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pragma solidity 0.4.24;
library SafeMath {
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;
}
function div(uint256 a, uint256 b) internal pure returns (uint256) {
return a / b;
}
function sub(uint256 a, uint256 b) internal pure returns (uint256) {
assert(b <= a);
return a - b;
}
function add(uint256 a, uint256 b) internal pure returns (uint256 c) {
c = a + b;
assert(c >= a);
return c;
}
}
contract customIcoToken{
using SafeMath for uint256;
/* Events */
event Transfer(address indexed from, address indexed to, uint256 value);
event Approval(address indexed owner, address indexed spender, uint256 value);
event LogRefund(address indexed _to, uint256 _value);
event CreateToken(address indexed _to, uint256 _value);
// metadata
string public name;
string public symbol;
uint256 public decimals;
// contracts
address public ethFundDeposit; // deposit address for ETH
address public tokenFundDeposit;
// crowdsale parameters
bool public isFinalized; // switched to true in operational state
uint256 public fundingStartBlock;
uint256 public fundingEndBlock;
uint256 public tokenFund;
uint256 public tokenExchangeRate;
uint256 public tokenCreationCap;
uint256 public tokenCreationMin;
/* Storage */
mapping(address => uint256) balances;
mapping (address => mapping (address => uint256)) internal allowed;
uint256 public totalSupply;
/* Getters */
function totalSupply() public view returns (uint256) {
return totalSupply;
}
function balanceOf(address _owner) public view returns (uint256 balance) {
return balances[_owner];
}
function allowance(address _owner, address _spender) public view returns (uint256) {
return allowed[_owner][_spender];
}
/* Methods */
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);
emit Transfer(_from, _to, _value);
return true;
}
function approve(address _spender, uint256 _value) public returns (bool) {
allowed[msg.sender][_spender] = _value;
emit Approval(msg.sender, _spender, _value);
return true;
}
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;
}
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;
}
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);
emit Transfer(msg.sender, _to, _value);
return true;
}
/* Crowdsale methods */
/// @dev Accepts ether and creates new tokens.
function createTokens() payable external {
require (isFinalized == false);
require(block.number > fundingStartBlock);
require(block.number < fundingEndBlock);
require(msg.value > 0);
uint256 tokens = msg.value.mul(tokenExchangeRate);
uint256 checkedSupply = totalSupply.add(tokens);
// return money if something goes wrong
require(tokenCreationCap >= checkedSupply); // odd fractions won't be found
totalSupply = checkedSupply;
balances[msg.sender] += tokens; // safeAdd not needed; bad semantics to use here
emit CreateToken(msg.sender, tokens); // logs token creation
}
/// @dev Ends the funding period and sends the ETH home
function finalize() external {
require(isFinalized == false);
require(msg.sender == ethFundDeposit);
require(totalSupply > tokenCreationMin); // have to sell minimum to move to operational
require(block.number > fundingEndBlock || totalSupply == tokenCreationCap);
// move to operational
isFinalized = true;
assert(ethFundDeposit.send(address(this).balance)); // send the eth
}
/// @dev Allows contributors to recover their ether in the case of a failed funding campaign.
function refund() external {
require(isFinalized == false); // prevents refund if operational
require(block.number > fundingEndBlock); // prevents refund until sale period is over
require(totalSupply < tokenCreationMin); // no refunds if we sold enough
require(msg.sender != tokenFundDeposit); // team not entitled to a refund
uint256 tokenVal = balances[msg.sender];
require(tokenVal > 0);
balances[msg.sender] = 0;
totalSupply = totalSupply.sub(tokenVal); // extra safe
uint256 ethVal = tokenVal / tokenExchangeRate; // should be safe; previous throws covers edges
emit LogRefund(msg.sender, ethVal); // log it
assert(msg.sender.send(ethVal)); // if you're using a contract; make sure it works with .send gas limits
}
constructor(
string _name,
string _symbol,
uint8 _decimals,
address _ethFundDeposit,
address _tokenFundDeposit,
uint256 _tokenFund,
uint256 _tokenExchangeRate,
uint256 _tokenCreationCap,
uint256 _tokenCreationMin,
uint256 _fundingStartBlock,
uint256 _fundingEndBlock) public
{
name = _name;
symbol = _symbol;
decimals = _decimals;
isFinalized = false; //controls pre through crowdsale state
ethFundDeposit = _ethFundDeposit;
tokenFundDeposit = _tokenFundDeposit;
tokenFund = _tokenFund*10**decimals;
tokenExchangeRate = _tokenExchangeRate;
tokenCreationCap = _tokenCreationCap*10**decimals;
tokenCreationMin = _tokenCreationMin*10**decimals;
fundingStartBlock = _fundingStartBlock;
fundingEndBlock = _fundingEndBlock;
totalSupply = tokenFund;
balances[tokenFundDeposit] = tokenFund;
emit CreateToken(tokenFundDeposit, tokenFund);
}
}