PricingStrategy.sol

/**
 * This smart contract code is Copyright 2017 TokenMarket Ltd. For more information see https://tokenmarket.net
 *
 * Licensed under the Apache License, version 2.0: https://github.com/TokenMarketNet/ico/blob/master/LICENSE.txt
 */

pragma solidity ^0.4.11;

/**
 * Interface for defining crowdsale pricing.
 */
contract PricingStrategy {

    /** Interface declaration. */
    function isPricingStrategy() public constant returns (bool) {
        return true;
    }

    /** Self check if all references are correctly set.
     *
     * Checks that pricing strategy matches crowdsale parameters.
     */
    function isSane(address crowdsale) public constant returns (bool) {
        return true;
    }

    /**
     * @dev Pricing tells if this is a presale purchase or not.
       @param purchaser Address of the purchaser
       @return False by default, true if a presale purchaser
     */
    function isPresalePurchase(address purchaser) public constant returns (bool) {
        return false;
    }

    /**
     * When somebody tries to buy tokens for X eth, calculate how many tokens they get.
     *
     *
     * @param value - What is the value of the transaction send in as wei
     * @param tokensSold - how much tokens have been sold this far
     * @param weiRaised - how much money has been raised this far in the main token sale - this number excludes presale
     * @param msgSender - who is the investor of this transaction
     * @param decimals - how many decimal units the token has
     * @return Amount of tokens the investor receives
     */
    function calculatePrice(uint value, uint weiRaised, uint tokensSold, address msgSender, uint decimals) public constant returns (uint tokenAmount);
}