contract SETIcoin is owned {
  // Public variables of the token
  using SafeMath for uint256;
  string public name = "South East Trading Investment";
  string public symbol = "SETI";
  uint256 public decimals = 18; // 18 decimals is the strongly suggested default, avoid changing it
  uint256 public totalSupply = 600000000 * (10 ** decimals) ; // 600 Million with 18 decimal points
  bool public safeguard; // putting safeguard on will halt all non-owner functions


  // This creates an array with all balances
  mapping (address => uint256) public balanceOf;
  mapping (address => mapping (address => uint256)) public allowance;
  mapping (address => bool) public frozenAccount;


  /* This generates a public event on the blockchain that will notify clients */
  event FrozenAccounts(address target, bool frozen);

  // This generates a public event on the blockchain that will notify clients
  event Transfer(address indexed from, address indexed to, uint256 value);

  // This notifies clients about the amount burnt
  event Burn(address indexed from, uint256 value);

  // Approval
  event Approval(address indexed tokenOwner, address indexed spender, uint256 indexed tokenAmount);


  /**
    * Constrctor function
    *
    * Initializes contract with initial supply tokens to the creator of the contract
    */
  constructor () public {

    //sending all the tokens to Owner
    balanceOf[owner] = totalSupply;

    emit Transfer(address(0), msg.sender, totalSupply);

  }

  /**
    * Internal transfer, only can be called by this contract
    */
  function _transfer(address _from, address _to, uint _value) internal {
    require(!safeguard, 'safeguard is active');
    // Prevent transfer to 0x0 address. Use burn() instead
    require(_to != address(0x0), 'zero address');

    uint previousBalances = balanceOf[_from].add(balanceOf[_to]);
    balanceOf[_from] = balanceOf[_from].sub(_value);
    balanceOf[_to] = balanceOf[_to].add(_value);

    assert(balanceOf[_from].add(balanceOf[_to]) == previousBalances);

    emit Transfer(_from, _to, _value);
  }

  /**
    * Transfer tokens
    *
    * Send `_value` tokens to `_to` from your account
    *
    * @param _to The address of the recipient
    * @param _value the amount to send
    */
  function transfer(address _to, uint256 _value) public returns (bool success) {
    _transfer(msg.sender, _to, _value);
    return true;
  }

  /**
    * Transfer tokens from other address
    *
    * Send `_value` tokens to `_to` in behalf of `_from`
    *
    * @param _from The address of the sender
    * @param _to The address of the recipient
    * @param _value the amount to send
    */
  function transferFrom(address _from, address _to, uint256 _value) public returns (bool success) {
    allowance[_from][msg.sender] = allowance[_from][msg.sender].sub(_value);
    _transfer(_from, _to, _value);
    return true;
  }

  /**
    * Set allowance for other address
    *
    * Allows `_spender` to spend no more than `_value` tokens in your behalf
    *
    * @param _spender The address authorized to spend
    * @param _value the max amount they can spend
    */
  function approve(address _spender, uint256 _value) public returns (bool success) {
    require(!safeguard, 'safeguard is active');
    allowance[msg.sender][_spender] = _value;
    emit Approval(msg.sender, _spender, _value);
    return true;
  }


  /**
    * Destroy tokens
    *
    * Remove `_value` tokens from the system irreversibly
    *
    * @param _value the amount of money to burn
    */
  function burn(uint256 _value) public returns (bool success) {
    require(!safeguard, 'safeguard is active');
    balanceOf[msg.sender] = balanceOf[msg.sender].sub(_value);
    totalSupply = totalSupply.sub(_value);
    emit Burn(msg.sender, _value);
    emit Transfer(msg.sender, address(0), _value);
    return true;
  }


  /// @notice `freeze? Prevent | Allow` `target` from sending & receiving tokens
  /// @param target Address to be frozen
  /// @param freeze either to freeze it or not
  function freezeAccount(address target, bool freeze) public onlyOwner {
    frozenAccount[target] = freeze;
    emit FrozenAccounts(target, freeze);
  }



  // Just in rare case, owner wants to transfer Ether from contract to owner address
  function manualWithdrawEther() public onlyOwner {
    address(owner).transfer(address(this).balance);
  }

  function manualWithdrawTokens(uint256 tokenAmount) public onlyOwner {
    // no need for overflow checking as that will be done in transfer function
    _transfer(address(this), owner, tokenAmount);
  }



  /**
    * Change safeguard status on or off
    *
    * When safeguard is true, then all the non-owner functions will stop working.
    * When safeguard is false, then all the functions will resume working back again!
    */
  function changeSafeguardStatus() public onlyOwner {
    if (safeguard == false) {
      safeguard = true;
    }
    else {
      safeguard = false;
    }
  }

  /********************************/
  /*    Code for the Air drop     */
  /********************************/

  /**
    * Run an Air-Drop
    *
    * It requires an array of all the addresses and amount of tokens to distribute
    * It will only process first 150 recipients. That limit is fixed to prevent gas limit
    */
  function airdrop(address[] memory recipients, uint[] memory tokenAmount) public onlyOwner {
    uint256 addressCount = recipients.length;
    require(addressCount <= 150, 'address count over 150');
    for(uint i = 0; i < addressCount; i++) {
      // This will loop through all the recipients and send them the specified tokens
      _transfer(address(this), recipients[i], tokenAmount[i]);
    }
  }
}
//*****************************************************************//
//------------------ SETI Coin main code starts -------------------//
//*****************************************************************//
function approve(address _spender, uint256 _value) public returns (bool success) {
  require(!safeguard, 'safeguard is active');
  allowance[msg.sender][_spender] = _value;
  emit Approval(msg.sender, _spender, _value);
  return true;
}

/**
 * Set allowance for other address
 *
 * Allows `_spender` to spend no more than `_value` tokens in your behalf
 *
 * @param _spender The address authorized to spend
 * @param _value the max amount they can spend
 */