// File: @solidstate/contracts/access/ownable/IOwnable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { IERC173 } from '../../interfaces/IERC173.sol';

interface IOwnable is IERC173 {}

// File: @solidstate/contracts/access/ownable/IOwnableInternal.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { IERC173Internal } from '../../interfaces/IERC173Internal.sol';

interface IOwnableInternal is IERC173Internal {
    error Ownable__NotOwner();
    error Ownable__NotTransitiveOwner();
}

// File: @solidstate/contracts/access/ownable/Ownable.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { IERC173 } from '../../interfaces/IERC173.sol';
import { IOwnable } from './IOwnable.sol';
import { OwnableInternal } from './OwnableInternal.sol';

/**
 * @title Ownership access control based on ERC173
 */
abstract contract Ownable is IOwnable, OwnableInternal {
    /**
     * @inheritdoc IERC173
     */
    function owner() public view virtual returns (address) {
        return _owner();
    }

    /**
     * @inheritdoc IERC173
     */
    function transferOwnership(address account) public virtual onlyOwner {
        _transferOwnership(account);
    }
}

// File: @solidstate/contracts/access/ownable/OwnableInternal.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { IERC173 } from '../../interfaces/IERC173.sol';
import { AddressUtils } from '../../utils/AddressUtils.sol';
import { IOwnableInternal } from './IOwnableInternal.sol';
import { OwnableStorage } from './OwnableStorage.sol';

abstract contract OwnableInternal is IOwnableInternal {
    using AddressUtils for address;

    modifier onlyOwner() {
        if (msg.sender != _owner()) revert Ownable__NotOwner();
        _;
    }

    modifier onlyTransitiveOwner() {
        if (msg.sender != _transitiveOwner())
            revert Ownable__NotTransitiveOwner();
        _;
    }

    function _owner() internal view virtual returns (address) {
        return OwnableStorage.layout().owner;
    }

    function _transitiveOwner() internal view virtual returns (address owner) {
        owner = _owner();

        while (owner.isContract()) {
            try IERC173(owner).owner() returns (address transitiveOwner) {
                owner = transitiveOwner;
            } catch {
                break;
            }
        }
    }

    function _transferOwnership(address account) internal virtual {
        _setOwner(account);
    }

    function _setOwner(address account) internal virtual {
        OwnableStorage.Layout storage l = OwnableStorage.layout();
        emit OwnershipTransferred(l.owner, account);
        l.owner = account;
    }
}

// File: @solidstate/contracts/access/ownable/OwnableStorage.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

library OwnableStorage {
    struct Layout {
        address owner;
    }

    bytes32 internal constant STORAGE_SLOT =
        keccak256('solidstate.contracts.storage.Ownable');

    function layout() internal pure returns (Layout storage l) {
        bytes32 slot = STORAGE_SLOT;
        assembly {
            l.slot := slot
        }
    }
}

// File: @solidstate/contracts/interfaces/IERC173.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { IERC173Internal } from './IERC173Internal.sol';

/**
 * @title Contract ownership standard interface
 * @dev see https://eips.ethereum.org/EIPS/eip-173
 */
interface IERC173 is IERC173Internal {
    /**
     * @notice get the ERC173 contract owner
     * @return conrtact owner
     */
    function owner() external view returns (address);

    /**
     * @notice transfer contract ownership to new account
     * @param account address of new owner
     */
    function transferOwnership(address account) external;
}

// File: @solidstate/contracts/interfaces/IERC173Internal.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

/**
 * @title Partial ERC173 interface needed by internal functions
 */
interface IERC173Internal {
    event OwnershipTransferred(
        address indexed previousOwner,
        address indexed newOwner
    );
}

// File: @solidstate/contracts/interfaces/IERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { IERC20Internal } from './IERC20Internal.sol';

/**
 * @title ERC20 interface
 * @dev see https://github.com/ethereum/EIPs/issues/20
 */
interface IERC20 is IERC20Internal {
    /**
     * @notice query the total minted token supply
     * @return token supply
     */
    function totalSupply() external view returns (uint256);

    /**
     * @notice query the token balance of given account
     * @param account address to query
     * @return token balance
     */
    function balanceOf(address account) external view returns (uint256);

    /**
     * @notice query the allowance granted from given holder to given spender
     * @param holder approver of allowance
     * @param spender recipient of allowance
     * @return token allowance
     */
    function allowance(
        address holder,
        address spender
    ) external view returns (uint256);

    /**
     * @notice grant approval to spender to spend tokens
     * @dev prefer ERC20Extended functions to avoid transaction-ordering vulnerability (see https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729)
     * @param spender recipient of allowance
     * @param amount quantity of tokens approved for spending
     * @return success status (always true; otherwise function should revert)
     */
    function approve(address spender, uint256 amount) external returns (bool);

    /**
     * @notice transfer tokens to given recipient
     * @param recipient beneficiary of token transfer
     * @param amount quantity of tokens to transfer
     * @return success status (always true; otherwise function should revert)
     */
    function transfer(
        address recipient,
        uint256 amount
    ) external returns (bool);

    /**
     * @notice transfer tokens to given recipient on behalf of given holder
     * @param holder holder of tokens prior to transfer
     * @param recipient beneficiary of token transfer
     * @param amount quantity of tokens to transfer
     * @return success status (always true; otherwise function should revert)
     */
    function transferFrom(
        address holder,
        address recipient,
        uint256 amount
    ) external returns (bool);
}

// File: @solidstate/contracts/interfaces/IERC20Internal.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

/**
 * @title Partial ERC20 interface needed by internal functions
 */
interface IERC20Internal {
    event Transfer(address indexed from, address indexed to, uint256 value);

    event Approval(
        address indexed owner,
        address indexed spender,
        uint256 value
    );
}

// File: @solidstate/contracts/utils/AddressUtils.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { UintUtils } from './UintUtils.sol';

library AddressUtils {
    using UintUtils for uint256;

    error AddressUtils__InsufficientBalance();
    error AddressUtils__NotContract();
    error AddressUtils__SendValueFailed();

    function toString(address account) internal pure returns (string memory) {
        return uint256(uint160(account)).toHexString(20);
    }

    function isContract(address account) internal view returns (bool) {
        uint256 size;
        assembly {
            size := extcodesize(account)
        }
        return size > 0;
    }

    function sendValue(address payable account, uint256 amount) internal {
        (bool success, ) = account.call{ value: amount }('');
        if (!success) revert AddressUtils__SendValueFailed();
    }

    function functionCall(
        address target,
        bytes memory data
    ) internal returns (bytes memory) {
        return
            functionCall(target, data, 'AddressUtils: failed low-level call');
    }

    function functionCall(
        address target,
        bytes memory data,
        string memory error
    ) internal returns (bytes memory) {
        return _functionCallWithValue(target, data, 0, error);
    }

    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value
    ) internal returns (bytes memory) {
        return
            functionCallWithValue(
                target,
                data,
                value,
                'AddressUtils: failed low-level call with value'
            );
    }

    function functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory error
    ) internal returns (bytes memory) {
        if (value > address(this).balance)
            revert AddressUtils__InsufficientBalance();
        return _functionCallWithValue(target, data, value, error);
    }

    /**
     * @notice execute arbitrary external call with limited gas usage and amount of copied return data
     * @dev derived from https://github.com/nomad-xyz/ExcessivelySafeCall (MIT License)
     * @param target recipient of call
     * @param gasAmount gas allowance for call
     * @param value native token value to include in call
     * @param maxCopy maximum number of bytes to copy from return data
     * @param data encoded call data
     * @return success whether call is successful
     * @return returnData copied return data
     */
    function excessivelySafeCall(
        address target,
        uint256 gasAmount,
        uint256 value,
        uint16 maxCopy,
        bytes memory data
    ) internal returns (bool success, bytes memory returnData) {
        returnData = new bytes(maxCopy);

        assembly {
            // execute external call via assembly to avoid automatic copying of return data
            success := call(
                gasAmount,
                target,
                value,
                add(data, 0x20),
                mload(data),
                0,
                0
            )

            // determine whether to limit amount of data to copy
            let toCopy := returndatasize()

            if gt(toCopy, maxCopy) {
                toCopy := maxCopy
            }

            // store the length of the copied bytes
            mstore(returnData, toCopy)

            // copy the bytes from returndata[0:toCopy]
            returndatacopy(add(returnData, 0x20), 0, toCopy)
        }
    }

    function _functionCallWithValue(
        address target,
        bytes memory data,
        uint256 value,
        string memory error
    ) private returns (bytes memory) {
        if (!isContract(target)) revert AddressUtils__NotContract();

        (bool success, bytes memory returnData) = target.call{ value: value }(
            data
        );

        if (success) {
            return returnData;
        } else if (returnData.length > 0) {
            assembly {
                let returnData_size := mload(returnData)
                revert(add(32, returnData), returnData_size)
            }
        } else {
            revert(error);
        }
    }
}

// File: @solidstate/contracts/utils/SafeERC20.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

import { IERC20 } from '../interfaces/IERC20.sol';
import { AddressUtils } from './AddressUtils.sol';

/**
 * @title Safe ERC20 interaction library
 * @dev derived from https://github.com/OpenZeppelin/openzeppelin-contracts/ (MIT license)
 */
library SafeERC20 {
    using AddressUtils for address;

    error SafeERC20__ApproveFromNonZeroToNonZero();
    error SafeERC20__DecreaseAllowanceBelowZero();
    error SafeERC20__OperationFailed();

    function safeTransfer(IERC20 token, address to, uint256 value) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transfer.selector, to, value)
        );
    }

    function safeTransferFrom(
        IERC20 token,
        address from,
        address to,
        uint256 value
    ) internal {
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.transferFrom.selector, from, to, value)
        );
    }

    /**
     * @dev safeApprove (like approve) should only be called when setting an initial allowance or when resetting it to zero; otherwise prefer safeIncreaseAllowance and safeDecreaseAllowance
     */
    function safeApprove(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        if ((value != 0) && (token.allowance(address(this), spender) != 0))
            revert SafeERC20__ApproveFromNonZeroToNonZero();

        _callOptionalReturn(
            token,
            abi.encodeWithSelector(token.approve.selector, spender, value)
        );
    }

    function safeIncreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        uint256 newAllowance = token.allowance(address(this), spender) + value;
        _callOptionalReturn(
            token,
            abi.encodeWithSelector(
                token.approve.selector,
                spender,
                newAllowance
            )
        );
    }

    function safeDecreaseAllowance(
        IERC20 token,
        address spender,
        uint256 value
    ) internal {
        unchecked {
            uint256 oldAllowance = token.allowance(address(this), spender);
            if (oldAllowance < value)
                revert SafeERC20__DecreaseAllowanceBelowZero();
            uint256 newAllowance = oldAllowance - value;
            _callOptionalReturn(
                token,
                abi.encodeWithSelector(
                    token.approve.selector,
                    spender,
                    newAllowance
                )
            );
        }
    }

    /**
     * @notice send transaction data and check validity of return value, if present
     * @param token ERC20 token interface
     * @param data transaction data
     */
    function _callOptionalReturn(IERC20 token, bytes memory data) private {
        bytes memory returndata = address(token).functionCall(
            data,
            'SafeERC20: low-level call failed'
        );

        if (returndata.length > 0) {
            if (!abi.decode(returndata, (bool)))
                revert SafeERC20__OperationFailed();
        }
    }
}

// File: @solidstate/contracts/utils/UintUtils.sol



// SPDX-License-Identifier: MIT

pragma solidity ^0.8.8;

/**
 * @title utility functions for uint256 operations
 * @dev derived from https://github.com/OpenZeppelin/openzeppelin-contracts/ (MIT license)
 */
library UintUtils {
    error UintUtils__InsufficientHexLength();

    bytes16 private constant HEX_SYMBOLS = '0123456789abcdef';

    function add(uint256 a, int256 b) internal pure returns (uint256) {
        return b < 0 ? sub(a, -b) : a + uint256(b);
    }

    function sub(uint256 a, int256 b) internal pure returns (uint256) {
        return b < 0 ? add(a, -b) : a - uint256(b);
    }

    function toString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return '0';
        }

        uint256 temp = value;
        uint256 digits;

        while (temp != 0) {
            digits++;
            temp /= 10;
        }

        bytes memory buffer = new bytes(digits);

        while (value != 0) {
            digits -= 1;
            buffer[digits] = bytes1(uint8(48 + uint256(value % 10)));
            value /= 10;
        }

        return string(buffer);
    }

    function toHexString(uint256 value) internal pure returns (string memory) {
        if (value == 0) {
            return '0x00';
        }

        uint256 length = 0;

        for (uint256 temp = value; temp != 0; temp >>= 8) {
            unchecked {
                length++;
            }
        }

        return toHexString(value, length);
    }

    function toHexString(
        uint256 value,
        uint256 length
    ) internal pure returns (string memory) {
        bytes memory buffer = new bytes(2 * length + 2);
        buffer[0] = '0';
        buffer[1] = 'x';

        unchecked {
            for (uint256 i = 2 * length + 1; i > 1; --i) {
                buffer[i] = HEX_SYMBOLS[value & 0xf];
                value >>= 4;
            }
        }

        if (value != 0) revert UintUtils__InsufficientHexLength();

        return string(buffer);
    }
}

// File: contracts/vesting/PremiaVesting.sol



// SPDX-License-Identifier: BUSL-1.1
// For further clarification please see https://license.premia.legal

pragma solidity ^0.8.0;

import {SafeERC20} from "@solidstate/contracts/utils/SafeERC20.sol";
import {IERC20} from "@solidstate/contracts/interfaces/IERC20.sol";

import {Ownable} from "@solidstate/contracts/access/ownable/Ownable.sol";
import {OwnableStorage} from "@solidstate/contracts/access/ownable/OwnableStorage.sol";

/// @author Premia
/// @title Vesting contract, releasing the allocations over the course of a given period
contract PremiaVesting is Ownable {
    using SafeERC20 for IERC20;

    error PremiaVesting__InvalidAmount();

    // The premia token
    IERC20 public premia;

    // The timestamp at which release ends
    uint256 public endTimestamp;
    // The timestamp at which last withdrawal has been done
    uint256 public lastWithdrawalTimestamp;

    // Amount available to withdraw. We leave this as internal, as this only gets updated on withdrawal.
    // `getAmountAvailableToWithdraw` returns a more up to date value, as it sums this value with pending update amount.
    // Once `endTimestamp` is passed, this value is ignored (We dont update it anymore, and we dont check it)
    uint256 internal amountAvailableToWithdraw;

    //////////////////////////////////////////////////
    //////////////////////////////////////////////////
    //////////////////////////////////////////////////

    // @param _premia The premia token
    constructor(
        IERC20 _premia,
        uint256 _startTimestamp,
        uint256 _releasePeriod
    ) {
        OwnableStorage.layout().owner = msg.sender;

        premia = _premia;
        endTimestamp = _startTimestamp + _releasePeriod;
        lastWithdrawalTimestamp = _startTimestamp;
    }

    //////////////////////////////////////////////////
    //////////////////////////////////////////////////
    //////////////////////////////////////////////////

    function getAmountAvailableToWithdraw() external view returns (uint256) {
        if (block.timestamp >= endTimestamp)
            return premia.balanceOf(address(this));

        return amountAvailableToWithdraw + _calculateUpdateAmount();
    }

    function withdraw(address _to, uint256 _amount) external onlyOwner {
        _update();

        if (
            block.timestamp < endTimestamp &&
            _amount > amountAvailableToWithdraw
        ) revert PremiaVesting__InvalidAmount();

        premia.safeTransfer(_to, _amount);

        if (block.timestamp < endTimestamp) {
            amountAvailableToWithdraw -= _amount;
        }
    }

    function _update() internal {
        if (
            block.timestamp == lastWithdrawalTimestamp ||
            block.timestamp >= endTimestamp
        ) return;

        uint256 updateAmount = _calculateUpdateAmount();
        lastWithdrawalTimestamp = block.timestamp;
        amountAvailableToWithdraw += updateAmount;
    }

    function _calculateUpdateAmount() internal view returns (uint256) {
        uint256 elapsedTime = block.timestamp - lastWithdrawalTimestamp;
        uint256 timeLeft = endTimestamp - lastWithdrawalTimestamp;
        uint256 balance = premia.balanceOf(address(this));

        return ((balance - amountAvailableToWithdraw) * elapsedTime) / timeLeft;
    }
}