// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";

/**
 * @title SOMA Token Rewards Contract.
 * @author SOMA.finance
 * @notice Interface for the {TokenRewards} contract.
 */
interface ITokenRewards {
    /**
     * @notice Emitted when an account claims tokens.
     * @param amount The amount of tokens claimed.
     * @param caller The address of the message sender that triggered the event.
     */
    event Claimed(uint256 amount, address caller);

    /**
     * @notice Emitted when the vesting period timestamps are updated.
     * @param startTime The timestamp marking the start of the vesting period.
     * @param endTime The timestamp marking the end of the vesting period.
     * @param caller The address of the message sender that triggered the event.
     */
    event UpdatedTimestamps(uint256 startTime, uint256 endTime, address caller);

    /**
     * @notice Emitted when rewards are deposited.
     * @param amount The amount of reward tokens deposited.
     * @param caller The address of the message sender that triggered the event.
     */
    event RewardsDeposited(uint256 amount, address caller);

    /**
     * @notice Emitted when tokens are seized.
     * @param amount The amount of reward tokens deposited.
     * @param seizeTo The address that receives seized tokens.
     * @param caller The address of the message sender that triggered the event.
     */
    event Seized(uint256 amount, address seizeTo, address caller);

    /**
     * @notice Returns the Token Rewards GLOBAL_ADMIN_ROLE.
     * @dev Equivalent to `keccak256("TokenRewards.ADMIN_ROLE")`.
     */
    function GLOBAL_ADMIN_ROLE() external view returns (bytes32);

    /**
     * @notice Returns the Token Rewards GLOBAL_SEIZE_ROLE.
     * @dev Equivalent to `keccak256("TokenRewards.SEIZE_ROLE")`.
     */
    function GLOBAL_SEIZE_ROLE() external view returns (bytes32);

    /**
     * @notice Returns the Token Rewards LOCAL_ADMIN_ROLE.
     */
    function LOCAL_ADMIN_ROLE() external returns (bytes32);

    /**
     * @notice Returns the Token Rewards LOCAL_SEIZE_ROLE.
     */
    function LOCAL_SEIZE_ROLE() external returns (bytes32);

    /**
     * @notice Updates the timestamps of the vesting period.
     * @param _startTime The new timestamp marking the start of the vesting period.
     * @param _endTime The new timestamp marking the end of the vesting period.
     * @custom:emits UpdatedTimestamps
     * @custom:requirement The `_startTime` must be less than the `_endTime`.
     */
    function updateTime(uint256 _startTime, uint256 _endTime) external;

    /**
     * @notice Returns the timestamp marking the start of the vesting period.
     */
    function startTime() external view returns (uint256);

    /**
     * @notice Returns the timestamp marking the end of the vesting period.
     */
    function endTime() external view returns (uint256);

    /**
     * @notice Returns the address of the reward token.
     */
    function rewardToken() external view returns (IERC20);

    /**
     * @notice Returns an account's claimed amount, denominated in the reward token.
     * @param user The account to return the claimed balance of.
     * @return The claimed amount of the account.
     */
    function claimedAmount(address user) external view returns (uint256);

    /**
     * @notice Returns the reward token balance of the contract.
     */
    function rewardTokenBalance() external view returns (uint256);

    /**
     * @notice Returns the duration of the vesting period in seconds.
     * @dev Returns `endTime` - `startTime`.
     */
    function duration() external view returns (uint256);

    /**
     * @notice Seizes the reward tokens.
     * @custom:emits Seized
     * @custom:requirement The function caller must have the GLOBAL_SEIZE_ROLE or LOCAL_SEIZE_ROLE.
     */
    function seize() external;

    /**
     * @notice Claims the reward tokens.
     * @param _proof The merkle proof used to verify the claimable rewards of the account.
     * @param _amount The amount of tokens to claim.
     * @custom:emits Claimed
     * @custom:requirement The SOMA contracts must not be paused.
     * @custom:requirement `_amount` must be greater than zero.
     * @custom:requirement The proof must be valid within the merkle tree.
     * @custom:requirement The claimable rewards balance for the account must be greater than zero.
     * @return Boolean indicating if the transaction was successful.
     */
    function claim(bytes32[] calldata _proof, uint256 _amount) external returns (bool);

    /**
     * @notice Returns the claimable balance of an account.
     * @param amount The total allocation of reward tokens for the account.
     * @param user The account to return the claimable rewards balance of.
     * @return The claimable balance of the account.
     */
    function claimableRewards(uint256 amount, address user) external view returns (uint256);
}