# @version 0.2.4
"""
@title Vesting Escrow
@author Curve Finance
@license MIT
@notice Vests `ERC20CRV` tokens for multiple addresses over multiple vesting periods
"""


from vyper.interfaces import ERC20

event Fund:
    recipient: indexed(address)
    amount: uint256

event Claim:
    recipient: indexed(address)
    claimed: uint256

event ToggleDisable:
    recipient: address
    disabled: bool

event CommitOwnership:
    admin: address

event ApplyOwnership:
    admin: address


token: public(address)
start_time: public(uint256)
end_time: public(uint256)
initial_locked: public(HashMap[address, uint256])
total_claimed: public(HashMap[address, uint256])

initial_locked_supply: public(uint256)
unallocated_supply: public(uint256)

can_disable: public(bool)
disabled_at: public(HashMap[address, uint256])

admin: public(address)
future_admin: public(address)

fund_admins_enabled: public(bool)
fund_admins: public(HashMap[address, bool])


@external
def __init__(
    _token: address,
    _start_time: uint256,
    _end_time: uint256,
    _can_disable: bool,
    _fund_admins: address[4]
):
    """
    @param _token Address of the ERC20 token being distributed
    @param _start_time Timestamp at which the distribution starts. Should be in
        the future, so that we have enough time to VoteLock everyone
    @param _end_time Time until everything should be vested
    @param _can_disable Whether admin can disable accounts in this deployment
    @param _fund_admins Temporary admin accounts used only for funding
    """
    assert _start_time >= block.timestamp
    assert _end_time > _start_time

    self.token = _token
    self.admin = msg.sender
    self.start_time = _start_time
    self.end_time = _end_time
    self.can_disable = _can_disable

    _fund_admins_enabled: bool = False
    for addr in _fund_admins:
        if addr != ZERO_ADDRESS:
            self.fund_admins[addr] = True
            if not _fund_admins_enabled:
                _fund_admins_enabled = True
                self.fund_admins_enabled = True



@external
def add_tokens(_amount: uint256):
    """
    @notice Transfer vestable tokens into the contract
    @dev Handled separate from `fund` to reduce transaction count when using funding admins
    @param _amount Number of tokens to transfer
    """
    assert msg.sender == self.admin  # dev: admin only
    assert ERC20(self.token).transferFrom(msg.sender, self, _amount)  # dev: transfer failed
    self.unallocated_supply += _amount


@external
@nonreentrant('lock')
def fund(_recipients: address[100], _amounts: uint256[100]):
    """
    @notice Vest tokens for multiple recipients
    @param _recipients List of addresses to fund
    @param _amounts Amount of vested tokens for each address
    """
    if msg.sender != self.admin:
        assert self.fund_admins[msg.sender]  # dev: admin only
        assert self.fund_admins_enabled  # dev: fund admins disabled

    _total_amount: uint256 = 0
    for i in range(100):
        amount: uint256 = _amounts[i]
        recipient: address = _recipients[i]
        if recipient == ZERO_ADDRESS:
            break
        _total_amount += amount
        self.initial_locked[recipient] += amount
        log Fund(recipient, amount)

    self.initial_locked_supply += _total_amount
    self.unallocated_supply -= _total_amount


@external
def toggle_disable(_recipient: address):
    """
    @notice Disable or re-enable a vested address's ability to claim tokens
    @dev When disabled, the address is only unable to claim tokens which are still
         locked at the time of this call. It is not possible to block the claim
         of tokens which have already vested.
    @param _recipient Address to disable or enable
    """
    assert msg.sender == self.admin  # dev: admin only
    assert self.can_disable, "Cannot disable"

    is_disabled: bool = self.disabled_at[_recipient] == 0
    if is_disabled:
        self.disabled_at[_recipient] = block.timestamp
    else:
        self.disabled_at[_recipient] = 0

    log ToggleDisable(_recipient, is_disabled)


@external
def disable_can_disable():
    """
    @notice Disable the ability to call `toggle_disable`
    """
    assert msg.sender == self.admin  # dev: admin only
    self.can_disable = False


@external
def disable_fund_admins():
    """
    @notice Disable the funding admin accounts
    """
    assert msg.sender == self.admin  # dev: admin only
    self.fund_admins_enabled = False


@internal
@view
def _total_vested_of(_recipient: address, _time: uint256 = block.timestamp) -> uint256:
    start: uint256 = self.start_time
    end: uint256 = self.end_time
    locked: uint256 = self.initial_locked[_recipient]
    if _time < start:
        return 0
    return min(locked * (_time - start) / (end - start), locked)


@internal
@view
def _total_vested() -> uint256:
    start: uint256 = self.start_time
    end: uint256 = self.end_time
    locked: uint256 = self.initial_locked_supply
    if block.timestamp < start:
        return 0
    return min(locked * (block.timestamp - start) / (end - start), locked)


@external
@view
def vestedSupply() -> uint256:
    """
    @notice Get the total number of tokens which have vested, that are held
            by this contract
    """
    return self._total_vested()


@external
@view
def lockedSupply() -> uint256:
    """
    @notice Get the total number of tokens which are still locked
            (have not yet vested)
    """
    return self.initial_locked_supply - self._total_vested()


@external
@view
def vestedOf(_recipient: address) -> uint256:
    """
    @notice Get the number of tokens which have vested for a given address
    @param _recipient address to check
    """
    return self._total_vested_of(_recipient)


@external
@view
def balanceOf(_recipient: address) -> uint256:
    """
    @notice Get the number of unclaimed, vested tokens for a given address
    @param _recipient address to check
    """
    return self._total_vested_of(_recipient) - self.total_claimed[_recipient]


@external
@view
def lockedOf(_recipient: address) -> uint256:
    """
    @notice Get the number of locked tokens for a given address
    @param _recipient address to check
    """
    return self.initial_locked[_recipient] - self._total_vested_of(_recipient)


@external
@nonreentrant('lock')
def claim(addr: address = msg.sender):
    """
    @notice Claim tokens which have vested
    @param addr Address to claim tokens for
    """
    t: uint256 = self.disabled_at[addr]
    if t == 0:
        t = block.timestamp
    claimable: uint256 = self._total_vested_of(addr, t) - self.total_claimed[addr]
    self.total_claimed[addr] += claimable
    assert ERC20(self.token).transfer(addr, claimable)

    log Claim(addr, claimable)


@external
def commit_transfer_ownership(addr: address) -> bool:
    """
    @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)

    return True


@external
def apply_transfer_ownership() -> bool:
    """
    @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)

    return True

# @version 0.2.4
"""
@title Curve DAO Token
@author Curve Finance
@license MIT
@notice ERC20 with piecewise-linear mining supply.
@dev Based on the ERC-20 token standard as defined at
     https://eips.ethereum.org/EIPS/eip-20
"""

from vyper.interfaces import ERC20

implements: ERC20


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

event Approval:
    _owner: indexed(address)
    _spender: indexed(address)
    _value: uint256

event UpdateMiningParameters:
    time: uint256
    rate: uint256
    supply: uint256

event SetMinter:
    minter: address

event SetAdmin:
    admin: address


name: public(String[64])
symbol: public(String[32])
decimals: public(uint256)

balanceOf: public(HashMap[address, uint256])
allowances: HashMap[address, HashMap[address, uint256]]
total_supply: uint256

minter: public(address)
admin: public(address)

# General constants
YEAR: constant(uint256) = 86400 * 365

# Allocation:
# =========
# * shareholders - 30%
# * emplyees - 3%
# * DAO-controlled reserve - 5%
# * Early users - 5%
# == 43% ==
# left for inflation: 57%

# Supply parameters
INITIAL_SUPPLY: constant(uint256) = 1_303_030_303
INITIAL_RATE: constant(uint256) = 274_815_283 * 10 ** 18 / YEAR  # leading to 43% premine
RATE_REDUCTION_TIME: constant(uint256) = YEAR
RATE_REDUCTION_COEFFICIENT: constant(uint256) = 1189207115002721024  # 2 ** (1/4) * 1e18
RATE_DENOMINATOR: constant(uint256) = 10 ** 18
INFLATION_DELAY: constant(uint256) = 86400

# Supply variables
mining_epoch: public(int128)
start_epoch_time: public(uint256)
rate: public(uint256)

start_epoch_supply: uint256


@external
def __init__(_name: String[64], _symbol: String[32], _decimals: uint256):
    """
    @notice Contract constructor
    @param _name Token full name
    @param _symbol Token symbol
    @param _decimals Number of decimals for token
    """
    init_supply: uint256 = INITIAL_SUPPLY * 10 ** _decimals
    self.name = _name
    self.symbol = _symbol
    self.decimals = _decimals
    self.balanceOf[msg.sender] = init_supply
    self.total_supply = init_supply
    self.admin = msg.sender
    log Transfer(ZERO_ADDRESS, msg.sender, init_supply)

    self.start_epoch_time = block.timestamp + INFLATION_DELAY - RATE_REDUCTION_TIME
    self.mining_epoch = -1
    self.rate = 0
    self.start_epoch_supply = init_supply


@internal
def _update_mining_parameters():
    """
    @dev Update mining rate and supply at the start of the epoch
         Any modifying mining call must also call this
    """
    _rate: uint256 = self.rate
    _start_epoch_supply: uint256 = self.start_epoch_supply

    self.start_epoch_time += RATE_REDUCTION_TIME
    self.mining_epoch += 1

    if _rate == 0:
        _rate = INITIAL_RATE
    else:
        _start_epoch_supply += _rate * RATE_REDUCTION_TIME
        self.start_epoch_supply = _start_epoch_supply
        _rate = _rate * RATE_DENOMINATOR / RATE_REDUCTION_COEFFICIENT

    self.rate = _rate

    log UpdateMiningParameters(block.timestamp, _rate, _start_epoch_supply)


@external
def update_mining_parameters():
    """
    @notice Update mining rate and supply at the start of the epoch
    @dev Callable by any address, but only once per epoch
         Total supply becomes slightly larger if this function is called late
    """
    assert block.timestamp >= self.start_epoch_time + RATE_REDUCTION_TIME  # dev: too soon!
    self._update_mining_parameters()


@external
def start_epoch_time_write() -> uint256:
    """
    @notice Get timestamp of the current mining epoch start
            while simultaneously updating mining parameters
    @return Timestamp of the epoch
    """
    _start_epoch_time: uint256 = self.start_epoch_time
    if block.timestamp >= _start_epoch_time + RATE_REDUCTION_TIME:
        self._update_mining_parameters()
        return self.start_epoch_time
    else:
        return _start_epoch_time


@external
def future_epoch_time_write() -> uint256:
    """
    @notice Get timestamp of the next mining epoch start
            while simultaneously updating mining parameters
    @return Timestamp of the next epoch
    """
    _start_epoch_time: uint256 = self.start_epoch_time
    if block.timestamp >= _start_epoch_time + RATE_REDUCTION_TIME:
        self._update_mining_parameters()
        return self.start_epoch_time + RATE_REDUCTION_TIME
    else:
        return _start_epoch_time + RATE_REDUCTION_TIME


@internal
@view
def _available_supply() -> uint256:
    return self.start_epoch_supply + (block.timestamp - self.start_epoch_time) * self.rate


@external
@view
def available_supply() -> uint256:
    """
    @notice Current number of tokens in existence (claimed or unclaimed)
    """
    return self._available_supply()


@external
@view
def mintable_in_timeframe(start: uint256, end: uint256) -> uint256:
    """
    @notice How much supply is mintable from start timestamp till end timestamp
    @param start Start of the time interval (timestamp)
    @param end End of the time interval (timestamp)
    @return Tokens mintable from `start` till `end`
    """
    assert start <= end  # dev: start > end
    to_mint: uint256 = 0
    current_epoch_time: uint256 = self.start_epoch_time
    current_rate: uint256 = self.rate

    # Special case if end is in future (not yet minted) epoch
    if end > current_epoch_time + RATE_REDUCTION_TIME:
        current_epoch_time += RATE_REDUCTION_TIME
        current_rate = current_rate * RATE_DENOMINATOR / RATE_REDUCTION_COEFFICIENT

    assert end <= current_epoch_time + RATE_REDUCTION_TIME  # dev: too far in future

    for i in range(999):  # Curve will not work in 1000 years. Darn!
        if end >= current_epoch_time:
            current_end: uint256 = end
            if current_end > current_epoch_time + RATE_REDUCTION_TIME:
                current_end = current_epoch_time + RATE_REDUCTION_TIME

            current_start: uint256 = start
            if current_start >= current_epoch_time + RATE_REDUCTION_TIME:
                break  # We should never get here but what if...
            elif current_start < current_epoch_time:
                current_start = current_epoch_time

            to_mint += current_rate * (current_end - current_start)

            if start >= current_epoch_time:
                break

        current_epoch_time -= RATE_REDUCTION_TIME
        current_rate = current_rate * RATE_REDUCTION_COEFFICIENT / RATE_DENOMINATOR  # double-division with rounding made rate a bit less => good
        assert current_rate <= INITIAL_RATE  # This should never happen

    return to_mint


@external
def set_minter(_minter: address):
    """
    @notice Set the minter address
    @dev Only callable once, when minter has not yet been set
    @param _minter Address of the minter
    """
    assert msg.sender == self.admin  # dev: admin only
    assert self.minter == ZERO_ADDRESS  # dev: can set the minter only once, at creation
    self.minter = _minter
    log SetMinter(_minter)


@external
def set_admin(_admin: address):
    """
    @notice Set the new admin.
    @dev After all is set up, admin only can change the token name
    @param _admin New admin address
    """
    assert msg.sender == self.admin  # dev: admin only
    self.admin = _admin
    log SetAdmin(_admin)


@external
@view
def totalSupply() -> uint256:
    """
    @notice Total number of tokens in existence.
    """
    return self.total_supply


@external
@view
def allowance(_owner : address, _spender : address) -> uint256:
    """
    @notice Check the amount of tokens that an owner allowed to a spender
    @param _owner The address which owns the funds
    @param _spender The address which will spend the funds
    @return uint256 specifying the amount of tokens still available for the spender
    """
    return self.allowances[_owner][_spender]


@external
def transfer(_to : address, _value : uint256) -> bool:
    """
    @notice Transfer `_value` tokens from `msg.sender` to `_to`
    @dev Vyper does not allow underflows, so the subtraction in
         this function will revert on an insufficient balance
    @param _to The address to transfer to
    @param _value The amount to be transferred
    @return bool success
    """
    assert _to != ZERO_ADDRESS  # dev: transfers to 0x0 are not allowed
    self.balanceOf[msg.sender] -= _value
    self.balanceOf[_to] += _value
    log Transfer(msg.sender, _to, _value)
    return True


@external
def transferFrom(_from : address, _to : address, _value : uint256) -> bool:
    """
     @notice Transfer `_value` tokens from `_from` to `_to`
     @param _from address The address which you want to send tokens from
     @param _to address The address which you want to transfer to
     @param _value uint256 the amount of tokens to be transferred
     @return bool success
    """
    assert _to != ZERO_ADDRESS  # dev: transfers to 0x0 are not allowed
    # NOTE: vyper does not allow underflows
    #       so the following subtraction would revert on insufficient balance
    self.balanceOf[_from] -= _value
    self.balanceOf[_to] += _value
    self.allowances[_from][msg.sender] -= _value
    log Transfer(_from, _to, _value)
    return True


@external
def approve(_spender : address, _value : uint256) -> bool:
    """
    @notice Approve `_spender` to transfer `_value` tokens on behalf of `msg.sender`
    @dev Approval may only be from zero -> nonzero or from nonzero -> zero in order
        to mitigate the potential race condition described here:
        https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
    @param _spender The address which will spend the funds
    @param _value The amount of tokens to be spent
    @return bool success
    """
    assert _value == 0 or self.allowances[msg.sender][_spender] == 0
    self.allowances[msg.sender][_spender] = _value
    log Approval(msg.sender, _spender, _value)
    return True


@external
def mint(_to: address, _value: uint256) -> bool:
    """
    @notice Mint `_value` tokens and assign them to `_to`
    @dev Emits a Transfer event originating from 0x00
    @param _to The account that will receive the created tokens
    @param _value The amount that will be created
    @return bool success
    """
    assert msg.sender == self.minter  # dev: minter only
    assert _to != ZERO_ADDRESS  # dev: zero address

    if block.timestamp >= self.start_epoch_time + RATE_REDUCTION_TIME:
        self._update_mining_parameters()

    _total_supply: uint256 = self.total_supply + _value
    assert _total_supply <= self._available_supply()  # dev: exceeds allowable mint amount
    self.total_supply = _total_supply

    self.balanceOf[_to] += _value
    log Transfer(ZERO_ADDRESS, _to, _value)

    return True


@external
def burn(_value: uint256) -> bool:
    """
    @notice Burn `_value` tokens belonging to `msg.sender`
    @dev Emits a Transfer event with a destination of 0x00
    @param _value The amount that will be burned
    @return bool success
    """
    self.balanceOf[msg.sender] -= _value
    self.total_supply -= _value

    log Transfer(msg.sender, ZERO_ADDRESS, _value)
    return True


@external
def set_name(_name: String[64], _symbol: String[32]):
    """
    @notice Change the token name and symbol to `_name` and `_symbol`
    @dev Only callable by the admin account
    @param _name New token name
    @param _symbol New token symbol
    """
    assert msg.sender == self.admin, "Only admin is allowed to change name"
    self.name = _name
    self.symbol = _symbol