pragma solidity ^0.4.25;

import "./FixedPrice.sol";

contract DynamicPrice is FixedPrice {

    uint releaseTime;
    uint lockTimeS;
    uint incentivePrice = 0;

    event FundsReleaseEvent(uint _releaseTime, uint _lockTimeS, uint _actualReleaseTime, uint _lockedFunds, uint _amountReturned);
    event StartService(bool _successPayment, uint _currentTime, uint _releaseTime);

    mapping(address => AccountData) accounts;

    // custom data structure to hold locked funds and time
    struct AccountData {
        uint balance;
        uint releaseTime;
        bool isFinished;
    }

    constructor(uint _price, uint _durationSeconds, address _endUserAddress) FixedPrice(_price, _durationSeconds, _endUserAddress) public {
    }

    // pay the max amount and lock funds
    function payService() public payable {
        require(msg.sender == endUserAddress);
        require(price > 0);
        assert(accounts[msg.sender].balance == 0);
        require(msg.value >= (price + incentivePrice));

        uint currentTime = now;
        // make sure that the incentive cannot be returned (flexible usage period)
        accounts[msg.sender].balance = msg.value - incentivePrice;
        accounts[msg.sender].releaseTime = currentTime + durationSeconds;
        accounts[msg.sender].isFinished = false;

        emit StartService(true, currentTime, releaseTime);
    }

    // check if user has funds due for pay out because lock time is over
    function triggerReleaseTime() {
        require(msg.sender == endUserAddress);
        require(accounts[msg.sender].isFinished != true);

        // split funds if there is remaining time
        if (accounts[msg.sender].releaseTime < now) {
            uint currentTime = now;
            uint gweiReturn = (accounts[msg.sender].releaseTime - currentTime) * (price / durationSeconds);

            msg.sender.send(gweiReturn);
            accounts[msg.sender].balance -= gweiReturn;
            accounts[msg.sender].isFinished = true;
            emit FundsReleaseEvent(releaseTime, lockTimeS, currentTime, price, gweiReturn);
        }
    }

    function checkLockState(){
        require(msg.sender == owner);

        uint currentTime = now;
        if (accounts[endUserAddress].releaseTime >= currentTime) {
            accounts[msg.sender].isFinished = true;
            emit FundsReleaseEvent(releaseTime, lockTimeS, currentTime, price, 0);
        }
        else {
            emit FundsReleaseEvent(releaseTime, lockTimeS, currentTime, price, -1);
        }
    }

    function getLockedFunds() constant returns (uint x) {
        return accounts[msg.sender].balance;
    }

    function getReleaseTime() constant returns (uint x) {
        return accounts[msg.sender].releaseTime;
    }

    function getCurrentTime() constant returns (uint x) {
        return now;
    }
}