// BEXCHAIN BEX20 reference for token: Bex World Game (BWG), decimals=18
// Deploy from Remix to get matching EVM bytecode, or import ABI via explorer API.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

/**
 * Reference BEX20 token layout for BEXCHAIN native tokens deployed via the explorer.
 * Use this file in Remix to interact with your token address (read balances via explorer/RPC).
 * For full on-chain bytecode match verification, deploy this contract from Remix first.
 */
contract BEX20Reference {
    string public name;
    string public symbol;
    uint8 public decimals;
    uint256 public totalSupply;
    address public owner;

    mapping(address => uint256) public balanceOf;
    mapping(address => mapping(address => uint256)) public allowance;

    event Transfer(address indexed from, address indexed to, uint256 value);
    event Approval(address indexed owner, address indexed spender, uint256 value);

    constructor(
        string memory _name,
        string memory _symbol,
        uint8 _decimals,
        uint256 _initialSupply,
        address _owner
    ) {
        name = _name;
        symbol = _symbol;
        decimals = _decimals;
        owner = _owner;
        totalSupply = _initialSupply;
        balanceOf[_owner] = _initialSupply;
        emit Transfer(address(0), _owner, _initialSupply);
    }

    function transfer(address to, uint256 amount) external returns (bool) {
        _transfer(msg.sender, to, amount);
        return true;
    }

    function approve(address spender, uint256 amount) external returns (bool) {
        allowance[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    function transferFrom(address from, address to, uint256 amount) external returns (bool) {
        uint256 allowed = allowance[from][msg.sender];
        require(allowed >= amount, "allowance");
        allowance[from][msg.sender] = allowed - amount;
        _transfer(from, to, amount);
        return true;
    }

    function _transfer(address from, address to, uint256 amount) internal {
        require(to != address(0), "zero");
        require(balanceOf[from] >= amount, "balance");
        balanceOf[from] -= amount;
        balanceOf[to] += amount;
        emit Transfer(from, to, amount);
    }
}