contract TokenSale is Owned, TokenController {
    using SafeMath for uint256;
    
    SHP public shp;
    AffiliateUtility public affiliateUtility;
    Trustee public trustee;

    address public etherEscrowAddress;
    address public bountyAddress;
    address public trusteeAddress;
    address public apiAddress;

    uint256 public founderTokenCount = 0;
    uint256 public reserveTokenCount = 0;

    uint256 constant public CALLER_EXCHANGE_RATE = 2000;
    uint256 constant public RESERVE_EXCHANGE_RATE = 1500;
    uint256 constant public FOUNDER_EXCHANGE_RATE = 1000;
    uint256 constant public BOUNTY_EXCHANGE_RATE = 500;
    uint256 constant public MAX_GAS_PRICE = 50000000000;

    bool public paused;
    bool public closed;

    mapping(address => bool) public approvedAddresses;

    event Contribution(uint256 etherAmount, address _caller);
    event NewSale(address indexed caller, uint256 etherAmount, uint256 tokensGenerated);
    event SaleClosed(uint256 when);
    
    modifier notPaused() {
        require(!paused);
        _;
    }

    modifier notClosed() {
        require(!closed);
        _;
    }

    modifier onlyApi() {
        require(msg.sender == apiAddress);
        _;
    }

    modifier isValidated() {
        require(msg.sender != 0x0);
        require(msg.value > 0);
        require(!isContract(msg.sender)); 
        require(tx.gasprice <= MAX_GAS_PRICE);
        _;
    }

    modifier isApproved() {
        require(approvedAddresses[msg.sender]);
        _;
    }

    /// @notice Adds an approved address for the sale
    /// @param _addr The address to approve for contribution
    function approveAddress(address _addr) public onlyApi {
        approvedAddresses[_addr] = true;
    }

    /// @notice This method sends the Ether received to the Ether escrow address
    /// and generates the calculated number of SHP tokens, sending them to the caller's address.
    /// It also generates the founder's tokens and the reserve tokens at the same time.
    function doBuy(
        address _caller,
        uint256 etherAmount
    )
        internal
    {

        Contribution(etherAmount, _caller);

        uint256 callerTokens = etherAmount.mul(CALLER_EXCHANGE_RATE);
        uint256 callerTokensWithDiscount = applyDiscount(etherAmount, callerTokens);

        uint256 reserveTokens = etherAmount.mul(RESERVE_EXCHANGE_RATE);
        uint256 founderTokens = etherAmount.mul(FOUNDER_EXCHANGE_RATE);
        uint256 bountyTokens = etherAmount.mul(BOUNTY_EXCHANGE_RATE);
        uint256 vestingTokens = founderTokens.add(reserveTokens);

        founderTokenCount = founderTokenCount.add(founderTokens);
        reserveTokenCount = reserveTokenCount.add(reserveTokens);

        payAffiliate(callerTokensWithDiscount, msg.value, msg.sender);

        shp.generateTokens(_caller, callerTokensWithDiscount);
        shp.generateTokens(bountyAddress, bountyTokens);
        shp.generateTokens(trusteeAddress, vestingTokens);

        NewSale(_caller, etherAmount, callerTokensWithDiscount);
        NewSale(trusteeAddress, etherAmount, vestingTokens);
        NewSale(bountyAddress, etherAmount, bountyTokens);

        etherEscrowAddress.transfer(etherAmount);
        updateCounters(etherAmount);
    }

    /// @notice Applies the discount based on the discount tiers
    /// @param _etherAmount The amount of ether used to evaluate the tier the contribution lies within
    /// @param _contributorTokens The tokens allocated based on the contribution
    function applyDiscount(uint256 _etherAmount, uint256 _contributorTokens) internal constant returns (uint256);

    /// @notice Updates the counters for the amount of Ether paid
    /// @param _etherAmount the amount of Ether paid
    function updateCounters(uint256 _etherAmount) internal;
    
    /// @notice Parent constructor. This needs to be extended from the child contracts
    /// @param _etherEscrowAddress the address that will hold the crowd funded Ether
    /// @param _bountyAddress the address that will hold the bounty scheme SHP
    /// @param _trusteeAddress the address that will hold the vesting SHP
    /// @param _affiliateUtilityAddress address of the deployed AffiliateUtility contract.
    function TokenSale (
        address _etherEscrowAddress,
        address _bountyAddress,
        address _trusteeAddress,
        address _affiliateUtilityAddress,
        address _apiAddress
    ) {
        etherEscrowAddress = _etherEscrowAddress;
        bountyAddress = _bountyAddress;
        trusteeAddress = _trusteeAddress;
        apiAddress = _apiAddress;
        affiliateUtility = AffiliateUtility(_affiliateUtilityAddress);
        trustee = Trustee(_trusteeAddress);
        paused = true;
        closed = false;
    }

    /// @notice Pays an affiliate if they are valid and present in the transaction data
    /// @param _tokens The contribution tokens used to calculate affiliate payment amount
    /// @param _etherValue The Ether value sent
    /// @param _caller The address of the caller
    function payAffiliate(uint256 _tokens, uint256 _etherValue, address _caller) internal {
        if (affiliateUtility.isAffiliateValid(_caller)) {
            address affiliate = affiliateUtility.getAffiliate(_caller);
            var (affiliateBonus, contributorBonus) = affiliateUtility.applyAffiliate(_caller, _tokens, _etherValue);
            shp.generateTokens(affiliate, affiliateBonus);
            shp.generateTokens(_caller, contributorBonus);
        }
    }

    /// @notice Sets the SHP token smart contract
    /// @param _shp the SHP token contract address
    function setShp(address _shp) public onlyOwner {
        shp = SHP(_shp);
    }

    /// @notice Transfers ownership of the token smart contract and trustee
    /// @param _tokenController the address of the new token controller
    /// @param _trusteeOwner the address of the new trustee owner
    function transferOwnership(address _tokenController, address _trusteeOwner) public onlyOwner {
        require(closed);
        require(_tokenController != 0x0);
        require(_trusteeOwner != 0x0);
        shp.changeController(_tokenController);
        trustee.changeOwner(_trusteeOwner);
    }

    /// @notice Internal function to determine if an address is a contract
    /// @param _caller The address being queried
    /// @return True if `caller` is a contract
    function isContract(address _caller) internal constant returns (bool) {
        uint size;
        assembly { size := extcodesize(_caller) }
        return size > 0;
    }

    /// @notice Pauses the contribution if there is any issue
    function pauseContribution() public onlyOwner {
        paused = true;
    }

    /// @notice Resumes the contribution
    function resumeContribution() public onlyOwner {
        paused = false;
    }

    //////////
    // MiniMe Controller Interface functions
    //////////

    // In between the offering and the network. Default settings for allowing token transfers.
    function proxyPayment(address) public payable returns (bool) {
        return false;
    }

    function onTransfer(address, address, uint256) public returns (bool) {
        return false;
    }

    function onApprove(address, address, uint256) public returns (bool) {
        return false;
    }
}
function applyDiscount(uint256 _etherAmount, uint256 _contributorTokens) internal constant returns (uint256);
/// @notice Applies the discount based on the discount tiers
/// @param _etherAmount The amount of ether used to evaluate the tier the contribution lies within
/// @param _contributorTokens The tokens allocated based on the contribution