Epochs feature

[0xlucian]

ERC20 Fraction Epochs

Overview

This feature introduces a flexible way to manage fractionalized NFTs by allowing multiple fractionalisation periods with different parameters. Each epoch represents a distinct period where token balances and total supply are tracked separately, enabling more flexible management of fractionalized assets.

Key Features

Epoch-Based Fractions Management

• Each epoch has its own dedicated ERC20 clone contract deployed via minimal proxy pattern
• Token balances are tracked separately for each epoch through independent ERC20 contracts
• Standard ERC20 operations work directly with the epoch's contract
• Fractionalisation events contain epoch id

Flexible Fractionalisation Parameters

• Allows updating buyout auction parameters when needed without the possibility of diluting unclaimed proceeds from auctions with different parameters
• Each epoch can have its own price oracle and exit price settings

Epoch Management

• Epochs advance only when fractionalisation that updates the buyout parameters occurs
• Each epoch maintains its own state, preventing interference between different fractionalisation periods
• The FermionFNFT contract tracks the current epoch and provides methods to access ERC20 clones

ERC20 Clone Access

• getERC20FractionsClone() returns the address of the current epoch's ERC20 clone
• getERC20FractionsClone(uint256 _epoch) returns the address of a specific epoch's ERC20 clone
• currentEpoch() returns the current epoch number

Claiming Mechanisms

• Fraction holders can claim proceeds from specific epochs
• Supports claiming from both current and previous epochs
• Maintains fair distribution of proceeds within each epoch

Backwards Compatibility

• Maintains standard ERC20 functionality through the clone contracts
• Provides additional methods for epoch-specific operations
• Fully compatible with existing ERC20 integrations

Usage

The Epochs feature works transparently for standard ERC20 operations while providing additional functionality for advanced use cases. Fraction holders interact directly with the ERC20 clone contracts using standard ERC20 methods, while the FermionFNFT contract provides methods to access the appropriate clone for each epoch.

To interact with fractions:

1. Get the current epoch's ERC20 clone address using getERC20FractionsClone()
2. Interact with the returned address using standard ERC20 methods (transfer, approve, etc.)
3. For specific epoch operations, first get the appropriate clone address using getERC20FractionsClone(epochNumber)

[zajck]

Looks good, I just added some suggestions.

[zajck]

In contracts/protocol/clients/FermionFNFT.sol, import in line 17 can be removed.
import { IERC721 } from "@openzeppelin/contracts/token/ERC721/IERC721.sol";

[zajck]

LGTM