NFT-Twinning-Smart-Contracts

Smart Contracts

• Language Used: Smartpy

• Blockchain: Tezos

• Testnet: Jakartanet

• Number of contracts: 2

• Contracts:

  • MintkartFA2 contract
  • Mintkart contract

• Contract Addresses:

  • MintkartFA2: KT1ACE6u6tY8owf7oBVnk8w7EouLNiwMALc5
  • Mintkart: KT1AgsSUecHJVwiBxzJo7JYogVwF6ti4bkXR

• Tezos smart contract explorers:

  • MintkartFA2: https://jakarta.tzstats.com/KT1ACE6u6tY8owf7oBVnk8w7EouLNiwMALc5
  • Mintkart: https://jakarta.tzstats.com/KT1AgsSUecHJVwiBxzJo7JYogVwF6ti4bkXR

• MintkartFA2 Contract

  • Storage:
    • administrator: Address of the main admin of the smart contract
    • sellers: List of all seller addresses in the Mintkart portal
    • customer_service: List of all customer service addresses in the Mintkart portal
    • all_tokens: List of all token IDs minted
    • ledger: Maintains a map between address + tokenID to balance i.e. {address, tokenId} : balance (i.e. balance of a address for a given tokenId)
    • metadata: Metadata of the smart contract
    • paused: If true, then smart contracts won't be executing any functions if calls are made
    • token_metadata: Maintains a map between tokenId and its metadata, i.e. tokenID : {warranty, artifactUri, name, symbol etc}
  • Entry points:
    • mint:
      • Params: [tokenId, metadata, itemId, warranty, mintkart_address]
      • Given the tokenID, and the metadata of the token, the entry point mints the token to the caller's address.
    • single_transfer:
      • Params: [from_, tokenId, to_]
      • Given the tokenID to be transferred, and the address to which the token need to be transferred to, this entry point transfers the token. It is transferred from the from_ address field.
    • init_replace_item:
      • Params: [tokenId, oldItemId, newItemId, mintkart_address]
      • It is used as the initializer for initializing the replacement of an item. It takes the old serial number and the tokenId, and updates it with the new serial number.
    • init_burn:
      • Params: [tokenId, mintkart_address]
      • It is used as the initializer for initializing the burn of an item. It takes the tokenId and burn it if its warranty has expired.
    • add_seller:
      • Params: [seller]
      • Used to whitelist the given seller address
    • add_customer_service
      • Params: [customer_service]
      • Used to whitelist the given customer service address

• Mintkart Contract

  • Storage:
    • fa2_contract_address: Address of FA2 contract
    • metadata : Metadata of the contract
    • warranties: Maintains a map between tokenID and warranty, its collection type, claimedOn date and burntOn date
    • replacements: Maintains a map between tokenID and its replacements history
    • twins: Maintains a map between serial number of an item and its NFT ID
    • rewards: Maintains a map between a user address and his/her collections claimed
  • Entry points:
    • set_fa2_contract_addr:
      • Params: [address]
      • Setter function, which sets the fa2 contract associated with the current marketplace contract
    • create_twin:
      • Params: [itemId, tokenId, seller, warranty]
      • This entry point can only be called by the MintkartFA2 contract. Given a serial number of an item, this creates a twin NFT on-chain.
    • buy:
      • Params: [itemId, buyer]
      • This entry point can only be called by the admin address (central server). Given the serial number, this transfers the specified to the ‘buyer’ address field.
    • replace_item:
      • Params: [tokenId, oldItemId, newItemId]
      • This entry point can only be called by the MintkartFA2 contract. This updates the item replacement history.
    • burn:
      • Params: [tokenId]
      • This entry point can only be called by the MintkartFA2 contract. Given a tokenID, this completely decays the particular NFT.

Gamification

For every NFT that is minted on-chain, we are assigning it to a collection based upon its various metadata variables. These can be either of the following:

Diamond Class

Gold Class

Silver Class

Bronze Class

After the user collects certain of these by certain amounts, he/she can claim special discount coupons.