pragma solidity ^0.4.10;
/* taking ideas from FirstBlood token */
contract SafeMath {
/* function assert(bool assertion) internal { */
/* if (!assertion) { */
/* throw; */
/* } */
/* } // assert no longer needed once solidity is on 0.4.10 */
function safeAdd(uint256 x, uint256 y) internal returns(uint256) {
uint256 z = x + y;
assert((z >= x) && (z >= y));
return z;
}
function safeSubtract(uint256 x, uint256 y) internal returns(uint256) {
assert(x >= y);
uint256 z = x - y;
return z;
}
function safeMult(uint256 x, uint256 y) internal returns(uint256) {
uint256 z = x * y;
assert((x == 0)||(z/x == y));
return z;
}
}
contract Token {
uint256 public totalSupply;
function balanceOf(address _owner) constant returns (uint256 balance);
function transfer(address _to, uint256 _value) returns (bool success);
function transferFrom(address _from, address _to, uint256 _value) returns (bool success);
function approve(address _spender, uint256 _value) returns (bool success);
function allowance(address _owner, address _spender) constant returns (uint256 remaining);
event Transfer(address indexed _from, address indexed _to, uint256 _value);
event Approval(address indexed _owner, address indexed _spender, uint256 _value);
}
/* ERC 20 token */
contract StandardToken is Token {
function transfer(address _to, uint256 _value) returns (bool success) {
if (balances[msg.sender] >= _value && _value > 0) {
balances[msg.sender] -= _value;
balances[_to] += _value;
Transfer(msg.sender, _to, _value);
return true;
} else {
return false;
}
}
function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0) {
balances[_to] += _value;
balances[_from] -= _value;
allowed[_from][msg.sender] -= _value;
Transfer(_from, _to, _value);
return true;
} else {
return false;
}
}
function balanceOf(address _owner) constant returns (uint256 balance) {
return balances[_owner];
}
function approve(address _spender, uint256 _value) returns (bool success) {
allowed[msg.sender][_spender] = _value;
Approval(msg.sender, _spender, _value);
return true;
}
function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
return allowed[_owner][_spender];
}
mapping (address => uint256) balances;
mapping (address => mapping (address => uint256)) allowed;
}
contract BAToken is StandardToken, SafeMath {
// metadata
string public constant name = "Basic Attention Token";
string public constant symbol = "BAT";
uint256 public constant decimals = 18;
string public version = "1.0";
// contracts
address public ethFundDeposit; // deposit address for ETH for Brave International
address public batFundDeposit; // deposit address for Brave International use and BAT User Fund
// crowdsale parameters
bool public isFinalized; // switched to true in operational state
uint256 public fundingStartBlock;
uint256 public fundingEndBlock;
uint256 public constant batFund = 500 * (10**6) * 10**decimals; // 500m BAT reserved for Brave Intl use
uint256 public constant tokenExchangeRate = 6400; // 6400 BAT tokens per 1 ETH
uint256 public constant tokenCreationCap = 1500 * (10**6) * 10**decimals;
uint256 public constant tokenCreationMin = 675 * (10**6) * 10**decimals;
// events
event LogRefund(address indexed _to, uint256 _value);
event CreateBAT(address indexed _to, uint256 _value);
// constructor
function BAToken(
address _ethFundDeposit,
address _batFundDeposit,
uint256 _fundingStartBlock,
uint256 _fundingEndBlock)
{
isFinalized = false; //controls pre through crowdsale state
ethFundDeposit = _ethFundDeposit;
batFundDeposit = _batFundDeposit;
fundingStartBlock = _fundingStartBlock;
fundingEndBlock = _fundingEndBlock;
totalSupply = batFund;
balances[batFundDeposit] = batFund; // Deposit Brave Intl share
CreateBAT(batFundDeposit, batFund); // logs Brave Intl fund
}
/// @dev Accepts ether and creates new BAT tokens.
function createTokens() payable external {
if (isFinalized) throw;
if (block.number < fundingStartBlock) throw;
if (block.number > fundingEndBlock) throw;
if (msg.value == 0) throw;
uint256 tokens = safeMult(msg.value, tokenExchangeRate); // check that we're not over totals
uint256 checkedSupply = safeAdd(totalSupply, tokens);
// return money if something goes wrong
if (tokenCreationCap < checkedSupply) throw; // odd fractions won't be found
totalSupply = checkedSupply;
balances[msg.sender] += tokens; // safeAdd not needed; bad semantics to use here
CreateBAT(msg.sender, tokens); // logs token creation
}
/// @dev Ends the funding period and sends the ETH home
function finalize() external {
if (isFinalized) throw;
if (msg.sender != ethFundDeposit) throw; // locks finalize to the ultimate ETH owner
if(totalSupply < tokenCreationMin) throw; // have to sell minimum to move to operational
if(block.number <= fundingEndBlock && totalSupply != tokenCreationCap) throw;
// move to operational
isFinalized = true;
if(!ethFundDeposit.send(this.balance)) throw; // send the eth to Brave International
}
/// @dev Allows contributors to recover their ether in the case of a failed funding campaign.
function refund() external {
if(isFinalized) throw; // prevents refund if operational
if (block.number <= fundingEndBlock) throw; // prevents refund until sale period is over
if(totalSupply >= tokenCreationMin) throw; // no refunds if we sold enough
if(msg.sender == batFundDeposit) throw; // Brave Intl not entitled to a refund
uint256 batVal = balances[msg.sender];
if (batVal == 0) throw;
balances[msg.sender] = 0;
totalSupply = safeSubtract(totalSupply, batVal); // extra safe
uint256 ethVal = batVal / tokenExchangeRate; // should be safe; previous throws covers edges
LogRefund(msg.sender, ethVal); // log it
if (!msg.sender.send(ethVal)) throw; // if you're using a contract; make sure it works with .send gas limits
}
}
