contract WanchainContribution is Owned {
    using SafeMath for uint;

    /// Constant fields
    /// Wanchain total tokens supply
    uint public constant WAN_TOTAL_SUPPLY = 210000000 ether;
    uint public constant EARLY_CONTRIBUTION_DURATION = 24 hours;
    uint public constant MAX_CONTRIBUTION_DURATION = 3 weeks;

    /// Exchange rates for first phase
    uint public constant PRICE_RATE_FIRST = 880;
    /// Exchange rates for second phase
    uint public constant PRICE_RATE_SECOND = 790;
    /// Exchange rates for last phase
    uint public constant PRICE_RATE_LAST = 750;

    /// ----------------------------------------------------------------------------------------------------
    /// |                                                  |                    |                 |        |
    /// |        PUBLIC SALE (PRESALE + OPEN SALE)         |      DEV TEAM      |    FOUNDATION   |  MINER |
    /// |                       51%                        |         20%        |       19%       |   10%  |    
    /// ----------------------------------------------------------------------------------------------------
      /// OPEN_SALE_STAKE + PRESALE_STAKE = 51; 51% sale for public
    uint public constant OPEN_SALE_STAKE = 510;  // 51% for open sale

    // Reserved stakes
    uint public constant DEV_TEAM_STAKE = 200;   // 20%
    uint public constant FOUNDATION_STAKE = 190; // 19%
    uint public constant MINERS_STAKE = 100;     // 10%

    uint public constant DIVISOR_STAKE = 1000;

    uint public constant PRESALE_RESERVERED_AMOUNT = 41506655 ether; //presale prize amount(40000*880)
  
    /// Holder address for presale and reserved tokens
    /// TODO: change addressed before deployed to main net

    // Addresses of Patrons
    address public constant DEV_TEAM_HOLDER = 0x0001cdC69b1eb8bCCE29311C01092Bdcc92f8f8F;
    address public constant FOUNDATION_HOLDER = 0x00dB4023b32008C45E62Add57De256a9399752D4;
    address public constant MINERS_HOLDER = 0x00f870D11eA43AA1c4C715c61dC045E32d232787;
    address public constant PRESALE_HOLDER = 0x00577c25A81fA2401C5246F4a7D5ebaFfA4b00Aa;
  
    uint public MAX_OPEN_SOLD = WAN_TOTAL_SUPPLY * OPEN_SALE_STAKE / DIVISOR_STAKE - PRESALE_RESERVERED_AMOUNT;

    /// Fields that are only changed in constructor    
    /// All deposited ETH will be instantly forwarded to this address.
    address public wanport;
    /// Early Adopters reserved start time
    uint public earlyReserveBeginTime;
    /// Contribution start time
    uint public startTime;
    /// Contribution end time
    uint public endTime;

    /// Fields that can be changed by functions
    /// Accumulator for open sold tokens
    uint public openSoldTokens;
    /// Due to an emergency, set this to true to halt the contribution
    bool public halted; 
    /// ERC20 compilant wanchain token contact instance
    WanToken public wanToken; 

    /// Quota for early adopters sale, Quota
    mapping (address => uint256) public earlyUserQuotas;
    /// tags show address can join in open sale
    mapping (address => uint256) public fullWhiteList;

    uint256 public normalBuyLimit = 65 ether;

    /*
     * EVENTS
     */

    event NewSale(address indexed destAddress, uint ethCost, uint gotTokens);
    //event PartnerAddressQuota(address indexed partnerAddress, uint quota);

    /*
     * MODIFIERS
     */

    modifier onlyWallet {
        require(msg.sender == wanport);
        _;
    }

    modifier notHalted() {
        require(!halted);
        _;
    }

    modifier initialized() {
        require(address(wanport) != 0x0);
        _;
    }    

    modifier notEarlierThan(uint x) {
        require(now >= x);
        _;
    }

    modifier earlierThan(uint x) {
        require(now < x);
        _;
    }

    modifier ceilingNotReached() {
        require(openSoldTokens < MAX_OPEN_SOLD);
        _;
    }  

    modifier isSaleEnded() {
        require(now > endTime || openSoldTokens >= MAX_OPEN_SOLD);
        _;
    }


    /**
     * CONSTRUCTOR 
     * 
     * @dev Initialize the Wanchain contribution contract
     * @param _wanport The escrow account address, all ethers will be sent to this address.
     * @param _bootTime ICO boot time
     */
    function WanchainContribution(address _wanport, uint _bootTime){
      require(_wanport != 0x0);

        halted = false;
      wanport = _wanport;
        earlyReserveBeginTime = _bootTime;
      startTime = earlyReserveBeginTime + EARLY_CONTRIBUTION_DURATION;
      endTime = startTime + MAX_CONTRIBUTION_DURATION;
        openSoldTokens = 0;
        /// Create wanchain token contract instance
      wanToken = new WanToken(this,startTime, endTime);

        /// Reserve tokens according wanchain ICO rules
      uint stakeMultiplier = WAN_TOTAL_SUPPLY / DIVISOR_STAKE;
    
        wanToken.mintToken(DEV_TEAM_HOLDER, DEV_TEAM_STAKE * stakeMultiplier);
        wanToken.mintToken(FOUNDATION_HOLDER, FOUNDATION_STAKE * stakeMultiplier);
        wanToken.mintToken(MINERS_HOLDER, MINERS_STAKE * stakeMultiplier);
    
        wanToken.mintToken(PRESALE_HOLDER, PRESALE_RESERVERED_AMOUNT);    
    
    }

    /**
     * Fallback function 
     * 
     * @dev If anybody sends Ether directly to this  contract, consider he is getting wan token
     */
    function () public payable {
      buyWanCoin(msg.sender);
    }

    /*
     * PUBLIC FUNCTIONS
     */

    /// @dev Exchange msg.value ether to WAN for account recepient
    /// @param receipient WAN tokens receiver
    function buyWanCoin(address receipient) 
        public 
        payable 
        notHalted 
        initialized 
        ceilingNotReached 
        notEarlierThan(earlyReserveBeginTime)
        earlierThan(endTime)
        returns (bool) 
    {
        require(receipient != 0x0);
        require(msg.value >= 0.1 ether);

        // Do not allow contracts to game the system
        require(!isContract(msg.sender));        

        if( now < startTime && now >= earlyReserveBeginTime)
            buyEarlyAdopters(receipient);
        else {
            require( tx.gasprice <= 50000000000 wei );
            require(msg.value <= normalBuyLimit);
            buyNormal(receipient);
        }

        return true;
    }

    function setNormalBuyLimit(uint256 limit)
        public
        initialized
        onlyOwner
        earlierThan(endTime)
    {
        normalBuyLimit = limit;
    }


    /// @dev batch set quota for early user quota
    function setEarlyWhitelistQuotas(address[] users, uint earlyCap, uint openTag)
        public
        onlyOwner
        earlierThan(earlyReserveBeginTime)
    {
        for( uint i = 0; i < users.length; i++) {
            earlyUserQuotas[users[i]] = earlyCap;
            fullWhiteList[users[i]] = openTag;
        }
    }

    /// @dev batch set quota for early user quota
    function setLaterWhiteList(address[] users, uint openTag)
        public
        onlyOwner
        earlierThan(endTime)
    {
        require(saleNotEnd());
        for( uint i = 0; i < users.length; i++) {
            fullWhiteList[users[i]] = openTag;
        }
    }

    /// @dev Emergency situation that requires contribution period to stop.
    /// Contributing not possible anymore.
    function halt() public onlyWallet{
        halted = true;
    }

    /// @dev Emergency situation resolved.
    /// Contributing becomes possible again withing the outlined restrictions.
    function unHalt() public onlyWallet{
        halted = false;
    }

    /// @dev Emergency situation
    function changeWalletAddress(address newAddress) onlyWallet { 
        wanport = newAddress; 
    }

    /// @return true if sale not ended, false otherwise.
    function saleNotEnd() constant returns (bool) {
        return now < endTime && openSoldTokens < MAX_OPEN_SOLD;
    }

    /// CONSTANT METHODS
    /// @dev Get current exchange rate
    function priceRate() public constant returns (uint) {
        // Three price tiers
        if (earlyReserveBeginTime <= now && now < startTime + 1 weeks)
            return PRICE_RATE_FIRST;
        if (startTime + 1 weeks <= now && now < startTime + 2 weeks)
            return PRICE_RATE_SECOND;
        if (startTime + 2 weeks <= now && now < endTime)
            return PRICE_RATE_LAST;
        // Should not be called before or after contribution period
        assert(false);
    }

    function claimTokens(address receipent)
        public
        isSaleEnded
    {
        wanToken.claimTokens(receipent);
    }

    /*
     * INTERNAL FUNCTIONS
     */

    /// @dev Buy wanchain tokens for early adopters
    function buyEarlyAdopters(address receipient) internal {
      uint quotaAvailable = earlyUserQuotas[receipient];
      require(quotaAvailable > 0);

        uint toFund = quotaAvailable.min256(msg.value);
        uint tokenAvailable4Adopter = toFund.mul(PRICE_RATE_FIRST);

      earlyUserQuotas[receipient] = earlyUserQuotas[receipient].sub(toFund);
      buyCommon(receipient, toFund, tokenAvailable4Adopter);
    }

    /// @dev Buy wanchain token normally
    function buyNormal(address receipient) internal {
        uint inWhiteListTag = fullWhiteList[receipient];
        require(inWhiteListTag > 0);

        // protect partner quota in stage one
        uint tokenAvailable = MAX_OPEN_SOLD.sub(openSoldTokens);
        require(tokenAvailable > 0);

      uint toFund;
      uint toCollect;
      (toFund, toCollect) = costAndBuyTokens(tokenAvailable);
        buyCommon(receipient, toFund, toCollect);
    }

    /// @dev Utility function for bug wanchain token
    function buyCommon(address receipient, uint toFund, uint wanTokenCollect) internal {
        require(msg.value >= toFund); // double check

        if(toFund > 0) {
            require(wanToken.mintToken(receipient, wanTokenCollect));         
            wanport.transfer(toFund);
            openSoldTokens = openSoldTokens.add(wanTokenCollect);
            NewSale(receipient, toFund, wanTokenCollect);            
        }

        uint toReturn = msg.value.sub(toFund);
        if(toReturn > 0) {
            msg.sender.transfer(toReturn);
        }
    }

    /// @dev Utility function for calculate available tokens and cost ethers
    function costAndBuyTokens(uint availableToken) constant internal returns (uint costValue, uint getTokens){
      // all conditions has checked in the caller functions
      uint exchangeRate = priceRate();
      getTokens = exchangeRate * msg.value;

      if(availableToken >= getTokens){
        costValue = msg.value;
      } else {
        costValue = availableToken / exchangeRate;
        getTokens = availableToken;
      }
    }

    /// @dev Internal function to determine if an address is a contract
    /// @param _addr The address being queried
    /// @return True if `_addr` is a contract
    function isContract(address _addr) constant internal returns(bool) {
        uint size;
        if (_addr == 0) return false;
        assembly {
            size := extcodesize(_addr)
        }
        return size > 0;
    }
}
/// @title Wanchain Contribution Contract
/// ICO Rules according: https://www.wanchain.org/crowdsale
/// For more information about this token sale, please visit https://wanchain.org
/// @author Zane Liang - <zaneliang@wanchain.org>
function buyWanCoin(address receipient) 
    public 
    payable 
    notHalted 
    initialized 
    ceilingNotReached 
    notEarlierThan(earlyReserveBeginTime)
    earlierThan(endTime)
    returns (bool) 
{
    require(receipient != 0x0);
    require(msg.value >= 0.1 ether);

    // Do not allow contracts to game the system
    require(!isContract(msg.sender));        

    if( now < startTime && now >= earlyReserveBeginTime)
        buyEarlyAdopters(receipient);
    else {
        require( tx.gasprice <= 50000000000 wei );
        require(msg.value <= normalBuyLimit);
        buyNormal(receipient);
    }

    return true;
}

/// @dev Exchange msg.value ether to WAN for account recepient
/// @param receipient WAN tokens receiver