event NewGauge:
    addr: address
    gauge_type: int128
    weight: uint256

@external
def add_gauge(addr: address, gauge_type: int128, weight: uint256 = 0):
    """
    @notice Add gauge `addr` of type `gauge_type` with weight `weight`
    @param addr Gauge address
    @param gauge_type Gauge type
    @param weight Gauge weight
    """
    assert msg.sender == self.admin
    assert (gauge_type >= 0) and (gauge_type < self.n_gauge_types)
    assert self.gauge_types_[addr] == 0  # dev: cannot add the same gauge twice

    n: int128 = self.n_gauges
    self.n_gauges = n + 1
    self.gauges[n] = addr

    self.gauge_types_[addr] = gauge_type + 1
    next_time: uint256 = (block.timestamp + WEEK) / WEEK * WEEK

    if weight > 0:
        _type_weight: uint256 = self._get_type_weight(gauge_type)
        _old_sum: uint256 = self._get_sum(gauge_type)
        _old_total: uint256 = self._get_total()

        self.points_sum[gauge_type][next_time].bias = weight + _old_sum
        self.time_sum[gauge_type] = next_time
        self.points_total[next_time] = _old_total + _type_weight * weight
        self.time_total = next_time

        self.points_weight[addr][next_time].bias = weight

    if self.time_sum[gauge_type] == 0:
        self.time_sum[gauge_type] = next_time
    self.time_weight[addr] = next_time

    log NewGauge(addr, gauge_type, weight)

event AddType:
    name: String[64]
    type_id: int128

@external
def add_type(_name: String[64], weight: uint256 = 0):
    """
    @notice Add gauge type with name `_name` and weight `weight`
    @param _name Name of gauge type
    @param weight Weight of gauge type
    """
    assert msg.sender == self.admin
    type_id: int128 = self.n_gauge_types
    self.gauge_type_names[type_id] = _name
    self.n_gauge_types = type_id + 1
    if weight != 0:
        self._change_type_weight(type_id, weight)
        log AddType(_name, type_id)

event NewTypeWeight:
    type_id: int128
    time: uint256
    weight: uint256
    total_weight: uint256

@external
def change_type_weight(type_id: int128, weight: uint256):
    """
    @notice Change gauge type `type_id` weight to `weight`
    @param type_id Gauge type id
    @param weight New Gauge weight
    """
    assert msg.sender == self.admin
    self._change_type_weight(type_id, weight)

@internal
def _change_type_weight(type_id: int128, weight: uint256):
    """
    @notice Change type weight
    @param type_id Type id
    @param weight New type weight
    """
    old_weight: uint256 = self._get_type_weight(type_id)
    old_sum: uint256 = self._get_sum(type_id)
    _total_weight: uint256 = self._get_total()
    next_time: uint256 = (block.timestamp + WEEK) / WEEK * WEEK

    _total_weight = _total_weight + old_sum * weight - old_sum * old_weight
    self.points_total[next_time] = _total_weight
    self.points_type_weight[type_id][next_time] = weight
    self.time_total = next_time
    self.time_type_weight[type_id] = next_time

    log NewTypeWeight(type_id, next_time, weight, _total_weight)

event CommitOwnership:
    admin: address

future_admin: public(address)  # Can and will be a smart contract

@external
def commit_transfer_ownership(addr: address):
    """
    @notice Transfer ownership of GaugeController to `addr`
    @param addr Address to have ownership transferred to
    """
    assert msg.sender == self.admin  # dev: admin only
    self.future_admin = addr
    log CommitOwnership(addr)

event ApplyOwnership:
    admin: address

@external
def apply_transfer_ownership():
    """
    @notice Apply pending ownership transfer
    """
    assert msg.sender == self.admin  # dev: admin only
    _admin: address = self.future_admin
    assert _admin != ZERO_ADDRESS  # dev: admin not set
    self.admin = _admin
    log ApplyOwnership(_admin)