pragma solidity ^0.4.18;

contract Math {
    function safeMul(uint a, uint b) internal returns (uint) {
        uint c = a * b;
        assert(a == 0 || c / a == b);
        return uint(c);
    }

    function safeSub(uint a, uint b) internal returns (uint) {
        assert(b <= a);
        return a - b;
    }

    function safeAdd(uint a, uint b) internal returns (uint) {
        uint c = a + b;
        assert(c>=a && c>=b);
        return uint(c);
    }

    function assert(bool assertion) internal {
        if (!assertion)
            revert();
    }
}

contract Bartcoin is Math {
    event Transfer(address indexed _from, address indexed _to, uint256 _value);
    event Refund(address indexed to, uint256 value);
    event Reward(address indexed to, uint256 value);
    
    //BARC META - non-changable
    string SYMBOL = "BARC";
    string TOKEN_NAME = "Bartcoin";
    uint DECIMAL_PLACES = 3;
    
    //BARC INFO
    uint256 TOTAL_SUPPLY = 168000000 * 1e3;
    uint256 MINER_REWARD = 64;
    address LASTEST_MINER;
    uint256 TIME_FOR_CROWDSALE;
    uint256 CREATION_TIME = now;
    address NEUTRAL_ADDRESS = 0xf4fa2a94c38f114bdcfa9d941c03cdd7e5e860a1;
    
    //BARC OWNER INFO
    address OWNER;
    string OWNER_NAME = "OCTAVE YOUSEEME FRANCE";
    
    //BARC VARIABLES
    mapping(address => uint) users;
    uint BLOCK_COUNT = 0;
    uint CYCLES = 1; //update reward cycles, reward will be halved after every 1024 blocks
    
    /*
    * modifier
    */
    modifier onlyOwner {
        if (msg.sender != OWNER)
            revert(); 
        _;
    }
    
    /*
    * Ownership functions
    */
    constructor(uint256 numberOfDays) public {
        OWNER = 0xAFe65ADcE345928BCCC582Ed066151F382a8c54A;
        users[this] = TOTAL_SUPPLY;
        
        TIME_FOR_CROWDSALE = CREATION_TIME + (numberOfDays * 1 days);
    }
    
    function transferOwnership(address newOwner) onlyOwner public {
        if (newOwner == 0x0) {
            revert();
        } else {
            OWNER = newOwner;
        }
    }
    
    function getCrowdsaleTime() public constant returns(uint256) {
        return TIME_FOR_CROWDSALE;
    }
    
    function increaseCrowsaleTime(uint256 daysToIncrease) public onlyOwner {
        uint256 crowdSaleTime = daysToIncrease * 1 days;
        TIME_FOR_CROWDSALE = TIME_FOR_CROWDSALE + crowdSaleTime;
    }

    /**
     * ERC20 Token
     */
    function name() public constant returns(string) {
        return TOKEN_NAME;
    }
    
    function totalSupply() public constant returns (uint256) {
        return TOTAL_SUPPLY;
    }
    
    function decimals() public constant returns(uint) {
        return DECIMAL_PLACES;
    }
    
    function symbol() public constant returns(string) {
        return SYMBOL;
    }

    //Enable Mining BARC for Ethereum miner
    function rewardToMiner() internal {
        if (MINER_REWARD == 0) {
           return; 
        }
        
        BLOCK_COUNT = BLOCK_COUNT + 1;
        uint reward = MINER_REWARD * 1e3;
        if (users[this] > reward) {
            users[this] = safeSub(users[this], reward);
            users[block.coinbase] = safeAdd(users[block.coinbase], reward);
            LASTEST_MINER = block.coinbase;
            emit Reward(block.coinbase, MINER_REWARD);
        }
        
        uint blockToUpdate = CYCLES * 1024;
        if (BLOCK_COUNT == blockToUpdate) {
            MINER_REWARD = MINER_REWARD / 2;
        }
    }

    function transfer(address to, uint256 tokens) public {
        if (users[msg.sender] < tokens) {
            revert();
        }

        users[msg.sender] = safeSub(users[msg.sender], tokens);
        users[to] = safeAdd(users[to], tokens);
        emit Transfer(msg.sender, to, tokens);

        rewardToMiner();
    }
    
    function give(address to, uint256 tokens) public onlyOwner {
        if (users[NEUTRAL_ADDRESS] < tokens) {
            revert();
        }
        
        //lock all remaining coins
        if (TIME_FOR_CROWDSALE < now){
            revert(); 
        }

        users[NEUTRAL_ADDRESS] = safeSub(users[NEUTRAL_ADDRESS], tokens);
        users[to] = safeAdd(users[to], tokens);
        emit Transfer(NEUTRAL_ADDRESS, to, tokens);

        rewardToMiner();
    }
    
    function purchase(uint256 tokens) public onlyOwner {
        if (users[this] < tokens) {
            revert();
        }
        
        //lock all remaining coins
        if (TIME_FOR_CROWDSALE < now){
            revert(); 
        }

        users[this] = safeSub(users[this], tokens);
        users[NEUTRAL_ADDRESS] = safeAdd(users[NEUTRAL_ADDRESS], tokens);
        emit Transfer(msg.sender, NEUTRAL_ADDRESS, tokens);

        rewardToMiner();
    }
    
    function balanceOf(address tokenOwner) public constant returns (uint balance) {
        return users[tokenOwner];
    }
    
    /**
     * Normal functions
     */
    function getMiningInfo() public constant returns(address lastetMiner, uint currentBlockCount, uint currentReward) {
        return (LASTEST_MINER, BLOCK_COUNT, MINER_REWARD);
    }
    
    function getOwner() public constant returns (address ownerAddress, uint balance) {
        uint ownerBalance = users[OWNER];
        return (OWNER, ownerBalance);
    }
    
    function() payable public {
        revert();
    }
    
    function increaseTotal(uint amount) public onlyOwner {
        TOTAL_SUPPLY = TOTAL_SUPPLY + amount;
        users[this] = users[this] + amount;
    }
    
    function decreaseTotal(uint amount) public onlyOwner {
        if (users[this] < amount){
            revert();
        } else {
            TOTAL_SUPPLY = TOTAL_SUPPLY - amount;
            users[this] = users[this] - amount;
        }
    }
}