Leofy

Introduction

This repository contains the smart contracts and transactions that implement the core functionality Leofy.

The smart contracts are written in Cadence, a new resource oriented smart contract programming language designed for the Flow Blockchain.

What is Leofy

Leofy is the first representation agency in the metaverse and exploitation of NFTs for main Artists on Spain and LATAM.

First Spanish-speaking portal for the commercialization of NFT on Flow.

What is Flow?

Flow is a new blockchain for open worlds. Read more about it here.

What is Cadence?

Cadence is a new Resource-oriented programming language for developing smart contracts for the Flow Blockchain. Read more about it here

We recommend that anyone who is reading this should have already completed the Cadence Tutorials so they can build a basic understanding of the programming language.

Resource-oriented programming, and by extension Cadence, is the perfect programming environment for Non-Fungible Tokens (NFTs), because users are able to store their NFT objects directly in their accounts and transact peer-to-peer. Please see the blog post about resources to understand why they are perfect for digital assets like LeofyNFTs or NBA Top Shot Moments or anothers recetly daps on the market.

Contributing

If you see an issue with the code for the contracts, the transactions, scripts, documentation, or anything else, please do not hesitate to make an issue or a pull request with your desired changes. This is an open source project and we welcome all assistance from the community!

LeofyNFT Contract Addresses

LeofyNFT.cdc: This is the main Leofy smart contract that defines the core functionality of the NFT.

Network	Contract Address
Testnet	0xd3af09bdd3c94553
Mainnet	0x14af75b8c487333c

LeofyCoin.cdc: This is the Leofy Fungible Token contract that allows purchase Leofy NFT's

Network	Contract Address
Testnet	0xd3af09bdd3c94553
Mainnet	0x14af75b8c487333c

LeofyMarketPlace.cdc: This is the Leofy MarketPlace contract that allow users sells their NFT Collections. NFT can be placed for BidAuction or directly with the purcharsePrice.

Network	Contract Address
Testnet	0xd3af09bdd3c94553
Mainnet	TBA

TBA: Soon we will launch a Marketplace Contract that will allow users to sell their NFTs.

Non Fungible Token Standard

The LeofyNFT contract utilize the Flow NFT standard which is equivalent to ERC-721 or ERC-1155 on Ethereum. If you want to build an NFT contract, please familiarize yourself with the Flow NFT standard before starting and make sure you utilize it in your project in order to be interoperable with other tokens and contracts that implement the standard.

Fungible Token Standard

The LeofyCoin contract utilize the Flow FT standard, which is used to make a purchase of NFT.

Directory Structure

The directories here are organized into contracts, transactions, scripts and lib/go testing library.

Contracts contain the source code for the Leofy contracts that are deployed to Flow.

Scripts contain read-only transactions to get information about the state of someones Collection or about the state of the Leofy contract.

Transactions contain the transactions that admins and users can use to perform actions in the smart contract like creating Items, mint NFT's for an specific Item, transfering NFT's, mint Leofy Fungible Token (LeofyCoin), transfer LeofyCoin, etc.

• contracts/ : Where the Leofy related smart contracts live.
• transactions/ : This directory contains all the transactions and scripts that are associated with the Leofy smart contracts.
• transactions/scripts/ : This contains all the read-only Cadence scripts that are used to read information from the smart contract or from a resource in account storage.
• lib/ : This directory contains packages for specific programming languages to be able to read copies of the Leofy smart contracts, transaction templates, and scripts. Also contains automated tests written in those languages. Currently, Go is the only language that is supported, but we are hoping to add javascript and other languages soon. See the README in lib/go/ for more information about how to use the Go packages.

LeofyNFT Contract Overview

Each Leofy NFT represents an Item (can be an Picture, Song, Video, Concert, or any Kind of art represented on NFT digital Asset)

Multiple NFTs can be minted inside the same Item and each receives a serial number.

Each NFT is a resource object with roughly the following structure:

pub resource NFT: NonFungibleToken.INFT, MetadataViews.Resolver  {
    pub let id: UInt64
    pub let itemID: UInt64
    pub let serialNumber: UInt32

    ...
}

The other types that are defined in LeofyNFT are as follows:

• ItemCollection: A resource that contains a dictionary with each Item created. This resource are stored on the main account address 'storage' to be used to Create New Items. It's also linked to a public capability asociated to a ItemCollectionPublic interface to have the capability to borrow an Item (With an ItemPublic interface reference).
• Item: An resource that contains variable data for an Item (like number of NFT's minted on that Item, or price), name, thumbnail or descritpion, and a NFTCollection minted for that Item. Also contains the functionality for Mint NFT's on that Item (only for admins), or borrow the NFTCollection of that Item.
• NFT: A resource type that is the NFT that represents the Item a user owns. It stores its unique ID and other metadata. This is the collectible object that the users can store in their accounts.
• Collection: Similar to the NFTCollection resource from the NFT example, this resource is a repository for a user's NFTs. Users can withdraw and deposit from this collection and get information about the contained NFTs.

Metadata structs associated with Items are stored in the main smart contract and can be queried by anyone.

For example, If users wanted to find out the author of the Item that the user has on their Collection, they would call a public function in the Leofy smart contract called getItemMetaDataByField inside the Item resource.

The power to create new Items, and mint NFT's inside each Item rests with the owner of the ItemCollection and Item resource. External users only can borrow by reference their public interface without the admin functions.

Each Item has a price for all their NFTCollection. Users can purchase an NFT with a LeofyCoin Vault.

Once a user owns a LeofyNFT object, that LeofyNFT is stored directly in their account storage via their Collection object. The collection object contains a dictionary that stores the LeofyNFT and gives utility functions to move them in and out and to read data about the collection and its LeofyNFT.

Leofy Marketplace Contract Overview

Leofy MarketPlace Contact, consist on a MarketPlaceCollection resource that contains a dictionary of MarketplaceItem.

pub resource MarketplaceCollection: MarketplaceCollectionPublic {
    access(account) var marketplaceItems: @{UInt64: MarketplaceItem}
    pub fun sellItem(...) -> Private Function
    pub fun cancelAuction(_ id: UInt64) -> Private Function 
    pub fun placeBid(...) -> Public Capability from MarketplaceCollectionPublic
    pub fun placePurchase(...) -> Public Capability from MarketplaceCollectionPublic
    pub fun getMarketplaceStatuses() -> Public Capability from MarketplaceCollectionPublic
    pub fun getMarketplaceStatus(_ id:UInt64) -> Public Capability from MarketplaceCollectionPublic
    pub fun settleAuction(...) -> Public Capability from MarketplaceCollectionPublic
}

The other types that are defined in LeofyMarketPlace are as follows:

• MarketplaceItem: A resource that contains the data of each Item that user want to sell. It contains the LeofyNFT.NFT (when user call a sellItem a new MarketplaceItem it's created and the NFT its moved here ). Also constains a FungibleToken.Vault used for Auctions and when user place a Bid deposited the Fungible tokens here.
• MarketplaceCollectionPublic: An interface for the public capability for MarketplaceCollection.
• LeofyMarketPlaceAdmin: A resource that the owner only will be the Account of the contract. It have the capability of change main contract variables like: cutPercentage, minimumBidIncrement, extendsTime, extendsWhenTimeLowerThan and marketplaceVault.

The main idea of the contract it's to make a Capability to our users to sell their NFT's.

When user create their LeofyMarketPlace.MarketplaceCollection they can call to the sellItem and put the NFT's on this collections available for sell.

There's two types of selling NFT's:

• Purchase: Directly calling the 'placePurchase' function, then it's checked that the vault.balance it's equal to the purchasePrice defined on the MarketplaceItem.
• Bid: Directly calling the 'placeBid' function. Users have to place a higher Bid (previous Bid Vault will be returned to the last Bidder). When the BidTime it's expired the 'settleAuction' can be called to send de Vault to the Seller and send the NFT to the high Bidder.

How to Run Transactions Against the Leofy Contracts

This repository contains sample transactions that can be executed against the Leofy contract either via Flow CLI or using VSCode. This section will describe how to create setup a public Collection on the Flow emulator.

Send Transaction with Flow CLI

1. Install the Flow CLI and emulator
2. Initialize the flow emulator configuration.
   flow emulator --init
3. Configure the contracts & deployment section of the initialized flow.json file.
4. Start the emulator.
   flow emulator
5. Deploy the NonFungibleToken, FungibleToken, MetadataViews & Leofy contracts to the flow emulator.
   flow project deploy --network=emulator
6. Use the Flow CLI to execute transactions against the emulator. This transaction creates a new set on the flow emulator called "new set name".
   flow transactions send ./transactions/LeofyNFT/setup_account.cdc"

How to run the automated tests for the contracts

See the lib/go README for instructions about how to run the automated tests.

Instructions create Fungible Token (LeofyCoin) Vault and send transfer

A common order of creating Vault and transfer fungibles.

1. Creating and Setup Vault on new account transactions/LeofyCoin/setup_account.cdc.
2. Mint tokens with Admin or Service Account transactions/LeofyCoin/mint_tokens.cdc.
3. Transfer Tokens to another account transactions/LeofyCoin/transfer_tokens.cdc.
4. Destroy Vault transactions/LeofyCoin/destroy_vault.cdc.

You can also see the scripts in transactions/LeofyCoin/scripts to see how information can be read from the real LeofyCoin contract deployed.

Instructions create Non Fungible Token (LeofyNFT) Collection, mint Items and NFTs

A common order of creating Items and mint NFT's inside that Items.

1. Creating and Setup Collection on new account transactions/LeofyNFT/setup_account.cdc.
2. Mint / create a new Item with Admin Account transactions/LeofyNFT/create_item.cdc.
3. Mint one NFT for an Item with Admin or Service Account transactions/LeofyNFT/mint_nft.cdc.
4. Batch Mint multiple NFTs for an Item with Admin or Service Account transactions/LeofyNFT/batch_mint_nft.cdc.
5. Transfer Tokens from Item to public account Collection (Only Admin) transactions/LeofyNFT/transfer_nft_item.cdc.
6. Transfer Tokens from public account Collection to another account (NFT Owner) transactions/LeofyNFT/transfer_nft_account.cdc.
7. Purchase NFT from Item Collection transactions/LeofyNFT/purchase_nft.cdc.

You can also see the scripts in transactions/LeofyNFT/scripts to see how information can be read from the real LeofyCoin contract deployed.

Leofy NFT Metadata

NFT metadata is represented in a flexible and modular way using the standard proposed in FLIP-0636. The LeofyNFT contract implements the MetadataViews.Resolver interface, which standardizes the display of LeofyNFT in accordance with FLIP-0636. The LeofyNFT contract also defines a custom view of moment Item data called LeofyNFTMetadataView.

License

The works in these folders /leofy-io/cadence/blob/master/contracts/LeofyCoin.cdc /leofy-io/cadence/blob/master/contracts/LeofyNFT.cdc /leofy-io/cadence/blob/master/contracts/LeofyMarketPlace.cdc

are under the Unlicense https://github.com/leofy-io/cadence/blob/master/LICENSE

Inspiration

• NBA Top Shot: https://nbatopshot.com/
• Viv3: https://viv3.com/
• Versus: https://www.versus.auction/