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

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

contract AllocationContract {
    address public admin;
    address public pendingAdmin;

    struct Allocation {
        uint256 amount;
        string item;
    }

    mapping(address => Allocation) public allocations;
    bool public isActive;

    constructor() {
        admin = msg.sender;
        isActive = true;
    }

    modifier onlyAdmin() {
        require(msg.sender == admin, "Only admin can call this function");
        _;
    }

    modifier contractIsActive() {
        require(isActive, "Contract is not active");
        _;
    }

    event AllocationClaimed(address indexed user, uint256 amount, string item);
    event AdminTransferInitiated(address indexed currentAdmin, address indexed newAdmin);
    event AdminTransferAccepted(address indexed newAdmin);

    function claimTokens(string calldata item) external contractIsActive {
        Allocation storage allocation = allocations[msg.sender];
        require(allocation.amount > 0, "No allocation available or allocation is zero");

        uint256 amount = allocation.amount;
        allocation.amount = 0;
        allocation.item = item;
        emit AllocationClaimed(msg.sender, amount, item);
    }

    function getAllocationInfo(address user) external view returns (uint256, string memory) {
        Allocation memory allocation = allocations[user];
        return (allocation.amount, allocation.item);
    }

    function uploadRecord(address user, uint256 amount) external onlyAdmin {
        allocations[user] = Allocation(amount, "");
    }

    function uploadBatchRecords(address[] calldata users, uint256[] calldata amounts) external onlyAdmin {
        require(users.length == amounts.length, "Users and amounts length mismatch");

        for (uint256 i = 0; i < users.length; i++) {
            allocations[users[i]] = Allocation(amounts[i], "");
        }
    }

    function deposit() external payable onlyAdmin contractIsActive {
        require(msg.value > 0, "You need to deposit some ETH");
    }

    function withdraw(uint256 amount) external onlyAdmin {
        require(amount <= address(this).balance, "Insufficient balance in the contract");
        payable(admin).transfer(amount);
    }

    function withdrawERC20(address tokenAddress, uint256 amount) external onlyAdmin {
        IERC20 token = IERC20(tokenAddress);
        require(token.balanceOf(address(this)) >= amount, "Insufficient token balance in the contract");
        token.transfer(admin, amount);
    }

    function initiateAdminTransfer(address newAdmin) external onlyAdmin {
        require(newAdmin != address(0), "New admin cannot be the zero address");
        pendingAdmin = newAdmin;
        emit AdminTransferInitiated(admin, newAdmin);
    }

    function acceptAdminTransfer() external {
        require(msg.sender == pendingAdmin, "Only the pending admin can accept the transfer");
        admin = pendingAdmin;
        pendingAdmin = address(0);
        emit AdminTransferAccepted(admin);
    }

    function deactivateContract() external onlyAdmin {
        isActive = false;
    }

    function activateContract() external onlyAdmin {
        isActive = true;
    }

    receive() external payable {}
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.0.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.20;

/**
 * @dev Interface of the ERC20 standard as defined in the EIP.
 */
interface IERC20 {
    /**
     * @dev Emitted when `value` tokens are moved from one account (`from`) to
     * another (`to`).
     *
     * Note that `value` may be zero.
     */
    event Transfer(address indexed from, address indexed to, uint256 value);

    /**
     * @dev Emitted when the allowance of a `spender` for an `owner` is set by
     * a call to {approve}. `value` is the new allowance.
     */
    event Approval(address indexed owner, address indexed spender, uint256 value);

    /**
     * @dev Returns the value of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the value of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves a `value` amount of tokens from the caller's account to `to`.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transfer(address to, uint256 value) external returns (bool);

    /**
     * @dev Returns the remaining number of tokens that `spender` will be
     * allowed to spend on behalf of `owner` through {transferFrom}. This is
     * zero by default.
     *
     * This value changes when {approve} or {transferFrom} are called.
     */
    function allowance(address owner, address spender) external view returns (uint256);

    /**
     * @dev Sets a `value` amount of tokens as the allowance of `spender` over the
     * caller's tokens.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * IMPORTANT: Beware that changing an allowance with this method brings the risk
     * that someone may use both the old and the new allowance by unfortunate
     * transaction ordering. One possible solution to mitigate this race
     * condition is to first reduce the spender's allowance to 0 and set the
     * desired value afterwards:
     * https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
     *
     * Emits an {Approval} event.
     */
    function approve(address spender, uint256 value) external returns (bool);

    /**
     * @dev Moves a `value` amount of tokens from `from` to `to` using the
     * allowance mechanism. `value` is then deducted from the caller's
     * allowance.
     *
     * Returns a boolean value indicating whether the operation succeeded.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address from, address to, uint256 value) external returns (bool);
}

{
  "compilationTarget": {
    "contracts/AllocationContract.sol": "AllocationContract"
  },
  "evmVersion": "paris",
  "libraries": {},
  "metadata": {
    "bytecodeHash": "ipfs"
  },
  "optimizer": {
    "enabled": false,
    "runs": 200
  },
  "remappings": []
}