// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.20;

/**
 * @dev Interface of the ERC-20 standard as defined in the ERC.
 */
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);
}

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v5.1.0) (token/ERC20/extensions/IERC20Metadata.sol)

pragma solidity ^0.8.20;

import {IERC20} from "../IERC20.sol";

/**
 * @dev Interface for the optional metadata functions from the ERC-20 standard.
 */
interface IERC20Metadata is IERC20 {
    /**
     * @dev Returns the name of the token.
     */
    function name() external view returns (string memory);

    /**
     * @dev Returns the symbol of the token.
     */
    function symbol() external view returns (string memory);

    /**
     * @dev Returns the decimals places of the token.
     */
    function decimals() external view returns (uint8);
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.28;

import {IPriceOracle} from "./interfaces/IPriceOracle.sol";
import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import {IERC20Metadata} from "@openzeppelin/contracts/token/ERC20/extensions/IERC20Metadata.sol";

contract SubscriptionManager {
    address public immutable ROOT;
    address public immutable USDC;
    IPriceOracle public immutable priceOracle;
    address public owner;

    // Subscription price in USD (with 6 decimals)
    uint256 public constant SUBSCRIPTION_PRICE_USD = 19_990_000; // $19.99
    uint256 public constant SUBSCRIPTION_DURATION = 365 days;

    mapping(address => uint256) public subscriptionExpiry;

    event SubscriptionPurchased(
        address subscriber,
        uint256 expiryDate,
        address paymentToken,
        uint256 paymentAmount
    );

    constructor(
        address _root,
        address _usdc,
        address _priceOracle
    ) {
        require(_root != address(0), "Invalid ROOT address");
        require(_usdc != address(0), "Invalid USDC address");
        require(_priceOracle != address(0), "Invalid price oracle address");
        
        ROOT = _root;
        USDC = _usdc;
        priceOracle = IPriceOracle(_priceOracle);
        owner = msg.sender;
    }

    modifier onlyOwner() {
        require(msg.sender == owner, "Caller is not the owner");
        _;
    }

    function withdraw(address token, uint256 amount) external onlyOwner {
        require(
            IERC20(token).balanceOf(address(this)) >= amount,
            "Insufficient balance"
        );
        IERC20(token).transfer(owner, amount);
    }

    function purchaseSubscription(address paymentToken) external {
        require(
            paymentToken == ROOT || paymentToken == USDC,
            "Invalid payment token"
        );

        uint256 paymentAmount;
        if (paymentToken == USDC) {
            // USDC has 6 decimals, so no conversion needed for price
            paymentAmount = SUBSCRIPTION_PRICE_USD;
        } else {
            // Convert USD price to ROOT amount using price oracle
            // priceOracle returns ROOT price in USD with 30 decimals
            uint256 rootPriceUSD = priceOracle.assetPrices(paymentToken);
            paymentAmount =
                (SUBSCRIPTION_PRICE_USD *
                    1e24 *
                    (10 ** IERC20Metadata(ROOT).decimals())) /
                rootPriceUSD;
        }

        // Transfer tokens from user
        IERC20(paymentToken).transferFrom(
            msg.sender,
            address(this),
            paymentAmount
        );

        // Update subscription expiry
        uint256 newExpiry;
        if (subscriptionExpiry[msg.sender] < block.timestamp) {
            newExpiry = block.timestamp + SUBSCRIPTION_DURATION;
        } else {
            newExpiry = subscriptionExpiry[msg.sender] + SUBSCRIPTION_DURATION;
        }
        subscriptionExpiry[msg.sender] = newExpiry;

        emit SubscriptionPurchased(
            msg.sender,
            newExpiry,
            paymentToken,
            paymentAmount
        );
    }

    function isSubscriptionActive(
        address subscriber
    ) public view returns (bool) {
        return subscriptionExpiry[subscriber] > block.timestamp;
    }
}

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.28;

interface IPriceOracle {
  function assetPrices(address asset) external view returns (uint);
}