// SPDX-License-Identifier: MIT

pragma solidity >=0.6.6 <0.9.0;

import "@chainlink/contracts/src/v0.6/interfaces/AggregatorV3Interface.sol";

contract FundMe{
    
    mapping(address => uint256) public addressToAmountFunded;
    address[] public funders;
    address public owner;
    
    constructor() public {
        owner = msg.sender;
    }
    
    function fund() public payable {
        // 50$
        uint256 minimumUSD = 50* 10**18;
        uint256 actualUSD = getConversionRate(msg.value);
        require (actualUSD > minimumUSD, "not enough ETH!");
        addressToAmountFunded[msg.sender] += msg.value;
        funders.push(msg.sender);
    }
    
    function getVersion() public view returns(uint256){
        // that says we have a contract that is located at this address and has the functiones deifned in the interface
        AggregatorV3Interface priceFeed = AggregatorV3Interface(0x8A753747A1Fa494EC906cE90E9f37563A8AF630e);
        return priceFeed.version();
    }
    
    function getDecimals() public view returns(uint8){
        AggregatorV3Interface priceFeed = AggregatorV3Interface(0x8A753747A1Fa494EC906cE90E9f37563A8AF630e);
        return priceFeed.decimals();
    }
    
    function getPrice() public view returns(uint256){
        AggregatorV3Interface priceFeed = AggregatorV3Interface(0x8A753747A1Fa494EC906cE90E9f37563A8AF630e);
        (, //uint80 roundId,
         int256 answer
         , //uint256 startedAt,
         , //uint256 updatedAt,
         , //uint80 answeredInRound
         ) = priceFeed.latestRoundData();
        return uint256(answer * 1000000000);
    }
    
    function getConversionRate(uint256 ethAmount) public view returns(uint256){
        // meins return getPrice() * addressToAmountFunded[msg.sender];
        uint256 ethPrice = getPrice();
        uint256 ethAmountInUSD = (ethPrice * ethAmount) / 100000000000000000;
        return ethAmountInUSD;
    }
    
    
    modifier onlyOwner {
        // only the owner
        require(msg.sender == owner, "not allowed");
        _;
    }
    
    function withdraw() payable onlyOwner public {
        msg.sender.transfer(address(this).balance);
        for (uint256 funderIndex=0; funderIndex<funders.length; funderIndex++){
            address funder = funders[funderIndex];
            addressToAmountFunded[funder] = 0;
        }
        funders = new address[](0);
    }
    
}