Cover Protocol

// SPDX-License-Identifier: None

pragma solidity ^0.7.4;

import "./utils/SafeMath.sol";
import "./utils/Ownable.sol";
import "./ERC20/ERC20.sol";

/**
 * @title COVER token contract
 * @author crypto-pumpkin@github
 */
contract COVER is Ownable, ERC20 {
  using SafeMath for uint256;

  bool private isReleased;
  address public blacksmith; // mining contract
  address public migrator; // migration contract
  uint256 public constant START_TIME = 1605830400; // 11/20/2020 12am UTC

  constructor () ERC20("Cover Protocol", "COVER") {
    // mint 1 token to create pool2
    _mint(0x2f80E5163A7A774038753593010173322eA6f9fe, 1e18);
  }

  function mint(address _account, uint256 _amount) public {
    require(isReleased, "$COVER: not released");
    require(msg.sender == migrator || msg.sender == blacksmith, "$COVER: caller not migrator or Blacksmith");

    _mint(_account, _amount);
  }

  function setBlacksmith(address _newBlacksmith) external returns (bool) {
    require(msg.sender == blacksmith, "$COVER: caller not blacksmith");

    blacksmith = _newBlacksmith;
    return true;
  }

  function setMigrator(address _newMigrator) external returns (bool) {
    require(msg.sender == migrator, "$COVER: caller not migrator");

    migrator = _newMigrator;
    return true;
  }

  /// @notice called once and only by owner
  function release(address _treasury, address _vestor, address _blacksmith, address _migrator) external onlyOwner {
    require(block.timestamp >= START_TIME, "$COVER: not started");
    require(isReleased == false, "$COVER: already released");

    isReleased = true;

    blacksmith = _blacksmith;
    migrator = _migrator;
    _mint(_treasury, 950e18);
    _mint(_vestor, 10800e18);
  }
}

// SPDX-License-Identifier: None

pragma solidity ^0.7.4;

import "../utils/SafeMath.sol";
import "./IERC20.sol";

contract ERC20 is 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;

  constructor (string memory name_, string memory symbol_) {
    _name = name_;
    _symbol = symbol_;
    _decimals = 18;
  }

  function name() public view returns (string memory) {
    return _name;
  }

  function symbol() public view returns (string memory) {
    return _symbol;
  }

  function decimals() public view returns (uint8) {
    return _decimals;
  }

  function totalSupply() public view override returns (uint256) {
    return _totalSupply;
  }

  function balanceOf(address account) public view override returns (uint256) {
    return _balances[account];
  }

  function transfer(address recipient, uint256 amount) public virtual override returns (bool) {
    _transfer(msg.sender, recipient, amount);
    return true;
  }

  function allowance(address owner, address spender) public view virtual override returns (uint256) {
    return _allowances[owner][spender];
  }

  function approve(address spender, uint256 amount) public virtual override returns (bool) {
    _approve(msg.sender, spender, amount);
    return true;
  }

  function transferFrom(address sender, address recipient, uint256 amount) public virtual override returns (bool) {
    _transfer(sender, recipient, amount);
    _approve(sender, msg.sender, _allowances[sender][msg.sender].sub(amount, "ERC20: transfer amount exceeds allowance"));
    return true;
  }

  function increaseAllowance(address spender, uint256 addedValue) public virtual returns (bool) {
    _approve(msg.sender, spender, _allowances[msg.sender][spender].add(addedValue));
    return true;
  }

  function decreaseAllowance(address spender, uint256 subtractedValue) public virtual returns (bool) {
    _approve(msg.sender, spender, _allowances[msg.sender][spender].sub(subtractedValue, "ERC20: decreased allowance below zero"));
    return true;
  }

  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");


    _balances[sender] = _balances[sender].sub(amount, "ERC20: transfer amount exceeds balance");
    _balances[recipient] = _balances[recipient].add(amount);
    emit Transfer(sender, recipient, amount);
  }

  function _mint(address account, uint256 amount) internal virtual {
    require(account != address(0), "ERC20: mint to the zero address");

    _totalSupply = _totalSupply.add(amount);
    _balances[account] = _balances[account].add(amount);
    emit Transfer(address(0), account, amount);
  }

  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);
  }
}

// SPDX-License-Identifier: None

pragma solidity ^0.7.4;

/**
 * @title Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);

    function balanceOf(address account) external view returns (uint256);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function approve(address spender, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
    function totalSupply() external view returns (uint256);
}

// SPDX-License-Identifier: None

pragma solidity ^0.7.4;

/**
 * @dev Contract module which provides a basic access control mechanism, where
 * there is an account (an owner) that can be granted exclusive access to
 * specific functions.
 * @author crypto-pumpkin@github
 *
 * By initialization, the owner account will be the one that called initializeOwner. This
 * can later be changed with {transferOwnership}.
 *
 * This module is used through inheritance. It will make available the modifier
 * `onlyOwner`, which can be applied to your functions to restrict their use to
 * the owner.
 */
contract Ownable {
    address private _owner;

    event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);

    /**
     * @dev COVER: Initializes the contract setting the deployer as the initial owner.
     */
    constructor () {
        _owner = msg.sender;
        emit OwnershipTransferred(address(0), _owner);
    }

    /**
     * @dev Returns the address of the current owner.
     */
    function owner() public view returns (address) {
        return _owner;
    }

    /**
     * @dev Throws if called by any account other than the owner.
     */
    modifier onlyOwner() {
        require(_owner == msg.sender, "Ownable: caller is not the owner");
        _;
    }

    /**
     * @dev Transfers ownership of the contract to a new account (`newOwner`).
     * Can only be called by the current owner.
     */
    function transferOwnership(address newOwner) public virtual onlyOwner {
        require(newOwner != address(0), "Ownable: new owner is the zero address");
        emit OwnershipTransferred(_owner, newOwner);
        _owner = newOwner;
    }
}

// SPDX-License-Identifier: None

pragma solidity ^0.7.4;

/**
 * @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, 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;
    }
}

{
  "compilationTarget": {
    "contracts/COVER.sol": "COVER"
  },
  "evmVersion": "istanbul",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": true,
    "runs": 200
  },
  "remappings": []
}