// File: src/Distributor.sol



// SPDX-License-Identifier: AGPL-3.0-or-later

pragma solidity 0.7.5;

import "./lib/SafeERC20.sol";
import "./lib/SafeMath.sol";
import "./lib/Address.sol";
import "./lib/IERC20.sol";
import "./lib/ITreasury.sol";
import "./Policy.sol";
import "./lib/IStaking.sol";

contract Distributor is Policy {
    using SafeMath for uint;
    using SafeMath for uint32;
    using SafeERC20 for IERC20;

    /* ====== VARIABLES ====== */

    address public immutable SYNC;
    address public immutable treasury;

    uint32 public immutable epochLength;
    uint32 public nextEpochTime;

    mapping(uint => Adjust) public adjustments;

    /* ====== STRUCTS ====== */

    struct Info {
        uint rate; // in ten-thousandths ( 5000 = 0.5% )
        address recipient;
    }
    Info[] public info;

    struct Adjust {
        bool add;
        uint rate;
        uint target;
    }

    /* ====== CONSTRUCTOR ====== */

    constructor(
        address _treasury,
        address _sync,
        uint32 _epochLength,
        uint32 _nextEpochTime
    ) {
        require(_treasury != address(0));
        treasury = _treasury;
        require(_sync != address(0));
        SYNC = _sync;
        epochLength = _epochLength;
        nextEpochTime = _nextEpochTime;
    }

    /* ====== PUBLIC FUNCTIONS ====== */

    /**
        @notice send epoch reward to staking contract
     */
    function distribute() external returns (bool) {
        if (nextEpochTime <= uint32(block.timestamp)) {
            nextEpochTime = nextEpochTime.add32(epochLength);

            for (uint i = 0; i < info.length; i++) {
                if (info[i].rate > 0) {
                    ITreasury(treasury).mintRewards(
                        info[i].recipient,
                        nextRewardAt(info[i].rate)
                    );
                    adjust(i);
                }
            }
            return true;
        } else {
            return false;
        }
    }

    /* ====== INTERNAL FUNCTIONS ====== */

    /**
        @notice increment reward rate for collector
     */
    function adjust(uint _index) internal {
        Adjust memory adjustment = adjustments[_index];
        if (adjustment.rate != 0) {
            if (adjustment.add) {
                // if rate should increase
                info[_index].rate = info[_index].rate.add(adjustment.rate); // raise rate
                if (info[_index].rate >= adjustment.target) {
                    // if target met
                    adjustments[_index].rate = 0; // turn off adjustment
                }
            } else {
                // if rate should decrease
                info[_index].rate = info[_index].rate.sub(adjustment.rate); // lower rate
                if (info[_index].rate <= adjustment.target) {
                    // if target met
                    adjustments[_index].rate = 0; // turn off adjustment
                }
            }
        }
    }

    /* ====== VIEW FUNCTIONS ====== */

    /**
        @notice view function for next reward at given rate
        @param _rate uint
        @return uint
     */
    function nextRewardAt(uint _rate) public view returns (uint) {
        return IERC20(SYNC).totalSupply().mul(_rate).div(1000000);
    }

    /**
        @notice view function for next reward for specified address
        @param _recipient address
        @return uint
     */
    function nextRewardFor(address _recipient) public view returns (uint) {
        uint reward;
        for (uint i = 0; i < info.length; i++) {
            if (info[i].recipient == _recipient) {
                reward = nextRewardAt(info[i].rate);
            }
        }
        return reward;
    }

    /* ====== POLICY FUNCTIONS ====== */

    /**
        @notice adds recipient for distributions
        @param _recipient address
        @param _rewardRate uint
     */
    function addRecipient(
        address _recipient,
        uint _rewardRate
    ) external onlyPolicy {
        require(_recipient != address(0));
        info.push(Info({recipient: _recipient, rate: _rewardRate}));
    }

    /**
        @notice removes recipient for distributions
        @param _index uint
        @param _recipient address
     */
    function removeRecipient(
        uint _index,
        address _recipient
    ) external onlyPolicy {
        require(_recipient == info[_index].recipient);
        info[_index].recipient = address(0);
        info[_index].rate = 0;
    }

    /**
        @notice set adjustment info for a collector's reward rate
        @param _index uint
        @param _add bool
        @param _rate uint
        @param _target uint
     */
    function setAdjustment(
        uint _index,
        bool _add,
        uint _rate,
        uint _target
    ) external onlyPolicy {
        adjustments[_index] = Adjust({add: _add, rate: _rate, target: _target});
    }
}

// File: src/lib/SafeERC20.sol



// SPDX-License-Identifier: AGPL-3.0-or-later
pragma solidity 0.7.5;
import "./SafeMath.sol";
import "./Address.sol";
import "./IERC20.sol";

library SafeERC20 {
    using SafeMath for uint256;
    using Address for address;

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transfer.selector, to, value));
    }

    function safeTransferFrom(IERC20 token, address from, address to, uint256 value) internal {
        callOptionalReturn(token, abi.encodeWithSelector(token.transferFrom.selector, from, to, value));
    }

    function safeApprove(IERC20 token, address spender, uint256 value) internal {
        // safeApprove should only be called when setting an initial allowance,
        // or when resetting it to zero. To increase and decrease it, use
        // 'safeIncreaseAllowance' and 'safeDecreaseAllowance'
        // solhint-disable-next-line max-line-length
        require((value == 0) || (token.allowance(address(this), spender) == 0),
            "SafeERC20: approve from non-zero to non-zero allowance"
        );
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, value));
    }

    function safeIncreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).add(value);
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    function safeDecreaseAllowance(IERC20 token, address spender, uint256 value) internal {
        uint256 newAllowance = token.allowance(address(this), spender).sub(value, "SafeERC20: decreased allowance below zero");
        callOptionalReturn(token, abi.encodeWithSelector(token.approve.selector, spender, newAllowance));
    }

    /**
     * @dev Imitates a Solidity high-level call (i.e. a regular function call to a contract), relaxing the requirement
     * on the return value: the return value is optional (but if data is returned, it must not be false).
     * @param token The token targeted by the call.
     * @param data The call data (encoded using abi.encode or one of its variants).
     */
    function callOptionalReturn(IERC20 token, bytes memory data) private {
        // We need to perform a low level call here, to bypass Solidity's return data size checking mechanism, since
        // we're implementing it ourselves.

        // A Solidity high level call has three parts:
        //  1. The target address is checked to verify it contains contract code
        //  2. The call itself is made, and success asserted
        //  3. The return value is decoded, which in turn checks the size of the returned data.
        // solhint-disable-next-line max-line-length
        require(address(token).isContract(), "SafeERC20: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = address(token).call(data);
        require(success, "SafeERC20: low-level call failed");

        if (returndata.length > 0) { // Return data is optional
            // solhint-disable-next-line max-line-length
            require(abi.decode(returndata, (bool)), "SafeERC20: ERC20 operation did not succeed");
        }
    }
}
// File: src/lib/SafeMath.sol



// SPDX-License-Identifier: AGPL-3.0-or-later
pragma solidity 0.7.5;

library SafeMath {
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    function add32(uint32 a, uint32 b) internal pure returns (uint32) {
        uint32 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    function sub(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    function sub32(uint32 a, uint32 b) internal pure returns (uint32) {
        return sub32(a, b, "SafeMath: subtraction overflow");
    }

    function sub32(
        uint32 a,
        uint32 b,
        string memory errorMessage
    ) internal pure returns (uint32) {
        require(b <= a, errorMessage);
        uint32 c = a - b;

        return c;
    }

    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    function mul32(uint32 a, uint32 b) internal pure returns (uint32) {
        if (a == 0) {
            return 0;
        }

        uint32 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    function div(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        uint256 c = a / b;
        // assert(a == b * c + a % b); // There is no case in which this doesn't hold

        return c;
    }

    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    function mod(
        uint256 a,
        uint256 b,
        string memory errorMessage
    ) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }

    function sqrrt(uint256 a) internal pure returns (uint c) {
        if (a > 3) {
            c = a;
            uint b = add(div(a, 2), 1);
            while (b < c) {
                c = b;
                b = div(add(div(a, b), b), 2);
            }
        } else if (a != 0) {
            c = 1;
        }
    }

    function percentageAmount(
        uint256 total_,
        uint8 percentage_
    ) internal pure returns (uint256 percentAmount_) {
        return div(mul(total_, percentage_), 1000);
    }

    function substractPercentage(
        uint256 total_,
        uint8 percentageToSub_
    ) internal pure returns (uint256 result_) {
        return sub(total_, div(mul(total_, percentageToSub_), 1000));
    }

    function percentageOfTotal(
        uint256 part_,
        uint256 total_
    ) internal pure returns (uint256 percent_) {
        return div(mul(part_, 100), total_);
    }

    function average(uint256 a, uint256 b) internal pure returns (uint256) {
        // (a + b) / 2 can overflow, so we distribute
        return (a / 2) + (b / 2) + (((a % 2) + (b % 2)) / 2);
    }

    function quadraticPricing(
        uint256 payment_,
        uint256 multiplier_
    ) internal pure returns (uint256) {
        return sqrrt(mul(multiplier_, payment_));
    }

    function bondingCurve(
        uint256 supply_,
        uint256 multiplier_
    ) internal pure returns (uint256) {
        return mul(multiplier_, supply_);
    }
}

// File: src/lib/Address.sol



// SPDX-License-Identifier: AGPL-3.0-or-later
pragma solidity 0.7.5;

library Address {
    /**
     * @dev Returns true if `account` is a contract.
     *
     * [IMPORTANT]
     * ====
     * It is unsafe to assume that an address for which this function returns
     * false is an externally-owned account (EOA) and not a contract.
     *
     * Among others, `isContract` will return false for the following
     * types of addresses:
     *
     *  - an externally-owned account
     *  - a contract in construction
     *  - an address where a contract will be created
     *  - an address where a contract lived, but was destroyed
     * ====
     */
    function isContract(address account) internal view returns (bool) {
        // This method relies in extcodesize, which returns 0 for contracts in
        // construction, since the code is only stored at the end of the
        // constructor execution.

        uint256 size;
        // solhint-disable-next-line no-inline-assembly
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    /**
     * @dev Replacement for Solidity's `transfer`: sends `amount` wei to
     * `recipient`, forwarding all available gas and reverting on errors.
     *
     * https://eips.ethereum.org/EIPS/eip-1884[EIP1884] increases the gas cost
     * of certain opcodes, possibly making contracts go over the 2300 gas limit
     * imposed by `transfer`, making them unable to receive funds via
     * `transfer`. {sendValue} removes this limitation.
     *
     * https://diligence.consensys.net/posts/2019/09/stop-using-soliditys-transfer-now/[Learn more].
     *
     * IMPORTANT: because control is transferred to `recipient`, care must be
     * taken to not create reentrancy vulnerabilities. Consider using
     * {ReentrancyGuard}
     */
    function sendValue(address payable recipient, uint256 amount) internal {
        require(
            address(this).balance >= amount,
            "Address: insufficient balance"
        );

        // solhint-disable-next-line avoid-low-level-calls, avoid-call-value
        (bool success, ) = recipient.call{value: amount}("");
        require(
            success,
            "Address: unable to send value, recipient may have reverted"
        );
    }

    /**
     * @dev Performs a Solidity function call using a low level `call`. A
     * plain`call` is an unsafe replacement for a function call: use this
     * function instead.
     *
     * If `target` reverts with a revert reason, it is bubbled up by this
     * function (like regular Solidity function calls).
     *
     * Requirements:
     *
     * - `target` must be a contract.
     * - calling `target` with `data` must not revert.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data
    ) internal returns (bytes memory) {
        return functionCall(target, data, "Address: low-level call failed");
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`], but with
     * `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but also transferring `value` wei to `target`.
     *
     * Requirements:
     *
     * - the calling contract must have an ETH balance of at least `value`.
     * - the called Solidity function must be `payable`.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return
            functionCallWithValue(
                target,
                data,
                value,
                "Address: low-level call with value failed"
            );
    }

    /**
     * @dev Same as {xref-Address-functionCallWithValue-address-bytes-uint256-}[`functionCallWithValue`], but
     * with `errorMessage` as a fallback revert reason when `target` reverts.
     *
     * _Available since v3.1._
     */
    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(
            address(this).balance >= value,
            "Address: insufficient balance for call"
        );
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{value: value}(
            data
        );
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _functionCallWithValue(
        address target,
        bytes memory data,
        uint256 weiValue,
        string memory errorMessage
    ) private returns (bytes memory) {
        require(isContract(target), "Address: call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.call{value: weiValue}(
            data
        );
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data
    ) internal view returns (bytes memory) {
        return
            functionStaticCall(
                target,
                data,
                "Address: low-level static call failed"
            );
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a static call.
     *
     * _Available since v3.3._
     */
    function functionStaticCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal view returns (bytes memory) {
        require(isContract(target), "Address: static call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.staticcall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.3._
     */
    function functionDelegateCall(
        address target,
        bytes memory data
    ) internal returns (bytes memory) {
        return
            functionDelegateCall(
                target,
                data,
                "Address: low-level delegate call failed"
            );
    }

    /**
     * @dev Same as {xref-Address-functionCall-address-bytes-string-}[`functionCall`],
     * but performing a delegate call.
     *
     * _Available since v3.3._
     */
    function functionDelegateCall(
        address target,
        bytes memory data,
        string memory errorMessage
    ) internal returns (bytes memory) {
        require(isContract(target), "Address: delegate call to non-contract");

        // solhint-disable-next-line avoid-low-level-calls
        (bool success, bytes memory returndata) = target.delegatecall(data);
        return _verifyCallResult(success, returndata, errorMessage);
    }

    function _verifyCallResult(
        bool success,
        bytes memory returndata,
        string memory errorMessage
    ) private pure returns (bytes memory) {
        if (success) {
            return returndata;
        } else {
            // Look for revert reason and bubble it up if present
            if (returndata.length > 0) {
                // The easiest way to bubble the revert reason is using memory via assembly

                // solhint-disable-next-line no-inline-assembly
                assembly {
                    let returndata_size := mload(returndata)
                    revert(add(32, returndata), returndata_size)
                }
            } else {
                revert(errorMessage);
            }
        }
    }

    function addressToString(
        address _address
    ) internal pure returns (string memory) {
        bytes32 _bytes = bytes32(uint256(_address));
        bytes memory HEX = "0123456789abcdef";
        bytes memory _addr = new bytes(42);

        _addr[0] = "0";
        _addr[1] = "x";

        for (uint256 i = 0; i < 20; i++) {
            _addr[2 + i * 2] = HEX[uint8(_bytes[i + 12] >> 4)];
            _addr[3 + i * 2] = HEX[uint8(_bytes[i + 12] & 0x0f)];
        }

        return string(_addr);
    }
}

// File: src/lib/IERC20.sol



// SPDX-License-Identifier: AGPL-3.0-or-later
pragma solidity 0.7.5;

interface IERC20 {
    function decimals() external view returns (uint8);

    /**
     * @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
    );
}

// File: src/lib/ITreasury.sol



// SPDX-License-Identifier: AGPL-3.0-or-later
pragma solidity 0.7.5;

interface ITreasury {
    function deposit(
        uint _amount,
        address _token,
        uint _profit
    ) external returns (uint send_);

    function withdraw(uint _amount, address _token) external;

    function incurDebt(uint _amount, address _token) external;

    function repayDebtWithReserve(uint _amount, address _token) external;

    function repayDebtWithOHM(uint _amount) external;

    function manage(address _token, uint _amount) external;

    function mintRewards(address _recipient, uint _amount) external;

    function auditReserves() external;

    function totalReserves() external view returns (uint);

    function totalDebt() external view returns (uint);

    function excessReserves() external view returns (uint);

    function valueOf(
        address _token,
        uint _amount
    ) external view returns (uint value_);
}

// File: src/Policy.sol



// SPDX-License-Identifier: AGPL-3.0-or-later
pragma solidity 0.7.5;

import "./lib/IPolicy.sol";

contract Policy is IPolicy {
    address internal _policy;
    address internal _newPolicy;

    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );

    constructor() {
        _policy = msg.sender;
        emit OwnershipTransferred(address(0), _policy);
    }

    function policy() public view override returns (address) {
        return _policy;
    }

    modifier onlyPolicy() {
        require(_policy == msg.sender, "Ownable: caller is not the owner");
        _;
    }

    function renouncePolicy() public virtual override onlyPolicy {
        emit OwnershipTransferred(_policy, address(0));
        _policy = address(0);
    }

    function pushPolicy(address newPolicy_) public virtual override onlyPolicy {
        require(
            newPolicy_ != address(0),
            "Ownable: new owner is the zero address"
        );
        _newPolicy = newPolicy_;
    }

    function pullPolicy() public virtual override {
        require(msg.sender == _newPolicy);
        emit OwnershipTransferred(_policy, _newPolicy);
        _policy = _newPolicy;
    }
}

// File: src/lib/IStaking.sol



// SPDX-License-Identifier: AGPL-3.0-or-later
pragma solidity 0.7.5;

interface IStaking {
    function stake(uint _amount, address _recipient) external returns (bool);

    function claim(address _recipient) external;

    struct Epoch {
        uint number;
        uint distribute;
        uint32 length;
        uint32 endTime;
    }


    function setEpochDistribution(uint _amount) external;


}

// File: src/lib/IPolicy.sol



// SPDX-License-Identifier: AGPL-3.0-or-later

pragma solidity 0.7.5;


interface IPolicy {

    function policy() external view returns (address);

    function renouncePolicy() external;
  
    function pushPolicy( address newPolicy_ ) external;

    function pullPolicy() external;
}