Contract

# @version 0.3.9

# Interfaces

from vyper.interfaces import ERC20 as IERC20
from vyper.interfaces import ERC721 as IERC721

interface IDelegationRegistry:
    def getHotWallet(cold_wallet: address) -> address: view
    def setHotWallet(hot_wallet_address: address, expiration_timestamp: uint256, lock_hot_wallet_address: bool): nonpayable
    def setExpirationTimestamp(expiration_timestamp: uint256): nonpayable


# Events


# Structs

struct Rental:
    id: bytes32 # keccak256 of the renter, token_id, start and expiration
    owner: address
    renter: address
    token_id: uint256
    start: uint256
    min_expiration: uint256
    expiration: uint256
    amount: uint256


struct Listing:
    token_id: uint256
    price: uint256 # price per hour, 0 means not listed
    min_duration: uint256 # min duration in hours
    max_duration: uint256 # max duration in hours, 0 means unlimited


# Global Variables

is_initialised: public(bool)
owner: public(address)
caller: public(address)
listing: public(Listing)
active_rental: public(Rental)
unclaimed_rewards: public(uint256)

payment_token_addr: public(address)
nft_contract_addr: public(address)
delegation_registry_addr: public(address)


##### EXTERNAL METHODS - WRITE #####

@external
def initialise(
    owner: address,
    payment_token_addr: address,
    nft_contract_addr: address,
    delegation_registry_addr: address
):
    assert not self.is_initialised, "already initialised"

    if self.caller != empty(address):
        assert msg.sender == self.caller, "not caller"
    else:
        self.caller = msg.sender

    self.owner = owner
    self.is_initialised = True

    self.payment_token_addr = payment_token_addr
    self.nft_contract_addr = nft_contract_addr
    self.delegation_registry_addr = delegation_registry_addr


@external
def deposit(token_id: uint256, price: uint256, min_duration: uint256, max_duration: uint256):
    assert self.is_initialised, "not initialised"
    assert msg.sender == self.caller, "not caller"
    assert IERC721(self.nft_contract_addr).ownerOf(token_id) == self.owner, "not owner of token"
    assert IERC721(self.nft_contract_addr).getApproved(token_id) == self, "not approved for token"

    if max_duration != 0 and min_duration > max_duration:
        raise "min duration > max duration"

    self.listing = Listing({
        token_id: token_id,
        price: price,
        min_duration: min_duration,
        max_duration: max_duration
    })

    # transfer token to this contract
    IERC721(self.nft_contract_addr).safeTransferFrom(self.owner, self, token_id, b"")

    # create delegation
    self._delegate_to_owner()


@external
def set_listing(sender: address, price: uint256, min_duration: uint256, max_duration: uint256):
    assert self.is_initialised, "not initialised"
    assert msg.sender == self.caller, "not caller"
    assert sender == self.owner, "not owner of vault"

    self._set_listing(sender, price, min_duration, max_duration)


@external
def set_listing_and_delegate_to_owner(sender: address, price: uint256, min_duration: uint256, max_duration: uint256):
    assert self.is_initialised, "not initialised"
    assert msg.sender == self.caller, "not caller"
    assert sender == self.owner, "not owner of vault"
    assert self.active_rental.expiration < block.timestamp, "active rental ongoing"

    self._set_listing(sender, price, min_duration, max_duration)
    self._delegate_to_owner()



@external
def start_rental(renter: address, expiration: uint256) -> Rental:
    assert self.is_initialised, "not initialised"
    assert msg.sender == self.caller, "not caller"
    assert self._is_active(), "listing does not exist"
    assert self.active_rental.expiration < block.timestamp, "active rental ongoing"
    assert self._is_within_duration_range(block.timestamp, expiration), "duration not respected"

    listing: Listing = self.listing

    rental_amount: uint256 = self._compute_rental_amount(block.timestamp, expiration, listing.price)
    assert IERC20(self.payment_token_addr).allowance(renter, self) >= rental_amount, "insufficient allowance"

    # transfer rental amount from renter to this contract
    assert IERC20(self.payment_token_addr).transferFrom(renter, self, rental_amount), "transferFrom failed"

    # create delegation
    if IDelegationRegistry(self.delegation_registry_addr).getHotWallet(self) == renter:
        IDelegationRegistry(self.delegation_registry_addr).setExpirationTimestamp(expiration)
    else:
        IDelegationRegistry(self.delegation_registry_addr).setHotWallet(renter, expiration, False)

    # store unclaimed rewards
    self._consolidate_claims()

    # create rental
    rental_id: bytes32 = self._compute_rental_id(renter, listing.token_id, block.timestamp, expiration)
    self.active_rental = Rental({
        id: rental_id,
        owner: self.owner,
        renter: renter,
        token_id: listing.token_id,
        start: block.timestamp,
        min_expiration: block.timestamp + listing.min_duration * 3600,
        expiration: expiration,
        amount: rental_amount
    })

    return self.active_rental


@external
def close_rental(sender: address) -> (Rental, uint256):
    assert self.is_initialised, "not initialised"
    assert msg.sender == self.caller, "not caller"

    rental: Rental = self.active_rental

    assert rental.expiration >= block.timestamp, "active rental does not exist"
    assert sender == rental.renter, "not renter of active rental"

    # compute amount to send back to renter
    real_expiration_adjusted: uint256 = block.timestamp
    if block.timestamp < rental.min_expiration:
        real_expiration_adjusted = rental.min_expiration
    pro_rata_rental_amount: uint256 = self._compute_real_rental_amount(
        rental.expiration - rental.start,
        real_expiration_adjusted - rental.start,
        rental.amount
    )
    payback_amount: uint256 = rental.amount - pro_rata_rental_amount

    # clear active rental
    rental.expiration = block.timestamp
    rental.amount = 0
    self.active_rental = rental

    # set unclaimed rewards
    self.unclaimed_rewards += pro_rata_rental_amount

    # revoke delegation
    IDelegationRegistry(self.delegation_registry_addr).setHotWallet(empty(address), 0, False)

    # transfer unused payment to renter
    assert IERC20(self.payment_token_addr).transfer(rental.renter, payback_amount), "transfer failed"

    return rental, pro_rata_rental_amount


@external
def claim(sender: address) -> uint256:
    assert self.is_initialised, "not initialised"
    assert msg.sender == self.caller, "not caller"
    assert sender == self.owner, "not owner of vault"
    assert self._claimable_rewards() > 0, "no rewards to claim"

    # consolidate last renting rewards if existing
    self._consolidate_claims()

    rewards_to_claim: uint256 = self.unclaimed_rewards

    # clear uncclaimed rewards
    self.unclaimed_rewards = 0

    # transfer reward to nft owner
    assert IERC20(self.payment_token_addr).transfer(self.active_rental.owner, rewards_to_claim), "transfer failed"

    return rewards_to_claim


@external
def withdraw(sender: address) -> uint256:
    assert self.is_initialised, "not initialised"
    assert msg.sender == self.caller, "not caller"
    assert sender == self.owner, "not owner of vault"
    assert self.active_rental.expiration < block.timestamp, "active rental ongoing"

    # consolidate last renting rewards if existing
    self._consolidate_claims()

    rewards_to_claim: uint256 = self.unclaimed_rewards
    token_id: uint256 = self.listing.token_id
    owner: address = self.owner

    # clear vault
    self.unclaimed_rewards = 0
    self.listing = empty(Listing)
    self.active_rental = empty(Rental)
    self.is_initialised = False
    self.owner = empty(address)

    # transfer token to owner
    IERC721(self.nft_contract_addr).safeTransferFrom(self, owner, token_id, b"")

    # transfer unclaimed rewards to owner
    if rewards_to_claim > 0:
        assert IERC20(self.payment_token_addr).transfer(owner, rewards_to_claim), "transfer failed"

    return rewards_to_claim


@external
def delegate_to_owner(sender: address):
    assert self.is_initialised, "not initialised"
    assert msg.sender == self.caller, "not caller"
    assert sender == self.owner, "not owner of vault"
    assert self.active_rental.expiration < block.timestamp, "active rental ongoing"

    self._delegate_to_owner()




##### INTERNAL METHODS #####

@internal
def _is_active() -> bool:
    return self.listing.price > 0

@internal
def _consolidate_claims():
    if self.active_rental.expiration < block.timestamp:
        self.unclaimed_rewards += self.active_rental.amount
        self.active_rental.amount = 0

@internal
def _is_within_duration_range(start: uint256, expiration: uint256) -> bool:
    return expiration - start >= self.listing.min_duration * 3600 and (self.listing.max_duration == 0 or expiration - start <= self.listing.max_duration * 3600)


@pure
@internal
def _compute_rental_id(renter: address, token_id: uint256, start: uint256, expiration: uint256) -> bytes32:
    return keccak256(concat(convert(renter, bytes32), convert(token_id, bytes32), convert(start, bytes32), convert(expiration, bytes32)))


@pure
@internal
def _compute_rental_amount(start: uint256, expiration: uint256, price: uint256) -> uint256:
    return (expiration - start) * price / 3600


@pure
@internal
def _compute_real_rental_amount(duration: uint256, real_duration: uint256, rental_amount: uint256) -> uint256:
    return rental_amount * real_duration / duration


@view
@internal
def _claimable_rewards() -> uint256:
    if self.active_rental.expiration < block.timestamp:
        return self.unclaimed_rewards + self.active_rental.amount
    else:
        return self.unclaimed_rewards

@internal
def _delegate_to_owner():
    delegation_registry: IDelegationRegistry = IDelegationRegistry(self.delegation_registry_addr)
    owner: address = self.owner
    if delegation_registry.getHotWallet(self) != owner:
        delegation_registry.setHotWallet(owner, max_value(uint256), False)


@internal
def _set_listing(sender: address, price: uint256, min_duration: uint256, max_duration: uint256):
    if max_duration != 0 and min_duration > max_duration:
        raise "min duration > max duration"

    self.listing.price = price
    self.listing.min_duration = min_duration
    self.listing.max_duration = max_duration



##### EXTERNAL METHODS - VIEW #####

@view
@external
def claimable_rewards() -> uint256:
    return self._claimable_rewards()


@view
@external
def onERC721Received(_operator: address, _from: address, _tokenId: uint256, _data: Bytes[1024]) -> bytes4:
    return method_id("onERC721Received(address,address,uint256,bytes)", output_type=bytes4)

[{"stateMutability":"nonpayable","type":"function","name":"initialise","inputs":[{"name":"owner","type":"address"},{"name":"payment_token_addr","type":"address"},{"name":"nft_contract_addr","type":"address"},{"name":"delegation_registry_addr","type":"address"}],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"deposit","inputs":[{"name":"token_id","type":"uint256"},{"name":"price","type":"uint256"},{"name":"min_duration","type":"uint256"},{"name":"max_duration","type":"uint256"}],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"set_listing","inputs":[{"name":"sender","type":"address"},{"name":"price","type":"uint256"},{"name":"min_duration","type":"uint256"},{"name":"max_duration","type":"uint256"}],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"set_listing_and_delegate_to_owner","inputs":[{"name":"sender","type":"address"},{"name":"price","type":"uint256"},{"name":"min_duration","type":"uint256"},{"name":"max_duration","type":"uint256"}],"outputs":[]},{"stateMutability":"nonpayable","type":"function","name":"start_rental","inputs":[{"name":"renter","type":"address"},{"name":"expiration","type":"uint256"}],"outputs":[{"name":"","type":"tuple","components":[{"name":"id","type":"bytes32"},{"name":"owner","type":"address"},{"name":"renter","type":"address"},{"name":"token_id","type":"uint256"},{"name":"start","type":"uint256"},{"name":"min_expiration","type":"uint256"},{"name":"expiration","type":"uint256"},{"name":"amount","type":"uint256"}]}]},{"stateMutability":"nonpayable","type":"function","name":"close_rental","inputs":[{"name":"sender","type":"address"}],"outputs":[{"name":"","type":"tuple","components":[{"name":"id","type":"bytes32"},{"name":"owner","type":"address"},{"name":"renter","type":"address"},{"name":"token_id","type":"uint256"},{"name":"start","type":"uint256"},{"name":"min_expiration","type":"uint256"},{"name":"expiration","type":"uint256"},{"name":"amount","type":"uint256"}]},{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"claim","inputs":[{"name":"sender","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"withdraw","inputs":[{"name":"sender","type":"address"}],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"nonpayable","type":"function","name":"delegate_to_owner","inputs":[{"name":"sender","type":"address"}],"outputs":[]},{"stateMutability":"view","type":"function","name":"claimable_rewards","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"onERC721Received","inputs":[{"name":"_operator","type":"address"},{"name":"_from","type":"address"},{"name":"_tokenId","type":"uint256"},{"name":"_data","type":"bytes"}],"outputs":[{"name":"","type":"bytes4"}]},{"stateMutability":"view","type":"function","name":"is_initialised","inputs":[],"outputs":[{"name":"","type":"bool"}]},{"stateMutability":"view","type":"function","name":"owner","inputs":[],"outputs":[{"name":"","type":"address"}]},{"stateMutability":"view","type":"function","name":"caller","inputs":[],"outputs":[{"name":"","type":"address"}]},{"stateMutability":"view","type":"function","name":"listing","inputs":[],"outputs":[{"name":"","type":"tuple","components":[{"name":"token_id","type":"uint256"},{"name":"price","type":"uint256"},{"name":"min_duration","type":"uint256"},{"name":"max_duration","type":"uint256"}]}]},{"stateMutability":"view","type":"function","name":"active_rental","inputs":[],"outputs":[{"name":"","type":"tuple","components":[{"name":"id","type":"bytes32"},{"name":"owner","type":"address"},{"name":"renter","type":"address"},{"name":"token_id","type":"uint256"},{"name":"start","type":"uint256"},{"name":"min_expiration","type":"uint256"},{"name":"expiration","type":"uint256"},{"name":"amount","type":"uint256"}]}]},{"stateMutability":"view","type":"function","name":"unclaimed_rewards","inputs":[],"outputs":[{"name":"","type":"uint256"}]},{"stateMutability":"view","type":"function","name":"payment_token_addr","inputs":[],"outputs":[{"name":"","type":"address"}]},{"stateMutability":"view","type":"function","name":"nft_contract_addr","inputs":[],"outputs":[{"name":"","type":"address"}]},{"stateMutability":"view","type":"function","name":"delegation_registry_addr","inputs":[],"outputs":[{"name":"","type":"address"}]}]