ERC721LazyMint

/**
*  @notice         Returns the metadata URI for an NFT.
*  @dev            See `BatchMintMetadata` for handling of metadata in this contract.
*
*  @param _tokenId The tokenId of an NFT.
*/
function tokenURI(uint256 _tokenId) public view virtual override returns (string memory) {
    string memory batchUri = _getBaseURI(_tokenId);
    return string(abi.encodePacked(batchUri, _tokenId.toString()));
}

/**
*  @notice          Lets an address claim multiple lazy minted NFTs at once to a recipient.
*                   This function prevents any reentrant calls, and is not allowed to be overridden.
*
*                   Contract creators should override `verifyClaim` and `transferTokensOnClaim`
*                   functions to create custom logic for verification and claiming,
*                   for e.g. price collection, allowlist, max quantity, etc.
*
*  @dev             The logic in `verifyClaim` determines whether the caller is authorized to mint NFTs.
*                   The logic in `transferTokensOnClaim` does actual minting of tokens,
*                   can also be used to apply other state changes.
*
*  @param _receiver  The recipient of the NFT to mint.
*  @param _quantity  The number of NFTs to mint.
*/
function claim(address _receiver, uint256 _quantity) public payable nonReentrant {
    require(_currentIndex + _quantity <= nextTokenIdToLazyMint, "Not enough lazy minted tokens.");
    verifyClaim(msg.sender, _quantity); // Add your claim verification logic by overriding this function.
 
    uint256 startTokenId = _transferTokensOnClaim(_receiver, _quantity); // Mints tokens. Apply any state updates by overriding this function.
    emit TokensClaimed(msg.sender, _receiver, startTokenId, _quantity);
}

/**
     *  @notice          Override this function to add logic for claim verification, based on conditions
     *                   such as allowlist, price, max quantity etc.
     *
     *  @dev             Checks a request to claim NFTs against a custom condition.
     *
     *  @param _claimer   Caller of the claim function.
     *  @param _quantity  The number of NFTs being claimed.
     */
    function verifyClaim(address _claimer, uint256 _quantity) public view virtual {}

/**
*  @notice         Lets an owner or approved operator burn the NFT of the given tokenId.
*  @dev            ERC721A's `_burn(uint256,bool)` internally checks for token approvals.
*
*  @param _tokenId The tokenId of the NFT to burn.
*/
function burn(uint256 _tokenId) external virtual {
    _burn(_tokenId, true);
}

/**
*  @notice          Mints tokens to receiver on claim.
*                   Any state changes related to `claim` must be applied
*                   here by overriding this function.
*
*  @dev             Override this function to add logic for state updation.
*                   When overriding, apply any state changes before `_safeMint`.
*/
function _transferTokensOnClaim(address _receiver, uint256 _quantity)
    internal
    virtual
    returns (uint256 startTokenId)
{
    startTokenId = _currentIndex;
    _safeMint(_receiver, _quantity);
}