VolcanoCoin.sol

// SPDX-License-Identifier: UNLICENSED 

pragma solidity ^0.8.0;

contract VolcanoCoin {
    uint256 totalSupply = 10000;
    
    address owner;
    
    modifier onlyOwner {
        require(msg.sender == owner);
        _;
    }
    
    event TotalSupplyIncrease(uint);
    event Transfer(uint, address);
    
    constructor() {
        owner = msg.sender;
        balances[msg.sender] = totalSupply;
        totalSupply = 0;
    }
    
    mapping(address => uint256) public balances;

    mapping(address => Payment[]) public payments;
    
    struct Payment {
        uint256 transferAmount;
        address recipient;
    }
    
    function getTotalSupply() public view returns (uint) {
        return totalSupply;
    }
    
    function increaseTotalSupplyWith1000() public onlyOwner {
        totalSupply += 1000;
        emit TotalSupplyIncrease(totalSupply);
    }
    
    function transfer(uint256 amount, address recipient) public {
        require(amount < balances[msg.sender]);
        balances[msg.sender] -= amount;
        balances[recipient] += amount;
        payments[msg.sender].push(Payment(amount, recipient));
        emit Transfer(amount, recipient);
    }
    
    function getBalance() public view returns (uint) {
        return balances[msg.sender];
    }
    
    function getBalanceOf(address addr) public view returns (uint) {
        return balances[addr];
    }
}