Advanced NFT

Description

This project implements an advanced NFT contract with cutting-edge features such as Merkle Tree-based airdrops, bitmap optimizations, commit-reveal random allocation, multicall for efficient transfers, and a state machine to control minting phases. The project is designed for scalability, security, and gas efficiency, leveraging OpenZeppelin libraries.

Features

1. Merkle Tree Airdrop

• Addresses in the Merkle Tree are allowed to mint NFTs during the presale.

• The contract supports two tracking mechanisms:

  • Mapping: A traditional approach using a mapping to track addresses.
  • Bitmap: A gas-optimized method using OpenZeppelin’s BitMaps.

2. Commit-Reveal Mechanism

• Ensures randomness during the NFT allocation process.
• Users commit a hash (NFT ID + secret) and reveal it after a delay of 10 blocks.
• Inspired by Cool Cats NFT but implemented without Chainlink.

3. Multicall

• Enables batch processing of NFT transfers in a single transaction.
• Prevents abuse by ensuring only allowed functions can be multicalled.

4. State Machine

• The contract operates in distinct phases:

  • Paused: No minting allowed.
  • Presale: Merkle Tree-based minting using mapping or bitmap.
  • Public Sale: Commit-reveal minting and multicall allowed.
  • Sold Out: Minting disabled.

• Each phase is enforced using require statements.

5. Pull-Pattern Fund Withdrawal

• Contributors can withdraw funds individually using the pull pattern, improving security.
• Allows withdrawals to multiple contributors.

6. Gas Optimizations

• Utilizes bitmap tracking for airdrop eligibility to reduce storage costs.
• Leverages OpenZeppelin’s nonReentrant modifier to prevent reentrancy attacks.

File Structure

AdvancedNFT/
├── contracts/
│   └── advancednft.sol         # Main NFT contract implementation
├── merkletree/
│   ├── merkleproof.mjs         # Script to generate Merkle Tree and proofs
│   ├── tree.json               # Serialized Merkle Tree data
│   ├── package.json            # Dependencies for the Merkle Tree scripts
│   └── .gitignore              # Ignore unnecessary files
├── answers.md                  # Answers to important questions
├── README.md                   # Documentation for the project

Installation

Prerequisites

• Node.js: To run the Merkle Tree scripts.
• Solidity Compiler: For compiling the contract.

Steps

1. Clone the repo:

clone https://github.com/username/AdvancedNFT.git
cd AdvancedNFT

2. Generate merkletree and proof or use existing ones.:

cd merkletree
npm install

3. Deploy the contract using Hardhat or Remix.

Usage

1. Generating Merkle Proofs

Run the merkleproof.mjs script to generate the Merkle Root and proofs:

node merkletree/merkleproof.mjs

Use the generated root and proofs in the contract.

2. Minting During Presale

Use mintWithMapping or mintWithBitmap with a valid Merkle Proof.

3. Commit-Reveal in Public Sale

• Get commit hash: Use the following command in the console to generate the commit hash:

  web3.utils.keccak256(
    web3.eth.abi.encodeParameters(
      ["uint256", "uint256"],
      [replace_with_nftId, replace_with_secret]
    )
  );

• Commit:

commit(hash);

• Reveal (after 10 blocks):

reveal(nftId, secret);

4. Batch Transfers

Prepare calldata using generateTransferFromData and call multicall with the encoded data.

5. Withdrawing Funds

Contributors can call withdraw() to claim their funds securely.

Tools and Libraries

• OpenZeppelin Contracts: Security and gas-efficient libraries.
• Hardhat: Testing and deployment.
• Merkle Tree Utilities: For secure airdrops.
• Solidity 0.8.x: Latest features with built-in overflow checks.

Contributing

1. Fork the repository.
2. git checkout -b feature-name
3. Submit a pull request.

License

This project is licensed under the MIT License.