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Created using remix-ide: Realtime Ethereum Contract Compiler and Runtime. Load this file by pasting this gists URL or ID at https://remix.ethereum.org/#version=soljson-v0.6.12+commit.27d51765.js&optimize=true&runs=200&gist=
pragma solidity ^0.6.8;
/*
SPDX-License-Identifier: MIT
A Bankteller Production
Bankroll Network
Copyright 2021
*/
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;
}
}
/**
* @dev Contract module which provides a basic access control mechanism, where
* there is an account (an owner) that can be granted exclusive access to
* specific functions.
*
* By default, the owner account will be the one that deploys the contract. This
* can later be changed with {transferOwnership}.
*
* This module is used through inheritance. It will make available the modifier
* `onlyOwner`, which can be applied to your functions to restrict their use to
* the owner.
*/
contract Ownable is Context {
address private _owner;
address private _previousOwner;
uint256 private _lockTime;
event OwnershipTransferred(address indexed previousOwner, address indexed newOwner);
/**
* @dev Initializes the contract setting the deployer as the initial owner.
*/
constructor () internal {
address msgSender = _msgSender();
_owner = msgSender;
emit OwnershipTransferred(address(0), msgSender);
}
/**
* @dev Returns the address of the current owner.
*/
function owner() public view returns (address) {
return _owner;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(_owner == _msgSender(), "Ownable: caller is not the owner");
_;
}
/**
* @dev Leaves the contract without owner. It will not be possible to call
* `onlyOwner` functions anymore. Can only be called by the current owner.
*
* NOTE: Renouncing ownership will leave the contract without an owner,
* thereby removing any functionality that is only available to the owner.
*/
function renounceOwnership() public virtual onlyOwner {
emit OwnershipTransferred(_owner, address(0));
_owner = address(0);
}
/**
* @dev Transfers ownership of the contract to a new account (`newOwner`).
* Can only be called by the current owner.
*/
function transferOwnership(address newOwner) public virtual onlyOwner {
require(newOwner != address(0), "Ownable: new owner is the zero address");
emit OwnershipTransferred(_owner, newOwner);
_owner = newOwner;
}
function getUnlockTime() public view returns (uint256) {
return _lockTime;
}
//Locks the contract for owner for the amount of time provided
function lock(uint256 time) public virtual onlyOwner {
_previousOwner = _owner;
_owner = address(0);
_lockTime = now + time;
emit OwnershipTransferred(_owner, address(0));
}
//Unlocks the contract for owner when _lockTime is exceeds
function unlock() public virtual {
require(_previousOwner == msg.sender, "You don't have permission to unlock");
require(now > _lockTime , "Contract is locked until 7 days");
emit OwnershipTransferred(_owner, _previousOwner);
_owner = _previousOwner;
}
}
/**
* @title Whitelist
* @dev The Whitelist contract has a whitelist of addresses, and provides basic authorization control functions.
* @dev This simplifies the implementation of "user permissions".
*/
contract Whitelist is Ownable {
mapping(address => bool) public whitelist;
event WhitelistedAddressAdded(address addr);
event WhitelistedAddressRemoved(address addr);
/**
* @dev Throws if called by any account that's not whitelisted.
*/
modifier onlyWhitelisted() {
require(whitelist[msg.sender], 'not whitelisted');
_;
}
/**
* @dev add an address to the whitelist
* @param addr address
* @return success true if the address was added to the whitelist, false if the address was already in the whitelist
*/
function addAddressToWhitelist(address addr) onlyOwner public returns(bool success) {
if (!whitelist[addr]) {
whitelist[addr] = true;
emit WhitelistedAddressAdded(addr);
success = true;
}
}
/**
* @dev add addresses to the whitelist
* @param addrs addresses
* @return success true if at least one address was added to the whitelist,
* false if all addresses were already in the whitelist
*/
function addAddressesToWhitelist(address[] calldata addrs) onlyOwner public returns(bool success) {
for (uint256 i = 0; i < addrs.length; i++) {
if (addAddressToWhitelist(addrs[i])) {
success = true;
}
}
}
/**
* @dev remove an address from the whitelist
* @param addr address
* @return success true if the address was removed from the whitelist,
* false if the address wasn't in the whitelist in the first place
*/
function removeAddressFromWhitelist(address addr) onlyOwner public returns(bool success) {
if (whitelist[addr]) {
whitelist[addr] = false;
emit WhitelistedAddressRemoved(addr);
success = true;
}
}
/**
* @dev remove addresses from the whitelist
* @param addrs addresses
* @return success true if at least one address was removed from the whitelist,
* false if all addresses weren't in the whitelist in the first place
*/
function removeAddressesFromWhitelist(address[] calldata addrs) onlyOwner public returns(bool success) {
for (uint256 i = 0; i < addrs.length; i++) {
if (removeAddressFromWhitelist(addrs[i])) {
success = true;
}
}
}
}
// File: openzeppelin-solidity/contracts/math/SafeMath.sol
/**
* @title SafeMath
* @dev Math operations with safety checks that throw on error
*/
library SafeMath {
/**
* @dev Multiplies two numbers, throws on overflow.
*/
function mul(uint256 a, uint256 b) internal pure returns (uint256 c) {
if (a == 0) {
return 0;
}
c = a * b;
assert(c / a == b);
return c;
}
/**
* @dev Integer division of two numbers, truncating the quotient.
*/
function div(uint256 a, uint256 b) internal pure returns (uint256) {
// assert(b > 0); // Solidity automatically throws when dividing by 0
// uint256 c = a / b;
// assert(a == b * c + a % b); // There is no case in which this doesn't hold
return a / b;
}
/**
* @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
*/
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
assert(b <= a);
return a - b;
}
/**
* @dev Adds two numbers, throws on overflow.
*/
function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
c = a + b;
assert(c >= a);
return c;
}
}
interface BEP20Basic {
function totalSupply() external view returns (uint256);
function balanceOf(address who) external view returns (uint256);
function transfer(address to, uint256 value) external returns (bool);
event Transfer(address indexed from, address indexed to, uint256 value);
}
/**
* @title Basic token
* @dev Basic version of StandardToken, with no allowances.
*/
contract BasicToken is BEP20Basic {
using SafeMath for uint256;
mapping(address => uint256) balances;
uint256 totalSupply_;
/**
* @dev total number of tokens in existence
*/
function totalSupply() public override view returns (uint256) {
return totalSupply_;
}
/**
* @dev transfer token for a specified address
* @param _to The address to transfer to.
* @param _value The amount to be transferred.
*/
function transfer(address _to, uint256 _value) public override returns (bool) {
require(_to != address(0));
require(_value <= balances[msg.sender]);
balances[msg.sender] = balances[msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
emit Transfer(msg.sender, _to, _value);
return true;
}
/**
* @dev Gets the balance of the specified address.
* @param _owner The address to query the the balance of.
* @return An uint256 representing the amount owned by the passed address.
*/
function balanceOf(address _owner) public override view returns (uint256) {
return balances[_owner];
}
}
/**
* @title BEP20 interface
* @dev see https://github.com/ethereum/EIPs/issues/20
*/
abstract contract BEP20 is BEP20Basic {
function allowance(address owner, address spender) public virtual view returns (uint256);
function transferFrom(address from, address to, uint256 value) public virtual returns (bool);
function approve(address spender, uint256 value) public virtual returns (bool);
event Approval(address indexed owner, address indexed spender, uint256 value);
}
/**
* @title Standard BEP20 token
*
* @dev Implementation of the basic standard token.
* @dev https://github.com/ethereum/EIPs/issues/20
*/
contract StandardToken is BEP20, BasicToken {
mapping(address => mapping(address => uint256)) internal allowed;
/**
* @dev Transfer tokens from one address to another
* @param _from address The address which you want to send tokens from
* @param _to address The address which you want to transfer to
* @param _value uint256 the amount of tokens to be transferred
*/
function transferFrom(address _from, address _to, uint256 _value) public override virtual returns (bool) {
require(_to != address(0));
require(_value <= balances[_from]);
require(_value <= allowed[_from][msg.sender]);
balances[_from] = balances[_from].sub(_value);
balances[_to] = balances[_to].add(_value);
allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
emit Transfer(_from, _to, _value);
return true;
}
/**
* @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
*
* 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
* @param _spender The address which will spend the funds.
* @param _value The amount of tokens to be spent.
*/
function approve(address _spender, uint256 _value) public override returns (bool) {
allowed[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
return true;
}
/**
* @dev Function to check the amount of tokens that an owner allowed to a spender.
* @param _owner address The address which owns the funds.
* @param _spender address The address which will spend the funds.
* @return A uint256 specifying the amount of tokens still available for the spender.
*/
function allowance(address _owner, address _spender) public override view returns (uint256) {
return allowed[_owner][_spender];
}
/**
* @dev Increase the amount of tokens that an owner allowed to a spender.
*
* approve should be called when allowed[_spender] == 0. To increment
* allowed value is better to use this function to avoid 2 calls (and wait until
* the first transaction is mined)
* From MonolithDAO Token.sol
* @param _spender The address which will spend the funds.
* @param _addedValue The amount of tokens to increase the allowance by.
*/
function increaseApproval(address _spender, uint _addedValue) public returns (bool) {
allowed[msg.sender][_spender] = allowed[msg.sender][_spender].add(_addedValue);
emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
/**
* @dev Decrease the amount of tokens that an owner allowed to a spender.
*
* approve should be called when allowed[_spender] == 0. To decrement
* allowed value is better to use this function to avoid 2 calls (and wait until
* the first transaction is mined)
* From MonolithDAO Token.sol
* @param _spender The address which will spend the funds.
* @param _subtractedValue The amount of tokens to decrease the allowance by.
*/
function decreaseApproval(address _spender, uint _subtractedValue) public returns (bool) {
uint oldValue = allowed[msg.sender][_spender];
if (_subtractedValue > oldValue) {
allowed[msg.sender][_spender] = 0;
} else {
allowed[msg.sender][_spender] = oldValue.sub(_subtractedValue);
}
emit Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
}
/**
* @title Mintable token
* @dev Simple BEP20 Token example, with mintable token creation
* @dev Issue: * https://github.com/OpenZeppelin/openzeppelin-solidity/issues/120
*/
contract MintableToken is StandardToken, Whitelist {
event Mint(address indexed to, uint256 amount);
event MintFinished();
bool public mintingFinished = false;
modifier canMint() {
require(!mintingFinished);
_;
}
/**
* @dev Function to mint tokens
* @param _to The address that will receive the minted tokens.
* @param _amount The amount of tokens to mint.
* @return A boolean that indicates if the operation was successful.
*/
function mint(address _to, uint256 _amount) onlyWhitelisted canMint public virtual returns (bool) {
require(_to != address(0));
totalSupply_ = totalSupply_.add(_amount);
balances[_to] = balances[_to].add(_amount);
emit Mint(_to, _amount);
emit Transfer(address(0), _to, _amount);
return true;
}
}
/**
* @title Burnable Token
* @dev Token that can be irreversibly burned (destroyed).
*/
contract BurnableToken is MintableToken {
using SafeMath for uint256;
event Burn(address indexed burner, uint256 value);
/**
* @dev Burns a specific amount of tokens.
* @param _value The amount of token to be burned.
*/
function burn(uint256 _value) public {
require(_value > 0);
require(_value <= balances[msg.sender]);
// no need to require value <= totalSupply, since that would imply the
// sender's balance is greater than the totalSupply, which *should* be an assertion failure
address burner = msg.sender;
balances[burner] = balances[burner].sub(_value);
totalSupply_ = totalSupply_.sub(_value);
Burn(burner, _value);
}
}
contract ElephantDollar is BurnableToken {
struct Stats {
uint256 txs;
}
string private _name;
string private _symbol;
uint8 public constant decimals = 18;
uint256 public constant MAX_INT = 2**256 - 1;
uint256 public constant targetSupply = MAX_INT;
uint256 public totalTxs;
uint256 public participants;
uint256 private mintedSupply_;
mapping(address => Stats) private stats;
/**
* @dev default constructor
*/
constructor(string memory name, string memory symbol) Ownable() public {
require(bytes(name).length > 0 && bytes(symbol).length > 0, "Description information must be set");
_name = name;
_symbol = symbol;
}
function name() public view returns (string memory) {
return _name;
}
function symbol() public view returns (string memory) {
return _symbol;
}
/**
* @dev Function to mint tokens (onlyOwner)
* @param _to The address that will receive the minted tokens.
* @param _amount The amount of tokens to mint.
* @return A boolean that indicates if the operation was successful.
*/
function mint(address _to, uint256 _amount) public override returns (bool) {
//Never fail, just don't mint if over
require(_amount > 0 && totalSupply_.add(_amount) <= targetSupply);
//Mint
super.mint(_to, _amount);
if (totalSupply_ == targetSupply) {
mintingFinished = true;
emit MintFinished();
}
/* Members */
if (stats[_to].txs == 0) {
participants += 1;
}
stats[_to].txs += 1;
totalTxs += 1;
return true;
}
/** @dev Transfers (using transferFrom) */
function transferFrom(address _from, address _to, uint256 _value) public override returns (bool) {
require(super.transferFrom(_from, _to, _value));
/* Members */
if (stats[_to].txs == 0) {
participants += 1;
}
stats[_to].txs += 1;
stats[_from].txs += 1;
totalTxs += 1;
return true;
}
/** @dev Transfers */
function transfer(address _to, uint256 _value) public override returns (bool) {
require(super.transfer(_to, _value));
/* Members */
if (stats[_to].txs == 0) {
participants += 1;
}
stats[_to].txs += 1;
stats[msg.sender].txs += 1;
totalTxs += 1;
return true;
}
/** @dev Returns the supply still available to mint */
function remainingMintableSupply() public view returns (uint256) {
return targetSupply.sub(totalSupply_);
}
}
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