Skip to content

Instantly share code, notes, and snippets.

@goastoman
Created February 16, 2018 10:27
Show Gist options
  • Save goastoman/b9aca046839c35d8907e62269eb6a53b to your computer and use it in GitHub Desktop.
Save goastoman/b9aca046839c35d8907e62269eb6a53b to your computer and use it in GitHub Desktop.
preico
pragma solidity ^0.4.18;
/**
* @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) {
if (a == 0) {
return 0;
}
uint256 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 c;
}
/**
* @dev Substracts 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) {
uint256 c = a + b;
assert(c >= a);
return c;
}
}
/**
* @title ERC20Basic
* @dev see https://github.com/ethereum/EIPs/issues/179
*/
contract ERC20Basic {
function totalSupply() public view returns (uint256);
function balanceOf(address who) public view returns (uint256);
function transfer(address to, uint256 value) public returns (bool);
event Transfer(address indexed from, address indexed to, uint256 value);
}
/**
* @title ERC20 interface
* @dev see https://github.com/ethereum/EIPs/issues/20
*/
contract ERC20 is ERC20Basic {
function allowance(address owner, address spender) public view returns (uint256);
function transferFrom(address from, address to, uint256 value) public returns (bool);
function approve(address spender, uint256 value) public returns (bool);
event Approval(address indexed owner, address indexed spender, uint256 value);
}
/**
* @title Basic token
* @dev Basic version of StandardToken, with no allowances.
*/
contract BasicToken is ERC20Basic {
using SafeMath for uint256;
mapping(address => uint256) balances;
uint256 totalSupply_;
/**
* @dev total number of tokens in existence
*/
function totalSupply() public 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 returns (bool) {
require(_to != address(0));
require(_value <= balances[msg.sender]);
// SafeMath.sub will throw if there is not enough balance.
balances[msg.sender] = balances[msg.sender].sub(_value);
balances[_to] = balances[_to].add(_value);
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 view returns (uint256 balance) {
return balances[_owner];
}
}
/**
* @title Standard ERC20 token
*
* @dev Implementation of the basic standard token.
* @dev https://github.com/ethereum/EIPs/issues/20
* @dev Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
*/
contract StandardToken is ERC20, 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 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);
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 returns (bool) {
allowed[msg.sender][_spender] = _value;
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 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);
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);
}
Approval(msg.sender, _spender, allowed[msg.sender][_spender]);
return true;
}
}
contract Ownable {
address public owner;
/**
* @dev The Ownable constructor sets the original `owner` of the contract to the sender
* account.
*/
function Ownable() {
owner = msg.sender;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlyOwner() {
require(msg.sender == owner);
_;
}
/**
* @dev Allows the current owner to transfer control of the contract to a newOwner.
* @param newOwner The address to transfer ownership to.
*/
function transferOwnership(address newOwner) onlyOwner {
require(newOwner != address(0));
owner = newOwner;
}
}
/**
* @title Mintable token
* @dev Simple ERC20 Token example, with mintable token creation
* @dev Issue: * https://github.com/OpenZeppelin/zeppelin-solidity/issues/120
* Based on code by TokenMarketNet: https://github.com/TokenMarketNet/ico/blob/master/contracts/MintableToken.sol
*/
contract MintableToken is StandardToken, Ownable {
string public constant name = "IdealToken";
string public constant symbol = "IT";
uint8 public constant decimals = 18;
address public saleAgent = address(0);
event Mint(address indexed to, uint256 amount);
event MintFinished();
bool public mintingFinished = false;
modifier canMint() {
require(!mintingFinished);
_;
}
/**
* @dev Throws if called by any account other than the owner.
*/
modifier onlySaleAgent() {
require(msg.sender == saleAgent || msg.sender == owner);
_;
}
function setSaleAgent(address _saleAgent) onlySaleAgent {
saleAgent = _saleAgent;
}
/**
* @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) onlySaleAgent canMint public returns (bool) {
totalSupply_ = totalSupply_.add(_amount);
balances[_to] = balances[_to].add(_amount);
Mint(_to, _amount);
Transfer(address(0), _to, _amount);
return true;
}
/**
* @dev Function to stop minting new tokens.
* @return True if the operation was successful.
*/
function finishMinting() onlyOwner canMint public returns (bool) {
mintingFinished = true;
MintFinished();
return true;
}
}
/**
* @title Crowdsale
* @dev Crowdsale is a base contract for managing a token crowdsale.
* Crowdsales have a start and end timestamps, where investors can make
* token purchases and the crowdsale will assign them tokens based
* on a token per ETH rate. Funds collected are forwarded to a wallet
* as they arrive. The contract requires a MintableToken that will be
* minted as contributions arrive, note that the crowdsale contract
* must be owner of the token in order to be able to mint it.
*/
contract Crowdsale {
using SafeMath for uint256;
// The token being sold
MintableToken public token;
// start and end timestamps where investments are allowed (both inclusive)
uint256 public constant startTime = 1518776100;
uint256 public constant endTime = 1518776400;
// address where funds are collected
address public constant wallet = 0x39f5C418E60a93e864E737242CB16771451f6690;
// how many token units a buyer gets per wei
uint256 public constant rate = 10;
// amount of raised money in wei
uint256 public weiRaised;
/**
* event for token purchase logging
* @param purchaser who paid for the tokens
* @param beneficiary who got the tokens
* @param value weis paid for purchase
* @param amount amount of tokens purchased
*/
event TokenPurchase(address indexed purchaser, address indexed beneficiary, uint256 value, uint256 amount);
function Crowdsale() public {
token = createTokenContract();
token.setSaleAgent(msg.sender);
}
// creates the token to be sold.
// override this method to have crowdsale of a specific mintable token.
function createTokenContract() internal returns (MintableToken) {
return new MintableToken();
}
// fallback function can be used to buy tokens
function () external payable {
buyTokens(msg.sender);
}
// low level token purchase function
function buyTokens(address beneficiary) public payable {
require(beneficiary != address(0));
require(validPurchase());
uint256 weiAmount = msg.value;
// calculate token amount to be created
uint256 tokens = getTokenAmount(weiAmount);
// update state
weiRaised = weiRaised.add(weiAmount);
token.mint(beneficiary, tokens);
TokenPurchase(msg.sender, beneficiary, weiAmount, tokens);
forwardFunds();
}
// @return true if crowdsale event has ended
function hasEnded() public view returns (bool) {
return now > endTime;
}
// Override this method to have a way to add business logic to your crowdsale when buying
function getTokenAmount(uint256 weiAmount) internal view returns(uint256) {
return weiAmount.mul(rate);
}
// send ether to the fund collection wallet
// override to create custom fund forwarding mechanisms
function forwardFunds() internal {
wallet.transfer(msg.value);
}
// @return true if the transaction can buy tokens
function validPurchase() internal view returns (bool) {
bool withinPeriod = now >= startTime && now <= endTime;
bool nonZeroPurchase = msg.value != 0;
return withinPeriod && nonZeroPurchase;
}
}
/**
* @title RefundVault
* @dev This contract is used for storing funds while a crowdsale
* is in progress. Supports refunding the money if crowdsale fails,
* and forwarding it if crowdsale is successful.
*/
contract RefundVault is Ownable {
using SafeMath for uint256;
enum State { Active, Refunding, Closed }
mapping (address => uint256) public deposited;
address public wallet;
State public state;
event Closed();
event RefundsEnabled();
event Refunded(address indexed beneficiary, uint256 weiAmount);
function RefundVault(address _wallet) public {
require(_wallet != 0x0); //
wallet = _wallet;
state = State.Active;
}
function deposit(address investor) onlyOwner public payable {
require(state == State.Active);
deposited[investor] = deposited[investor].add(msg.value);
}
function close() onlyOwner public {
require(state == State.Active);
state = State.Closed;
Closed();
wallet.transfer(this.balance);
}
function enableRefunds() onlyOwner public {
require(state == State.Active);
state = State.Refunding;
RefundsEnabled();
}
function refund(address investor) public {
require(state == State.Refunding);
uint256 depositedValue = deposited[investor];
deposited[investor] = 0;
investor.transfer(depositedValue);
Refunded(investor, depositedValue);
}
}
/**
* @title FinalizableCrowdsale
* @dev Extension of Crowdsale where an owner can do extra work
* after finishing.
*/
contract FinalizableCrowdsale is Crowdsale, Ownable {
using SafeMath for uint256;
bool public isFinalized = false;
event Finalized();
/**
* @dev Must be called after crowdsale ends, to do some extra finalization
* work. Calls the contract's finalization function.
*/
function finalize() onlyOwner public {
require(!isFinalized);
require(hasEnded());
finalization();
Finalized();
isFinalized = true;
}
/**
* @dev Can be overridden to add finalization logic. The overriding function
* should call super.finalization() to ensure the chain of finalization is
* executed entirely.
*/
function finalization() internal {
}
}
/**
* @title RefundableCrowdsale
* @dev Extension of Crowdsale contract that adds a funding goal, and
* the possibility of users getting a refund if goal is not met.
* Uses a RefundVault as the crowdsale's vault.
*/
contract RefundableCrowdsale is FinalizableCrowdsale {
using SafeMath for uint256;
// maximum
uint256 public cap = 10 * (1 ether);
// minimum amount of funds to be raised in weis
uint256 public goal = 5 * (1 ether);
// refund vault used to hold funds while crowdsale is running
RefundVault public vault;
// address where funds are collected
address wallet = 0x39f5C418E60a93e864E737242CB16771451f6690;
function RefundableCrowdsale() public {
vault = new RefundVault(wallet);
}
// overriding Crowdsale#hasEnded to add cap logic
// @return true if crowdsale event has ended
function hasEnded() public view returns (bool) {
bool capReached = weiRaised >= cap;
return capReached || super.hasEnded();
}
// overriding Crowdsale#validPurchase to add extra cap logic
// @return true if investors can buy at the moment
function validPurchase() internal view returns (bool) {
bool withinCap = weiRaised.add(msg.value) <= cap;
return withinCap && super.validPurchase();
}
// if crowdsale is unsuccessful, investors can claim refunds here
function claimRefund() public {
require(isFinalized);
require(!goalReached());
vault.refund(msg.sender);
}
function goalReached() public view returns (bool) {
return weiRaised >= goal;
}
// vault finalization task, called when owner calls finalize()
function finalization() internal {
if (goalReached()) {
vault.close();
} else {
vault.enableRefunds();
}
super.finalization();
}
// We're overriding the fund forwarding from Crowdsale.
// In addition to sending the funds, we want to call
// the RefundVault deposit function
function forwardFunds() internal {
vault.deposit.value(msg.value)(msg.sender);
}
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment