NftExampleToken1155.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.3;

import "@openzeppelin/contracts/token/ERC1155/utils/ERC1155Holder.sol";
import "@openzeppelin/contracts/token/ERC1155/IERC1155.sol";
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";

/*
* LIFE TOKEN CONTRACT
*/
contract NftExampleToken1155 is ERC20,ERC1155Holder {

    IERC1155 public nft;
    mapping(uint256=> address) public tokenOwnerOf;
    mapping(uint256=> uint256) public tokenStakedAt;
    uint256 public EMISSION_RATE=(50*10**decimals())/1 days;

    /* ========== CONSTRUCTOR ========== */
    constructor(address _nft) ERC20("Example", "EXAMPLE") {

        nft=IERC1155(_nft);
    }

    function stake(uint256 tokenId) external{
        nft.safeTransferFrom(msg.sender, address(this), tokenId, 1, "");
        tokenOwnerOf[tokenId]=msg.sender;
        tokenStakedAt[tokenId]=block.timestamp;
    }

    function calculateTokens(uint256 tokenId)public view returns(uint){

        uint256 timeElapsed=block.timestamp-tokenStakedAt[tokenId];
        return timeElapsed*EMISSION_RATE;

    }

    modifier checkOwner(uint256 tokenId){
        require(tokenOwnerOf[tokenId]==msg.sender,"You are not the owner");
        _;
    }

    function unstake(uint256 tokenId) external checkOwner(tokenId){
       _mint(msg.sender, calculateTokens(tokenId));
       nft.safeTransferFrom(address(this),msg.sender,tokenId, 1, "");
       delete tokenOwnerOf[tokenId];
       delete tokenStakedAt[tokenId];
    }
}