pragma solidity ^0.4.24;

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);
}

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 BasicToken is ERC20Basic {
    using SafeMath for uint256;
    mapping(address => uint256) internal balances;
    uint256 internal totalSupply_;

    function totalSupply() public view returns (uint256) {
        return totalSupply_;
    }

    function transfer(address _to, uint256 _value) public returns (bool) {
        require(_value <= balances[msg.sender]);
        require(_to != address(0));
        balances[msg.sender] = balances[msg.sender].sub(_value);
        balances[_to] = balances[_to].add(_value);
        emit Transfer(msg.sender, _to, _value);
        return true;
    }

    function balanceOf(address _owner) public view returns (uint256) {
        return balances[_owner];
    }
}

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
    );
}

contract StandardToken is ERC20, BasicToken {
    mapping(address => mapping(address => uint256)) internal allowed;

    function transferFrom(
        address _from,
        address _to,
        uint256 _value
    )
    public
    returns (bool)
    {
        require(_value <= balances[_from]);
        require(_value <= allowed[_from][msg.sender]);
        require(_to != address(0));
        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 allowance(
        address _owner,
        address _spender
    )
    public
    view
    returns (uint256)
    {
        return allowed[_owner][_spender];
    }

    function increaseApproval(
        address _spender,
        uint256 _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,
        uint256 _subtractedValue
    )
    public
    returns (bool)
    {
        uint256 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;
    }
}

contract Ownable {
    address public owner;

    event OwnershipRenounced(address indexed previousOwner);
    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );
    constructor() public {
        owner = msg.sender;
    }
    modifier onlyOwner() {
        require(msg.sender == owner);
        _;
    }
    function renounceOwnership() public onlyOwner {
        emit OwnershipRenounced(owner);
        owner = address(0);
    }

    function transferOwnership(address _newOwner) public onlyOwner {
        _transferOwnership(_newOwner);
    }

    function _transferOwnership(address _newOwner) internal {
        require(_newOwner != address(0));
        emit OwnershipTransferred(owner, _newOwner);
        owner = _newOwner;
    }
}

contract MintableToken is StandardToken, Ownable {
    event Mint(address indexed to, uint256 amount);
    event MintFinished();

    bool public mintingFinished = false;
    modifier canMint() {
        require(!mintingFinished);
        _;
    }
    modifier hasMintPermission() {
        require(msg.sender == owner);
        _;
    }
    function mint(
        address _to,
        uint256 _amount
    )
    public
    hasMintPermission
    canMint
    returns (bool)
    {
        totalSupply_ = totalSupply_.add(_amount);
        balances[_to] = balances[_to].add(_amount);
        emit Mint(_to, _amount);
        emit Transfer(address(0), _to, _amount);
        return true;
    }

    function finishMinting() public onlyOwner canMint returns (bool) {
        mintingFinished = true;
        emit MintFinished();
        return true;
    }
}

contract DetailedERC20 is ERC20 {
    string public name;
    string public symbol;
    uint8 public decimals;
    constructor(string _name, string _symbol, uint8 _decimals) public {
        name = _name;
        symbol = _symbol;
        decimals = _decimals;
    }
}

contract WAS_Token is MintableToken, DetailedERC20 {
    uint256 public totalSupplyLimit = 260260676;
    constructor() DetailedERC20("Wasi", "WAS", 0) public {
    }
    function burnUnsoldTokens() public onlyOwner {
        balances[owner] = 0;
    }
}

contract WAS_CrowdsaleReservations {
    using SafeMath for uint256;
    uint256 public reserveTokensTeamPercent = 5;    //    13013033 tokens
    uint256 public reservedTokensTeam;
    uint256 public tokensCrowdsalePurchased;
    uint256 public reservedTokensCrowdsalePurchase;
    constructor(uint256 _totalSupply) public {
        calculateReservations(_totalSupply);
    }
    function calculateReservations(uint256 _totalSupply) private {
        reservedTokensTeam = _totalSupply.mul(reserveTokensTeamPercent).div(100);
        reservedTokensCrowdsalePurchase = 50 * (10 ** 6);
        //    50m
    }
}

library SafeERC20 {
    function safeTransfer(
        ERC20Basic _token,
        address _to,
        uint256 _value
    )
    internal
    {
        require(_token.transfer(_to, _value));
    }

    function safeTransferFrom(
        ERC20 _token,
        address _from,
        address _to,
        uint256 _value
    )
    internal
    {
        require(_token.transferFrom(_from, _to, _value));
    }

    function safeApprove(
        ERC20 _token,
        address _spender,
        uint256 _value
    )
    internal
    {
        require(_token.approve(_spender, _value));
    }
}

contract Crowdsale {
    using SafeMath for uint256;
    using SafeERC20 for ERC20;
    ERC20 public token;
    address public wallet;
    uint256 public rate;
    uint256 public weiRaised;

    event TokenPurchase(
        address indexed purchaser,
        address indexed beneficiary,
        uint256 value,
        uint256 amount
    );
    constructor(uint256 _rate, address _wallet, ERC20 _token) public {
        require(_rate > 0);
        require(_wallet != address(0));
        require(_token != address(0));
        rate = _rate;
        wallet = _wallet;
        token = _token;
    }
    function() external payable {
        buyTokens(msg.sender);
    }

    function buyTokens(address _beneficiary) public payable {
        uint256 weiAmount = msg.value;
        _preValidatePurchase(_beneficiary, weiAmount);
        uint256 tokens = _getTokenAmount(weiAmount);
        weiRaised = weiRaised.add(weiAmount);
        _processPurchase(_beneficiary, tokens);
        emit TokenPurchase(
            msg.sender,
            _beneficiary,
            weiAmount,
            tokens
        );
        _updatePurchasingState(_beneficiary, weiAmount);
        _forwardFunds();
        _postValidatePurchase(_beneficiary, weiAmount);
    }

    function _preValidatePurchase(
        address _beneficiary,
        uint256 _weiAmount
    )
    internal
    {
        require(_beneficiary != address(0));
        require(_weiAmount != 0);
    }

    function _postValidatePurchase(
        address _beneficiary,
        uint256 _weiAmount
    )
    internal
    {
    }

    function _deliverTokens(
        address _beneficiary,
        uint256 _tokenAmount
    )
    internal
    {
        token.safeTransfer(_beneficiary, _tokenAmount);
    }

    function _processPurchase(
        address _beneficiary,
        uint256 _tokenAmount
    )
    internal
    {
        _deliverTokens(_beneficiary, _tokenAmount);
    }

    function _updatePurchasingState(
        address _beneficiary,
        uint256 _weiAmount
    )
    internal
    {
    }

    function _getTokenAmount(uint256 _weiAmount)
    internal view returns (uint256)
    {
        return _weiAmount.mul(rate);
    }

    function _forwardFunds() internal {
        wallet.transfer(msg.value);
    }
}

contract TimedCrowdsale is Crowdsale {
    using SafeMath for uint256;
    uint256 public openingTime;
    uint256 public closingTime;
    modifier onlyWhileOpen {
        require(block.timestamp >= openingTime && block.timestamp <= closingTime);
        _;
    }
    constructor(uint256 _openingTime, uint256 _closingTime) public {
        require(_openingTime >= block.timestamp);
        require(_closingTime >= _openingTime);
        openingTime = _openingTime;
        closingTime = _closingTime;
    }
    function hasClosed() public view returns (bool) {
        return block.timestamp > closingTime;
    }

    function _preValidatePurchase(
        address _beneficiary,
        uint256 _weiAmount
    )
    internal
    onlyWhileOpen
    {
        super._preValidatePurchase(_beneficiary, _weiAmount);
    }
}

contract FinalizableCrowdsale is Ownable, TimedCrowdsale {
    using SafeMath for uint256;
    bool public isFinalized = false;

    event Finalized();

    function finalize() public onlyOwner {
        require(!isFinalized);
        require(hasClosed());
        finalization();
        emit Finalized();
        isFinalized = true;
    }

    function finalization() internal {
    }
}

contract WAS_Crowdsale_Stages is FinalizableCrowdsale, WAS_CrowdsaleReservations {
    uint256[] rateETH;
    uint256[] openingTimings;
    uint256[] closingTimings;
    uint256[] stagePurchaseTokensMinimum;
    modifier onlyWhileOpen {
        bool stageRunning;
        uint256 stageIdx;
        (stageRunning, stageIdx) = currentStage();
        require(stageRunning, "no stage is currently running");
        _;
    }
    constructor(uint256[] _rateETH, uint256[] _openingTimings, uint256[] _closingTimings)
    TimedCrowdsale(_openingTimings[0], _closingTimings[_closingTimings.length - 1])
    public {
        validateRates(_rateETH);
        validateOpeningAndClosingTimings(_openingTimings, _closingTimings);
        rateETH = _rateETH;
        openingTimings = _openingTimings;
        closingTimings = _closingTimings;
        stagePurchaseTokensMinimum = [0, 100];
    }
    function hasOpened() public view returns (bool) {
        return now >= openingTime;
    }

    function currentRateETH() public view returns (uint256) {
        bool stageRunning;
        uint256 stageIdx;
        (stageRunning, stageIdx) = currentStage();
        require(stageRunning, "no stage is currently running");
        return rateETH[stageIdx];
    }

    function currentDiscount(uint256 _tokenPurchasedAmount) public view returns (uint256) {
        bool stageRunning;
        uint256 stageIdx;
        (stageRunning, stageIdx) = currentStage();
        require(stageRunning, "no stage is currently running");
        return discountPercentForStage(stageIdx, _tokenPurchasedAmount);
    }

    function currentStage() public view returns (bool, uint256) {
        for (uint256 i = 0; i < closingTimings.length; i ++) {
            if (block.timestamp <= closingTimings[i] && block.timestamp >= openingTimings[i]) {
                return (true, i);
            }
        }
        return (false, 0);
    }

    function updateStageRateETH(uint256 _stage, uint256 _rateETH) public onlyOwner {
        rateETH[_stage] = _rateETH;
    }

    function updateOpeningAndClosingTimings(uint256[] _openingTimings, uint256[] _closingTimings) public onlyOwner {
        validateOpeningAndClosingTimings(_openingTimings, _closingTimings);
        openingTimings = _openingTimings;
        closingTimings = _closingTimings;
    }

    function validateRates(uint256[] _rateETH) private pure {
        for (uint256 i = 0; i < _rateETH.length; i ++) {
            require(_rateETH[i] > 0, "rate must be > 0");
        }
    }

    function validateOpeningAndClosingTimings(uint256[] _openingTimings, uint256[] _closingTimings) private view {
        require(_openingTimings.length == _closingTimings.length, "timings length differs");
        require(_openingTimings[0] > block.timestamp, "should open in future");
        for (uint256 i = 0; i < _openingTimings.length; i ++) {
            require(_closingTimings[i] > _openingTimings[i], "closing time of stage must be > opening time of same stage");
            if (i > 0) {
                require(_openingTimings[i] > _openingTimings[i - 1], "opening time must be > than previous opening time");
            }
        }
    }

    function discountPercentForStage(uint256 _stage, uint256 _tokenPurchasedAmount) private pure returns (uint256) {
        if (_stage == 0) {
            return 30;
        } else if (_stage == 1) {
            if (_tokenPurchasedAmount >= 15000) {
                return 10;
            } else if (_tokenPurchasedAmount >= 10000) {
                return 7;
            } else if (_tokenPurchasedAmount >= 5000) {
                return 5;
            }
        }
        return 0;
    }
}

contract Pausable is Ownable {
    event Pause();
    event Unpause();

    bool public paused = false;
    modifier whenNotPaused() {
        require(!paused);
        _;
    }
    modifier whenPaused() {
        require(paused);
        _;
    }
    function pause() public onlyOwner whenNotPaused {
        paused = true;
        emit Pause();
    }

    function unpause() public onlyOwner whenPaused {
        paused = false;
        emit Unpause();
    }
}

library Roles {
    struct Role {
        mapping(address => bool) bearer;
    }

    function add(Role storage _role, address _addr)
    internal
    {
        _role.bearer[_addr] = true;
    }

    function remove(Role storage _role, address _addr)
    internal
    {
        _role.bearer[_addr] = false;
    }

    function check(Role storage _role, address _addr)
    internal
    view
    {
        require(has(_role, _addr));
    }

    function has(Role storage _role, address _addr)
    internal
    view
    returns (bool)
    {
        return _role.bearer[_addr];
    }
}

contract RBAC {
    using Roles for Roles.Role;
    mapping(string => Roles.Role) private roles;

    event RoleAdded(address indexed operator, string role);
    event RoleRemoved(address indexed operator, string role);

    function checkRole(address _operator, string _role)
    public
    view
    {
        roles[_role].check(_operator);
    }

    function hasRole(address _operator, string _role)
    public
    view
    returns (bool)
    {
        return roles[_role].has(_operator);
    }

    function addRole(address _operator, string _role)
    internal
    {
        roles[_role].add(_operator);
        emit RoleAdded(_operator, _role);
    }

    function removeRole(address _operator, string _role)
    internal
    {
        roles[_role].remove(_operator);
        emit RoleRemoved(_operator, _role);
    }
    modifier onlyRole(string _role)
    {
        checkRole(msg.sender, _role);
        _;
    }
}

contract Whitelist is Ownable, RBAC {
    string public constant ROLE_WHITELISTED = "whitelist";
    modifier onlyIfWhitelisted(address _operator) {
        checkRole(_operator, ROLE_WHITELISTED);
        _;
    }
    function addAddressToWhitelist(address _operator)
    public
    onlyOwner
    {
        addRole(_operator, ROLE_WHITELISTED);
    }

    function whitelist(address _operator)
    public
    view
    returns (bool)
    {
        return hasRole(_operator, ROLE_WHITELISTED);
    }

    function addAddressesToWhitelist(address[] _operators)
    public
    onlyOwner
    {
        for (uint256 i = 0; i < _operators.length; i++) {
            addAddressToWhitelist(_operators[i]);
        }
    }

    function removeAddressFromWhitelist(address _operator)
    public
    onlyOwner
    {
        removeRole(_operator, ROLE_WHITELISTED);
    }

    function removeAddressesFromWhitelist(address[] _operators)
    public
    onlyOwner
    {
        for (uint256 i = 0; i < _operators.length; i++) {
            removeAddressFromWhitelist(_operators[i]);
        }
    }
}

contract WhitelistedCrowdsale is Whitelist, Crowdsale {
    function _preValidatePurchase(
        address _beneficiary,
        uint256 _weiAmount
    )
    internal
    onlyIfWhitelisted(_beneficiary)
    {
        super._preValidatePurchase(_beneficiary, _weiAmount);
    }
}

contract Destructible is Ownable {
    function destroy() public onlyOwner {
        selfdestruct(owner);
    }

    function destroyAndSend(address _recipient) public onlyOwner {
        selfdestruct(_recipient);
    }
}

contract WAS_Crowdsale is WhitelistedCrowdsale, Destructible, Pausable, WAS_Crowdsale_Stages {
    WAS_Token token;
    constructor(address _wallet, ERC20 _token, uint256[] _rateETH, uint256[] _openingTimings, uint256[] _closingTimings)
    Crowdsale(1, _wallet, _token)
    WAS_Crowdsale_Stages(_rateETH, _openingTimings, _closingTimings)
    WAS_CrowdsaleReservations(WAS_Token(_token).totalSupplyLimit())
    public {
        require(_token != address(0), "token address cannt be 0");
        token = WAS_Token(_token);
    }
    function mintTotalSupplyAndTeam(address _teamAddress) public onlyOwner {
        require(_teamAddress != address(0), "team address can not be 0");
        require(reservedTokensTeam > 0, "team tokens can not be 0");
        token.mint(_teamAddress, reservedTokensTeam);
        uint256 purchaseTokens = token.totalSupplyLimit().sub(reservedTokensTeam);
        token.mint(address(this), purchaseTokens);
        token.finishMinting();
    }

    function manualTransfer(address _to, uint256 _tokenAmount) public onlyOwner {
        bool stageRunning;
        uint256 stageIdx;
        (stageRunning, stageIdx) = currentStage();
        require(stageRunning, "no stage is currently running");
        require(stageIdx == 0, "manual transfer allowed during first stage only");
        require(tokensCrowdsalePurchased.add(_tokenAmount) <= reservedTokensCrowdsalePurchase, "not enough tokens to manually transfer");
        tokensCrowdsalePurchased = tokensCrowdsalePurchased.add(_tokenAmount);
        token.transfer(_to, _tokenAmount);
    }

    function destroy() public onlyOwner {
        require(hasClosed(), "crowdsale must be closed");
        require(isFinalized, "crowdsale must be finalized");
        selfdestruct(owner);
    }

    function destroyAndSend(address _recipient) public onlyOwner {
        require(hasClosed(), "crowdsale must be closed");
        require(isFinalized, "crowdsale must be finalized");
        selfdestruct(_recipient);
    }

    function finalization() internal {
        uint256 unpurchasedTokens = token.balanceOf(address(this));
        token.transfer(owner, unpurchasedTokens);
        super.finalization();
    }

    function _preValidatePurchase(
        address _beneficiary,
        uint256 _weiAmount
    )
    internal
    whenNotPaused()
    onlyWhileOpen()
    {
        super._preValidatePurchase(_beneficiary, _weiAmount);
    }

    function _getTokenAmount(uint256 _weiAmount)
    internal view returns (uint256)
    {
        uint256 rateETH = currentRateETH();
        uint256 tokens = _weiAmount.mul(rateETH).div(uint256(10 ** 18));
        uint256 discount = currentDiscount(tokens);
        if (discount > 0) {
            tokens = tokens.add(tokens.mul(discount).div(100));
        }
        return tokens;
    }

    function _processPurchase(
        address _beneficiary,
        uint256 _tokenAmount
    )
    internal
    {
        bool stageRunning;
        uint256 stageIdx;
        (stageRunning, stageIdx) = currentStage();
        require(stageRunning, "no stage is currently running");
        require(_tokenAmount >= stagePurchaseTokensMinimum[stageIdx], "token amount is less than minimum for stage");
        require(tokensCrowdsalePurchased.add(_tokenAmount) <= reservedTokensCrowdsalePurchase, "not enough tokens to purchase");
        tokensCrowdsalePurchased = tokensCrowdsalePurchased.add(_tokenAmount);
        super._processPurchase(_beneficiary, _tokenAmount);
    }
}