DSLA Community Faucet vs Ampleforth's Geyser
683 linee
/**
 *Submitted for verification at Etherscan.io on 2020-08-15
*/
/**
 *Submitted for verification at Etherscan.io on 2020-08-15
*/
/**
/**
 *Submitted for verification at Etherscan.io on 2020-07-11
 *Submitted for verification at Etherscan.io on 2020-07-11
*/
*/
// File: openzeppelin-solidity/contracts/math/SafeMath.sol
// File: openzeppelin-solidity/contracts/math/SafeMath.sol
pragma solidity ^0.5.0;
pragma solidity ^0.5.0;
/**
/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 * checks.
 *
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 * operation overflows.
 *
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 * class of bugs, so it's recommended to use it always.
 */
 */
library SafeMath {
library SafeMath {
    /**
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     * overflow.
     *
     *
     * Counterpart to Solidity's `+` operator.
     * Counterpart to Solidity's `+` operator.
     *
     *
     * Requirements:
     * Requirements:
     * - Addition cannot overflow.
     * - Addition cannot overflow.
     */
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        require(c >= a, "SafeMath: addition overflow");
        return c;
        return c;
    }
    }
    /**
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     * overflow (when the result is negative).
     *
     *
     * Counterpart to Solidity's `-` operator.
     * Counterpart to Solidity's `-` operator.
     *
     *
     * Requirements:
     * Requirements:
     * - Subtraction cannot overflow.
     * - Subtraction cannot overflow.
     */
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
        return sub(a, b, "SafeMath: subtraction overflow");
    }
    }
    /**
    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     * overflow (when the result is negative).
     *
     *
     * Counterpart to Solidity's `-` operator.
     * Counterpart to Solidity's `-` operator.
     *
     *
     * Requirements:
     * Requirements:
     * - Subtraction cannot overflow.
     * - Subtraction cannot overflow.
     *
     *
     * _Available since v2.4.0._
     * _Available since v2.4.0._
     */
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        require(b <= a, errorMessage);
        uint256 c = a - b;
        uint256 c = a - b;
        return c;
        return c;
    }
    }
    /**
    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     * overflow.
     *
     *
     * Counterpart to Solidity's `*` operator.
     * Counterpart to Solidity's `*` operator.
     *
     *
     * Requirements:
     * Requirements:
     * - Multiplication cannot overflow.
     * - Multiplication cannot overflow.
     */
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
        if (a == 0) {
            return 0;
            return 0;
        }
        }
        uint256 c = a * b;
        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");
        require(c / a == b, "SafeMath: multiplication overflow");
        return c;
        return c;
    }
    }
    /**
    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     * division by zero. The result is rounded towards zero.
     *
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     *
     * Requirements:
     * Requirements:
     * - The divisor cannot be zero.
     * - The divisor cannot be zero.
     */
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
        return div(a, b, "SafeMath: division by zero");
    }
    }
    /**
    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     * division by zero. The result is rounded towards zero.
     *
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     *
     * Requirements:
     * Requirements:
     * - The divisor cannot be zero.
     * - The divisor cannot be zero.
     *
     *
     * _Available since v2.4.0._
     * _Available since v2.4.0._
     */
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        // Solidity only automatically asserts when dividing by 0
        // Solidity only automatically asserts when dividing by 0
        require(b > 0, errorMessage);
        require(b > 0, errorMessage);
        uint256 c = a / b;
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold
        return c;
        return c;
    }
    }
    /**
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     * Reverts when dividing by zero.
     *
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     * invalid opcode to revert (consuming all remaining gas).
     *
     *
     * Requirements:
     * Requirements:
     * - The divisor cannot be zero.
     * - The divisor cannot be zero.
     */
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
        return mod(a, b, "SafeMath: modulo by zero");
    }
    }
    /**
    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     * Reverts with custom message when dividing by zero.
     *
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     * invalid opcode to revert (consuming all remaining gas).
     *
     *
     * Requirements:
     * Requirements:
     * - The divisor cannot be zero.
     * - The divisor cannot be zero.
     *
     *
     * _Available since v2.4.0._
     * _Available since v2.4.0._
     */
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        require(b != 0, errorMessage);
        return a % b;
        return a % b;
    }
    }
}
}
// File: openzeppelin-solidity/contracts/token/ERC20/IERC20.sol
// File: openzeppelin-solidity/contracts/token/ERC20/IERC20.sol
pragma solidity ^0.5.0;
pragma solidity ^0.5.0;
/**
/**
 * @dev Interface of the ERC20 standard as defined in the EIP. Does not include
 * @dev Interface of the ERC20 standard as defined in the EIP. Does not include
 * the optional functions; to access them see {ERC20Detailed}.
 * the optional functions; to access them see {ERC20Detailed}.
 */
 */
interface IERC20 {
interface IERC20 {
    /**
    /**
     * @dev Returns the amount of tokens in existence.
     * @dev Returns the amount of tokens in existence.
     */
     */
    function totalSupply() external view returns (uint256);
    function totalSupply() external view returns (uint256);
    /**
    /**
     * @dev Returns the amount of tokens owned by `account`.
     * @dev Returns the amount of tokens owned by `account`.
     */
     */
    function balanceOf(address account) external view returns (uint256);
    function balanceOf(address account) external view returns (uint256);
    /**
    /**
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     * @dev Moves `amount` tokens from the caller's account to `recipient`.
     *
     *
     * Returns a boolean value indicating whether the operation succeeded.
     * Returns a boolean value indicating whether the operation succeeded.
     *
     *
     * Emits a {Transfer} event.
     * Emits a {Transfer} event.
     */
     */
    function transfer(address recipient, uint256 amount) external returns (bool);
    function transfer(address recipient, uint256 amount) external returns (bool);
    /**
    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     * zero by default.
     *
     *
     * This value changes when {approve} or {transferFrom} are called.
     * This value changes when {approve} or {transferFrom} are called.
     */
     */
    function allowance(address owner, address spender) external view returns (uint256);
    function allowance(address owner, address spender) external view returns (uint256);
    /**
    /**
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     * @dev Sets `amount` as the allowance of `spender` over the caller's tokens.
     *
     *
     * Returns a boolean value indicating whether the operation succeeded.
     * Returns a boolean value indicating whether the operation succeeded.
     *
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * 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
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     *
     * Emits an {Approval} event.
     * Emits an {Approval} event.
     */
     */
    function approve(address spender, uint256 amount) external returns (bool);
    function approve(address spender, uint256 amount) external returns (bool);
    /**
    /**
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * @dev Moves `amount` tokens from `sender` to `recipient` using the
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance mechanism. `amount` is then deducted from the caller's
     * allowance.
     * allowance.
     *
     *
     * Returns a boolean value indicating whether the operation succeeded.
     * Returns a boolean value indicating whether the operation succeeded.
     *
     *
     * Emits a {Transfer} event.
     * Emits a {Transfer} event.
     */
     */
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    /**
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     * another (`to`).
     *
     *
     * Note that `value` may be zero.
     * Note that `value` may be zero.
     */
     */
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Transfer(address indexed from, address indexed to, uint256 value);
    /**
    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     * a call to {approve}. `value` is the new allowance.
     */
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);
}
}
// File: openzeppelin-solidity/contracts/GSN/Context.sol
// File: openzeppelin-solidity/contracts/GSN/Context.sol
pragma solidity ^0.5.0;
pragma solidity ^0.5.0;
/*
/*
 * @dev Provides information about the current execution context, including the
 * @dev Provides information about the current execution context, including the
 * sender of the transaction and its data. While these are generally available
 * 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
 * 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
 * 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
 * paying for execution may not be the actual sender (as far as an application
 * is concerned).
 * is concerned).
 *
 *
 * This contract is only required for intermediate, library-like contracts.
 * This contract is only required for intermediate, library-like contracts.
 */
 */
contract Context {
contract Context {
    // Empty internal constructor, to prevent people from mistakenly deploying
    // Empty internal constructor, to prevent people from mistakenly deploying
    // an instance of this contract, which should be used via inheritance.
    // an instance of this contract, which should be used via inheritance.
    constructor () internal { }
    constructor () internal { }
    // solhint-disable-previous-line no-empty-blocks
    // solhint-disable-previous-line no-empty-blocks
    function _msgSender() internal view returns (address payable) {
    function _msgSender() internal view returns (address payable) {
        return msg.sender;
        return msg.sender;
    }
    }
    function _msgData() internal view returns (bytes memory) {
    function _msgData() internal view returns (bytes memory) {
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        this; // silence state mutability warning without generating bytecode - see https://github.com/ethereum/solidity/issues/2691
        return msg.data;
        return msg.data;
    }
    }
}
}
// File: openzeppelin-solidity/contracts/ownership/Ownable.sol
// File: openzeppelin-solidity/contracts/ownership/Ownable.sol
pragma solidity ^0.5.0;
pragma solidity ^0.5.0;
/**
/**
 * @dev Contract module which provides a basic access control mechanism, where
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 * specific functions.
 *
 *
 * This module is used through inheritance. It will make available the modifier
 * 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
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 * the owner.
 */
 */
contract Ownable is Context {
contract Ownable is Context {
    address private _owner;
    address private _owner;
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
    /**
    /**
     * @dev Initializes the contract setting the deployer as the initial owner.
     * @dev Initializes the contract setting the deployer as the initial owner.
     */
     */
    constructor () internal {
    constructor () internal {
        _owner = _msgSender();
        _owner = _msgSender();
        emit OwnershipTransferred(address(0), _owner);
        emit OwnershipTransferred(address(0), _owner);
    }
    }
    /**
    /**
     * @dev Returns the address of the current owner.
     * @dev Returns the address of the current owner.
     */
     */
    function owner() public view returns (address) {
    function owner() public view returns (address) {
        return _owner;
        return _owner;
    }
    }
    /**
    /**
     * @dev Throws if called by any account other than the owner.
     * @dev Throws if called by any account other than the owner.
     */
     */
    modifier onlyOwner() {
    modifier onlyOwner() {
        require(isOwner(), "Ownable: caller is not the owner");
        require(isOwner(), "Ownable: caller is not the owner");
        _;
        _;
    }
    }
    /**
    /**
     * @dev Returns true if the caller is the current owner.
     * @dev Returns true if the caller is the current owner.
     */
     */
    function isOwner() public view returns (bool) {
    function isOwner() public view returns (bool) {
        return _msgSender() == _owner;
        return _msgSender() == _owner;
    }
    }
    /**
    /**
     * @dev Leaves the contract without owner. It will not be possible to call
     * @dev Leaves the contract without owner. It will not be possible to call
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     * `onlyOwner` functions anymore. Can only be called by the current owner.
     *
     *
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * NOTE: Renouncing ownership will leave the contract without an owner,
     * thereby removing any functionality that is only available to the owner.
     * thereby removing any functionality that is only available to the owner.
     */
     */
    function renounceOwnership() public onlyOwner {
    function renounceOwnership() public onlyOwner {
        emit OwnershipTransferred(_owner, address(0));
        emit OwnershipTransferred(_owner, address(0));
        _owner = address(0);
        _owner = address(0);
    }
    }
    /**
    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     * Can only be called by the current owner.
     */
     */
    function transferOwnership(address newOwner) public onlyOwner {
    function transferOwnership(address newOwner) public onlyOwner {
        _transferOwnership(newOwner);
        _transferOwnership(newOwner);
    }
    }
    /**
    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     */
     */
    function _transferOwnership(address newOwner) internal {
    function _transferOwnership(address newOwner) internal {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
        _owner = newOwner;
    }
    }
}
}
// File: contracts/IStaking.sol
// File: contracts/IStaking.sol
pragma solidity 0.5.0;
pragma solidity 0.5.0;
/**
/**
 * @title Staking interface, as defined by EIP-900.
 * @title Staking interface, as defined by EIP-900.
 * @dev https://github.com/ethereum/EIPs/blob/master/EIPS/eip-900.md
 * @dev https://github.com/ethereum/EIPs/blob/master/EIPS/eip-900.md
 */
 */
contract IStaking {
contract IStaking {
    event Staked(address indexed user, uint256 amount, uint256 total, bytes data);
    event Staked(address indexed user, uint256 amount, uint256 total, bytes data);
    event Unstaked(address indexed user, uint256 amount, uint256 total, bytes data);
    event Unstaked(address indexed user, uint256 amount, uint256 total, bytes data);
    function stake(uint256 amount, bytes calldata data) external;
    function stake(uint256 amount, bytes calldata data) external;
    function stakeFor(address user, uint256 amount, bytes calldata data) external;
    function stakeFor(address user, uint256 amount, bytes calldata data) external;
    function unstake(uint256 amount, bytes calldata data) external;
    function unstake(uint256 amount, bytes calldata data) external;
    function totalStakedFor(address addr) public view returns (uint256);
    function totalStakedFor(address addr) public view returns (uint256);
    function totalStaked() public view returns (uint256);
    function totalStaked() public view returns (uint256);
    function token() external view returns (address);
    function token() external view returns (address);
    /**
    /**
     * @return False. This application does not support staking history.
     * @return False. This application does not support staking history.
     */
     */
    function supportsHistory() external pure returns (bool) {
    function supportsHistory() external pure returns (bool) {
        return false;
        return false;
    }
    }
}
}
// File: contracts/TokenPool.sol
// File: contracts/TokenPool.sol
pragma solidity 0.5.0;
pragma solidity 0.5.0;
/**
/**
 * @title A simple holder of tokens.
 * @title A simple holder of tokens.
 * This is a simple contract to hold tokens. It's useful in the case where a separate contract
 * This is a simple contract to hold tokens. It's useful in the case where a separate contract
 * needs to hold multiple distinct pools of the same token.
 * needs to hold multiple distinct pools of the same token.
 */
 */
contract TokenPool is Ownable {
contract TokenPool is Ownable {
    IERC20 public token;
    IERC20 public token;
    constructor(IERC20 _token) public {
    constructor(IERC20 _token) public {
        token = _token;
        token = _token;
    }
    }
    function balance() public view returns (uint256) {
    function balance() public view returns (uint256) {
        return token.balanceOf(address(this));
        return token.balanceOf(address(this));
    }
    }
    function transfer(address to, uint256 value) external onlyOwner returns (bool) {
    function transfer(address to, uint256 value) external onlyOwner returns (bool) {
        return token.transfer(to, value);
        return token.transfer(to, value);
    }
    }
}
}
// File: contracts/TokenGeyser.sol
// File: contracts/TokenGeyser.sol
pragma solidity 0.5.0;
pragma solidity 0.5.0;
/**
/**
 * @title Token Geyser
 * @title Token Geyser
 * @dev A smart-contract based mechanism to distribute tokens over time, inspired loosely by
 * @dev A smart-contract based mechanism to distribute tokens over time, inspired loosely by
 *      Compound and Uniswap.
 *      Compound and Uniswap.
 *
 *
 *      Distribution tokens are added to a locked pool in the contract and become unlocked over time
 *      Distribution tokens are added to a locked pool in the contract and become unlocked over time
 *      according to a once-configurable unlock schedule. Once unlocked, they are available to be
 *      according to a once-configurable unlock schedule. Once unlocked, they are available to be
 *      claimed by users.
 *      claimed by users.
 *
 *
 *      A user may deposit tokens to accrue ownership share over the unlocked pool. This owner share
 *      A user may deposit tokens to accrue ownership share over the unlocked pool. This owner share
 *      is a function of the number of tokens deposited as well as the length of time deposited.
 *      is a function of the number of tokens deposited as well as the length of time deposited.
 *      Specifically, a user's share of the currently-unlocked pool equals their "deposit-seconds"
 *      Specifically, a user's share of the currently-unlocked pool equals their "deposit-seconds"
 *      divided by the global "deposit-seconds". This aligns the new token distribution with long
 *      divided by the global "deposit-seconds". This aligns the new token distribution with long
 *      term supporters of the project, addressing one of the major drawbacks of simple airdrops.
 *      term supporters of the project, addressing one of the major drawbacks of simple airdrops.
 *
 *
 *      More background and motivation available at:
 *      More background and motivation available at:
 *      https://github.com/ampleforth/RFCs/blob/master/RFCs/rfc-1.md
 *      https://github.com/ampleforth/RFCs/blob/master/RFCs/rfc-1.md
 */
 */
contract TokenGeyser is IStaking, Ownable {
contract TokenGeyser is IStaking, Ownable {
    using SafeMath for uint256;
    using SafeMath for uint256;
    event Staked(address indexed user, uint256 amount, uint256 total, bytes data);
    event Staked(address indexed user, uint256 amount, uint256 total, bytes data);
    event Unstaked(address indexed user, uint256 amount, uint256 total, bytes data);
    event Unstaked(address indexed user, uint256 amount, uint256 total, bytes data);
    event TokensClaimed(address indexed user, uint256 amount);
    event TokensClaimed(address indexed user, uint256 amount);
    event TokensLocked(uint256 amount, uint256 durationSec, uint256 total);
    event TokensLocked(uint256 amount, uint256 durationSec, uint256 total);
    // amount: Unlocked tokens, total: Total locked tokens
    // amount: Unlocked tokens, total: Total locked tokens
    event TokensUnlocked(uint256 amount, uint256 total);
    event TokensUnlocked(uint256 amount, uint256 total);
    TokenPool private _stakingPool;
    TokenPool private _stakingPool;
    TokenPool private _unlockedPool;
    TokenPool private _unlockedPool;
    TokenPool private _lockedPool;
    TokenPool private _lockedPool;
    //
    //
    // Time-bonus params
    // Time-bonus params
    //
    //
    uint256 public constant BONUS_DECIMALS = 2;
    uint256 public constant BONUS_DECIMALS = 2;
    uint256 public startBonus = 0;
    uint256 public startBonus = 0;
    uint256 public bonusPeriodSec = 0;
    uint256 public bonusPeriodSec = 0;
    //
    //
    // Global accounting state
    // Global accounting state
    //
    //
    uint256 public totalLockedShares = 0;
    uint256 public totalLockedShares = 0;
    uint256 public totalStakingShares = 0;
    uint256 public totalStakingShares = 0;
    uint256 private _totalStakingShareSeconds = 0;
    uint256 private _totalStakingShareSeconds = 0;
    uint256 private _lastAccountingTimestampSec = now;
    uint256 private _lastAccountingTimestampSec = now;
    uint256 private _maxUnlockSchedules = 0;
    uint256 private _maxUnlockSchedules = 0;
    uint256 private _initialSharesPerToken = 0;
    uint256 private _initialSharesPerToken = 0;
    //
    //
    // User accounting state
    // User accounting state
    //
    //
    // Represents a single stake for a user. A user may have multiple.
    // Represents a single stake for a user. A user may have multiple.
    struct Stake {
    struct Stake {
        uint256 stakingShares;
        uint256 stakingShares;
        uint256 timestampSec;
        uint256 timestampSec;
    }
    }
    // Caches aggregated values from the User->Stake[] map to save computation.
    // Caches aggregated values from the User->Stake[] map to save computation.
    // If lastAccountingTimestampSec is 0, there's no entry for that user.
    // If lastAccountingTimestampSec is 0, there's no entry for that user.
    struct UserTotals {
    struct UserTotals {
        uint256 stakingShares;
        uint256 stakingShares;
        uint256 stakingShareSeconds;
        uint256 stakingShareSeconds;
        uint256 lastAccountingTimestampSec;
        uint256 lastAccountingTimestampSec;
    }
    }
    // Aggregated staking values per user
    // Aggregated staking values per user
    mapping(address => UserTotals) private _userTotals;
    mapping(address => UserTotals) private _userTotals;
    // The collection of stakes for each user. Ordered by timestamp, earliest to latest.
    // The collection of stakes for each user. Ordered by timestamp, earliest to latest.
    mapping(address => Stake[]) private _userStakes;
    mapping(address => Stake[]) private _userStakes;
    //
    //
    // Locked/Unlocked Accounting state
    // Locked/Unlocked Accounting state
    //
    //
    struct UnlockSchedule {
    struct UnlockSchedule {
        uint256 initialLockedShares;
        uint256 initialLockedShares;
        uint256 unlockedShares;
        uint256 unlockedShares;
        uint256 lastUnlockTimestampSec;
        uint256 lastUnlockTimestampSec;
        uint256 endAtSec;
        uint256 endAtSec;
        uint256 durationSec;
        uint256 durationSec;
    }
    }
    UnlockSchedule[] public unlockSchedules;
    UnlockSchedule[] public unlockSchedules;
    /**
    /**
     * @param stakingToken The token users deposit as stake.
     * @param stakingToken The token users deposit as stake.
     * @param distributionToken The token users receive as they unstake.
     * @param distributionToken The token users receive as they unstake.
     * @param maxUnlockSchedules Max number of unlock stages, to guard against hitting gas limit.
     * @param maxUnlockSchedules Max number of unlock stages, to guard against hitting gas limit.
     * @param startBonus_ Starting time bonus, BONUS_DECIMALS fixed point.
     * @param startBonus_ Starting time bonus, BONUS_DECIMALS fixed point.
     *                    e.g. 25% means user gets 25% of max distribution tokens.
     *                    e.g. 25% means user gets 25% of max distribution tokens.
     * @param bonusPeriodSec_ Length of time for bonus to increase linearly to max.
     * @param bonusPeriodSec_ Length of time for bonus to increase linearly to max.
     * @param initialSharesPerToken Number of shares to mint per staking token on first stake.
     * @param initialSharesPerToken Number of shares to mint per staking token on first stake.
     */
     */
    constructor(IERC20 stakingToken, IERC20 distributionToken, uint256 maxUnlockSchedules,
    constructor(IERC20 stakingToken, IERC20 distributionToken, uint256 maxUnlockSchedules,
                uint256 startBonus_, uint256 bonusPeriodSec_, uint256 initialSharesPerToken) public {
                uint256 startBonus_, uint256 bonusPeriodSec_, uint256 initialSharesPerToken) public {
        // The start bonus must be some fraction of the max. (i.e. <= 100%)
        // The start bonus must be some fraction of the max. (i.e. <= 100%)
        require(startBonus_ <= 10**BONUS_DECIMALS, 'TokenGeyser: start bonus too high');
        require(startBonus_ <= 10**BONUS_DECIMALS, 'TokenGeyser: start bonus too high');
        // If no period is desired, instead set startBonus = 100%
        // If no period is desired, instead set startBonus = 100%
        // and bonusPeriod to a small value like 1sec.
        // and bonusPeriod to a small value like 1sec.
        require(bonusPeriodSec_ != 0, 'TokenGeyser: bonus period is zero');
        require(bonusPeriodSec_ != 0, 'TokenGeyser: bonus period is zero');
        require(initialSharesPerToken > 0, 'TokenGeyser: initialSharesPerToken is zero');
        require(initialSharesPerToken > 0, 'TokenGeyser: initialSharesPerToken is zero');
        _stakingPool = new TokenPool(stakingToken);
        _stakingPool = new TokenPool(stakingToken);
        _unlockedPool = new TokenPool(distributionToken);
        _unlockedPool = new TokenPool(distributionToken);
        _lockedPool = new TokenPool(distributionToken);
        _lockedPool = new TokenPool(distributionToken);
        startBonus = startBonus_;
        startBonus = startBonus_;
        bonusPeriodSec = bonusPeriodSec_;
        bonusPeriodSec = bonusPeriodSec_;
        _maxUnlockSchedules = maxUnlockSchedules;
        _maxUnlockSchedules = maxUnlockSchedules;
        _initialSharesPerToken = initialSharesPerToken;
        _initialSharesPerToken = initialSharesPerToken;
    }
    }
    /**
    /**
     * @return The token users deposit as stake.
     * @return The token users deposit as stake.
     */
     */
    function getStakingToken() public view returns (IERC20) {
    function getStakingToken() public view returns (IERC20) {
        return _stakingPool.token();
        return _stakingPool.token();
    }
    }
    /**
    /**
     * @return The token users receive as they unstake.
     * @return The token users receive as they unstake.
     */
     */
    function getDistributionToken() public view returns (IERC20) {
    function getDistributionToken() public view returns (IERC20) {
        assert(_unlockedPool.token() == _lockedPool.token());
        assert(_unlockedPool.token() == _lockedPool.token());
        return _unlockedPool.token();
        return _unlockedPool.token();
    }
    }
    /**
    /**
     * @dev Transfers amount of deposit tokens from the user.
     * @dev Transfers amount of deposit tokens from the user.
     * @param amount Number of deposit tokens to stake.
     * @param amount Number of deposit tokens to stake.
     * @param data Not used.
     * @param data Not used.
     */
     */
    function stake(uint256 amount, bytes calldata data) external {
    function stake(uint256 amount, bytes calldata data) external {
        _stakeFor(msg.sender, msg.sender, amount);
        _stakeFor(msg.sender, msg.sender, amount);
    }
    }
    /**
    /**
     * @dev Transfers amount of deposit tokens from the caller on behalf of user.
     * @dev Transfers amount of deposit tokens from the caller on behalf of user.
     * @param user User address who gains credit for this stake operation.
     * @param user User address who gains credit for this stake operation.
     * @param amount Number of deposit tokens to stake.
     * @param amount Number of deposit tokens to stake.
     * @param data Not used.
     * @param data Not used.
     */
     */
    function stakeFor(address user, uint256 amount, bytes calldata data) external onlyOwner {
    function stakeFor(address user, uint256 amount, bytes calldata data) external onlyOwner {
        _stakeFor(msg.sender, user, amount);
        _stakeFor(msg.sender, user, amount);
    }
    }
    /**
    /**
     * @dev Private implementation of staking methods.
     * @dev Private implementation of staking methods.
     * @param staker User address who deposits tokens to stake.
     * @param staker User address who deposits tokens to stake.
     * @param beneficiary User address who gains credit for this stake operation.
     * @param beneficiary User address who gains credit for this stake operation.
     * @param amount Number of deposit tokens to stake.
     * @param amount Number of deposit tokens to stake.
     */
     */
    function _stakeFor(address staker, address beneficiary, uint256 amount) private {
    function _stakeFor(address staker, address beneficiary, uint256 amount) private {
        require(amount > 0, 'TokenGeyser: stake amount is zero');
        require(amount > 0, 'TokenGeyser: stake amount is zero');
        require(beneficiary != address(0), 'TokenGeyser: beneficiary is zero address');
        require(beneficiary != address(0), 'TokenGeyser: beneficiary is zero address');
        require(totalStakingShares == 0 || totalStaked() > 0,
        require(totalStakingShares == 0 || totalStaked() > 0,
                'TokenGeyser: Invalid state. Staking shares exist, but no staking tokens do');
                'TokenGeyser: Invalid state. Staking shares exist, but no staking tokens do');
        uint256 mintedStakingShares = (totalStakingShares > 0)
        uint256 mintedStakingShares = (totalStakingShares > 0)
            ? totalStakingShares.mul(amount).div(totalStaked())
            ? totalStakingShares.mul(amount).div(totalStaked())
            : amount.mul(_initialSharesPerToken);
            : amount.mul(_initialSharesPerToken);
        require(mintedStakingShares > 0, 'TokenGeyser: Stake amount is too small');
        require(mintedStakingShares > 0, 'TokenGeyser: Stake amount is too small');
        updateAccounting();
        updateAccounting();
        // 1. User Accounting
        // 1. User Accounting
        UserTotals storage totals = _userTotals[beneficiary];
        UserTotals storage totals = _userTotals[beneficiary];
        totals.stakingShares = totals.stakingShares.add(mintedStakingShares);
        totals.stakingShares = totals.stakingShares.add(mintedStakingShares);
        totals.lastAccountingTimestampSec = now;
        totals.lastAccountingTimestampSec = now;
        Stake memory newStake = Stake(mintedStakingShares, now);
        Stake memory newStake = Stake(mintedStakingShares, now);
        _userStakes[beneficiary].push(newStake);
        _userStakes[beneficiary].push(newStake);
        // 2. Global Accounting
        // 2. Global Accounting
        totalStakingShares = totalStakingShares.add(mintedStakingShares);
        totalStakingShares = totalStakingShares.add(mintedStakingShares);
        // Already set in updateAccounting()
        // Already set in updateAccounting()
        // _lastAccountingTimestampSec = now;
        // _lastAccountingTimestampSec = now;
        // interactions
        // interactions
        require(_stakingPool.token().transferFrom(staker, address(_stakingPool), amount),
        require(_stakingPool.token().transferFrom(staker, address(_stakingPool), amount),
            'TokenGeyser: transfer into staking pool failed');
            'TokenGeyser: transfer into staking pool failed');
        emit Staked(beneficiary, amount, totalStakedFor(beneficiary), "");
        emit Staked(beneficiary, amount, totalStakedFor(beneficiary), "");
    }
    }
    /**
    /**
     * @dev Unstakes a certain amount of previously deposited tokens. User also receives their
     * @dev Unstakes a certain amount of previously deposited tokens. User also receives their
     * alotted number of distribution tokens.
     * alotted number of distribution tokens.
     * @param amount Number of deposit tokens to unstake / withdraw.
     * @param amount Number of deposit tokens to unstake / withdraw.
     * @param data Not used.
     * @param data Not used.
     */
     */
    function unstake(uint256 amount, bytes calldata data) external {
    function unstake(uint256 amount, bytes calldata data) external {
        _unstake(amount);
        _unstake(amount);
    }
    }
    /**
    /**
     * @param amount Number of deposit tokens to unstake / withdraw.
     * @param amount Number of deposit tokens to unstake / withdraw.
     * @return The total number of distribution tokens that would be rewarded.
     * @return The total number of distribution tokens that would be rewarded.
     */
     */
    function unstakeQuery(uint256 amount) public returns (uint256) {
    function unstakeQuery(uint256 amount) public returns (uint256) {
        return _unstake(amount);
        return _unstake(amount);
    }
    }
    /**
    /**
     * @dev Unstakes a certain amount of previously deposited tokens. User also receives their
     * @dev Unstakes a certain amount of previously deposited tokens. User also receives their
     * alotted number of distribution tokens.
     * alotted number of distribution tokens.
     * @param amount Number of deposit tokens to unstake / withdraw.
     * @param amount Number of deposit tokens to unstake / withdraw.
     * @return The total number of distribution tokens rewarded.
     * @return The total number of distribution tokens rewarded.
     */
     */
    function _unstake(uint256 amount) private returns (uint256) {
    function _unstake(uint256 amount) private returns (uint256) {
        updateAccounting();
        updateAccounting();
        // checks
        // checks
        require(amount > 0, 'TokenGeyser: unstake amount is zero');
        require(amount > 0, 'TokenGeyser: unstake amount is zero');
        require(totalStakedFor(msg.sender) >= amount,
        require(totalStakedFor(msg.sender) >= amount,
            'TokenGeyser: unstake amount is greater than total user stakes');
            'TokenGeyser: unstake amount is greater than total user stakes');
        uint256 stakingSharesToBurn = totalStakingShares.mul(amount).div(totalStaked());
        uint256 stakingSharesToBurn = totalStakingShares.mul(amount).div(totalStaked());
        require(stakingSharesToBurn > 0, 'TokenGeyser: Unable to unstake amount this small');
        require(stakingSharesToBurn > 0, 'TokenGeyser: Unable to unstake amount this small');
        // 1. User Accounting
        // 1. User Accounting
        UserTotals storage totals = _userTotals[msg.sender];
        UserTotals storage totals = _userTotals[msg.sender];
        Stake[] storage accountStakes = _userStakes[msg.sender];
        Stake[] storage accountStakes = _userStakes[msg.sender];
        // Redeem from most recent stake and go backwards in time.
        // Redeem from most recent stake and go backwards in time.
        uint256 stakingShareSecondsToBurn = 0;
        uint256 stakingShareSecondsToBurn = 0;
        uint256 sharesLeftToBurn = stakingSharesToBurn;
        uint256 sharesLeftToBurn = stakingSharesToBurn;
        uint256 rewardAmount = 0;
        uint256 rewardAmount = 0;
        while (sharesLeftToBurn > 0) {
        while (sharesLeftToBurn > 0) {
            Stake storage lastStake = accountStakes[accountStakes.length - 1];
            Stake storage lastStake = accountStakes[accountStakes.length - 1];
            uint256 stakeTimeSec = now.sub(lastStake.timestampSec);
            uint256 stakeTimeSec = now.sub(lastStake.timestampSec);
            uint256 newStakingShareSecondsToBurn = 0;
            uint256 newStakingShareSecondsToBurn = 0;
            if (lastStake.stakingShares <= sharesLeftToBurn) {
            if (lastStake.stakingShares <= sharesLeftToBurn) {
                // fully redeem a past stake
                // fully redeem a past stake
                newStakingShareSecondsToBurn = lastStake.stakingShares.mul(stakeTimeSec);
                newStakingShareSecondsToBurn = lastStake.stakingShares.mul(stakeTimeSec);
                rewardAmount = computeNewReward(rewardAmount, newStakingShareSecondsToBurn, stakeTimeSec);
                rewardAmount = computeNewReward(rewardAmount, newStakingShareSecondsToBurn, stakeTimeSec);
                stakingShareSecondsToBurn = stakingShareSecondsToBurn.add(newStakingShareSecondsToBurn);
                stakingShareSecondsToBurn = stakingShareSecondsToBurn.add(newStakingShareSecondsToBurn);
                sharesLeftToBurn = sharesLeftToBurn.sub(lastStake.stakingShares);
                sharesLeftToBurn = sharesLeftToBurn.sub(lastStake.stakingShares);
                accountStakes.length--;
                accountStakes.length--;
            } else {
            } else {
                // partially redeem a past stake
                // partially redeem a past stake
                newStakingShareSecondsToBurn = sharesLeftToBurn.mul(stakeTimeSec);
                newStakingShareSecondsToBurn = sharesLeftToBurn.mul(stakeTimeSec);
                rewardAmount = computeNewReward(rewardAmount, newStakingShareSecondsToBurn, stakeTimeSec);
                rewardAmount = computeNewReward(rewardAmount, newStakingShareSecondsToBurn, stakeTimeSec);
                stakingShareSecondsToBurn = stakingShareSecondsToBurn.add(newStakingShareSecondsToBurn);
                stakingShareSecondsToBurn = stakingShareSecondsToBurn.add(newStakingShareSecondsToBurn);
                lastStake.stakingShares = lastStake.stakingShares.sub(sharesLeftToBurn);
                lastStake.stakingShares = lastStake.stakingShares.sub(sharesLeftToBurn);
                sharesLeftToBurn = 0;
                sharesLeftToBurn = 0;
            }
            }
        }
        }
        totals.stakingShareSeconds = totals.stakingShareSeconds.sub(stakingShareSecondsToBurn);
        totals.stakingShareSeconds = totals.stakingShareSeconds.sub(stakingShareSecondsToBurn);
        totals.stakingShares = totals.stakingShares.sub(stakingSharesToBurn);
        totals.stakingShares = totals.stakingShares.sub(stakingSharesToBurn);
        // Already set in updateAccounting
        // Already set in updateAccounting
        // totals.lastAccountingTimestampSec = now;
        // totals.lastAccountingTimestampSec = now;
        // 2. Global Accounting
        // 2. Global Accounting
        _totalStakingShareSeconds = _totalStakingShareSeconds.sub(stakingShareSecondsToBurn);
        _totalStakingShareSeconds = _totalStakingShareSeconds.sub(stakingShareSecondsToBurn);
        totalStakingShares = totalStakingShares.sub(stakingSharesToBurn);
        totalStakingShares = totalStakingShares.sub(stakingSharesToBurn);
        // Already set in updateAccounting
        // Already set in updateAccounting
        // _lastAccountingTimestampSec = now;
        // _lastAccountingTimestampSec = now;
        // interactions
        // interactions
        require(_stakingPool.transfer(msg.sender, amount),
        require(_stakingPool.transfer(msg.sender, amount),
            'TokenGeyser: transfer out of staking pool failed');
            'TokenGeyser: transfer out of staking pool failed');
        require(_unlockedPoo
        require(_unlockedPool.transfer(msg.sender, rewardAmount),
            'TokenGeyser: transfer out of unlocked pool failed');
        emit Unstaked(msg.sen