openzeppelin-contracts/contracts/governance/IGovernor.sol

// SPDX-License-Identifier: MIT
// OpenZeppelin Contracts (last updated v4.9.0) (governance/IGovernor.sol)

pragma solidity ^0.8.19;

import {IERC165} from "../interfaces/IERC165.sol";
import {IERC6372} from "../interfaces/IERC6372.sol";

/**
 * @dev Interface of the {Governor} core.
 */
abstract contract IGovernor is IERC165, IERC6372 {
    enum ProposalState {
        Pending,
        Active,
        Canceled,
        Defeated,
        Succeeded,
        Queued,
        Expired,
        Executed
    }

    /**
     * @dev Empty proposal or a mismatch between the parameters length for a proposal call.
     */
    error GovernorInvalidProposalLength(uint256 targets, uint256 calldatas, uint256 values);

    /**
     * @dev The vote was already cast.
     */
    error GovernorAlreadyCastVote(address voter);

    /**
     * @dev Token deposits are disabled in this contract.
     */
    error GovernorDisabledDeposit();

    /**
     * @dev The `account` is not a proposer.
     */
    error GovernorOnlyProposer(address account);

    /**
     * @dev The `account` is not the governance executor.
     */
    error GovernorOnlyExecutor(address account);

    /**
     * @dev The `proposalId` doesn't exist.
     */
    error GovernorNonexistentProposal(uint256 proposalId);

    /**
     * @dev The current state of a proposal is not the required for performing an operation.
     * The `expectedStates` is a bitmap with the bits enabled for each ProposalState enum position
     * counting from right to left.
     *
     * NOTE: If `expectedState` is `bytes32(0)`, the proposal is expected to not be in any state (i.e. not exist).
     * This is the case when a proposal that is expected to be unset is already initiated (the proposal is duplicated).
     *
     * See {Governor-_encodeStateBitmap}.
     */
    error GovernorUnexpectedProposalState(uint256 proposalId, ProposalState current, bytes32 expectedStates);

    /**
     * @dev The voting period set is not a valid period.
     */
    error GovernorInvalidVotingPeriod(uint256 votingPeriod);

    /**
     * @dev The `proposer` does not have the required votes to operate on a proposal.
     */
    error GovernorInsufficientProposerVotes(address proposer, uint256 votes, uint256 threshold);

    /**
     * @dev The vote type used is not valid for the corresponding counting module.
     */
    error GovernorInvalidVoteType();

    /**
     * @dev The provided signature is not valid for the expected `voter`.
     * If the `voter` is a contract, the signature is not valid using {IERC1271-isValidSignature}.
     */
    error GovernorInvalidSignature(address voter);

    /**
     * @dev Emitted when a proposal is created.
     */
    event ProposalCreated(
        uint256 proposalId,
        address proposer,
        address[] targets,
        uint256[] values,
        string[] signatures,
        bytes[] calldatas,
        uint256 voteStart,
        uint256 voteEnd,
        string description
    );

    /**
     * @dev Emitted when a proposal is canceled.
     */
    event ProposalCanceled(uint256 proposalId);

    /**
     * @dev Emitted when a proposal is executed.
     */
    event ProposalExecuted(uint256 proposalId);

    /**
     * @dev Emitted when a vote is cast without params.
     *
     * Note: `support` values should be seen as buckets. Their interpretation depends on the voting module used.
     */
    event VoteCast(address indexed voter, uint256 proposalId, uint8 support, uint256 weight, string reason);

    /**
     * @dev Emitted when a vote is cast with params.
     *
     * Note: `support` values should be seen as buckets. Their interpretation depends on the voting module used.
     * `params` are additional encoded parameters. Their interpepretation also depends on the voting module used.
     */
    event VoteCastWithParams(
        address indexed voter,
        uint256 proposalId,
        uint8 support,
        uint256 weight,
        string reason,
        bytes params
    );

    /**
     * @notice module:core
     * @dev Name of the governor instance (used in building the ERC712 domain separator).
     */
    function name() public view virtual returns (string memory);

    /**
     * @notice module:core
     * @dev Version of the governor instance (used in building the ERC712 domain separator). Default: "1"
     */
    function version() public view virtual returns (string memory);

    /**
     * @notice module:core
     * @dev See {IERC6372}
     */
    function clock() public view virtual returns (uint48);

    /**
     * @notice module:core
     * @dev See EIP-6372.
     */
    // solhint-disable-next-line func-name-mixedcase
    function CLOCK_MODE() public view virtual returns (string memory);

    /**
     * @notice module:voting
     * @dev A description of the possible `support` values for {castVote} and the way these votes are counted, meant to
     * be consumed by UIs to show correct vote options and interpret the results. The string is a URL-encoded sequence of
     * key-value pairs that each describe one aspect, for example `support=bravo&quorum=for,abstain`.
     *
     * There are 2 standard keys: `support` and `quorum`.
     *
     * - `support=bravo` refers to the vote options 0 = Against, 1 = For, 2 = Abstain, as in `GovernorBravo`.
     * - `quorum=bravo` means that only For votes are counted towards quorum.
     * - `quorum=for,abstain` means that both For and Abstain votes are counted towards quorum.
     *
     * If a counting module makes use of encoded `params`, it should  include this under a `params` key with a unique
     * name that describes the behavior. For example:
     *
     * - `params=fractional` might refer to a scheme where votes are divided fractionally between for/against/abstain.
     * - `params=erc721` might refer to a scheme where specific NFTs are delegated to vote.
     *
     * NOTE: The string can be decoded by the standard
     * https://developer.mozilla.org/en-US/docs/Web/API/URLSearchParams[`URLSearchParams`]
     * JavaScript class.
     */
    // solhint-disable-next-line func-name-mixedcase
    function COUNTING_MODE() public view virtual returns (string memory);

    /**
     * @notice module:core
     * @dev Hashing function used to (re)build the proposal id from the proposal details..
     */
    function hashProposal(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) public pure virtual returns (uint256);

    /**
     * @notice module:core
     * @dev Current state of a proposal, following Compound's convention
     */
    function state(uint256 proposalId) public view virtual returns (ProposalState);

    /**
     * @notice module:core
     * @dev Timepoint used to retrieve user's votes and quorum. If using block number (as per Compound's Comp), the
     * snapshot is performed at the end of this block. Hence, voting for this proposal starts at the beginning of the
     * following block.
     */
    function proposalSnapshot(uint256 proposalId) public view virtual returns (uint256);

    /**
     * @notice module:core
     * @dev Timepoint at which votes close. If using block number, votes close at the end of this block, so it is
     * possible to cast a vote during this block.
     */
    function proposalDeadline(uint256 proposalId) public view virtual returns (uint256);

    /**
     * @notice module:core
     * @dev The account that created a proposal.
     */
    function proposalProposer(uint256 proposalId) public view virtual returns (address);

    /**
     * @notice module:user-config
     * @dev Delay, between the proposal is created and the vote starts. The unit this duration is expressed in depends
     * on the clock (see EIP-6372) this contract uses.
     *
     * This can be increased to leave time for users to buy voting power, or delegate it, before the voting of a
     * proposal starts.
     *
     * NOTE: While this interface returns a uint256, timepoints are stored as uint48 following the ERC-6372 clock type.
     * Consequently this value must fit in a uint48 (when added to the current clock). See {IERC6372-clock}.
     */
    function votingDelay() public view virtual returns (uint256);

    /**
     * @notice module:user-config
     * @dev Delay between the vote start and vote end. The unit this duration is expressed in depends on the clock
     * (see EIP-6372) this contract uses.
     *
     * NOTE: The {votingDelay} can delay the start of the vote. This must be considered when setting the voting
     * duration compared to the voting delay.
     *
     * NOTE: This value is stored when the proposal is submitted so that possible changes to the value do not affect
     * proposals that have already been submitted. The type used to save it is a uint32. Consequently, while this
     * interface returns a uint256, the value it returns should fit in a uint32.
     */
    function votingPeriod() public view virtual returns (uint256);

    /**
     * @notice module:user-config
     * @dev Minimum number of cast voted required for a proposal to be successful.
     *
     * NOTE: The `timepoint` parameter corresponds to the snapshot used for counting vote. This allows to scale the
     * quorum depending on values such as the totalSupply of a token at this timepoint (see {ERC20Votes}).
     */
    function quorum(uint256 timepoint) public view virtual returns (uint256);

    /**
     * @notice module:reputation
     * @dev Voting power of an `account` at a specific `timepoint`.
     *
     * Note: this can be implemented in a number of ways, for example by reading the delegated balance from one (or
     * multiple), {ERC20Votes} tokens.
     */
    function getVotes(address account, uint256 timepoint) public view virtual returns (uint256);

    /**
     * @notice module:reputation
     * @dev Voting power of an `account` at a specific `timepoint` given additional encoded parameters.
     */
    function getVotesWithParams(
        address account,
        uint256 timepoint,
        bytes memory params
    ) public view virtual returns (uint256);

    /**
     * @notice module:voting
     * @dev Returns whether `account` has cast a vote on `proposalId`.
     */
    function hasVoted(uint256 proposalId, address account) public view virtual returns (bool);

    /**
     * @dev Create a new proposal. Vote start after a delay specified by {IGovernor-votingDelay} and lasts for a
     * duration specified by {IGovernor-votingPeriod}.
     *
     * Emits a {ProposalCreated} event.
     */
    function propose(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        string memory description
    ) public virtual returns (uint256 proposalId);

    /**
     * @dev Execute a successful proposal. This requires the quorum to be reached, the vote to be successful, and the
     * deadline to be reached.
     *
     * Emits a {ProposalExecuted} event.
     *
     * Note: some module can modify the requirements for execution, for example by adding an additional timelock.
     */
    function execute(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) public payable virtual returns (uint256 proposalId);

    /**
     * @dev Cancel a proposal. A proposal is cancellable by the proposer, but only while it is Pending state, i.e.
     * before the vote starts.
     *
     * Emits a {ProposalCanceled} event.
     */
    function cancel(
        address[] memory targets,
        uint256[] memory values,
        bytes[] memory calldatas,
        bytes32 descriptionHash
    ) public virtual returns (uint256 proposalId);

    /**
     * @dev Cast a vote
     *
     * Emits a {VoteCast} event.
     */
    function castVote(uint256 proposalId, uint8 support) public virtual returns (uint256 balance);

    /**
     * @dev Cast a vote with a reason
     *
     * Emits a {VoteCast} event.
     */
    function castVoteWithReason(
        uint256 proposalId,
        uint8 support,
        string calldata reason
    ) public virtual returns (uint256 balance);

    /**
     * @dev Cast a vote with a reason and additional encoded parameters
     *
     * Emits a {VoteCast} or {VoteCastWithParams} event depending on the length of params.
     */
    function castVoteWithReasonAndParams(
        uint256 proposalId,
        uint8 support,
        string calldata reason,
        bytes memory params
    ) public virtual returns (uint256 balance);

    /**
     * @dev Cast a vote using the voter's signature, including ERC-1271 signature support.
     *
     * Emits a {VoteCast} event.
     */
    function castVoteBySig(
        uint256 proposalId,
        uint8 support,
        address voter,
        bytes memory signature
    ) public virtual returns (uint256 balance);

    /**
     * @dev Cast a vote with a reason and additional encoded parameters using the voter's signature,
     * including ERC-1271 signature support.
     *
     * Emits a {VoteCast} or {VoteCastWithParams} event depending on the length of params.
     */
    function castVoteWithReasonAndParamsBySig(
        uint256 proposalId,
        uint8 support,
        address voter,
        string calldata reason,
        bytes memory params,
        bytes memory signature
    ) public virtual returns (uint256 balance);
}