Liquidity Gauge V6

event Deposit:
    provider: indexed(address)
    value: uint256

event Transfer:
    _from: indexed(address)
    _to: indexed(address)
    _value: uint256

@external
@nonreentrant('lock')
def deposit(_value: uint256, _addr: address = msg.sender, _claim_rewards: bool = False):
    """
    @notice Deposit `_value` LP tokens
    @dev Depositting also claims pending reward tokens
    @param _value Number of tokens to deposit
    @param _addr Address to deposit for
    """
    assert _addr != empty(address)  # dev: cannot deposit for zero address
    self._checkpoint(_addr)

    if _value != 0:
        is_rewards: bool = self.reward_count != 0
        total_supply: uint256 = self.totalSupply
        if is_rewards:
            self._checkpoint_rewards(_addr, total_supply, _claim_rewards, empty(address))

        total_supply += _value
        new_balance: uint256 = self.balanceOf[_addr] + _value
        self.balanceOf[_addr] = new_balance
        self.totalSupply = total_supply

        self._update_liquidity_limit(_addr, new_balance, total_supply)

        ERC20(self.lp_token).transferFrom(msg.sender, self, _value)

        log Deposit(_addr, _value)
        log Transfer(empty(address), _addr, _value)

event Withdraw:
    provider: indexed(address)
    value: uint256

event Transfer:
    _from: indexed(address)
    _to: indexed(address)
    _value: uint256

@external
@nonreentrant('lock')
def withdraw(_value: uint256, _claim_rewards: bool = False):
    """
    @notice Withdraw `_value` LP tokens
    @dev Withdrawing also claims pending reward tokens
    @param _value Number of tokens to withdraw
    """
    self._checkpoint(msg.sender)

    if _value != 0:
        is_rewards: bool = self.reward_count != 0
        total_supply: uint256 = self.totalSupply
        if is_rewards:
            self._checkpoint_rewards(msg.sender, total_supply, _claim_rewards, empty(address))

        total_supply -= _value
        new_balance: uint256 = self.balanceOf[msg.sender] - _value
        self.balanceOf[msg.sender] = new_balance
        self.totalSupply = total_supply

        self._update_liquidity_limit(msg.sender, new_balance, total_supply)

        ERC20(self.lp_token).transfer(msg.sender, _value)

    log Withdraw(msg.sender, _value)
    log Transfer(msg.sender, empty(address), _value)

@external
@nonreentrant('lock')
def claim_rewards(_addr: address = msg.sender, _receiver: address = empty(address)):
    """
    @notice Claim available reward tokens for `_addr`
    @param _addr Address to claim for
    @param _receiver Address to transfer rewards to - if set to
                    empty(address), uses the default reward receiver
                    for the caller
    """
    if _receiver != empty(address):
        assert _addr == msg.sender  # dev: cannot redirect when claiming for another user
    self._checkpoint_rewards(_addr, self.totalSupply, True, _receiver)

@internal
def _checkpoint_rewards(_user: address, _total_supply: uint256, _claim: bool, _receiver: address):
    """
    @notice Claim pending rewards and checkpoint rewards for a user
    """

    user_balance: uint256 = 0
    receiver: address = _receiver
    if _user != empty(address):
        user_balance = self.balanceOf[_user]
        if _claim and _receiver == empty(address):
            # if receiver is not explicitly declared, check if a default receiver is set
            receiver = self.rewards_receiver[_user]
            if receiver == empty(address):
                # if no default receiver is set, direct claims to the user
                receiver = _user

    reward_count: uint256 = self.reward_count
    for i in range(MAX_REWARDS):
        if i == reward_count:
            break
        token: address = self.reward_tokens[i]

        integral: uint256 = self.reward_data[token].integral
        last_update: uint256 = min(block.timestamp, self.reward_data[token].period_finish)
        duration: uint256 = last_update - self.reward_data[token].last_update

        if duration != 0 and _total_supply != 0:
            self.reward_data[token].last_update = last_update
            integral += duration * self.reward_data[token].rate * 10**18 / _total_supply
            self.reward_data[token].integral = integral

        if _user != empty(address):
            integral_for: uint256 = self.reward_integral_for[token][_user]
            new_claimable: uint256 = 0

            if integral_for < integral:
                self.reward_integral_for[token][_user] = integral
                new_claimable = user_balance * (integral - integral_for) / 10**18

            claim_data: uint256 = self.claim_data[_user][token]
            total_claimable: uint256 = (claim_data >> 128) + new_claimable
            if total_claimable > 0:
                total_claimed: uint256 = claim_data % 2**128
                if _claim:
                    assert ERC20(token).transfer(receiver, total_claimable, default_return_value=True)
                    self.claim_data[_user][token] = total_claimed + total_claimable
                elif new_claimable > 0:
                    self.claim_data[_user][token] = total_claimed + (total_claimable << 128)

# user -> [uint128 claimable amount][uint128 claimed amount]
claim_data: HashMap[address, HashMap[address, uint256]]

@view
@external
def claimed_reward(_addr: address, _token: address) -> uint256:
    """
    @notice Get the number of already-claimed reward tokens for a user
    @param _addr Account to get reward amount for
    @param _token Token to get reward amount for
    @return uint256 Total amount of `_token` already claimed by `_addr`
    """
    return self.claim_data[_addr][_token] % 2**128

reward_integral_for: public(HashMap[address, HashMap[address, uint256]])

@view
@external
def claimable_reward(_user: address, _reward_token: address) -> uint256:
    """
    @notice Get the number of claimable reward tokens for a user
    @param _user Account to get reward amount for
    @param _reward_token Token to get reward amount for
    @return uint256 Claimable reward token amount
    """
    integral: uint256 = self.reward_data[_reward_token].integral
    total_supply: uint256 = self.totalSupply
    if total_supply != 0:
        last_update: uint256 = min(block.timestamp, self.reward_data[_reward_token].period_finish)
        duration: uint256 = last_update - self.reward_data[_reward_token].last_update
        integral += (duration * self.reward_data[_reward_token].rate * 10**18 / total_supply)

    integral_for: uint256 = self.reward_integral_for[_reward_token][_user]
    new_claimable: uint256 = self.balanceOf[_user] * (integral - integral_for) / 10**18

    return (self.claim_data[_user][_reward_token] >> 128) + new_claimable

rewards_receiver: public(HashMap[address, address])

rewards_receiver: public(HashMap[address, address])

@external
def set_rewards_receiver(_receiver: address):
    """
    @notice Set the default reward receiver for the caller.
    @dev When set to empty(address), rewards are sent to the caller
    @param _receiver Receiver address for any rewards claimed via `claim_rewards`
    """
    self.rewards_receiver[msg.sender] = _receiver

struct Reward:
    token: address
    distributor: address
    period_finish: uint256
    rate: uint256
    last_update: uint256
    integral: uint256

reward_data: public(HashMap[address, Reward])

MAX_REWARDS: constant(uint256) = 8

# array of reward tokens
reward_tokens: public(address[MAX_REWARDS])

reward_count: public(uint256)

manager: public(address)

@external
def __init__(_lp_token: address):
    """
    @notice Contract constructor
    @param _lp_token Liquidity Pool contract address
    """
    self.lp_token = _lp_token
    self.factory = msg.sender
    self.manager = tx.origin

    ...

@external
def add_reward(_reward_token: address, _distributor: address):
    """
    @notice Add additional rewards to be distributed to stakers
    @param _reward_token The token to add as an additional reward
    @param _distributor Address permitted to fund this contract with the reward token
    """
    assert msg.sender in [self.manager, Factory(self.factory).admin()]  # dev: only manager or factory admin
    assert _distributor != empty(address)  # dev: distributor cannot be zero address

    reward_count: uint256 = self.reward_count
    assert reward_count < MAX_REWARDS
    assert self.reward_data[_reward_token].distributor == empty(address)

    self.reward_data[_reward_token].distributor = _distributor
    self.reward_tokens[reward_count] = _reward_token
    self.reward_count = reward_count + 1

event SetGaugeManager:
    _gauge_manager: address 

manager: public(address)

@external
def set_gauge_manager(_gauge_manager: address):
    """
    @notice Change the gauge manager for a gauge
    @dev The manager of this contract, or the ownership admin can outright modify gauge
        managership. A gauge manager can also transfer managership to a new manager via this
        method, but only for the gauge which they are the manager of.
    @param _gauge_manager The account to set as the new manager of the gauge.
    """
    assert msg.sender in [self.manager, Factory(self.factory).admin()]  # dev: only manager or factory admin

    self.manager = _gauge_manager
    log SetGaugeManager(_gauge_manager)

reward_data: public(HashMap[address, Reward])

@external
def set_reward_distributor(_reward_token: address, _distributor: address):
    """
    @notice Reassign the reward distributor for a reward token
    @param _reward_token The reward token to reassign distribution rights to
    @param _distributor The address of the new distributor
    """
    current_distributor: address = self.reward_data[_reward_token].distributor

    assert msg.sender in [current_distributor, Factory(self.factory).admin(), self.manager]
    assert current_distributor != empty(address)
    assert _distributor != empty(address)

    self.reward_data[_reward_token].distributor = _distributor

WEEK: constant(uint256) = 604800

@external
@nonreentrant("lock")
def deposit_reward_token(_reward_token: address, _amount: uint256, _epoch: uint256 = WEEK):
    """
    @notice Deposit a reward token for distribution
    @param _reward_token The reward token being deposited
    @param _amount The amount of `_reward_token` being deposited
    @param _epoch The duration the rewards are distributed across.
    """
    assert msg.sender == self.reward_data[_reward_token].distributor

    self._checkpoint_rewards(empty(address), self.totalSupply, False, empty(address))

    # transferFrom reward token and use transferred amount henceforth:
    amount_received: uint256 = ERC20(_reward_token).balanceOf(self)
    assert ERC20(_reward_token).transferFrom(
        msg.sender,
        self,
        _amount,
        default_return_value=True
    )
    amount_received = ERC20(_reward_token).balanceOf(self) - amount_received

    period_finish: uint256 = self.reward_data[_reward_token].period_finish
    assert amount_received > _epoch  # dev: rate will tend to zero!

    if block.timestamp >= period_finish:
        self.reward_data[_reward_token].rate = amount_received / _epoch
    else:
        remaining: uint256 = period_finish - block.timestamp
        leftover: uint256 = remaining * self.reward_data[_reward_token].rate
        self.reward_data[_reward_token].rate = (amount_received + leftover) / _epoch

    self.reward_data[_reward_token].last_update = block.timestamp
    self.reward_data[_reward_token].period_finish = block.timestamp + _epoch

TOKENLESS_PRODUCTION: constant(uint256) = 40

working_balances: public(HashMap[address, uint256])

@internal
def _update_liquidity_limit(addr: address, l: uint256, L: uint256):
    """
    @notice Calculate limits which depend on the amount of CRV token per-user.
            Effectively it calculates working balances to apply amplification
            of CRV production by CRV
    @param addr User address
    @param l User's amount of liquidity (LP tokens)
    @param L Total amount of liquidity (LP tokens)
    """
    # To be called after totalSupply is updated
    voting_balance: uint256 = VotingEscrowBoost(VEBOOST_PROXY).adjusted_balance_of(addr)
    voting_total: uint256 = ERC20(VOTING_ESCROW).totalSupply()

    lim: uint256 = l * TOKENLESS_PRODUCTION / 100
    if voting_total > 0:
        lim += L * voting_balance / voting_total * (100 - TOKENLESS_PRODUCTION) / 100

    lim = min(l, lim)
    old_bal: uint256 = self.working_balances[addr]
    self.working_balances[addr] = lim
    _working_supply: uint256 = self.working_supply + lim - old_bal
    self.working_supply = _working_supply

    log UpdateLiquidityLimit(addr, l, L, lim, _working_supply)

working_supply: public(uint256) 

@internal
def _update_liquidity_limit(addr: address, l: uint256, L: uint256):
    """
    @notice Calculate limits which depend on the amount of CRV token per-user.
            Effectively it calculates working balances to apply amplification
            of CRV production by CRV
    @param addr User address
    @param l User's amount of liquidity (LP tokens)
    @param L Total amount of liquidity (LP tokens)
    """
    # To be called after totalSupply is updated
    voting_balance: uint256 = VotingEscrowBoost(VEBOOST_PROXY).adjusted_balance_of(addr)
    voting_total: uint256 = ERC20(VOTING_ESCROW).totalSupply()

    lim: uint256 = l * TOKENLESS_PRODUCTION / 100
    if voting_total > 0:
        lim += L * voting_balance / voting_total * (100 - TOKENLESS_PRODUCTION) / 100

    lim = min(l, lim)
    old_bal: uint256 = self.working_balances[addr]
    self.working_balances[addr] = lim
    _working_supply: uint256 = self.working_supply + lim - old_bal
    self.working_supply = _working_supply

    log UpdateLiquidityLimit(addr, l, L, lim, _working_supply)

@external
def user_checkpoint(addr: address) -> bool:
    """
    @notice Record a checkpoint for `addr`
    @param addr User address
    @return bool success
    """
    assert msg.sender in [addr, MINTER]  # dev: unauthorized
    self._checkpoint(addr)
    self._update_liquidity_limit(addr, self.balanceOf[addr], self.totalSupply)
    return True

@internal
def _checkpoint(addr: address):
    """
    @notice Checkpoint for a user
    @dev Updates the CRV emissions a user is entitled to receive
    @param addr User address
    """
    _period: int128 = self.period
    _period_time: uint256 = self.period_timestamp[_period]
    _integrate_inv_supply: uint256 = self.integrate_inv_supply[_period]

    inflation_params: uint256 = self.inflation_params
    prev_future_epoch: uint256 = inflation_params >> 216
    gauge_is_killed: bool = self.is_killed

    rate: uint256 = inflation_params % 2 ** 216
    new_rate: uint256 = rate
    if gauge_is_killed:
        rate = 0
        new_rate = 0

    if prev_future_epoch >= _period_time:
        future_epoch_time_write: uint256 = CRV20(CRV).future_epoch_time_write()
        if not gauge_is_killed:
            new_rate = CRV20(CRV).rate()
        self.inflation_params = (future_epoch_time_write << 216) + new_rate

    # Update integral of 1/supply
    if block.timestamp > _period_time:
        _working_supply: uint256 = self.working_supply
        Controller(GAUGE_CONTROLLER).checkpoint_gauge(self)
        prev_week_time: uint256 = _period_time
        week_time: uint256 = min((_period_time + WEEK) / WEEK * WEEK, block.timestamp)

        for i in range(500):
            dt: uint256 = week_time - prev_week_time
            w: uint256 = Controller(GAUGE_CONTROLLER).gauge_relative_weight(self, prev_week_time)

            if _working_supply > 0:
                if prev_future_epoch >= prev_week_time and prev_future_epoch < week_time:
                    # If we went across one or multiple epochs, apply the rate
                    # of the first epoch until it ends, and then the rate of
                    # the last epoch.
                    # If more than one epoch is crossed - the gauge gets less,
                    # but that'd meen it wasn't called for more than 1 year
                    _integrate_inv_supply += rate * w * (prev_future_epoch - prev_week_time) / _working_supply
                    rate = new_rate
                    _integrate_inv_supply += rate * w * (week_time - prev_future_epoch) / _working_supply
                else:
                    _integrate_inv_supply += rate * w * dt / _working_supply
                # On precisions of the calculation
                # rate ~= 10e18
                # last_weight > 0.01 * 1e18 = 1e16 (if pool weight is 1%)
                # _working_supply ~= TVL * 1e18 ~= 1e26 ($100M for example)
                # The largest loss is at dt = 1
                # Loss is 1e-9 - acceptable

            if week_time == block.timestamp:
                break
            prev_week_time = week_time
            week_time = min(week_time + WEEK, block.timestamp)

    _period += 1
    self.period = _period
    self.period_timestamp[_period] = block.timestamp
    self.integrate_inv_supply[_period] = _integrate_inv_supply

    # Update user-specific integrals
    _working_balance: uint256 = self.working_balances[addr]
    self.integrate_fraction[addr] += _working_balance * (_integrate_inv_supply - self.integrate_inv_supply_of[addr]) / 10 ** 18
    self.integrate_inv_supply_of[addr] = _integrate_inv_supply
    self.integrate_checkpoint_of[addr] = block.timestamp

@internal
def _update_liquidity_limit(addr: address, l: uint256, L: uint256):
    """
    @notice Calculate limits which depend on the amount of CRV token per-user.
            Effectively it calculates working balances to apply amplification
            of CRV production by CRV
    @param addr User address
    @param l User's amount of liquidity (LP tokens)
    @param L Total amount of liquidity (LP tokens)
    """
    # To be called after totalSupply is updated
    voting_balance: uint256 = VotingEscrowBoost(VEBOOST_PROXY).adjusted_balance_of(addr)
    voting_total: uint256 = ERC20(VOTING_ESCROW).totalSupply()

    lim: uint256 = l * TOKENLESS_PRODUCTION / 100
    if voting_total > 0:
        lim += L * voting_balance / voting_total * (100 - TOKENLESS_PRODUCTION) / 100

    lim = min(l, lim)
    old_bal: uint256 = self.working_balances[addr]
    self.working_balances[addr] = lim
    _working_supply: uint256 = self.working_supply + lim - old_bal
    self.working_supply = _working_supply

    log UpdateLiquidityLimit(addr, l, L, lim, _working_supply)

event UpdateLiquidityLimit:
    user: indexed(address)
    original_balance: uint256
    original_supply: uint256
    working_balance: uint256
    working_supply: uint256

@external
def kick(addr: address):
    """
    @notice Kick `addr` for abusing their boost
    @dev Only if either they had another voting event, or their voting escrow lock expired
    @param addr Address to kick
    """
    t_last: uint256 = self.integrate_checkpoint_of[addr]
    t_ve: uint256 = VotingEscrow(VOTING_ESCROW).user_point_history__ts(
        addr, VotingEscrow(VOTING_ESCROW).user_point_epoch(addr)
    )
    _balance: uint256 = self.balanceOf[addr]

    assert ERC20(VOTING_ESCROW).balanceOf(addr) == 0 or t_ve > t_last # dev: kick not allowed
    assert self.working_balances[addr] > _balance * TOKENLESS_PRODUCTION / 100  # dev: kick not needed

    self._checkpoint(addr)
    self._update_liquidity_limit(addr, self.balanceOf[addr], self.totalSupply)

@internal
def _checkpoint(addr: address):
    """
    @notice Checkpoint for a user
    @dev Updates the CRV emissions a user is entitled to receive
    @param addr User address
    """
    _period: int128 = self.period
    _period_time: uint256 = self.period_timestamp[_period]
    _integrate_inv_supply: uint256 = self.integrate_inv_supply[_period]

    inflation_params: uint256 = self.inflation_params
    prev_future_epoch: uint256 = inflation_params >> 216
    gauge_is_killed: bool = self.is_killed

    rate: uint256 = inflation_params % 2 ** 216
    new_rate: uint256 = rate
    if gauge_is_killed:
        rate = 0
        new_rate = 0

    if prev_future_epoch >= _period_time:
        future_epoch_time_write: uint256 = CRV20(CRV).future_epoch_time_write()
        if not gauge_is_killed:
            new_rate = CRV20(CRV).rate()
        self.inflation_params = (future_epoch_time_write << 216) + new_rate

    # Update integral of 1/supply
    if block.timestamp > _period_time:
        _working_supply: uint256 = self.working_supply
        Controller(GAUGE_CONTROLLER).checkpoint_gauge(self)
        prev_week_time: uint256 = _period_time
        week_time: uint256 = min((_period_time + WEEK) / WEEK * WEEK, block.timestamp)

        for i in range(500):
            dt: uint256 = week_time - prev_week_time
            w: uint256 = Controller(GAUGE_CONTROLLER).gauge_relative_weight(self, prev_week_time)

            if _working_supply > 0:
                if prev_future_epoch >= prev_week_time and prev_future_epoch < week_time:
                    # If we went across one or multiple epochs, apply the rate
                    # of the first epoch until it ends, and then the rate of
                    # the last epoch.
                    # If more than one epoch is crossed - the gauge gets less,
                    # but that'd meen it wasn't called for more than 1 year
                    _integrate_inv_supply += rate * w * (prev_future_epoch - prev_week_time) / _working_supply
                    rate = new_rate
                    _integrate_inv_supply += rate * w * (week_time - prev_future_epoch) / _working_supply
                else:
                    _integrate_inv_supply += rate * w * dt / _working_supply
                # On precisions of the calculation
                # rate ~= 10e18
                # last_weight > 0.01 * 1e18 = 1e16 (if pool weight is 1%)
                # _working_supply ~= TVL * 1e18 ~= 1e26 ($100M for example)
                # The largest loss is at dt = 1
                # Loss is 1e-9 - acceptable

            if week_time == block.timestamp:
                break
            prev_week_time = week_time
            week_time = min(week_time + WEEK, block.timestamp)

    _period += 1
    self.period = _period
    self.period_timestamp[_period] = block.timestamp
    self.integrate_inv_supply[_period] = _integrate_inv_supply

    # Update user-specific integrals
    _working_balance: uint256 = self.working_balances[addr]
    self.integrate_fraction[addr] += _working_balance * (_integrate_inv_supply - self.integrate_inv_supply_of[addr]) / 10 ** 18
    self.integrate_inv_supply_of[addr] = _integrate_inv_supply
    self.integrate_checkpoint_of[addr] = block.timestamp

@internal
def _update_liquidity_limit(addr: address, l: uint256, L: uint256):
    """
    @notice Calculate limits which depend on the amount of CRV token per-user.
            Effectively it calculates working balances to apply amplification
            of CRV production by CRV
    @param addr User address
    @param l User's amount of liquidity (LP tokens)
    @param L Total amount of liquidity (LP tokens)
    """
    # To be called after totalSupply is updated
    voting_balance: uint256 = VotingEscrowBoost(VEBOOST_PROXY).adjusted_balance_of(addr)
    voting_total: uint256 = ERC20(VOTING_ESCROW).totalSupply()

    lim: uint256 = l * TOKENLESS_PRODUCTION / 100
    if voting_total > 0:
        lim += L * voting_balance / voting_total * (100 - TOKENLESS_PRODUCTION) / 100

    lim = min(l, lim)
    old_bal: uint256 = self.working_balances[addr]
    self.working_balances[addr] = lim
    _working_supply: uint256 = self.working_supply + lim - old_bal
    self.working_supply = _working_supply

    log UpdateLiquidityLimit(addr, l, L, lim, _working_supply)

is_killed: public(bool)

@internal
def _checkpoint(addr: address):
    """
    @notice Checkpoint for a user
    @dev Updates the CRV emissions a user is entitled to receive
    @param addr User address
    """
    _period: int128 = self.period
    _period_time: uint256 = self.period_timestamp[_period]
    _integrate_inv_supply: uint256 = self.integrate_inv_supply[_period]

    inflation_params: uint256 = self.inflation_params
    prev_future_epoch: uint256 = inflation_params >> 216
    gauge_is_killed: bool = self.is_killed

    rate: uint256 = inflation_params % 2 ** 216
    new_rate: uint256 = rate
    if gauge_is_killed:
        rate = 0
        new_rate = 0
    ...

is_killed: public(bool)

@external
def set_killed(_is_killed: bool):
    """
    @notice Set the killed status for this contract
    @dev When killed, the gauge always yields a rate of 0 and so cannot mint CRV
    @param _is_killed Killed status to set
    """
    assert msg.sender == Factory(self.factory).admin()  # dev: only owner

    self.is_killed = _is_killed

integrate_fraction: public(HashMap[address, uint256])

period: public(int128)

period_timestamp: public(uint256[100000000000000000000000000000])

inflation_params: uint256

@view
@external
def inflation_rate() -> uint256:
    """
    @notice Get the locally stored CRV inflation rate
    """
    return self.inflation_params % 2 ** 216

inflation_params: uint256

@view
@external
def future_epoch_time() -> uint256:
    """
    @notice Get the locally stored CRV future epoch start time
    """
    return self.inflation_params >> 216

factory: public(address)

@external
def __init__(_lp_token: address):
    """
    @notice Contract constructor
    @param _lp_token Liquidity Pool contract address
    """
    self.lp_token = _lp_token
    self.factory = msg.sender
    self.manager = tx.origin
    ...

lp_token: public(address)

@external
def __init__(_lp_token: address):
    """
    @notice Contract constructor
    @param _lp_token Liquidity Pool contract address
    """
    self.lp_token = _lp_token
    self.factory = msg.sender
    self.manager = tx.origin
    ...