// File: contracts/Context.sol

// SPDX-License-Identifier: MIT

pragma solidity >=0.6.0 <0.8.0;

/*
 * @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 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;
    }
}

// File: contracts/IERC20.sol


pragma solidity >=0.6.0 <0.8.0;

/**
 * @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);
}

// File: contracts/SafeMath.sol


pragma solidity >=0.6.0 <0.8.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMath {
    /**
     * @dev Returns the addition of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryAdd(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        uint256 c = a + b;
        if (c < a) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the substraction of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function trySub(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b > a) return (false, 0);
        return (true, a - b);
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, with an overflow flag.
     *
     * _Available since v3.4._
     */
    function tryMul(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) return (true, 0);
        uint256 c = a * b;
        if (c / a != b) return (false, 0);
        return (true, c);
    }

    /**
     * @dev Returns the division of two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryDiv(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a / b);
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers, with a division by zero flag.
     *
     * _Available since v3.4._
     */
    function tryMod(uint256 a, uint256 b) internal pure returns (bool, uint256) {
        if (b == 0) return (false, 0);
        return (true, a % b);
    }

    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");
        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b <= a, "SafeMath: subtraction overflow");
        return a - b;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    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;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: division by zero");
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        require(b > 0, "SafeMath: modulo by zero");
        return a % b;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {trySub}.
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        return a - b;
    }

    /**
     * @dev Returns the integer division of two unsigned integers, reverting with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryDiv}.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a / b;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * reverting with custom message when dividing by zero.
     *
     * CAUTION: This function is deprecated because it requires allocating memory for the error
     * message unnecessarily. For custom revert reasons use {tryMod}.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b > 0, errorMessage);
        return a % b;
    }
}

// File: contracts/ERC20.sol


pragma solidity >=0.6.0 <0.8.0;




/**
 * @dev Implementation of the {IERC20} interface.
 *
 * This implementation is agnostic to the way tokens are created. This means
 * that a supply mechanism has to be added in a derived contract using {_mint}.
 * For a generic mechanism see {ERC20PresetMinterPauser}.
 *
 * TIP: For a detailed writeup see our guide
 * https://forum.zeppelin.solutions/t/how-to-implement-erc20-supply-mechanisms/226[How
 * to implement supply mechanisms].
 *
 * We have followed general OpenZeppelin guidelines: functions revert instead
 * of returning `false` on failure. This behavior is nonetheless conventional
 * and does not conflict with the expectations of ERC20 applications.
 *
 * Additionally, an {Approval} event is emitted on calls to {transferFrom}.
 * This allows applications to reconstruct the allowance for all accounts just
 * by listening to said events. Other implementations of the EIP may not emit
 * these events, as it isn't required by the specification.
 *
 * Finally, the non-standard {decreaseAllowance} and {increaseAllowance}
 * functions have been added to mitigate the well-known issues around setting
 * allowances. See {IERC20-approve}.
 */
contract ERC20 is Context, IERC20 {
    using SafeMath for uint256;

    mapping (address => uint256) private _balances;

    mapping (address => mapping (address => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;
    uint8 private _decimals;

    /**
     * @dev Sets the values for {name} and {symbol}, initializes {decimals} with
     * a default value of 18.
     *
     * To select a different value for {decimals}, use {_setupDecimals}.
     *
     * All three of these values are immutable: they can only be set once during
     * construction.
     */
    constructor (string memory name_, string memory symbol_) public {
        _name = name_;
        _symbol = symbol_;
        _decimals = 18;
    }

    /**
     * @dev Returns the name of the token.
     */
    function name() public view virtual returns (string memory) {
        return _name;
    }

    /**
     * @dev Returns the symbol of the token, usually a shorter version of the
     * name.
     */
    function symbol() public view virtual returns (string memory) {
        return _symbol;
    }

    /**
     * @dev Returns the number of decimals used to get its user representation.
     * For example, if `decimals` equals `2`, a balance of `505` tokens should
     * be displayed to a user as `5,05` (`505 / 10 ** 2`).
     *
     * Tokens usually opt for a value of 18, imitating the relationship between
     * Ether and Wei. This is the value {ERC20} uses, unless {_setupDecimals} is
     * called.
     *
     * NOTE: This information is only used for _display_ purposes: it in
     * no way affects any of the arithmetic of the contract, including
     * {IERC20-balanceOf} and {IERC20-transfer}.
     */
    function decimals() public view virtual returns (uint8) {
        return _decimals;
    }

    /**
     * @dev See {IERC20-totalSupply}.
     */
    function totalSupply() public view virtual override returns (uint256) {
        return _totalSupply;
    }

    /**
     * @dev See {IERC20-balanceOf}.
     */
    function balanceOf(address account) public view virtual override returns (uint256) {
        return _balances[account];
    }

    /**
     * @dev See {IERC20-transfer}.
     *
     * Requirements:
     *
     * - `recipient` cannot be the zero address.
     * - the caller must have a balance of at least `amount`.
     */
    function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(_msgSender(), recipient, amount);
        return true;
    }

    /**
     * @dev See {IERC20-allowance}.
     */
    function allowance(address owner, address spender) public view virtual override returns (uint256) {
        return _allowances[owner][spender];
    }

    /**
     * @dev See {IERC20-approve}.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function approve(address spender, uint256 amount) public virtual override returns (bool) {
        _approve(_msgSender(), spender, amount);
        return true;
    }

    /**
     * @dev See {IERC20-transferFrom}.
     *
     * Emits an {Approval} event indicating the updated allowance. This is not
     * required by the EIP. See the note at the beginning of {ERC20}.
     *
     * Requirements:
     *
     * - `sender` and `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     * - the caller must have allowance for ``sender``'s tokens of at least
     * `amount`.
     */
    function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
        _transfer(sender, recipient, amount);
        _approve(sender, _msgSender(), _allowances[sender][_msgSender()].sub(amount, "ERC20: transfer amount exceeds allowance"));
        return true;
    }

    /**
     * @dev Atomically increases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     */
    function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].add(addedValue));
        return true;
    }

    /**
     * @dev Atomically decreases the allowance granted to `spender` by the caller.
     *
     * This is an alternative to {approve} that can be used as a mitigation for
     * problems described in {IERC20-approve}.
     *
     * Emits an {Approval} event indicating the updated allowance.
     *
     * Requirements:
     *
     * - `spender` cannot be the zero address.
     * - `spender` must have allowance for the caller of at least
     * `subtractedValue`.
     */
    function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
        _approve(_msgSender(), spender, _allowances[_msgSender()][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
        return true;
    }

    /**
     * @dev Moves tokens `amount` from `sender` to `recipient`.
     *
     * This is internal function is equivalent to {transfer}, and can be used to
     * e.g. implement automatic token fees, slashing mechanisms, etc.
     *
     * Emits a {Transfer} event.
     *
     * Requirements:
     *
     * - `sender` cannot be the zero address.
     * - `recipient` cannot be the zero address.
     * - `sender` must have a balance of at least `amount`.
     */
    function _transfer(address sender, address recipient, uint256 amount) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
        _balances[recipient] = _balances[recipient].add(amount);
        emit Transfer(sender, recipient, amount);
    }

    /** @dev Creates `amount` tokens and assigns them to `account`, increasing
     * the total supply.
     *
     * Emits a {Transfer} event with `from` set to the zero address.
     *
     * Requirements:
     *
     * - `to` cannot be the zero address.
     */
    function _mint(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: mint to the zero address");

        _beforeTokenTransfer(address(0), account, amount);

        _totalSupply = _totalSupply.add(amount);
        _balances[account] = _balances[account].add(amount);
        emit Transfer(address(0), account, amount);
    }

    /**
     * @dev Destroys `amount` tokens from `account`, reducing the
     * total supply.
     *
     * Emits a {Transfer} event with `to` set to the zero address.
     *
     * Requirements:
     *
     * - `account` cannot be the zero address.
     * - `account` must have at least `amount` tokens.
     */
    function _burn(address account, uint256 amount) internal virtual {
        require(account != address(0), "ERC20: burn from the zero address");

        _beforeTokenTransfer(account, address(0), amount);

        _balances[account] = _balances[account].sub(amount, "ERC20: burn amount exceeds balance");
        _totalSupply = _totalSupply.sub(amount);
        emit Transfer(account, address(0), amount);
    }

    /**
     * @dev Sets `amount` as the allowance of `spender` over the `owner` s tokens.
     *
     * This internal function is equivalent to `approve`, and can be used to
     * e.g. set automatic allowances for certain subsystems, etc.
     *
     * Emits an {Approval} event.
     *
     * Requirements:
     *
     * - `owner` cannot be the zero address.
     * - `spender` cannot be the zero address.
     */
    function _approve(address owner, address spender, uint256 amount) internal virtual {
        require(owner != address(0), "ERC20: approve from the zero address");
        require(spender != address(0), "ERC20: approve to the zero address");

        _allowances[owner][spender] = amount;
        emit Approval(owner, spender, amount);
    }

    /**
     * @dev Sets {decimals} to a value other than the default one of 18.
     *
     * WARNING: This function should only be called from the constructor. Most
     * applications that interact with token contracts will not expect
     * {decimals} to ever change, and may work incorrectly if it does.
     */
    function _setupDecimals(uint8 decimals_) internal virtual {
        _decimals = decimals_;
    }

    /**
     * @dev Hook that is called before any transfer of tokens. This includes
     * minting and burning.
     *
     * Calling conditions:
     *
     * - when `from` and `to` are both non-zero, `amount` of ``from``'s tokens
     * will be to transferred to `to`.
     * - when `from` is zero, `amount` tokens will be minted for `to`.
     * - when `to` is zero, `amount` of ``from``'s tokens will be burned.
     * - `from` and `to` are never both zero.
     *
     * To learn more about hooks, head to xref:ROOT:extending-contracts.adoc#using-hooks[Using Hooks].
     */
    function _beforeTokenTransfer(address from, address to, uint256 amount) internal virtual { }
}

// File: contracts/SafeMathCopy.sol


pragma solidity ^0.6.0;

/**
 * @dev Wrappers over Solidity's arithmetic operations with added overflow
 * checks.
 *
 * Arithmetic operations in Solidity wrap on overflow. This can easily result
 * in bugs, because programmers usually assume that an overflow raises an
 * error, which is the standard behavior in high level programming languages.
 * `SafeMath` restores this intuition by reverting the transaction when an
 * operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 */
library SafeMathCopy { // To avoid namespace collision between openzeppelin safemath and uniswap safemath
    /**
     * @dev Returns the addition of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `+` operator.
     *
     * Requirements:
     *
     * - Addition cannot overflow.
     */
    function add(uint256 a, uint256 b) internal pure returns (uint256) {
        uint256 c = a + b;
        require(c >= a, "SafeMath: addition overflow");

        return c;
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b) internal pure returns (uint256) {
        return sub(a, b, "SafeMath: subtraction overflow");
    }

    /**
     * @dev Returns the subtraction of two unsigned integers, reverting with custom message on
     * overflow (when the result is negative).
     *
     * Counterpart to Solidity's `-` operator.
     *
     * Requirements:
     *
     * - Subtraction cannot overflow.
     */
    function sub(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b <= a, errorMessage);
        uint256 c = a - b;

        return c;
    }

    /**
     * @dev Returns the multiplication of two unsigned integers, reverting on
     * overflow.
     *
     * Counterpart to Solidity's `*` operator.
     *
     * Requirements:
     *
     * - Multiplication cannot overflow.
     */
    function mul(uint256 a, uint256 b) internal pure returns (uint256) {
        // Gas optimization: this is cheaper than requiring 'a' not being zero, but the
        // benefit is lost if 'b' is also tested.
        // See: https://github.com/OpenZeppelin/openzeppelin-contracts/pull/522
        if (a == 0) {
            return 0;
        }

        uint256 c = a * b;
        require(c / a == b, "SafeMath: multiplication overflow");

        return c;
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function div(uint256 a, uint256 b) internal pure returns (uint256) {
        return div(a, b, "SafeMath: division by zero");
    }

    /**
     * @dev Returns the integer division of two unsigned integers. Reverts with custom message on
     * division by zero. The result is rounded towards zero.
     *
     * Counterpart to Solidity's `/` operator. Note: this function uses a
     * `revert` opcode (which leaves remaining gas untouched) while Solidity
     * uses an invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be 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;
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b) internal pure returns (uint256) {
        return mod(a, b, "SafeMath: modulo by zero");
    }

    /**
     * @dev Returns the remainder of dividing two unsigned integers. (unsigned integer modulo),
     * Reverts with custom message when dividing by zero.
     *
     * Counterpart to Solidity's `%` operator. This function uses a `revert`
     * opcode (which leaves remaining gas untouched) while Solidity uses an
     * invalid opcode to revert (consuming all remaining gas).
     *
     * Requirements:
     *
     * - The divisor cannot be zero.
     */
    function mod(uint256 a, uint256 b, string memory errorMessage) internal pure returns (uint256) {
        require(b != 0, errorMessage);
        return a % b;
    }
}

// File: contracts/Decimal.sol

/*
    Copyright 2019 dYdX Trading Inc.
    Copyright 2020 Empty Set Squad <emptysetsquad@protonmail.com>
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.
    You may obtain a copy of the License at
    http://www.apache.org/licenses/LICENSE-2.0
    Unless required by applicable law or agreed to in writing, software
    distributed under the License is distributed on an "AS IS" BASIS,
    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    See the License for the specific language governing permissions and
    limitations under the License.
*/

pragma solidity ^0.6.0;
pragma experimental ABIEncoderV2;


/**
 * @title Decimal
 * @author dYdX
 *
 * Library that defines a fixed-point number with 18 decimal places.
 */
library Decimal {
    using SafeMathCopy for uint256;

    // ============ Constants ============

    uint256 private constant BASE = 10**18;

    // ============ Structs ============


    struct D256 {
        uint256 value;
    }

    // ============ Static Functions ============

    function zero()
    internal
    pure
    returns (D256 memory)
    {
        return D256({ value: 0 });
    }

    function one()
    internal
    pure
    returns (D256 memory)
    {
        return D256({ value: BASE });
    }

    function from(
        uint256 a
    )
    internal
    pure
    returns (D256 memory)
    {
        return D256({ value: a.mul(BASE) });
    }

    function ratio(
        uint256 a,
        uint256 b
    )
    internal
    pure
    returns (D256 memory)
    {
        return D256({ value: getPartial(a, BASE, b) });
    }

    // ============ Self Functions ============

    function add(
        D256 memory self,
        uint256 b
    )
    internal
    pure
    returns (D256 memory)
    {
        return D256({ value: self.value.add(b.mul(BASE)) });
    }

    function sub(
        D256 memory self,
        uint256 b
    )
    internal
    pure
    returns (D256 memory)
    {
        return D256({ value: self.value.sub(b.mul(BASE)) });
    }

    function sub(
        D256 memory self,
        uint256 b,
        string memory reason
    )
    internal
    pure
    returns (D256 memory)
    {
        return D256({ value: self.value.sub(b.mul(BASE), reason) });
    }

    function mul(
        D256 memory self,
        uint256 b
    )
    internal
    pure
    returns (D256 memory)
    {
        return D256({ value: self.value.mul(b) });
    }

    function div(
        D256 memory self,
        uint256 b
    )
    internal
    pure
    returns (D256 memory)
    {
        return D256({ value: self.value.div(b) });
    }

    function pow(
        D256 memory self,
        uint256 b
    )
    internal
    pure
    returns (D256 memory)
    {
        if (b == 0) {
            return from(1);
        }

        D256 memory temp = D256({ value: self.value });
        for (uint256 i = 1; i < b; i++) {
            temp = mul(temp, self);
        }

        return temp;
    }

    function add(
        D256 memory self,
        D256 memory b
    )
    internal
    pure
    returns (D256 memory)
    {
        return D256({ value: self.value.add(b.value) });
    }

    function sub(
        D256 memory self,
        D256 memory b
    )
    internal
    pure
    returns (D256 memory)
    {
        return D256({ value: self.value.sub(b.value) });
    }

    function sub(
        D256 memory self,
        D256 memory b,
        string memory reason
    )
    internal
    pure
    returns (D256 memory)
    {
        return D256({ value: self.value.sub(b.value, reason) });
    }

    function mul(
        D256 memory self,
        D256 memory b
    )
    internal
    pure
    returns (D256 memory)
    {
        return D256({ value: getPartial(self.value, b.value, BASE) });
    }

    function div(
        D256 memory self,
        D256 memory b
    )
    internal
    pure
    returns (D256 memory)
    {
        return D256({ value: getPartial(self.value, BASE, b.value) });
    }

    function equals(D256 memory self, D256 memory b) internal pure returns (bool) {
        return self.value == b.value;
    }

    function greaterThan(D256 memory self, D256 memory b) internal pure returns (bool) {
        return compareTo(self, b) == 2;
    }

    function lessThan(D256 memory self, D256 memory b) internal pure returns (bool) {
        return compareTo(self, b) == 0;
    }

    function greaterThanOrEqualTo(D256 memory self, D256 memory b) internal pure returns (bool) {
        return compareTo(self, b) > 0;
    }

    function lessThanOrEqualTo(D256 memory self, D256 memory b) internal pure returns (bool) {
        return compareTo(self, b) < 2;
    }

    function isZero(D256 memory self) internal pure returns (bool) {
        return self.value == 0;
    }

    function asUint256(D256 memory self) internal pure returns (uint256) {
        return self.value.div(BASE);
    }

    // ============ Core Methods ============

    function getPartial(
        uint256 target,
        uint256 numerator,
        uint256 denominator
    )
    private
    pure
    returns (uint256)
    {
        return target.mul(numerator).div(denominator);
    }

    function compareTo(
        D256 memory a,
        D256 memory b
    )
    private
    pure
    returns (uint256)
    {
        if (a.value == b.value) {
            return 1;
        }
        return a.value > b.value ? 2 : 0;
    }
}

// File: contracts/IGenesisGroup.sol

pragma solidity ^0.6.0;



/// @title Genesis Group interface
/// @author Fei Protocol
interface IGenesisGroup {
    // ----------- Events -----------

    event Purchase(address indexed _to, uint256 _value);

    event Redeem(
        address indexed _to,
        uint256 _amountIn,
        uint256 _amountFei,
        uint256 _amountTribe
    );

    event Commit(address indexed _from, address indexed _to, uint256 _amount);

    event Launch(uint256 _timestamp);

    // ----------- Governor-only state changing API -----------
    
    function initGenesis() external;

    // ----------- State changing API -----------

    function purchase(address to, uint256 value) external payable;

    function redeem(address to) external;

    function commit(
        address from,
        address to,
        uint256 amount
    ) external;

    function launch() external;

    function emergencyExit(address from, address payable to) external;

    // ----------- Getters -----------

    function getAmountOut(uint256 amountIn, bool inclusive)
        external
        view
        returns (uint256 feiAmount, uint256 tribeAmount);

    function getAmountsToRedeem(address to)
        external
        view
        returns (
            uint256 feiAmount,
            uint256 genesisTribe,
            uint256 idoTribe
        );

    function committedFGEN(address account) external view returns (uint256);

    function totalCommittedFGEN() external view returns (uint256);

    function totalCommittedTribe() external view returns (uint256);

    function launchBlock() external view returns (uint256);
}

// File: contracts/IDOInterface.sol

pragma solidity ^0.6.0;


/// @title IDO interface
/// @author Fei Protocol
interface IDOInterface {
    // ----------- Events -----------

    event Deploy(uint256 _amountFei, uint256 _amountTribe);

    // ----------- Genesis Group only state changing API -----------

    function deploy(Decimal.D256 calldata feiRatio) external;

    function swapFei(uint256 amountFei) external returns (uint256);

    // ----------- Governor only state changing API -----------

    function unlockLiquidity() external;

}

// File: contracts/SafeCast.sol


pragma solidity >=0.6.0 <0.8.0;


/**
 * @dev Wrappers over Solidity's uintXX/intXX casting operators with added overflow
 * checks.
 *
 * Downcasting from uint256/int256 in Solidity does not revert on overflow. This can
 * easily result in undesired exploitation or bugs, since developers usually
 * assume that overflows raise errors. `SafeCast` restores this intuition by
 * reverting the transaction when such an operation overflows.
 *
 * Using this library instead of the unchecked operations eliminates an entire
 * class of bugs, so it's recommended to use it always.
 *
 * Can be combined with {SafeMath} and {SignedSafeMath} to extend it to smaller types, by performing
 * all math on `uint256` and `int256` and then downcasting.
 */
library SafeCast {

    /**
     * @dev Returns the downcasted uint128 from uint256, reverting on
     * overflow (when the input is greater than largest uint128).
     *
     * Counterpart to Solidity's `uint128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     */
    function toUint128(uint256 value) internal pure returns (uint128) {
        require(value < 2**128, "SafeCast: value doesn\'t fit in 128 bits");
        return uint128(value);
    }

    /**
     * @dev Returns the downcasted uint64 from uint256, reverting on
     * overflow (when the input is greater than largest uint64).
     *
     * Counterpart to Solidity's `uint64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     */
    function toUint64(uint256 value) internal pure returns (uint64) {
        require(value < 2**64, "SafeCast: value doesn\'t fit in 64 bits");
        return uint64(value);
    }

    /**
     * @dev Returns the downcasted uint32 from uint256, reverting on
     * overflow (when the input is greater than largest uint32).
     *
     * Counterpart to Solidity's `uint32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     */
    function toUint32(uint256 value) internal pure returns (uint32) {
        require(value < 2**32, "SafeCast: value doesn\'t fit in 32 bits");
        return uint32(value);
    }

    /**
     * @dev Returns the downcasted uint16 from uint256, reverting on
     * overflow (when the input is greater than largest uint16).
     *
     * Counterpart to Solidity's `uint16` operator.
     *
     * Requirements:
     *
     * - input must fit into 16 bits
     */
    function toUint16(uint256 value) internal pure returns (uint16) {
        require(value < 2**16, "SafeCast: value doesn\'t fit in 16 bits");
        return uint16(value);
    }

    /**
     * @dev Returns the downcasted uint8 from uint256, reverting on
     * overflow (when the input is greater than largest uint8).
     *
     * Counterpart to Solidity's `uint8` operator.
     *
     * Requirements:
     *
     * - input must fit into 8 bits.
     */
    function toUint8(uint256 value) internal pure returns (uint8) {
        require(value < 2**8, "SafeCast: value doesn\'t fit in 8 bits");
        return uint8(value);
    }

    /**
     * @dev Converts a signed int256 into an unsigned uint256.
     *
     * Requirements:
     *
     * - input must be greater than or equal to 0.
     */
    function toUint256(int256 value) internal pure returns (uint256) {
        require(value >= 0, "SafeCast: value must be positive");
        return uint256(value);
    }

    /**
     * @dev Returns the downcasted int128 from int256, reverting on
     * overflow (when the input is less than smallest int128 or
     * greater than largest int128).
     *
     * Counterpart to Solidity's `int128` operator.
     *
     * Requirements:
     *
     * - input must fit into 128 bits
     *
     * _Available since v3.1._
     */
    function toInt128(int256 value) internal pure returns (int128) {
        require(value >= -2**127 && value < 2**127, "SafeCast: value doesn\'t fit in 128 bits");
        return int128(value);
    }

    /**
     * @dev Returns the downcasted int64 from int256, reverting on
     * overflow (when the input is less than smallest int64 or
     * greater than largest int64).
     *
     * Counterpart to Solidity's `int64` operator.
     *
     * Requirements:
     *
     * - input must fit into 64 bits
     *
     * _Available since v3.1._
     */
    function toInt64(int256 value) internal pure returns (int64) {
        require(value >= -2**63 && value < 2**63, "SafeCast: value doesn\'t fit in 64 bits");
        return int64(value);
    }

    /**
     * @dev Returns the downcasted int32 from int256, reverting on
     * overflow (when the input is less than smallest int32 or
     * greater than largest int32).
     *
     * Counterpart to Solidity's `int32` operator.
     *
     * Requirements:
     *
     * - input must fit into 32 bits
     *
     * _Available since v3.1._
     */
    function toInt32(int256 value) internal pure returns (int32) {
        require(value >= -2**31 && value < 2**31, "SafeCast: value doesn\'t fit in 32 bits");
        return int32(value);
    }

    /**
     * @dev Returns the downcasted int16 from int256, reverting on
     * overflow (when the input is less than smallest int16 or
     * greater than largest int16).
     *
     * Counterpart to Solidity's `int16` operator.
     *
     * Requirements:
     *
     * - input must fit into 16 bits
     *
     * _Available since v3.1._
     */
    function toInt16(int256 value) internal pure returns (int16) {
        require(value >= -2**15 && value < 2**15, "SafeCast: value doesn\'t fit in 16 bits");
        return int16(value);
    }

    /**
     * @dev Returns the downcasted int8 from int256, reverting on
     * overflow (when the input is less than smallest int8 or
     * greater than largest int8).
     *
     * Counterpart to Solidity's `int8` operator.
     *
     * Requirements:
     *
     * - input must fit into 8 bits.
     *
     * _Available since v3.1._
     */
    function toInt8(int256 value) internal pure returns (int8) {
        require(value >= -2**7 && value < 2**7, "SafeCast: value doesn\'t fit in 8 bits");
        return int8(value);
    }

    /**
     * @dev Converts an unsigned uint256 into a signed int256.
     *
     * Requirements:
     *
     * - input must be less than or equal to maxInt256.
     */
    function toInt256(uint256 value) internal pure returns (int256) {
        require(value < 2**255, "SafeCast: value doesn't fit in an int256");
        return int256(value);
    }
}

// File: contracts/Timed.sol

pragma solidity ^0.6.0;


/// @title an abstract contract for timed events
/// @author Fei Protocol
abstract contract Timed {
    using SafeCast for uint256;

    /// @notice the start timestamp of the timed period
    uint256 public startTime;

    /// @notice the duration of the timed period
    uint256 public duration;

    event DurationUpdate(uint256 _duration);

    event TimerReset(uint256 _startTime);

    constructor(uint256 _duration) public {
        _setDuration(_duration);
    }

    modifier duringTime() {
        require(isTimeStarted(), "Timed: time not started");
        require(!isTimeEnded(), "Timed: time ended");
        _;
    }

    modifier afterTime() {
        require(isTimeEnded(), "Timed: time not ended");
        _;
    }

    /// @notice return true if time period has ended
    function isTimeEnded() public view returns (bool) {
        return remainingTime() == 0;
    }

    /// @notice number of seconds remaining until time is up
    /// @return remaining
    function remainingTime() public view returns (uint256) {
        return duration - timeSinceStart(); // duration always >= timeSinceStart which is on [0,d]
    }

    /// @notice number of seconds since contract was initialized
    /// @return timestamp
    /// @dev will be less than or equal to duration
    function timeSinceStart() public view returns (uint256) {
        if (!isTimeStarted()) {
            return 0; // uninitialized
        }
        uint256 _duration = duration;
        // solhint-disable-next-line not-rely-on-time
        uint256 timePassed = block.timestamp - startTime; // block timestamp always >= startTime
        return timePassed > _duration ? _duration : timePassed;
    }

    function isTimeStarted() public view returns (bool) {
        return startTime != 0;
    }

    function _initTimed() internal {
        // solhint-disable-next-line not-rely-on-time
        startTime = block.timestamp;
        
        // solhint-disable-next-line not-rely-on-time
        emit TimerReset(block.timestamp);
    }

    function _setDuration(uint _duration) internal {
        duration = _duration;
        emit DurationUpdate(_duration);
    }
}

// File: contracts/IPermissions.sol

pragma solidity ^0.6.0;

/// @title Permissions interface
/// @author Fei Protocol
interface IPermissions {
    // ----------- Governor only state changing api -----------

    function createRole(bytes32 role, bytes32 adminRole) external;

    function grantMinter(address minter) external;

    function grantBurner(address burner) external;

    function grantPCVController(address pcvController) external;

    function grantGovernor(address governor) external;

    function grantGuardian(address guardian) external;

    function revokeMinter(address minter) external;

    function revokeBurner(address burner) external;

    function revokePCVController(address pcvController) external;

    function revokeGovernor(address governor) external;

    function revokeGuardian(address guardian) external;

    // ----------- Revoker only state changing api -----------

    function revokeOverride(bytes32 role, address account) external;

    // ----------- Getters -----------

    function isBurner(address _address) external view returns (bool);

    function isMinter(address _address) external view returns (bool);

    function isGovernor(address _address) external view returns (bool);

    function isGuardian(address _address) external view returns (bool);

    function isPCVController(address _address) external view returns (bool);
}

// File: contracts/IFei.sol

pragma solidity ^0.6.2;


/// @title FEI stablecoin interface
/// @author Fei Protocol
interface IFei is IERC20 {
    // ----------- Events -----------

    event Minting(
        address indexed _to,
        address indexed _minter,
        uint256 _amount
    );

    event Burning(
        address indexed _to,
        address indexed _burner,
        uint256 _amount
    );

    event IncentiveContractUpdate(
        address indexed _incentivized,
        address indexed _incentiveContract
    );

    // ----------- State changing api -----------

    function burn(uint256 amount) external;

    function permit(
        address owner,
        address spender,
        uint256 value,
        uint256 deadline,
        uint8 v,
        bytes32 r,
        bytes32 s
    ) external;

    // ----------- Burner only state changing api -----------

    function burnFrom(address account, uint256 amount) external;

    // ----------- Minter only state changing api -----------

    function mint(address account, uint256 amount) external;

    // ----------- Governor only state changing api -----------

    function setIncentiveContract(address account, address incentive) external;

    // ----------- Getters -----------

    function incentiveContract(address account) external view returns (address);
}

// File: contracts/ICore.sol

pragma solidity ^0.6.0;



/// @title Core Interface
/// @author Fei Protocol
interface ICore is IPermissions {
    // ----------- Events -----------

    event FeiUpdate(address indexed _fei);
    event TribeUpdate(address indexed _tribe);
    event GenesisGroupUpdate(address indexed _genesisGroup);
    event TribeAllocation(address indexed _to, uint256 _amount);
    event GenesisPeriodComplete(uint256 _timestamp);

    // ----------- Governor only state changing api -----------

    function init() external;

    // ----------- Governor only state changing api -----------

    function setFei(address token) external;

    function setTribe(address token) external;

    function setGenesisGroup(address _genesisGroup) external;

    function allocateTribe(address to, uint256 amount) external;

    // ----------- Genesis Group only state changing api -----------

    function completeGenesisGroup() external;

    // ----------- Getters -----------

    function fei() external view returns (IFei);

    function tribe() external view returns (IERC20);

    function genesisGroup() external view returns (address);

    function hasGenesisGroupCompleted() external view returns (bool);
}

// File: contracts/ICoreRef.sol

pragma solidity ^0.6.0;


/// @title CoreRef interface
/// @author Fei Protocol
interface ICoreRef {
    // ----------- Events -----------

    event CoreUpdate(address indexed _core);

    // ----------- Governor only state changing api -----------

    function setCore(address core) external;

    function pause() external;

    function unpause() external;

    // ----------- Getters -----------

    function core() external view returns (ICore);

    function fei() external view returns (IFei);

    function tribe() external view returns (IERC20);

    function feiBalance() external view returns (uint256);

    function tribeBalance() external view returns (uint256);
}

// File: contracts/Pausable.sol


pragma solidity >=0.6.0 <0.8.0;


/**
 * @dev Contract module which allows children to implement an emergency stop
 * mechanism that can be triggered by an authorized account.
 *
 * This module is used through inheritance. It will make available the
 * modifiers `whenNotPaused` and `whenPaused`, which can be applied to
 * the functions of your contract. Note that they will not be pausable by
 * simply including this module, only once the modifiers are put in place.
 */
abstract contract Pausable is Context {
    /**
     * @dev Emitted when the pause is triggered by `account`.
     */
    event Paused(address account);

    /**
     * @dev Emitted when the pause is lifted by `account`.
     */
    event Unpaused(address account);

    bool private _paused;

    /**
     * @dev Initializes the contract in unpaused state.
     */
    constructor () internal {
        _paused = false;
    }

    /**
     * @dev Returns true if the contract is paused, and false otherwise.
     */
    function paused() public view virtual returns (bool) {
        return _paused;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    modifier whenNotPaused() {
        require(!paused(), "Pausable: paused");
        _;
    }

    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    modifier whenPaused() {
        require(paused(), "Pausable: not paused");
        _;
    }

    /**
     * @dev Triggers stopped state.
     *
     * Requirements:
     *
     * - The contract must not be paused.
     */
    function _pause() internal virtual whenNotPaused {
        _paused = true;
        emit Paused(_msgSender());
    }

    /**
     * @dev Returns to normal state.
     *
     * Requirements:
     *
     * - The contract must be paused.
     */
    function _unpause() internal virtual whenPaused {
        _paused = false;
        emit Unpaused(_msgSender());
    }
}

// File: contracts/Address.sol


pragma solidity >=0.6.2 <0.8.0;

/**
 * @dev Collection of functions related to the address type
 */
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 on 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} or the
     * https://solidity.readthedocs.io/en/v0.5.11/security-considerations.html#use-the-checks-effects-interactions-pattern[checks-effects-interactions pattern].
     */
    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).
     *
     * Returns the raw returned data. To convert to the expected return value,
     * use https://solidity.readthedocs.io/en/latest/units-and-global-variables.html?highlight=abi.decode#abi-encoding-and-decoding-functions[`abi.decode`].
     *
     * 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);
    }

    /**
     * @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 v3.4._
     */
    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 v3.4._
     */
    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);
            }
        }
    }
}

// File: contracts/CoreRef.sol

pragma solidity ^0.6.0;




/// @title A Reference to Core
/// @author Fei Protocol
/// @notice defines some modifiers and utilities around interacting with Core
abstract contract CoreRef is ICoreRef, Pausable {
    ICore private _core;

    /// @notice CoreRef constructor
    /// @param core Fei Core to reference
    constructor(address core) public {
        _core = ICore(core);
    }

    modifier ifMinterSelf() {
        if (_core.isMinter(address(this))) {
            _;
        }
    }

    modifier ifBurnerSelf() {
        if (_core.isBurner(address(this))) {
            _;
        }
    }

    modifier onlyMinter() {
        require(_core.isMinter(msg.sender), "CoreRef: Caller is not a minter");
        _;
    }

    modifier onlyBurner() {
        require(_core.isBurner(msg.sender), "CoreRef: Caller is not a burner");
        _;
    }

    modifier onlyPCVController() {
        require(
            _core.isPCVController(msg.sender),
            "CoreRef: Caller is not a PCV controller"
        );
        _;
    }

    modifier onlyGovernor() {
        require(
            _core.isGovernor(msg.sender),
            "CoreRef: Caller is not a governor"
        );
        _;
    }

    modifier onlyGuardianOrGovernor() {
        require(
            _core.isGovernor(msg.sender) ||
            _core.isGuardian(msg.sender),
            "CoreRef: Caller is not a guardian or governor"
        );
        _;
    }

    modifier onlyFei() {
        require(msg.sender == address(fei()), "CoreRef: Caller is not FEI");
        _;
    }

    modifier onlyGenesisGroup() {
        require(
            msg.sender == _core.genesisGroup(),
            "CoreRef: Caller is not GenesisGroup"
        );
        _;
    }

    modifier postGenesis() {
        require(
            _core.hasGenesisGroupCompleted(),
            "CoreRef: Still in Genesis Period"
        );
        _;
    }

    modifier nonContract() {
        require(!Address.isContract(msg.sender), "CoreRef: Caller is a contract");
        _;
    }

    /// @notice set new Core reference address
    /// @param core the new core address
    function setCore(address core) external override onlyGovernor {
        _core = ICore(core);
        emit CoreUpdate(core);
    }

    /// @notice set pausable methods to paused
    function pause() public override onlyGuardianOrGovernor {
        _pause();
    }

    /// @notice set pausable methods to unpaused
    function unpause() public override onlyGuardianOrGovernor {
        _unpause();
    }

    /// @notice address of the Core contract referenced
    /// @return ICore implementation address
    function core() public view override returns (ICore) {
        return _core;
    }

    /// @notice address of the Fei contract referenced by Core
    /// @return IFei implementation address
    function fei() public view override returns (IFei) {
        return _core.fei();
    }

    /// @notice address of the Tribe contract referenced by Core
    /// @return IERC20 implementation address
    function tribe() public view override returns (IERC20) {
        return _core.tribe();
    }

    /// @notice fei balance of contract
    /// @return fei amount held
    function feiBalance() public view override returns (uint256) {
        return fei().balanceOf(address(this));
    }

    /// @notice tribe balance of contract
    /// @return tribe amount held
    function tribeBalance() public view override returns (uint256) {
        return tribe().balanceOf(address(this));
    }

    function _burnFeiHeld() internal {
        fei().burn(feiBalance());
    }

    function _mintFei(uint256 amount) internal {
        fei().mint(address(this), amount);
    }
}

// File: contracts/IOracle.sol

pragma solidity ^0.6.0;


/// @title generic oracle interface for Fei Protocol
/// @author Fei Protocol
interface IOracle {
    // ----------- Events -----------

    event Update(uint256 _peg);

    // ----------- State changing API -----------

    function update() external returns (bool);

    // ----------- Getters -----------

    function read() external view returns (Decimal.D256 memory, bool);

    function isOutdated() external view returns (bool);
    
}

// File: contracts/IBondingCurve.sol

pragma solidity ^0.6.0;


interface IBondingCurve {
    // ----------- Events -----------

    event ScaleUpdate(uint256 _scale);

    event BufferUpdate(uint256 _buffer);

    event IncentiveAmountUpdate(uint256 _incentiveAmount);

    event Purchase(address indexed _to, uint256 _amountIn, uint256 _amountOut);

    event Allocate(address indexed _caller, uint256 _amount);

    // ----------- State changing Api -----------

    function purchase(address to, uint256 amountIn)
        external
        payable
        returns (uint256 amountOut);

    function allocate() external;

    // ----------- Governor only state changing api -----------

    function setBuffer(uint256 _buffer) external;

    function setScale(uint256 _scale) external;

    function setAllocation(
        address[] calldata pcvDeposits,
        uint256[] calldata ratios
    ) external;

    function setIncentiveAmount(uint256 _incentiveAmount) external;

    function setIncentiveFrequency(uint256 _frequency) external;

    // ----------- Getters -----------

    function getCurrentPrice() external view returns (Decimal.D256 memory);

    function getAverageUSDPrice(uint256 amountIn)
        external
        view
        returns (Decimal.D256 memory);

    function getAmountOut(uint256 amountIn)
        external
        view
        returns (uint256 amountOut);

    function scale() external view returns (uint256);

    function atScale() external view returns (bool);

    function buffer() external view returns (uint256);

    function totalPurchased() external view returns (uint256);

    function getTotalPCVHeld() external view returns (uint256);

    function incentiveAmount() external view returns (uint256);
}

// File: contracts/IBondingCurveOracle.sol

pragma solidity ^0.6.0;




/// @title bonding curve oracle interface for Fei Protocol
/// @author Fei Protocol
interface IBondingCurveOracle is IOracle {
    // ----------- Genesis Group only state changing API -----------

    function init(Decimal.D256 calldata initialUSDPrice) external;

    // ----------- Getters -----------

    function uniswapOracle() external view returns (IOracle);

    function bondingCurve() external view returns (IBondingCurve);

    function initialUSDPrice() external view returns (Decimal.D256 memory);
}

// File: contracts/GenesisGroup.sol

pragma solidity ^0.6.0;








/// @title Equal access to the first bonding curve transaction and the IDO
/// @author Fei Protocol
contract GenesisGroup is IGenesisGroup, CoreRef, ERC20, Timed {
    using Decimal for Decimal.D256;

    IBondingCurve private bondingcurve;

    IBondingCurveOracle private bondingCurveOracle;

    IDOInterface private ido;
    uint256 private exchangeRateDiscount;

    /// @notice amount of FGEN pre-committed and burned per account
    mapping(address => uint256) public override committedFGEN;

    /// @notice total amount of FGEN pre-committed and burned
    uint256 public override totalCommittedFGEN;

    /// @notice total amount of TRIBE coming from the IDO and pre-committed FGEN
    /// @dev is 0 pre-launch
    uint256 public override totalCommittedTribe;
    
    /// @notice the block number of the genesis launch
    uint256 public override launchBlock;

    /// @notice GenesisGroup constructor
    /// @param _core Fei Core address to reference
    /// @param _bondingcurve Bonding curve address for purchase
    /// @param _ido IDO contract to deploy
    /// @param _oracle Bonding curve oracle
    /// @param _duration duration of the Genesis Period
    /// @param _exchangeRateDiscount a divisor on the FEI/TRIBE ratio at Genesis to deploy to the IDO
    constructor(
        address _core,
        address _bondingcurve,
        address _ido,
        address _oracle,
        uint256 _duration,
        uint256 _exchangeRateDiscount
    )
        public
        CoreRef(_core)
        ERC20("Feii Genesis Group", "FGEN")
        Timed(_duration)
    {
        bondingcurve = IBondingCurve(_bondingcurve);

        exchangeRateDiscount = _exchangeRateDiscount;
        ido = IDOInterface(_ido);

        uint256 maxTokens = uint256(-1);
        fei().approve(_ido, maxTokens);

        bondingCurveOracle = IBondingCurveOracle(_oracle);
    }

    function initGenesis() external override onlyGovernor {
        _initTimed();
    }

    function setBondingcurve(address _bondingcurve) external onlyGovernor {
        bondingcurve = IBondingCurve(_bondingcurve);
    }
    function setIDO(address _ido) external onlyGovernor {
        ido = IDOInterface(_ido);
        fei().approve(_ido, uint256(-1));
    }
    function setOracle(address _oracle) external onlyGovernor {
        bondingCurveOracle = IBondingCurveOracle(_oracle);
    }

    /// @notice allows for entry into the Genesis Group via ETH. Only callable during Genesis Period.
    /// @param to address to send FGEN Genesis tokens to
    /// @param value amount of ETH to deposit
    function purchase(address to, uint256 value)
        external
        payable
        override
        duringTime
    {
        require(msg.value == value, "GenesisGroup: value mismatch");
        require(value != 0, "GenesisGroup: no value sent");

        _mint(to, value);

        emit Purchase(to, value);
    }

    /// @notice commit Genesis FEI to purchase TRIBE in DEX offering
    /// @param from address to source FGEN Genesis shares from
    /// @param to address to earn TRIBE and redeem post launch
    /// @param amount of FGEN Genesis shares to commit
    function commit(
        address from,
        address to,
        uint256 amount
    ) external override duringTime {
        _burnFrom(from, amount);

        committedFGEN[to] = committedFGEN[to].add(amount);
        totalCommittedFGEN = totalCommittedFGEN.add(amount);

        emit Commit(from, to, amount);
    }

    /// @notice redeem FGEN genesis tokens for FEI and TRIBE. Only callable post launch
    /// @param to address to send redeemed FEI and TRIBE to.
    function redeem(address to) external override {
        (uint256 feiAmount, uint256 genesisTribe, uint256 idoTribe) =
            getAmountsToRedeem(to);
        require(
            block.number > launchBlock,
            "GenesisGroup: No redeeming in launch block"
        );

        // Total tribe to redeem
        uint256 tribeAmount = genesisTribe.add(idoTribe);
        require(tribeAmount != 0, "GenesisGroup: No redeemable TRIBE");

        // Burn FGEN
        uint256 amountIn = balanceOf(to);
        _burnFrom(to, amountIn);

        // Reset committed
        uint256 committed = committedFGEN[to];
        committedFGEN[to] = 0;
        totalCommittedFGEN = totalCommittedFGEN.sub(committed);

        totalCommittedTribe = totalCommittedTribe.sub(idoTribe);

        // send FEI and TRIBE
        if (feiAmount != 0) {
            fei().transfer(to, feiAmount);
        }
        tribe().transfer(to, tribeAmount);

        emit Redeem(to, amountIn, feiAmount, tribeAmount);
    }

    /// @notice launch Fei Protocol. Callable once Genesis Period has ended
    function launch() external override nonContract afterTime {

        // Complete Genesis
        core().completeGenesisGroup();
        launchBlock = block.number;

        address genesisGroup = address(this);
        uint256 balance = genesisGroup.balance;

        // Initialize bonding curve oracle
        bondingCurveOracle.init(bondingcurve.getAverageUSDPrice(balance));

        // bonding curve purchase and PCV allocation
        bondingcurve.purchase{value: balance}(genesisGroup, balance);
        bondingcurve.allocate();

        ido.deploy(_feiTribeExchangeRate());

        // swap pre-committed FEI on IDO and store TRIBE
        uint256 amountFei =
            feiBalance().mul(totalCommittedFGEN) /
                (totalSupply().add(totalCommittedFGEN));
        if (amountFei != 0) {
            totalCommittedTribe = ido.swapFei(amountFei);
        }

        // solhint-disable-next-line not-rely-on-time
        emit Launch(block.timestamp);
    }

    // Add a backdoor out of Genesis in case of brick
    function emergencyExit(address from, address payable to) external override {
        require(
            // solhint-disable-next-line not-rely-on-time
            block.timestamp > (startTime + duration + 3 days),
            "GenesisGroup: Not in exit window"
        );
        require(
            !core().hasGenesisGroupCompleted(),
            "GenesisGroup: Launch already happened"
        );

        uint256 heldFGEN = balanceOf(from);
        uint256 committed = committedFGEN[from];
        uint256 total = heldFGEN.add(committed);

        require(total != 0, "GenesisGroup: No FGEN or committed balance");
        require(
            msg.sender == from || allowance(from, msg.sender) >= total,
            "GenesisGroup: Not approved for emergency withdrawal"
        );
        assert(address(this).balance >= total); // ETH can only be removed by launch which blocks this method or this method in event of launch failure

        _burnFrom(from, heldFGEN);
        committedFGEN[from] = 0;
        totalCommittedFGEN = totalCommittedFGEN.sub(committed);

        to.transfer(total);
    }

    /// @notice calculate amount of FEI and TRIBE redeemable by an account post-genesis
    /// @return feiAmount the amount of FEI received by the user
    /// @return genesisTribe the amount of TRIBE received by the user per GenesisGroup
    /// @return idoTribe the amount of TRIBE received by the user per pre-committed FEI trading in the IDO
    /// @dev this function is only callable post launch
    function getAmountsToRedeem(address to)
        public
        view
        override
        postGenesis
        returns (
            uint256 feiAmount,
            uint256 genesisTribe,
            uint256 idoTribe
        )
    {
        uint256 userFGEN = balanceOf(to);
        uint256 userCommittedFGEN = committedFGEN[to];

        uint256 circulatingFGEN = totalSupply();
        uint256 totalFGEN = circulatingFGEN.add(totalCommittedFGEN);

        // subtract IDO purchased TRIBE amount
        uint256 totalGenesisTribe = tribeBalance().sub(totalCommittedTribe);

        if (circulatingFGEN != 0) {
            // portion of remaining uncommitted FEI
            feiAmount = feiBalance().mul(userFGEN) / circulatingFGEN;
        }

        if (totalFGEN != 0) {
            // portion including both committed and uncommitted FGEN
            genesisTribe =
                totalGenesisTribe.mul(userFGEN.add(userCommittedFGEN)) /
                totalFGEN;
        }

        if (totalCommittedFGEN != 0) {
            // portion including only committed FGEN of IDO TRIBE
            idoTribe =
                totalCommittedTribe.mul(userCommittedFGEN) /
                totalCommittedFGEN;
        }

        return (feiAmount, genesisTribe, idoTribe);
    }

    /// @notice calculate amount of FEI and TRIBE received if the Genesis Group ended now.
    /// @param amountIn amount of FGEN held or equivalently amount of ETH purchasing with
    /// @param inclusive if true, assumes the `amountIn` is part of the existing FGEN supply. Set to false to simulate a new purchase.
    /// @return feiAmount the amount of FEI received by the user
    /// @return tribeAmount the amount of TRIBE received by the user
    function getAmountOut(uint256 amountIn, bool inclusive)
        public
        view
        override
        returns (uint256 feiAmount, uint256 tribeAmount)
    {
        uint256 totalIn = totalSupply().add(totalCommittedFGEN);
        if (!inclusive) {
            // exclusive from current supply, so we add it in
            totalIn = totalIn.add(amountIn);
        }
        require(amountIn <= totalIn, "GenesisGroup: Not enough supply");

        uint256 totalFei = bondingcurve.getAmountOut(totalIn);
        uint256 totalTribe = tribeBalance();

        // return portions of total FEI and TRIBE
        return (
            totalFei.mul(amountIn) / totalIn,
            totalTribe.mul(amountIn) / totalIn
        );
    }

    function _burnFrom(address account, uint256 amount) internal {
        if (msg.sender != account) {
            uint256 decreasedAllowance =
                allowance(account, _msgSender()).sub(
                    amount,
                    "GenesisGroup: burn amount exceeds allowance"
                );
            _approve(account, _msgSender(), decreasedAllowance);
        }
        _burn(account, amount);
    }

    function _feiTribeExchangeRate()
        internal
        view
        returns (Decimal.D256 memory)
    {
        return
            Decimal.ratio(feiBalance(), tribeBalance()).div(
                exchangeRateDiscount
            );
    }
}