pragma solidity ^0.4.23;

/**
 * @title Ownable
 * @dev The Ownable contract has an owner address, and provides basic authorization control
 * functions, this simplifies the implementation of "user permissions".
 */
contract Ownable {
  address public owner;


  event OwnershipRenounced(address indexed previousOwner);
  event OwnershipTransferred(
    address indexed previousOwner,
    address indexed newOwner
  );


  /**
   * @dev The Ownable constructor sets the original `owner` of the contract to the sender
   * account.
   */
  constructor() public {
    owner = msg.sender;
  }

  /**
   * @dev Throws if called by any account other than the owner.
   */
  modifier onlyOwner() {
    require(msg.sender == owner);
    _;
  }

  /**
   * @dev Allows the current owner to relinquish control of the contract.
   * @notice Renouncing to ownership will leave the contract without an owner.
   * It will not be possible to call the functions with the `onlyOwner`
   * modifier anymore.
   */
  function renounceOwnership() public onlyOwner {
    emit OwnershipRenounced(owner);
    owner = address(0);
  }

  /**
   * @dev Allows the current owner to transfer control of the contract to a newOwner.
   * @param _newOwner The address to transfer ownership to.
   */
  function transferOwnership(address _newOwner) public onlyOwner {
    _transferOwnership(_newOwner);
  }

  /**
   * @dev Transfers control of the contract to a newOwner.
   * @param _newOwner The address to transfer ownership to.
   */
  function _transferOwnership(address _newOwner) internal {
    require(_newOwner != address(0));
    emit OwnershipTransferred(owner, _newOwner);
    owner = _newOwner;
  }
}

/**
 * @title SafeMath
 * @dev Math operations with safety checks that throw on error
 */
library SafeMath {

  /**
  * @dev Multiplies two numbers, throws on overflow.
  */
  function mul(uint256 _a, uint256 _b) internal pure returns (uint256 c) {
    // Gas optimization: this is cheaper than asserting 'a' not being zero, but the
    // benefit is lost if 'b' is also tested.
    // See: https://github.com/OpenZeppelin/openzeppelin-solidity/pull/522
    if (_a == 0) {
      return 0;
    }

    c = _a * _b;
    assert(c / _a == _b);
    return c;
  }

  /**
  * @dev Integer division of two numbers, truncating the quotient.
  */
  function div(uint256 _a, uint256 _b) internal pure returns (uint256) {
    // assert(_b > 0); // Solidity automatically throws when dividing by 0
    // uint256 c = _a / _b;
    // assert(_a == _b * c + _a % _b); // There is no case in which this doesn't hold
    return _a / _b;
  }

  /**
  * @dev Subtracts two numbers, throws on overflow (i.e. if subtrahend is greater than minuend).
  */
  function sub(uint256 _a, uint256 _b) internal pure returns (uint256) {
    assert(_b <= _a);
    return _a - _b;
  }

  /**
  * @dev Adds two numbers, throws on overflow.
  */
  function add(uint256 _a, uint256 _b) internal pure returns (uint256 c) {
    c = _a + _b;
    assert(c >= _a);
    return c;
  }
}

/**
 * @title ERC20Basic
 * @dev Simpler version of ERC20 interface
 * See https://github.com/ethereum/EIPs/issues/179
 */
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);
}

/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
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);
}

/**
 * @title Basic token
 * @dev Basic version of StandardToken, with no allowances.
 */
contract BasicToken is ERC20Basic {
  using SafeMath for uint256;

  mapping(address => uint256) public balances;

  uint256 internal totalSupply_;

  /**
  * @dev Total number of tokens in existence
  */
  function totalSupply() public view returns (uint256) {
    return totalSupply_;
  }

  /**
  * @dev Transfer token for a specified address
  * @param _to The address to transfer to.
  * @param _value The amount to be transferred.
  */
  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;
  }

  /**
  * @dev Gets the balance of the specified address.
  * @param _owner The address to query the the balance of.
  * @return An uint256 representing the amount owned by the passed address.
  */
  function balanceOf(address _owner) public view returns (uint256) {
    return balances[_owner];
  }

}

/**
 * @title Standard ERC20 token
 *
 * @dev Implementation of the basic standard token.
 * https://github.com/ethereum/EIPs/issues/20
 * Based on code by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
 */
contract StandardToken is ERC20, BasicToken {

  mapping (address => mapping (address => uint256)) internal allowed;


  /**
   * @dev Transfer tokens from one address to another
   * @param _from address The address which you want to send tokens from
   * @param _to address The address which you want to transfer to
   * @param _value uint256 the amount of tokens to be transferred
   */
  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;
  }

  /**
   * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
   * Beware that changing an allowance with this method brings the risk that someone may use both the old
   * and the new allowance by unfortunate transaction ordering. One possible solution to mitigate this
   * race condition is to first reduce the spender's allowance to 0 and set the desired value afterwards:
   * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
   * @param _spender The address which will spend the funds.
   * @param _value The amount of tokens to be spent.
   */
  function approve(address _spender, uint256 _value) public returns (bool) {
    allowed[msg.sender][_spender] = _value;
    emit Approval(msg.sender, _spender, _value);
    return true;
  }

  /**
   * @dev Function to check the amount of tokens that an owner allowed to a spender.
   * @param _owner address The address which owns the funds.
   * @param _spender address The address which will spend the funds.
   * @return A uint256 specifying the amount of tokens still available for the spender.
   */
  function allowance(
    address _owner,
    address _spender
   )
    public
    view
    returns (uint256)
  {
    return allowed[_owner][_spender];
  }

  /**
   * @dev Increase the amount of tokens that an owner allowed to a spender.
   * approve should be called when allowed[_spender] == 0. To increment
   * allowed value is better to use this function to avoid 2 calls (and wait until
   * the first transaction is mined)
   * From MonolithDAO Token.sol
   * @param _spender The address which will spend the funds.
   * @param _addedValue The amount of tokens to increase the allowance by.
   */
  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;
  }

  /**
   * @dev Decrease the amount of tokens that an owner allowed to a spender.
   * approve should be called when allowed[_spender] == 0. To decrement
   * allowed value is better to use this function to avoid 2 calls (and wait until
   * the first transaction is mined)
   * From MonolithDAO Token.sol
   * @param _spender The address which will spend the funds.
   * @param _subtractedValue The amount of tokens to decrease the allowance by.
   */
  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;
  }

}

/**
 * @title Burnable Token
 * @dev Token that can be irreversibly burned (destroyed).
 */
contract BurnableToken is StandardToken {

  event Burn(address indexed burner, uint256 value);

  /**
   * @dev Burns a specific amount of tokens.
   * @param _value The amount of token to be burned.
   */
  function burn(uint256 _value) public {
    _burn(msg.sender, _value);
  }

  /**
   * @dev Burns a specific amount of tokens from the target address and decrements allowance
   * @param _from address The address which you want to send tokens from
   * @param _value uint256 The amount of token to be burned
   */
  function burnFrom(address _from, uint256 _value) public {
    require(_value <= allowed[_from][msg.sender]);
    // Should https://github.com/OpenZeppelin/zeppelin-solidity/issues/707 be accepted,
    // this function needs to emit an event with the updated approval.
    allowed[_from][msg.sender] = allowed[_from][msg.sender].sub(_value);
    _burn(_from, _value);
  }

  function _burn(address _who, uint256 _value) internal {
    require(_value <= balances[_who]);
    // no need to require value <= totalSupply, since that would imply the
    // sender's balance is greater than the totalSupply, which *should* be an assertion failure

    balances[_who] = balances[_who].sub(_value);
    totalSupply_ = totalSupply_.sub(_value);
    emit Burn(_who, _value);
  }
}

contract AvailComToken is BurnableToken, Ownable {

    string public constant name = "AvailCom Token";
    string public constant symbol = "AVL";
    uint32 public constant decimals = 4;

    constructor () public {
        // 0000 is added to the totalSupply because decimal 4
        totalSupply_ = 22000000000000;
        balances[msg.sender] = totalSupply_;
    }
}


/**
 * @title RBAC (Role-Based Access Control)
 * @author Matt Condon (@Shrugs)
 * @dev Stores and provides setters and getters for roles and addresses.
 * Supports unlimited numbers of roles and addresses.
 * See //contracts/mocks/RBACMock.sol for an example of usage.
 * This RBAC method uses strings to key roles. It may be beneficial
 * for you to write your own implementation of this interface using Enums or similar.
 */
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);

  /**
   * @dev reverts if addr does not have role
   * @param _operator address
   * @param _role the name of the role
   * // reverts
   */
  function checkRole(address _operator, string _role) public view {
    roles[_role].check(_operator);
  }

  /**
   * @dev determine if addr has role
   * @param _operator address
   * @param _role the name of the role
   * @return bool
   */
  function hasRole(address _operator, string _role) public view returns (bool) {
    return roles[_role].has(_operator);
  }

  /**
   * @dev add a role to an address
   * @param _operator address
   * @param _role the name of the role
   */
  function addRole(address _operator, string _role) internal {
    roles[_role].add(_operator);
    emit RoleAdded(_operator, _role);
  }

  /**
   * @dev remove a role from an address
   * @param _operator address
   * @param _role the name of the role
   */
  function removeRole(address _operator, string _role) internal {
    roles[_role].remove(_operator);
    emit RoleRemoved(_operator, _role);
  }

  /**
   * @dev modifier to scope access to a single role (uses msg.sender as addr)
   * @param _role the name of the role
   * // reverts
   */
  modifier onlyRole(string _role) {
    checkRole(msg.sender, _role);
    _;
  }
}

/**
 * @title Roles
 * @author Francisco Giordano (@frangio)
 * @dev Library for managing addresses assigned to a Role.
 * See RBAC.sol for example usage.
 */
library Roles {

  struct Role {
    mapping (address => bool) bearer;
  }

  /**
   * @dev give an account access to this role
   */
  function add(Role storage _role, address _account) internal {
    _role.bearer[_account] = true;
  }

  /**
   * @dev remove an account's access to this role
   */
  function remove(Role storage _role, address _account) internal {
    _role.bearer[_account] = false;
  }

  /**
   * @dev check if an account has this role
   * // reverts
   */
  function check(Role storage _role, address _account) internal view {
    require(has(_role, _account));
  }

  /**
   * @dev check if an account has this role
   * @return bool
   */
  function has(Role storage _role, address _account) internal view returns (bool) {
    return _role.bearer[_account];
  }
}

/**
 * @title Whitelist
 * @dev The Whitelist contract has a whitelist of addresses, and provides basic authorization control functions.
 * This simplifies the implementation of "user permissions".
 */
contract Whitelist is Ownable, RBAC {
  string public constant ROLE_WHITELISTED = "whitelist";

  /**
   * @dev Throws if operator is not whitelisted.
   * @param _operator address
   */
  modifier onlyIfWhitelisted(address _operator) {
    checkRole(_operator, ROLE_WHITELISTED);
    _;
  }


  function addMassAddressToWhitelist(address[] _operator) public onlyOwner {
    for (uint i = 0; i < _operator.length; i++) {
        address addr = _operator[i];
        addRole(addr, ROLE_WHITELISTED);
    }
  }


  /**
   * @dev add an address to the whitelist
   * @param _operator address
   * @return true if the address was added to the whitelist, false if the address was already in the whitelist
   */
  function addAddressToWhitelist(address _operator) public onlyOwner {
    addRole(_operator, ROLE_WHITELISTED);
  }

  /**
   * @dev getter to determine if address is in whitelist
   */
  function whitelist(address _operator) public view returns (bool) {
    return hasRole(_operator, ROLE_WHITELISTED);
  }

  /**
   * @dev add addresses to the whitelist
   * @param _operators addresses
   * @return true if at least one address was added to the whitelist,
   * false if all addresses were already in the whitelist
   */
  function addAddressesToWhitelist(address[] _operators) public onlyOwner {
    for (uint256 i = 0; i < _operators.length; i++) {
      addAddressToWhitelist(_operators[i]);
    }
  }

  /**
   * @dev remove an address from the whitelist
   * @param _operator address
   * @return true if the address was removed from the whitelist,
   * false if the address wasn't in the whitelist in the first place
   */
  function removeAddressFromWhitelist(address _operator) public onlyOwner {
    removeRole(_operator, ROLE_WHITELISTED);
  }

  /**
   * @dev remove addresses from the whitelist
   * @param _operators addresses
   * @return true if at least one address was removed from the whitelist,
   * false if all addresses weren't in the whitelist in the first place
   */
  function removeAddressesFromWhitelist(address[] _operators) public onlyOwner {
    for (uint256 i = 0; i < _operators.length; i++) {
      removeAddressFromWhitelist(_operators[i]);
    }
  }
}




/**
 * @title Crowdsale
 * @dev Crowdsale is a base contract for managing a token crowdsale,
 * allowing investors to purchase tokens with ether. This contract implements
 * such functionality in its most fundamental form and can be extended to provide additional
 * functionality and/or custom behavior.
 * The external interface represents the basic interface for purchasing tokens, and conform
 * the base architecture for crowdsales. They are *not* intended to be modified / overridden.
 * The internal interface conforms the extensible and modifiable surface of crowdsales. Override
 * the methods to add functionality. Consider using 'super' where appropriate to concatenate
 * behavior.
 */
contract Crowdsale is Ownable, Whitelist {
  using SafeMath for uint256;

  // The token being sold
  AvailComToken public token;

  // Variable for tracking whether ICO is complete
  bool public fifishICO = false;

  // Address where funds are collected
  address public wallet;

  // How many token units a buyer gets per wei.
  // The rate is the conversion between wei and the smallest and indivisible token unit.
  // So, if you are using a rate of 1 with a DetailedERC20 token with 3 decimals called TOK
  // 1 wei will give you 1 unit, or 0.001 TOK.
  uint256 public rate;

  // Start time for test contract
  uint public start = 1534291200; 
  // uint public start = 1534291200; // 15.08.2018

  uint public period = 30;
  uint public hardcap = 800 * 1 ether;

  // Bonus on the closed sale of tokens - 50%
  uint public bonusPersent = 50;

  // Amount of wei raised
  uint256 public weiRaised;

  // The minimum purchase amount of tokens. Can be changed during ICO
  uint256 public etherLimit = 1 ether;

  /**
   * Event for token purchase logging
   * @param purchaser who paid for the tokens
   * @param beneficiary who got the tokens
   * @param value weis paid for purchase
   * @param amount amount of tokens purchased
   */
  event TokenPurchase(address indexed purchaser, address indexed beneficiary, uint256 value, uint256 amount);

    // Time check modifier
    modifier saleICOn() {
    	require(now > start && now < start + period * 1 days);
    	_;
    }
    
    // Check modifier on the collected hardcap
    modifier isUnderHardCap() {
        require(wallet.balance <= hardcap);
        _;
    }

  /**
   * @param _token Address of the token being sold
   */
  constructor (AvailComToken _token) public {
    require(_token != address(0));

    // 0000 is added to the rate because decimal 4
    rate = 167000000;
    wallet = msg.sender;
    token = _token;
  }

  // -----------------------------------------
  // Crowdsale external interface
  // -----------------------------------------

  /**
   * @dev fallback function ***DO NOT OVERRIDE***
   */
  function () saleICOn isUnderHardCap external payable {
    require(!fifishICO);

    if (!whitelist(msg.sender)) {
      require(msg.value >= etherLimit);
    }

    buyTokens(msg.sender);
  }

  function buyTokens(address _beneficiary) public payable {

    uint256 weiAmount = msg.value;
    _preValidatePurchase(_beneficiary, weiAmount);

    // calculate token amount to be created
    uint256 tokens = _getTokenAmount(weiAmount);

    // update state
    weiRaised = weiRaised.add(weiAmount);

    _processPurchase(_beneficiary, tokens);
    emit TokenPurchase(msg.sender, _beneficiary, weiAmount, tokens);

    _forwardFunds();
  }

  function _preValidatePurchase(address _beneficiary, uint256 _weiAmount) internal {
    require(_beneficiary != address(0));
    require(_weiAmount != 0);
  }

  function _deliverTokens(address _beneficiary, uint256 _tokenAmount) internal {
    // Adding a bonus tokens to purchase
    _tokenAmount = _tokenAmount + (_tokenAmount * bonusPersent / 100);
    // Сonversion from wei
    _tokenAmount = _tokenAmount / 1000000000000000000;
    token.transfer(_beneficiary, _tokenAmount);
  }

  function _processPurchase(address _beneficiary, uint256 _tokenAmount) internal {
    _deliverTokens(_beneficiary, _tokenAmount);
  }

  /**
   * @dev Override to extend the way in which ether is converted to tokens.
   * @param _weiAmount Value in wei to be converted into tokens
   * @return Number of tokens that can be purchased with the specified _weiAmount
   */
  function _getTokenAmount(uint256 _weiAmount) internal view returns (uint256) {
    return _weiAmount.mul(rate);
  }

  /**
   * @dev Determines how ETH is stored/forwarded on purchases.
   */
  function _forwardFunds() internal {
    wallet.transfer(msg.value);
  }

  // ICO completion function. 
  // At the end of ICO all unallocated tokens are returned to the address of the creator of the contract
  function finishCrowdsale() public onlyOwner {
    uint _value = token.balanceOf(this);
    token.transfer(wallet, _value);
    fifishICO = true;
  }

  // The function of changing the minimum purchase amount of tokens.
  function editEtherLimit (uint256 _value) public onlyOwner {
    etherLimit = _value;
    etherLimit = etherLimit * 1 ether;
  }

}