that can hold additional parameters
   * @param specId The Job Specification ID that the request will be created for
   * @param callbackAddress The callback address that the response will be sent to
   * @param callbackFunctionSignature The callback function signature to use for the callback address
   * @return A Chainlink Request struct in memory
   */
  function buildChainlinkRequest(
    bytes32 specId,
    address callbackAddress,
    bytes4 callbackFunctionSignature
  )
    internal
    pure
    returns (
      Chainlink.Request memory
    )
  {
    Chainlink.Request memory req;
    return req.initialize(specId, callbackAddress, callbackFunctionSignature);
  }

  /**
   * @notice Creates a Chainlink request to the stored oracle address
   * @dev Calls `chainlinkRequestTo` with the stored oracle address
   * @param req The initialized Chainlink Request
   * @param payment The amount of LINK to send for the request
   * @return requestId The request ID
   */
  function sendChainlinkRequest(
    Chainlink.Request memory req,
    uint256 payment
  )
    internal
    returns (
      bytes32
    )
  {
    return sendChainlinkRequestTo(address(oracle), req, payment);
  }

  /**
   * @notice Creates a Chainlink request to the specified oracle address
   * @dev Generates and stores a request ID, increments the local nonce, and uses `transferAndCall` to
   * send LINK which creates a request on the target oracle contract.
   * Emits ChainlinkRequested event.
   * @param oracleAddress The address of the oracle for the request
   * @param req The initialized Chainlink Request
   * @param payment The amount of LINK to send for the request
   * @return requestId The request ID
   */
  function sendChainlinkRequestTo(
    address oracleAddress,
    Chainlink.Request memory req,
    uint256 payment
  )
    internal
    returns (
      bytes32 requestId
    )
  {
    return rawRequest(oracleAddress, req, payment, ORACLE_ARGS_VERSION, oracle.oracleRequest.selector);
  }

  /**
   * @notice Creates a Chainlink request to the stored oracle address
   * @dev This function supports multi-word response
   * @dev Calls `requestOracleDataFrom` with the stored oracle address
   * @param req The initialized Chainlink Request
   * @param payment The amount of LINK to send for the request
   * @return requestId The request ID
   */
  function requestOracleData(
    Chainlink.Request memory req,
    uint256 payment
  )
    internal
    returns (
      bytes32
    )
  {
    return requestOracleDataFrom(address(oracle), req, payment);
  }

  /**
   * @notice Creates a Chainlink request to the specified oracle address
   * @dev This function supports multi-word response
   * @dev Generates and stores a request ID, increments the local nonce, and uses `transferAndCall` to
   * send LINK which creates a request on the target oracle contract.
   * Emits ChainlinkRequested event.
   * @param oracleAddress The address of the oracle for the request
   * @param req The initialized Chainlink Request
   * @param payment The amount of LINK to send for the request
   * @return requestId The request ID
   */
  function requestOracleDataFrom(
    address oracleAddress,
    Chainlink.Request memory req,
    uint256 payment
  )
    internal
    returns (
      bytes32 requestId
    )
  {
    return rawRequest(oracleAddress, req, payment, OPERATOR_ARGS_VERSION, oracle.requestOracleData.selector);
  }

  /**
   * @notice Make a request to an oracle
   * @param oracleAddress The address of the oracle for the request
   * @param req The initialized Chainlink Request
   * @param payment The amount of LINK to send for the request
   * @param argsVersion The version of data support (single word, multi word)
   * @return requestId The request ID
   */
  function rawRequest(
    address oracleAddress,
    Chainlink.Request memory req,
    uint256 payment,
    uint256 argsVersion,
    bytes4 funcSelector
  )
    private
    returns (
      bytes32 requestId
    )
  {
    requestId = keccak256(abi.encodePacked(this, requestCount));
    req.nonce = requestCount;
    pendingRequests[requestId] = oracleAddress;
    emit ChainlinkRequested(requestId);
    bytes memory encodedData = abi.encodeWithSelector(
      funcSelector,
      SENDER_OVERRIDE, // Sender value - overridden by onTokenTransfer by the requesting contract's address
      AMOUNT_OVERRIDE, // Amount value - overridden by onTokenTransfer by the actual amount of LINK sent
      req.id,
      req.callbackAddress,
      req.callbackFunctionId,
      req.nonce,
      argsVersion,
      req.buf.buf);
    require(link.transferAndCall(oracleAddress, payment, encodedData), "unable to transferAndCall to oracle");
    requestCount += 1;
  }

  /**
   * @notice Allows a request to be cancelled if it has not been fulfilled
   * @dev Requires keeping track of the expiration value emitted from the oracle contract.
   * Deletes the request from the `pendingRequests` mapping.
   * Emits ChainlinkCancelled event.
   * @param requestId The request ID
   * @param payment The amount of LINK sent for the request
   * @param callbackFunc The callback function specified for the request
   * @param expiration The time of the expiration for the request
   */
  function cancelChainlinkRequest(
    bytes32 requestId,
    uint256 payment,
    bytes4 callbackFunc,
    uint256 expiration
  )
    internal
  {
    OperatorInterface requested = OperatorInterface(pendingRequests[requestId]);
    delete pendingRequests[requestId];
    emit ChainlinkCancelled(requestId);
    requested.cancelOracleRequest(requestId, payment, callbackFunc, expiration);
  }

  /**
   * @notice Sets the stored oracle address
   * @param oracleAddress The address of the oracle contract
   */
  function setChainlinkOracle(
    address oracleAddress
  )
    internal
  {
    oracle = OperatorInterface(oracleAddress);
  }

  /**
   * @notice Sets the LINK token address
   * @param linkAddress The address of the LINK token contract
   */
  function setChainlinkToken(
    address linkAddress
  )
    internal
  {
    link = LinkTokenInterface(linkAddress);
  }

  /**
   * @notice Sets the Chainlink token address for the public
   * network as given by the Pointer contract
   */
  function setPublicChainlinkToken() 
    internal
  {
    setChainlinkToken(PointerInterface(LINK_TOKEN_POINTER).getAddress());
  }

  /**
   * @notice Retrieves the stored address of the LINK token
   * @return The address of the LINK token
   */
  function chainlinkTokenAddress()
    internal
    view
    returns (
      address
    )
  {
    return address(link);
  }

  /**
   * @notice Retrieves the stored address of the oracle contract
   * @return The address of the oracle contract
   */
  function chainlinkOracleAddress()
    internal
    view
    returns (
      address
    )
  {
    return address(oracle);
  }

  /**
   * @notice Allows for a request which was created on another contract to be fulfilled
   * on this contract
   * @param oracleAddress The address of the oracle contract that will fulfill the request
   * @param requestId The request ID used for the response
   */
  function addChainlinkExternalRequest(
    address oracleAddress,
    bytes32 requestId
  )
    internal
    notPendingRequest(requestId)
  {
    pendingRequests[requestId] = oracleAddress;
  }

  /**
   * @notice Sets the stored oracle and LINK token contracts with the addresses resolved by ENS
   * @dev Accounts for subnodes having different resolvers
   * @param ensAddress The address of the ENS contract
   * @param node The ENS node hash
   */
  function useChainlinkWithENS(
    address ensAddress,
    bytes32 node
  )
    internal
  {
    ens = ENSInterface(ensAddress);
    ensNode = node;
    bytes32 linkSubnode = keccak256(abi.encodePacked(ensNode, ENS_TOKEN_SUBNAME));
    ENSResolver_Chainlink resolver = ENSResolver_Chainlink(ens.resolver(linkSubnode));
    setChainlinkToken(resolver.addr(linkSubnode));
    updateChainlinkOracleWithENS();
  }

  /**
   * @notice Sets the stored oracle contract with the address resolved by ENS
   * @dev This may be called on its own as long as `useChainlinkWithENS` has been called previously
   */
  function updateChainlinkOracleWithENS()
    internal
  {
    bytes32 oracleSubnode = keccak256(abi.encodePacked(ensNode, ENS_ORACLE_SUBNAME));
    ENSResolver_Chainlink resolver = ENSResolver_Chainlink(ens.resolver(oracleSubnode));
    setChainlinkOracle(resolver.addr(oracleSubnode));
  }

  /**
   * @notice Ensures that the fulfillment is valid for this contract
   * @dev Use if the contract developer prefers methods instead of modifiers for validation
   * @param requestId The request ID for fulfillment
   */
  function validateChainlinkCallback(
    bytes32 requestId
  )
    internal
    recordChainlinkFulfillment(requestId)
    // solhint-disable-next-line no-empty-blocks
  {}

  /**
   * @dev Reverts if the sender is not the oracle of the request.
   * Emits ChainlinkFulfilled event.
   * @param requestId The request ID for fulfillment
   */
  modifier recordChainlinkFulfillment(
    bytes32 requestId
  )
  {
    require(msg.sender == pendingRequests[requestId],
            "Source must be the oracle of the request");
    delete pendingRequests[requestId];
    emit ChainlinkFulfilled(requestId);
    _;
  }

  /**
   * @dev Reverts if the request is already pending
   * @param requestId The request ID for fulfillment
   */
  modifier notPendingRequest(
    bytes32 requestId
  )
  {
    require(pendingRequests[requestId] == address(0), "Request is already pending");
    _;
  }
}

/******************************************/
/*       IERC20 starts here               */
/******************************************/

// File: @openzeppelin/contracts/token/ERC20/IERC20.sol

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Returns the amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);

    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
}

/******************************************/
/*          Context starts here           */
/******************************************/

// File: @openzeppelin/contracts/GSN/Context.sol

/*
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * via msg.sender and msg.data, they should not be accessed in such a direct
 * manner, since when dealing with GSN meta-transactions the account sending and
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 *
 * This contract is only required for intermediate, library-like contracts.
 */
abstract contract Context {
    function _msgSender() internal view virtual returns (address payable) {
        return payable(msg.sender);
    }

    function _msgData() internal view virtual returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
    }
}

/******************************************/
/*           Ownable starts here          */
/******************************************/

// File: @openzeppelin/contracts/access/Ownable.sol

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 *
 * By default, the owner account will be the one that deploys the contract. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
abstract contract Ownable is Context {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
    constructor () {
        address msgSender = _msgSender();
        _owner = msgSender;
        emit OwnershipTransferred(address(0), msgSender);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(_owner == _msgSender(), "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     */
    function renounceOwnership() public virtual onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

/******************************************/
/*       Benchmark starts here            */
/******************************************/

abstract contract Benchmark 
{
    function rebase(uint256 supplyDelta, bool increaseSupply) external virtual returns (uint256);
    
    function totalSupply() external virtual view returns (uint256);
}

/******************************************/
/*       BenchmarkSync starts here        */
/******************************************/

abstract contract Sync 
{
    function syncPools() external virtual;
}

/******************************************/
/*       KeeperRebase starts here         */
/******************************************/

contract KeeperRebase is KeeperCompatibleInterface, ChainlinkClient, Ownable {

    using Chainlink for Chainlink.Request;

    uint256 public FEE = 1 * 10 ** 18;
    bytes32 public JOBID = bytes32("2bde90044c644ac192cc015c9274d870");
    address public constant LINK = 0x514910771AF9Ca656af840dff83E8264EcF986CA;
    address public constant ORACLE = 0x049Bd8C3adC3fE7d3Fc2a44541d955A537c2A484;
    Benchmark public constant BENCHMARK = Benchmark(0x67c597624B17b16fb77959217360B7cD18284253);
    Sync public SYNC = Sync(0x4C3aA5160aE34210CC5B783Cd642e4bAACF34b40);

    uint256 public keeperInterval;
    uint256 public lastRebase;
    int256 public latestPrice;
    int256 public targetPrice;
    bool public rebaseActive;

    event UpkeepPerformed();
    event RebasePerformed(uint256 supplyDelta, bool increaseSupply);

    constructor() {
        setChainlinkToken(LINK);
        setChainlinkOracle(ORACLE);
        lastRebase = block.timestamp;
    }
    
/******************************************/
/*       Administration starts here       */
/******************************************/

    function setJobId(bytes32 _jobId) external onlyOwner {
        JOBID = _jobId;
    } 
    
    function setFee(uint256 _fee) external onlyOwner {
        FEE = _fee;
    } 

    function setKeeperInterval(uint256 _interval) external onlyOwner {
        keeperInterval = _interval;
    } 

    function setTargetPrice(int256 _targetPrice) external onlyOwner {
        targetPrice = _targetPrice;
    } 

    function setSyncContract(address _sync) external onlyOwner {
        SYNC = Sync(_sync);
    }

    function setRebaseActive(bool _active) external onlyOwner {
        rebaseActive = _active;
    }
    
/******************************************/
/*       KeeperNetwork starts here        */
/******************************************/

    function checkUpkeep(bytes calldata checkData) external override returns (bool upkeepNeeded, bytes memory performData) {
        upkeepNeeded = (block.timestamp - lastRebase) > keeperInterval;
    }

    function performUpkeep(bytes calldata performData) external override {
        require((block.timestamp - lastRebase) > keeperInterval, "Too soon.");
        lastRebase = block.timestamp;
        initiateRebase();

        emit UpkeepPerformed();
    }

/******************************************/
/*        MARK Oracle starts here         */
/******************************************/

    function abs(int x) private pure returns (int) {
        return x >= 0 ? x : -x;
    }

    function initiatePublicRebase() external {
        IERC20(LINK).transferFrom(msg.sender, address(this), FEE);
        initiateRebase();
    }
    
    function initiateRebase() internal {
        sendChainlinkRequest(buildChainlinkRequest(JOBID, address(this), this.rebaseCallback.selector), FEE);
    }

    function rebaseCallback(bytes32 _requestId, uint256 _price) external {
        validateChainlinkCallback(_requestId);

        latestPrice = int(_price);
        int256 rebasePercentage = (latestPrice - targetPrice) * 1e18 / targetPrice;
        uint256 absolutePercentage = uint256(abs(rebasePercentage));
        uint256 supplyDelta = BENCHMARK.totalSupply() * absolutePercentage / 1e18;
        bool increaseSupply = rebasePercentage >= 0 ? true : false;
       
        if (rebaseActive == true) {
        BENCHMARK.rebase(supplyDelta, increaseSupply);
        SYNC.syncPools();
        }

        emit RebasePerformed(supplyDelta, increaseSupply);
    }

}