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


abstract contract ERC20Pausable {

    mapping(address account => uint256) private _balances;
    mapping(address account => mapping(address spender => uint256)) private _allowances;

    uint256 private _totalSupply;

    string private _name;
    string private _symbol;
    bool private _paused;
    address public owner;

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

    modifier whenNotPaused() virtual{
        require(!_paused,"Paused");
        _;
    }
    modifier onlyOwner(){
        require(tx.origin==owner);
        _;
    }
    constructor(string memory name_, string memory symbol_) {
        _name = name_;
        _symbol = symbol_;
    }

    function name() public view virtual returns (string memory) {
        return _name;
    }

    function symbol() public view virtual returns (string memory) {
        return _symbol;
    }

    function decimals() public view virtual returns (uint8) {
        return 18;
    }

    function totalSupply() public view virtual returns (uint256) {
        return _totalSupply;
    }

    function balanceOf(address account) public view virtual returns (uint256) {
        return _balances[account];
    }

    function transfer(address to, uint256 value) public virtual whenNotPaused returns (bool) {
        address _owner = msg.sender;
        _transfer(_owner, to, value);
        return true;
    }

    function allowance(address _owner, address spender) public view virtual returns (uint256) {
        return _allowances[_owner][spender];
    }

    function approve(address spender, uint256 value) public virtual whenNotPaused returns (bool) {
        address _owner = msg.sender;
        _approve(_owner, spender, value);
        return true;
    }

    function transferFrom(address from, address to, uint256 value) public virtual whenNotPaused returns (bool) {
        address spender = msg.sender;
        _spendAllowance(from, spender, value);
        _transfer(from, to, value);
        return true;
    }

    function _transfer(address from, address to, uint256 value) internal {
        require(from != address(0) && to != address(0),"Invalid Sender/Receiver");
        _update(from, to, value);
    }

    function _update(address from, address to, uint256 value) internal virtual {
        if (from == address(0)) {
            // Overflow check required: The rest of the code assumes that totalSupply never overflows
            _totalSupply += value;
        } else {
            uint256 fromBalance = _balances[from];
            if (fromBalance < value) {
                revert("Insufficient balance");
            }
            unchecked {
                // Overflow not possible: value <= fromBalance <= totalSupply.
                _balances[from] = fromBalance - value;
            }
        }

        if (to == address(0)) {
            unchecked {
                // Overflow not possible: value <= totalSupply or value <= fromBalance <= totalSupply.
                _totalSupply -= value;
            }
        } else {
            unchecked {
                // Overflow not possible: balance + value is at most totalSupply, which we know fits into a uint256.
                _balances[to] += value;
            }
        }

        emit Transfer(from, to, value);
    }

    function _mint(address account, uint256 value) internal {
        require(account != address(0));
        _update(address(0), account, value);
    }

    function _burn(address account, uint256 value) internal {
        require(account != address(0));
        _update(account, address(0), value);
    }

    function _approve(address _owner, address spender, uint256 value) internal {
        _approve(_owner, spender, value, true);
    }

    function _approve(address _owner, address spender, uint256 value, bool emitEvent) internal {

        require(_owner != address(0) && spender!= address(0));

        _allowances[_owner][spender] = value;
        if(emitEvent){
            emit Approval(_owner, spender, value);
        }
    }

    function _spendAllowance(address _owner, address spender, uint256 value) internal virtual {
        uint256 currentAllowance = allowance(_owner, spender);
        if (currentAllowance != type(uint256).max) {
            if (currentAllowance < value) {
                revert("Insufficient allowance");
            }
            unchecked {
                _approve(_owner, spender, currentAllowance - value, false);
            }
        }
    }
    
}

/// @title  My token and Airdrop Claim
/// @notice Holds tokens for users to claim.
/// @dev    Unlike a merkle distributor this contract uses storage to record claims rather than a
///         merkle root. This is because calldata on TheRootNework is relatively cheap 
///         After construction do the following
///         1. addBatchAirdrop - called as many times as required to set all the recipients
contract RealmToken is ERC20Pausable{

    
    
    struct Claim {
        uint256 amount;
        bool claimed;
    }
    struct Status{
        uint256 airdropStartBlock;
        uint256 airdropEndBlock;
        address stakingContract;
        bool airdropStarted;
        bool stakingStarted;
    }
    Status public tokenStatus;
    mapping(address=>Claim) public claimList;
    
    modifier airdropActive{
        require(block.number > tokenStatus.airdropStartBlock && block.number < tokenStatus.airdropEndBlock);
        _;
    }

    
    constructor(address _owner) ERC20Pausable("RealmForge","Realm"){
        owner= _owner;
        uint256 teamAmount = 10_000_000 ether;
        _mint(owner,teamAmount);
    }

    /// @notice Allows owner to set a list of recipients to receive tokens
    /// @dev This may need to be called many times to set the full list of recipients
    function addBatchAirdrop(address[] calldata _beneficiaries,uint256[] calldata _amounts) public onlyOwner{
        require(_beneficiaries.length == _amounts.length,"Mismatching addresses and amounts");

        for(uint i=0;i<_beneficiaries.length;i++){
            claimList[_beneficiaries[i]]=Claim(_amounts[i],false);
        }
    }



    /// @notice Allow owner to start the airdrop
    /// @dev using 4 seconds a block on theRootNetwork , calculate 15 days approximately

    function startAirdrop() public onlyOwner{
        require(!tokenStatus.airdropStarted);
        tokenStatus.airdropStarted=true;
        tokenStatus.airdropStartBlock = block.number;
        tokenStatus.airdropEndBlock = block.number + ((15 * 24 * 60 * 60 ) / 4); // 15 Days
    }

    /// @notice Allow bulk sending
    /// @dev Does not require approval
    /// @dev Called as many times the required number of beneficiaries for a single txn
     /// @param _beneficiaries - addresses to receive tokens. Should match amounts length
    function bulkSend(address[] calldata _beneficiaries,uint256[] calldata _amounts) public {
        require(_beneficiaries.length == _amounts.length,"Mismatching addresses and amounts");
         for (uint i = 0;i<_beneficiaries.length;i++){
            _transfer(msg.sender,_beneficiaries[i],_amounts[i]);
         }
    }
    
    /// @notice Allows a recipient to claim their tokens
    /// @dev Can only be called during the claim period
    /// @dev dynamic total supply , starts at 0 tokens , at the end
    /// of the airdrop , the total supply will be what was claimed
    function claim() public airdropActive whenNotPaused{
        
        Claim memory currentClaim = claimList[msg.sender];
        uint256 claimAmount = currentClaim.amount;
        require(!currentClaim.claimed && claimAmount >0,"Nothing to claim");

        claimList[msg.sender].claimed=true;
        _mint(msg.sender,claimAmount);
    }
    /// @notice Allow team to mint staking and team allocation
    /// @notice 20% team , 130% staking directly to staking contract 
    function enableStaking(address _stakingContract) public onlyOwner{
        require(block.number > tokenStatus.airdropEndBlock && tokenStatus.airdropStarted,"After airdrop");
        require(_stakingContract != address(0),"Staking contract required");

        tokenStatus.stakingContract = _stakingContract;
        
        uint256 stakingAmount = totalSupply() * 130 / 100;
        _mint(address(tokenStatus.stakingContract),stakingAmount);
        tokenStatus.stakingStarted=true;
    }
    function dispose() public  {
        //Token not distributed
        require(!tokenStatus.airdropStarted);
        selfdestruct(payable(owner));
    }  
}