Contract Source Code:
File 1 of 1 : ZanCoin
pragma solidity ^0.4.21;
// ----------------------------------------------------------------------------
// ZAN token contract
//
// Symbol : ZAN
// Name : ZAN Coin
// Total supply: 17,148,385.000000000000000000
// Decimals : 18
//
// ----------------------------------------------------------------------------
// ----------------------------------------------------------------------------
// Safe maths
// ----------------------------------------------------------------------------
library SafeMath {
function add(uint a, uint b) internal pure returns (uint c) {
c = a + b;
assert(c >= a);
}
function sub(uint a, uint b) internal pure returns (uint c) {
assert(b <= a);
c = a - b;
}
function mul(uint a, uint b) internal pure returns (uint c) {
c = a * b;
assert(a == 0 || c / a == b);
}
function div(uint a, uint b) internal pure returns (uint c) {
assert(b > 0);
c = a / b;
}
}
// ----------------------------------------------------------------------------
// ERC Token Standard #20 Interface
// https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md
// ----------------------------------------------------------------------------
contract ERC20Interface {
function totalSupply() public constant returns (uint);
function balanceOf(address tokenOwner) public constant returns (uint balance);
function allowance(address tokenOwner, address spender) public constant returns (uint remaining);
function transfer(address to, uint tokens) public returns (bool success);
function approve(address spender, uint tokens) public returns (bool success);
function transferFrom(address from, address to, uint tokens) public returns (bool success);
event Transfer(address indexed from, address indexed to, uint tokens);
event Approval(address indexed tokenOwner, address indexed spender, uint tokens);
}
// ----------------------------------------------------------------------------
// Contract function to receive approval and execute function in one call
//
// Borrowed from MiniMeToken
// ----------------------------------------------------------------------------
contract ApproveAndCallFallBack {
function receiveApproval(address from, uint tokens, address token, bytes data) public;
}
// ----------------------------------------------------------------------------
// Owned contract
// ----------------------------------------------------------------------------
contract Owned {
address public owner;
address public newOwner;
event OwnershipTransferred(address indexed _from, address indexed _to);
function Owned() public {
owner = msg.sender;
}
modifier onlyOwner {
require(msg.sender == owner);
_;
}
function transferOwnership(address _newOwner) public onlyOwner {
newOwner = _newOwner;
}
function acceptOwnership() public {
require(msg.sender == newOwner);
emit OwnershipTransferred(owner, newOwner);
owner = newOwner;
newOwner = address(0);
}
}
// ----------------------------------------------------------------------------
// ERC20 Token, with the addition of symbol, name and decimals and an
// initial fixed supply
// ----------------------------------------------------------------------------
contract ZanCoin is ERC20Interface, Owned {
using SafeMath for uint;
// ------------------------------------------------------------------------
// Metadata
// ------------------------------------------------------------------------
string public symbol;
string public name;
uint8 public decimals;
uint public _totalSupply;
mapping(address => uint) public balances;
mapping(address => mapping(address => uint)) public allowed;
// ------------------------------------------------------------------------
// Crowdsale data
// ------------------------------------------------------------------------
bool public isInPreSaleState;
bool public isInRoundOneState;
bool public isInRoundTwoState;
bool public isInFinalState;
uint public stateStartDate;
uint public stateEndDate;
uint public saleCap;
uint public exchangeRate;
uint public burnedTokensCount;
event SwitchCrowdSaleStage(string stage, uint exchangeRate);
event BurnTokens(address indexed burner, uint amount);
event PurchaseZanTokens(address indexed contributor, uint eth_sent, uint zan_received);
// ------------------------------------------------------------------------
// Constructor
// ------------------------------------------------------------------------
function ZanCoin() public {
symbol = "ZAN";
name = "ZAN Coin";
decimals = 18;
_totalSupply = 17148385 * 10**uint(decimals);
balances[owner] = _totalSupply;
isInPreSaleState = false;
isInRoundOneState = false;
isInRoundTwoState = false;
isInFinalState = false;
burnedTokensCount = 0;
}
// ------------------------------------------------------------------------
// Total supply
// ------------------------------------------------------------------------
function totalSupply() public constant returns (uint) {
return _totalSupply - balances[address(0)];
}
// ------------------------------------------------------------------------
// Get the token balance for account `tokenOwner`
// ------------------------------------------------------------------------
function balanceOf(address tokenOwner) public constant returns (uint balance) {
return balances[tokenOwner];
}
// ------------------------------------------------------------------------
// Transfer the balance from token owner's account to `to` account
// - Owner's account must have sufficient balance to transfer
// - 0 value transfers are allowed
// ------------------------------------------------------------------------
function transfer(address to, uint tokens) public returns (bool success) {
balances[msg.sender] = balances[msg.sender].sub(tokens);
balances[to] = balances[to].add(tokens);
emit Transfer(msg.sender, to, tokens);
return true;
}
// ------------------------------------------------------------------------
// Token owner can approve for `spender` to transferFrom(...) `tokens`
// from the token owner's account
//
// https://github.com/ethereum/EIPs/blob/master/EIPS/eip-20-token-standard.md
// recommends that there are no checks for the approval double-spend attack
// as this should be implemented in user interfaces
// ------------------------------------------------------------------------
function approve(address spender, uint tokens) public returns (bool success) {
allowed[msg.sender][spender] = tokens;
emit Approval(msg.sender, spender, tokens);
return true;
}
// ------------------------------------------------------------------------
// Transfer `tokens` from the `from` account to the `to` account
//
// The calling account must already have sufficient tokens approve(...)-d
// for spending from the `from` account and
// - From account must have sufficient balance to transfer
// - Spender must have sufficient allowance to transfer
// - 0 value transfers are allowed
// ------------------------------------------------------------------------
function transferFrom(address from, address to, uint tokens) public returns (bool success) {
balances[from] = balances[from].sub(tokens);
allowed[from][msg.sender] = allowed[from][msg.sender].sub(tokens);
balances[to] = balances[to].add(tokens);
emit Transfer(from, to, tokens);
return true;
}
// ------------------------------------------------------------------------
// Returns the amount of tokens approved by the owner that can be
// transferred to the spender's account
// ------------------------------------------------------------------------
function allowance(address tokenOwner, address spender) public constant returns (uint remaining) {
return allowed[tokenOwner][spender];
}
// ------------------------------------------------------------------------
// Token owner can approve for `spender` to transferFrom(...) `tokens`
// from the token owner's account. The `spender` contract function
// `receiveApproval(...)` is then executed
// ------------------------------------------------------------------------
function approveAndCall(address spender, uint tokens, bytes data) public returns (bool success) {
allowed[msg.sender][spender] = tokens;
emit Approval(msg.sender, spender, tokens);
ApproveAndCallFallBack(spender).receiveApproval(msg.sender, tokens, this, data);
return true;
}
// ------------------------------------------------------------------------
// Accepts ETH and transfers ZAN tokens based on exchage rate and state
// ------------------------------------------------------------------------
function () public payable {
uint eth_sent = msg.value;
uint tokens_amount = eth_sent.mul(exchangeRate);
require(eth_sent > 0);
require(exchangeRate > 0);
require(stateStartDate < now && now < stateEndDate);
require(balances[owner] >= tokens_amount);
require(_totalSupply - (balances[owner] - tokens_amount) <= saleCap);
// Don't accept ETH in the final state
require(!isInFinalState);
require(isInPreSaleState || isInRoundOneState || isInRoundTwoState);
balances[owner] = balances[owner].sub(tokens_amount);
balances[msg.sender] = balances[msg.sender].add(tokens_amount);
emit PurchaseZanTokens(msg.sender, eth_sent, tokens_amount);
}
// ------------------------------------------------------------------------
// Switches crowdsale stages: PreSale -> Round One -> Round Two
// ------------------------------------------------------------------------
function switchCrowdSaleStage() external onlyOwner {
require(!isInFinalState && !isInRoundTwoState);
if (!isInPreSaleState) {
isInPreSaleState = true;
exchangeRate = 1500;
saleCap = (3 * 10**6) * (uint(10) ** decimals);
emit SwitchCrowdSaleStage("PreSale", exchangeRate);
}
else if (!isInRoundOneState) {
isInRoundOneState = true;
exchangeRate = 1200;
saleCap = saleCap + ((4 * 10**6) * (uint(10) ** decimals));
emit SwitchCrowdSaleStage("RoundOne", exchangeRate);
}
else if (!isInRoundTwoState) {
isInRoundTwoState = true;
exchangeRate = 900;
saleCap = saleCap + ((5 * 10**6) * (uint(10) ** decimals));
emit SwitchCrowdSaleStage("RoundTwo", exchangeRate);
}
stateStartDate = now + 5 minutes;
stateEndDate = stateStartDate + 7 days;
}
// ------------------------------------------------------------------------
// Switches to Complete stage of the contract. Sends all funds collected
// to the contract owner.
// ------------------------------------------------------------------------
function completeCrowdSale() external onlyOwner {
require(!isInFinalState);
require(isInPreSaleState && isInRoundOneState && isInRoundTwoState);
owner.transfer(address(this).balance);
exchangeRate = 0;
isInFinalState = true;
emit SwitchCrowdSaleStage("Complete", exchangeRate);
}
// ------------------------------------------------------------------------
// Token holders are able to burn their tokens.
// ------------------------------------------------------------------------
function burn(uint amount) public {
require(amount > 0);
require(amount <= balances[msg.sender]);
balances[msg.sender] = balances[msg.sender].sub(amount);
_totalSupply = _totalSupply.sub(amount);
burnedTokensCount = burnedTokensCount + amount;
emit BurnTokens(msg.sender, amount);
}
// ------------------------------------------------------------------------
// Owner can transfer out any accidentally sent ERC20 tokens
// ------------------------------------------------------------------------
function transferAnyERC20Token(address tokenAddress, uint tokens) public onlyOwner returns (bool success) {
return ERC20Interface(tokenAddress).transfer(owner, tokens);
}
}