pragma solidity ^0.4.16;

contract Token {

    /// @return total amount of tokens
    function totalSupply() constant returns (uint256 supply) {}

    /// @param _owner The address from which the balance will be retrieved
    /// @return The balance
    function balanceOf(address _owner) constant returns (uint256 balance) {}

    /// @notice send `_value` token to `_to` from `msg.sender`
    /// @param _to The address of the recipient
    /// @param _value The amount of token to be transferred
    /// @return Whether the transfer was successful or not
    function transfer(address _to, uint256 _value) returns (bool success) {}

    /// @notice send `_value` token to `_to` from `_from` on the condition it is approved by `_from`
    /// @param _from The address of the sender
    /// @param _to The address of the recipient
    /// @param _value The amount of token to be transferred
    /// @return Whether the transfer was successful or not
    function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {}

    /// @notice `msg.sender` approves `_addr` to spend `_value` tokens
    /// @param _spender The address of the account able to transfer the tokens
    /// @param _value The amount of wei to be approved for transfer
    /// @return Whether the approval was successful or not
    function approve(address _spender, uint256 _value) returns (bool success) {}

    /// @param _owner The address of the account owning tokens
    /// @param _spender The address of the account able to transfer the tokens
    /// @return Amount of remaining tokens allowed to spent
    function allowance(address _owner, address _spender) constant returns (uint256 remaining) {}

    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Approval(address indexed _owner, address indexed _spender, uint256 _value);
    
}



contract StandardToken is Token {

    function transfer(address _to, uint256 _value) returns (bool success) {
        //Default assumes totalSupply can't be over max (2^256 - 1).
        //If your token leaves out totalSupply and can issue more tokens as time goes on, you need to check if it doesn't wrap.
        //Replace the if with this one instead.
        //if (balances[msg.sender] >= _value && balances[_to] + _value > balances[_to]) {
        if (balances[msg.sender] >= _value && _value > 0) {
            balances[msg.sender] -= _value;
            balances[_to] += _value;
            Transfer(msg.sender, _to, _value);
            return true;
        } else { return false; }
    }

    function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
        //same as above. Replace this line with the following if you want to protect against wrapping uints.
        //if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && balances[_to] + _value > balances[_to]) {
        if (balances[_from] >= _value && allowed[_from][msg.sender] >= _value && _value > 0) {
            balances[_to] += _value;
            balances[_from] -= _value;
            allowed[_from][msg.sender] -= _value;
            Transfer(_from, _to, _value);
            return true;
        } else { return false; }
    }

    function balanceOf(address _owner) constant returns (uint256 balance) {
        return balances[_owner];
    }

    function approve(address _spender, uint256 _value) returns (bool success) {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);
        return true;
    }

    function allowance(address _owner, address _spender) constant returns (uint256 remaining) {
      return allowed[_owner][_spender];
    }

    mapping (address => uint256) balances;
    mapping (address => mapping (address => uint256)) allowed;
    uint256 public totalSupply;
}


//name this contract whatever you'd like
contract FarmCoin is StandardToken {

    function () {
        //if ether is sent to this address, send it back.
        throw;
    }

    /* Public variables of the token */

    /*
    NOTE:
    The following variables are OPTIONAL vanities. One does not have to include them.
    They allow one to customise the token contract & in no way influences the core functionality.
    Some wallets/interfaces might not even bother to look at this information.
    */
    string public name = 'FarmCoin';                   //fancy name: eg Simon Bucks
    uint8 public decimals = 18;                //How many decimals to show. ie. There could 1000 base units with 3 decimals. Meaning 0.980 SBX = 980 base units. It's like comparing 1 wei to 1 ether.
    string public symbol = 'FARM';                 //An identifier: eg SBX
    string public version = 'H1.0';       //human 0.1 standard. Just an arbitrary versioning scheme.

//
// CHANGE THESE VALUES FOR YOUR TOKEN
//

//make sure this function name matches the contract name above. So if you're token is called TutorialToken, make sure the //contract name above is also TutorialToken instead of ERC20Token

    function FarmCoin(
        ) {
        balances[msg.sender] = 5000000000000000000000000;               // Give the creator all initial tokens (100000 for example)
        totalSupply = 5000000000000000000000000;                        // Update total supply (100000 for example)
        name = "FarmCoin";                                   // Set the name for display purposes
        decimals = 18;                            // Amount of decimals for display purposes
        symbol = "FARM";                               // Set the symbol for display purposes
    }

    /* Approves and then calls the receiving contract */
    function approveAndCall(address _spender, uint256 _value, bytes _extraData) returns (bool success) {
        allowed[msg.sender][_spender] = _value;
        Approval(msg.sender, _spender, _value);

        //call the receiveApproval function on the contract you want to be notified. This crafts the function signature manually so one doesn't have to include a contract in here just for this.
        //receiveApproval(address _from, uint256 _value, address _tokenContract, bytes _extraData)
        //it is assumed that when does this that the call *should* succeed, otherwise one would use vanilla approve instead.
        if(!_spender.call(bytes4(bytes32(sha3("receiveApproval(address,uint256,address,bytes)"))), msg.sender, _value, this, _extraData)) { throw; }
        return true;
    }
}

contract FarmCoinSale is FarmCoin {

    uint256 public maxMintable;
    uint256 public totalMinted;
    uint256 public decimals = 18;
    uint public endBlock;
    uint public startBlock;
    uint public rate;
    uint public exchangeRate= rate;
    uint public startTime;
    bool public isFunding;
    address public ETHWallet;
    uint256 public heldTotal;

    bool private configSet;
    address public creator;

    mapping (address => uint256) public heldTokens;
    mapping (address => uint) public heldTimeline;

    event Contribution(address from, uint256 amount);
    event ReleaseTokens(address from, uint256 amount);


    function FarmCoinSale() {
        startBlock = block.number;
        maxMintable = 5000000000000000000000000; // 3 million max sellable (18 decimals)
        ETHWallet = 0x3b444fC8c2C45DCa5e6610E49dC54423c5Dcd86E;
        isFunding = true;
        
        creator = msg.sender;
        createHeldCoins();
        startTime = 1517461200000;
        exchangeRate= rate;
        }

 // start and end dates where crowdsale is allowed (both inclusive)
  uint256 constant public START = 1517461200000; // +new Date(2018, 2, 1) / 1000
  uint256 constant public END = 1522555200000; // +new Date(2018, 4, 1) / 1000

// @return the rate in FARM per 1 ETH according to the time of the tx and the FARM pricing program.
    // @Override
  function getRate() constant returns (uint256 rate) {
    if      (now < START)            return rate = 840; // presale, 40% bonus
    else if (now <= START +  6 days) return rate = 810; // day 1 to 6, 35% bonus
    else if (now <= START + 13 days) return rate = 780; // day 7 to 13, 30% bonus
    else if (now <= START + 20 days) return rate = 750; // day 14 to 20, 25% bonus
    else if (now <= START + 28 days) return rate = 720; // day 21 to 28, 20% bonus
    return rate = 600; // no bonus
  }

    // setup function to be ran only 1 time
    // setup token address
    // setup end Block number
    function setup(address TOKEN, uint endBlockTime) {
        require(!configSet);
        endBlock = endBlockTime;
        configSet = true;
    }

    function closeSale() external {
      require(msg.sender==creator);
      isFunding = false;
    }

    // CONTRIBUTE FUNCTION
    // converts ETH to TOKEN and sends new TOKEN to the sender
    function contribute() external payable {
        require(msg.value>0);
        require(isFunding);
        require(block.number <= endBlock);
        uint256 amount = msg.value * exchangeRate;
        uint256 total = totalMinted + amount;
        require(total<=maxMintable);
        totalMinted += total;
        ETHWallet.transfer(msg.value);
        Contribution(msg.sender, amount);
    }

    // update the ETH/COIN rate
    function updateRate(uint256 rate) external {
        require(msg.sender==creator);
        require(isFunding);
        exchangeRate = rate;
    }

    // change creator address
    function changeCreator(address _creator) external {
        require(msg.sender==creator);
        creator = _creator;
    }

    // change transfer status for FarmCoin token
    function changeTransferStats(bool _allowed) external {
        require(msg.sender==creator);
     }

    // internal function that allocates a specific amount of ATYX at a specific block number.
    // only ran 1 time on initialization
    function createHeldCoins() internal {
        // TOTAL SUPPLY = 5,000,000
        createHoldToken(msg.sender, 1000);
        createHoldToken(0xd9710D829fa7c36E025011b801664009E4e7c69D, 100000000000000000000000);
        createHoldToken(0xd9710D829fa7c36E025011b801664009E4e7c69D, 100000000000000000000000);
    }

    // function to create held tokens for developer
    function createHoldToken(address _to, uint256 amount) internal {
        heldTokens[_to] = amount;
        heldTimeline[_to] = block.number + 0;
        heldTotal += amount;
        totalMinted += heldTotal;
    }

    // function to release held tokens for developers
    function releaseHeldCoins() external {
        uint256 held = heldTokens[msg.sender];
        uint heldBlock = heldTimeline[msg.sender];
        require(!isFunding);
        require(held >= 0);
        require(block.number >= heldBlock);
        heldTokens[msg.sender] = 0;
        heldTimeline[msg.sender] = 0;
        ReleaseTokens(msg.sender, held);
    }


}