feat: init IHypercertToken.sol

Author: tnkshuuhei

Diff for: src/interfaces/IHypercertToken.sol

@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.28;
+
+/// @title Interface for hypercert token interactions
+/// @author bitbeckers
+/// @notice This interface declares the required functionality for a hypercert token
+/// @notice This interface does not specify the underlying token type (e.g. 721 or 1155)
+interface IHypercertToken {
+    /**
+     * AllowAll = Unrestricted
+     * DisallowAll = Transfers disabled after minting
+     * FromCreatorOnly = Only the original creator can transfer
+     */
+    /// @dev Transfer restriction policies on hypercerts
+    enum TransferRestrictions {
+        AllowAll,
+        DisallowAll,
+        FromCreatorOnly
+    }
+
+    /// @dev Emitted when token with tokenID `claimID` is stored, with external data reference via `uri`.
+    event ClaimStored(uint256 indexed claimID, string uri, uint256 totalUnits);
+
+    /// @dev Function called to store a claim referenced via `uri` with a maximum number of fractions `units`.
+    function mintClaim(address account, uint256 units, string memory uri, TransferRestrictions restrictions) external;
+
+    /// @dev Function called to store a claim referenced via `uri` with a set of `fractions`.
+    /// @dev Fractions are internally summed to total units.
+    function mintClaimWithFractions(
+        address account,
+        uint256 units,
+        uint256[] memory fractions,
+        string memory uri,
+        TransferRestrictions restrictions
+    )
+        external;
+
+    /// @dev Function called to split `tokenID` and transfer `to` into units declared in `values`.
+    /// @notice The sum of `values` must equal the current value of `_tokenID`.
+    function splitFraction(address to, uint256 tokenID, uint256[] memory _values) external;
+
+    /// @dev Function called to merge tokens within `tokenIDs`.
+    /// @notice Tokens that have been merged are burned.
+    function mergeFractions(address account, uint256[] memory tokenIDs) external;
+
+    /// @dev Function to burn the token at `tokenID` for `account`
+    /// @notice Operator must be allowed by `creator` and the token must represent the total amount of available units.
+    function burnFraction(address account, uint256 tokenID) external;
+
+    /// @dev Function to burn the tokens at `tokenIDs` for `account`
+    /// @notice Operator must be allowed by `creator` and the tokens must represent the total amount of available units.
+    function batchBurnFraction(address account, uint256[] memory tokenIDs) external;
+
+    /// @dev Returns the `units` held by a (fractional) token at `claimID`
+    /// @dev If `tokenID` is a base type, the total amount of `units` for the claim is returned.
+    /// @dev If `tokenID` is a fractional token, the `units` held by the token is returned
+    function unitsOf(uint256 tokenID) external view returns (uint256 units);
+
+    /// @dev Returns the `units` held by `account` of a (fractional) token at `claimID`
+    /// @dev If `tokenID` is a base type, the total amount of `units` held by `account` for the claim is returned.
+    /// @dev If `tokenID` is a fractional token, the `units` held by `account` the token is returned
+    function unitsOf(address account, uint256 tokenID) external view returns (uint256 units);
+
+    /// @dev Returns the `uri` for metadata of the claim represented by `tokenID`
+    /// @dev Metadata must conform to { Hypercert Metadata } spec (based on ERC1155 Metadata)
+    function uri(uint256 tokenID) external view returns (string memory metadata);
+}