// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts v4.4.1 (utils/introspection/IERC165.sol)

pragma solidity ^0.8.0;

/**
 * @dev Interface of the ERC165 standard, as defined in the
 * https://eips.ethereum.org/EIPS/eip-165[EIP].
 *
 * Implementers can declare support of contract interfaces, which can then be
 * queried by others ({ERC165Checker}).
 *
 * For an implementation, see {ERC165}.
 */
interface IERC165 {
    /**
     * @dev Returns true if this contract implements the interface defined by
     * `interfaceId`. See the corresponding
     * https://eips.ethereum.org/EIPS/eip-165#how-interfaces-are-identified[EIP section]
     * to learn more about how these ids are created.
     *
     * This function call must use less than 30 000 gas.
     */
    function supportsInterface(bytes4 interfaceId) external view returns (bool);
}


// OpenZeppelin Contracts v4.4.1 (utils/introspection/ERC165.sol)

pragma solidity ^0.8.0;


/**
 * @dev Implementation of the {IERC165} interface.
 *
 * Contracts that want to implement ERC165 should inherit from this contract and override {supportsInterface} to check
 * for the additional interface id that will be supported. For example:
 *
 * ```solidity
 * function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
 *     return interfaceId == type(MyInterface).interfaceId || super.supportsInterface(interfaceId);
 * }
 * ```
 *
 * Alternatively, {ERC165Storage} provides an easier to use but more expensive implementation.
 */
abstract contract ERC165 is IERC165 {
    /**
     * @dev See {IERC165-supportsInterface}.
     */
    function supportsInterface(bytes4 interfaceId) public view virtual override returns (bool) {
        return interfaceId == type(IERC165).interfaceId;
    }
}

// OpenZeppelin Contracts (last updated v4.8.0) (token/ERC721/IERC721.sol)

pragma solidity ^0.8.0;

/**
 * @dev Required interface of an ERC721 compliant contract.
 */
interface IERC721 is IERC165 {
    /**
     * @dev Emitted when `tokenId` token is transferred from `from` to `to`.
     */
    event Transfer(address indexed from, address indexed to, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables `approved` to manage the `tokenId` token.
     */
    event Approval(address indexed owner, address indexed approved, uint256 indexed tokenId);

    /**
     * @dev Emitted when `owner` enables or disables (`approved`) `operator` to manage all of its assets.
     */
    event ApprovalForAll(address indexed owner, address indexed operator, bool approved);

    /**
     * @dev Returns the number of tokens in ``owner``'s account.
     */
    function balanceOf(address owner) external view returns (uint256 balance);

    /**
     * @dev Returns the owner of the `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function ownerOf(uint256 tokenId) external view returns (address owner);

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(address from, address to, uint256 tokenId, bytes calldata data) external;

    /**
     * @dev Safely transfers `tokenId` token from `from` to `to`, checking first that contract recipients
     * are aware of the ERC721 protocol to prevent tokens from being forever locked.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must exist and be owned by `from`.
     * - If the caller is not `from`, it must have been allowed to move this token by either {approve} or {setApprovalForAll}.
     * - If `to` refers to a smart contract, it must implement {IERC721Receiver-onERC721Received}, which is called upon a safe transfer.
     *
     * Emits a {Transfer} event.
     */
    function safeTransferFrom(address from, address to, uint256 tokenId) external;

    /**
     * @dev Transfers `tokenId` token from `from` to `to`.
     *
     * WARNING: Note that the caller is responsible to confirm that the recipient is capable of receiving ERC721
     * or else they may be permanently lost. Usage of {safeTransferFrom} prevents loss, though the caller must
     * understand this adds an external call which potentially creates a reentrancy vulnerability.
     *
     * Requirements:
     *
     * - `from` cannot be the zero address.
     * - `to` cannot be the zero address.
     * - `tokenId` token must be owned by `from`.
     * - If the caller is not `from`, it must be approved to move this token by either {approve} or {setApprovalForAll}.
     *
     * Emits a {Transfer} event.
     */
    function transferFrom(address from, address to, uint256 tokenId) external;

    /**
     * @dev Gives permission to `to` to transfer `tokenId` token to another account.
     * The approval is cleared when the token is transferred.
     *
     * Only a single account can be approved at a time, so approving the zero address clears previous approvals.
     *
     * Requirements:
     *
     * - The caller must own the token or be an approved operator.
     * - `tokenId` must exist.
     *
     * Emits an {Approval} event.
     */
    function approve(address to, uint256 tokenId) external;

    /**
     * @dev Approve or remove `operator` as an operator for the caller.
     * Operators can call {transferFrom} or {safeTransferFrom} for any token owned by the caller.
     *
     * Requirements:
     *
     * - The `operator` cannot be the caller.
     *
     * Emits an {ApprovalForAll} event.
     */
    function setApprovalForAll(address operator, bool approved) external;

    /**
     * @dev Returns the account approved for `tokenId` token.
     *
     * Requirements:
     *
     * - `tokenId` must exist.
     */
    function getApproved(uint256 tokenId) external view returns (address operator);

    /**
     * @dev Returns if the `operator` is allowed to manage all of the assets of `owner`.
     *
     * See {setApprovalForAll}
     */
    function isApprovedForAll(address owner, address operator) external view returns (bool);
}

// OpenZeppelin Contracts (last updated v4.8.0) (security/ReentrancyGuard.sol)

pragma solidity ^0.8.0;

/**
 * @dev Contract module that helps prevent reentrant calls to a function.
 *
 * Inheriting from `ReentrancyGuard` will make the {nonReentrant} modifier
 * available, which can be applied to functions to make sure there are no nested
 * (reentrant) calls to them.
 *
 * Note that because there is a single `nonReentrant` guard, functions marked as
 * `nonReentrant` may not call one another. This can be worked around by making
 * those functions `private`, and then adding `external` `nonReentrant` entry
 * points to them.
 *
 * TIP: If you would like to learn more about reentrancy and alternative ways
 * to protect against it, check out our blog post
 * https://blog.openzeppelin.com/reentrancy-after-istanbul/[Reentrancy After Istanbul].
 */
abstract contract ReentrancyGuard {
    // Booleans are more expensive than uint256 or any type that takes up a full
    // word because each write operation emits an extra SLOAD to first read the
    // slot's contents, replace the bits taken up by the boolean, and then write
    // back. This is the compiler's defense against contract upgrades and
    // pointer aliasing, and it cannot be disabled.

    // The values being non-zero value makes deployment a bit more expensive,
    // but in exchange the refund on every call to nonReentrant will be lower in
    // amount. Since refunds are capped to a percentage of the total
    // transaction's gas, it is best to keep them low in cases like this one, to
    // increase the likelihood of the full refund coming into effect.
    uint256 private constant _NOT_ENTERED = 1;
    uint256 private constant _ENTERED = 2;

    uint256 private _status;

    constructor() {
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Prevents a contract from calling itself, directly or indirectly.
     * Calling a `nonReentrant` function from another `nonReentrant`
     * function is not supported. It is possible to prevent this from happening
     * by making the `nonReentrant` function external, and making it call a
     * `private` function that does the actual work.
     */
    modifier nonReentrant() {
        _nonReentrantBefore();
        _;
        _nonReentrantAfter();
    }

    function _nonReentrantBefore() private {
        // On the first call to nonReentrant, _status will be _NOT_ENTERED
        require(_status != _ENTERED, "ReentrancyGuard: reentrant call");

        // Any calls to nonReentrant after this point will fail
        _status = _ENTERED;
    }

    function _nonReentrantAfter() private {
        // By storing the original value once again, a refund is triggered (see
        // https://eips.ethereum.org/EIPS/eip-2200)
        _status = _NOT_ENTERED;
    }

    /**
     * @dev Returns true if the reentrancy guard is currently set to "entered", which indicates there is a
     * `nonReentrant` function in the call stack.
     */
    function _reentrancyGuardEntered() internal view returns (bool) {
        return _status == _ENTERED;
    }
}

// OpenZeppelin Contracts (last updated v4.6.0) (token/ERC20/IERC20.sol)

pragma solidity ^0.8.0;

/**
 * @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 amount of tokens in existence.
     */
    function totalSupply() external view returns (uint256);

    /**
     * @dev Returns the amount of tokens owned by `account`.
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @dev Moves `amount` 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 amount) 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 `amount` 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 amount) external returns (bool);

    /**
     * @dev Moves `amount` tokens from `from` to `to` using the
     * allowance mechanism. `amount` 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 amount) external returns (bool);
}

error PriceNotMet(address nftAddress, uint256 tokenId, uint256 price);
error ItemNotForSale(address nftAddress, uint256 tokenId);
error NotListed(address nftAddress, uint256 tokenId);
error AlreadyListed(address nftAddress, uint256 tokenId);
error NoProceeds();
error NotOwner();
error NotApprovedForMarketplace();
error PriceMustBeAboveZero();

contract Marketplace is ReentrancyGuard {

    

    enum PriceType {
        ETHER,
        TOKEN
    }

    struct Listing {
        uint256 price;
        address seller;
        address nftAddress;
        uint256 tokenId;
        Payment payment;
    }

    struct Payment {
    PriceType priceType;
    address tokenAddress;
}

    event ItemListed(
        address indexed seller,
        address indexed nftAddress,
        uint256 indexed tokenId,
        uint256 price,
       Payment payment
    );

    event ItemCanceled(
        address indexed seller,
        address indexed nftAddress,
        uint256 indexed tokenId,
        Payment payment
    );

    event ItemBought(
        address indexed buyer,
        address indexed nftAddress,
        uint256 indexed tokenId,
        uint256 price,
        Payment payment
    );

    mapping(address => mapping(uint256 => Listing)) private s_listings;

        uint256 listingCounter;

    Listing[] private s_listingsArray;

    modifier notListed(address nftAddress, uint256 tokenId, address owner) {
        Listing memory listing = s_listings[nftAddress][tokenId];
        if (listing.price > 0) {
            revert("Already listed");
        }
        _;
    }

    modifier isOwner(address nftAddress, uint256 tokenId, address spender) {
        IERC721 nft = IERC721(nftAddress);
        address owner = nft.ownerOf(tokenId);
        if (spender != owner) {
            revert("Not owner");
        }
        _;
    }

    modifier isListed(address nftAddress, uint256 tokenId) {
        Listing memory listing = s_listings[nftAddress][tokenId];
        if (listing.price <= 0) {
            revert("Not listed");
        }
        _;
    }
function isApprovedForMarketplace(address nftAddress, uint256 tokenId) internal view returns (bool) {
    IERC721 nft = IERC721(nftAddress);
    return nft.getApproved(tokenId) == address(this);
}

function listItem(
    address nftAddress,
    uint256 tokenId,
    uint256 price,
    Payment memory payment
) external notListed(nftAddress, tokenId, msg.sender) isOwner(nftAddress, tokenId, msg.sender) {
    require(price > 0, "Price must be above zero");

    {
    IERC721 nft = IERC721(nftAddress);
    require(nft.getApproved(tokenId) == address(this), "Not approved for marketplace");
    }

    {
    s_listings[nftAddress][tokenId] = Listing(price, msg.sender, nftAddress, tokenId, payment);
    s_listingsArray.push(Listing(price, msg.sender, nftAddress, tokenId, payment));
    }
    listingCounter++;

    emit ItemListed(msg.sender, nftAddress, tokenId, price, payment);
}




   function cancelListing(address nftAddress, uint256 tokenId, Payment memory payment) external nonReentrant {
    Listing storage listing = s_listings[nftAddress][tokenId];
    require(listing.seller == msg.sender, "Not the seller");
    listingCounter--;
    delete s_listings[nftAddress][tokenId];

    uint256 listingIndex;
    uint256 length = s_listingsArray.length;
    for (uint256 i = 0; i < length; i++) {
        if (s_listingsArray[i].nftAddress == nftAddress && s_listingsArray[i].tokenId == tokenId) {
            listingIndex = i;
            break;
        }
    }

    if (listingIndex != 0) {
        s_listingsArray[listingIndex] = s_listingsArray[length - 1];
        s_listingsArray.pop();
        emit ItemCanceled(msg.sender, nftAddress, tokenId, payment);
    }
}



   function buyItem(address nftAddress, uint256 tokenId, Payment memory payment) external payable nonReentrant {
    Listing memory listing = s_listings[nftAddress][tokenId];
    require(listing.price > 0, "Item not listed");
    

    IERC721 nft = IERC721(nftAddress);
    require(nft.ownerOf(tokenId) == listing.seller, "Seller no longer owner");

   require(listing.payment.priceType == PriceType.ETHER || listing.payment.priceType == PriceType.TOKEN, "Invalid payment type");

    if (listing.payment.priceType == PriceType.ETHER) {
    require(msg.value >= listing.price, "Insufficient payment");
    nft.safeTransferFrom(listing.seller, msg.sender, tokenId);
    (bool success, ) = payable(listing.seller).call{value: listing.price}("");
    require(success, "Payment failed");
    } else {
    IERC20 token = IERC20(listing.payment.tokenAddress);
    require(token.allowance(msg.sender, address(this)) >= listing.price, "Token allowance not enough");
    require(token.transferFrom(msg.sender, listing.seller, listing.price), "Transfer failed");
    nft.safeTransferFrom(listing.seller, msg.sender, tokenId);
    }

    delete s_listings[nftAddress][tokenId];
    for (uint i = 0; i < s_listingsArray.length; i++) {
        if (s_listingsArray[i].nftAddress == nftAddress && s_listingsArray[i].tokenId == tokenId) {
            delete s_listingsArray[i];
                listingCounter--;
            break;
        }
    }
    
    emit ItemBought(msg.sender, nftAddress, tokenId, listing.price, payment);
}


  function updateListing(
        address nftAddress,
        uint256 tokenId,
        uint256 newPrice,
        Payment memory payment
    )
        external
        isListed(nftAddress, tokenId)
        nonReentrant
        isOwner(nftAddress, tokenId, msg.sender)
    {
        if (newPrice == 0) {
            revert("Price must be above zero");
        }
            s_listings[nftAddress][tokenId].price = newPrice;
        

        emit ItemListed(msg.sender, nftAddress, tokenId, newPrice, payment);
    }

function getListingByIndex(address nftAddress, uint256 index) public view returns (address owner, uint256 tokenId, uint256 price, PriceType priceType, address tokenAddress) {
    Listing memory listing = s_listings[nftAddress][index];
    owner = listing.seller;
    tokenId = listing.tokenId;
    price = listing.price;
    priceType = listing.payment.priceType;
    tokenAddress = listing.payment.tokenAddress;
}
}