bitshares.py

# -*- coding: utf-8 -*-
import logging

from datetime import datetime, timedelta

from graphenecommon.chain import AbstractGrapheneChain

from bitsharesapi.bitsharesnoderpc import BitSharesNodeRPC
from bitsharesbase import operations
from bitsharesbase.account import PublicKey
from bitsharesbase.asset_permissions import asset_permissions, toint

from .account import Account
from .amount import Amount
from .asset import Asset
from .committee import Committee
from .exceptions import AccountExistsException, KeyAlreadyInStoreException
from .instance import set_shared_blockchain_instance, shared_blockchain_instance
from .price import Price
from .storage import get_default_config_store
from .transactionbuilder import ProposalBuilder, TransactionBuilder
from .vesting import Vesting
from .wallet import Wallet
from .witness import Witness
from .worker import Worker
from .htlc import Htlc


# from .utils import formatTime

log = logging.getLogger(__name__)


class BitShares(AbstractGrapheneChain):
    """
    Connect to the BitShares network.

    :param str node: Node to connect to *(optional)*
    :param str rpcuser: RPC user *(optional)*
    :param str rpcpassword: RPC password *(optional)*
    :param bool nobroadcast: Do **not** broadcast a transaction!
        *(optional)*
    :param bool debug: Enable Debugging *(optional)*
    :param array,dict,string keys: Predefine the wif keys to shortcut the
        wallet database *(optional)*
    :param bool offline: Boolean to prevent connecting to network (defaults
        to ``False``) *(optional)*
    :param str proposer: Propose a transaction using this proposer
        *(optional)*
    :param int proposal_expiration: Expiration time (in seconds) for the
        proposal *(optional)*
    :param int proposal_review: Review period (in seconds) for the proposal
        *(optional)*
    :param int expiration: Delay in seconds until transactions are supposed
        to expire *(optional)*
    :param str blocking: Wait for broadcasted transactions to be included
        in a block and return full transaction (can be "head" or
        "irrversible")
    :param bool bundle: Do not broadcast transactions right away, but allow
        to bundle operations *(optional)*

    Three wallet operation modes are possible:

    * **Wallet Database**: Here, the bitshareslibs load the keys from the
      locally stored wallet SQLite database (see ``storage.py``).
      To use this mode, simply call ``BitShares()`` without the
      ``keys`` parameter
    * **Providing Keys**: Here, you can provide the keys for
      your accounts manually. All you need to do is add the wif
      keys for the accounts you want to use as a simple array
      using the ``keys`` parameter to ``BitShares()``.
    * **Force keys**: This more is for advanced users and
      requires that you know what you are doing. Here, the
      ``keys`` parameter is a dictionary that overwrite the
      ``active``, ``owner``, or ``memo`` keys for
      any account. This mode is only used for *foreign*
      signatures!

    If no node is provided, it will connect to the node of
    http://uptick.rocks. It is **highly** recommended that you
    pick your own node instead. Default settings can be changed with:

    .. code-block:: python

        uptick set node <host>

    where ``<host>`` starts with ``ws://`` or ``wss://``.

    The purpose of this class it to simplify interaction with
    BitShares.

    The idea is to have a class that allows to do this:

    .. code-block:: python

        from bitshares import BitShares
        bitshares = BitShares()
        print(bitshares.info())

    All that is requires is for the user to have added a key with
    ``uptick``

    .. code-block:: bash

        uptick addkey

    and setting a default author:

    .. code-block:: bash

        uptick set default_account xeroc

    This class also deals with edits, votes and reading content.
    """

    def define_classes(self):
        from .blockchainobject import BlockchainObject

        self.wallet_class = Wallet
        self.account_class = Account
        self.rpc_class = BitSharesNodeRPC
        self.default_key_store_app_name = "bitshares"
        self.proposalbuilder_class = ProposalBuilder
        self.transactionbuilder_class = TransactionBuilder
        self.blockchainobject_class = BlockchainObject

    # -------------------------------------------------------------------------
    # Simple Transfer
    # -------------------------------------------------------------------------
    def transfer(self, to, amount, asset, memo="", account=None, **kwargs):
        """
        Transfer an asset to another account.

        :param str to: Recipient
        :param float amount: Amount to transfer
        :param str asset: Asset to transfer
        :param str memo: (optional) Memo, may begin with `#` for encrypted
            messaging
        :param str account: (optional) the source account for the transfer
            if not ``default_account``
        """
        from .memo import Memo

        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")

        account = Account(account, blockchain_instance=self)
        amount = Amount(amount, asset, blockchain_instance=self)
        to = Account(to, blockchain_instance=self)

        memoObj = Memo(from_account=account, to_account=to, blockchain_instance=self)

        op = operations.Transfer(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "from": account["id"],
                "to": to["id"],
                "amount": {"amount": int(amount), "asset_id": amount.asset["id"]},
                "memo": memoObj.encrypt(memo),
                "prefix": self.prefix,
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)

    # -------------------------------------------------------------------------
    # Account related calls
    # -------------------------------------------------------------------------
    def _store_keys(self, *args):
        for k in args:
            try:
                self.wallet.addPrivateKey(str(k))
            except KeyAlreadyInStoreException:
                pass

    def create_account(
        self,
        account_name,
        registrar=None,
        referrer="1.2.35641",
        referrer_percent=50,
        owner_key=None,
        active_key=None,
        memo_key=None,
        owner_account=None,
        active_account=None,
        password=None,
        additional_owner_keys=None,
        additional_active_keys=None,
        additional_owner_accounts=None,
        additional_active_accounts=None,
        proxy_account="proxy-to-self",
        storekeys=True,
        **kwargs
    ):
        """
        Create new account on BitShares.

        The brainkey/password can be used to recover all generated keys
        (see `bitsharesbase.account` for more details.

        By default, this call will use ``default_account`` to
        register a new name ``account_name`` with all keys being
        derived from a new brain key that will be returned. The
        corresponding keys will automatically be installed in the
        wallet.

        .. warning:: Don't call this method unless you know what
                      you are doing! Be sure to understand what this
                      method does and where to find the private keys
                      for your account.

        .. note:: Please note that this imports private keys
                  (if password is present) into the wallet by
                  default. However, it **does not import the owner
                  key** for security reasons. Do NOT expect to be
                  able to recover it from the wallet if you lose
                  your password!

        :param str account_name: (**required**) new account name
        :param str registrar: which account should pay the registration fee
                            (defaults to ``default_account``)
        :param str owner_key: Main owner key
        :param str active_key: Main active key
        :param str memo_key: Main memo_key
        :param str password: Alternatively to providing keys, one
                             can provide a password from which the
                             keys will be derived
        :param array additional_owner_keys:  Additional owner public keys
        :param array additional_active_keys: Additional active public keys
        :param array additional_owner_accounts: Additional owner account
            names
        :param array additional_active_accounts: Additional acctive account
            names
        :param bool storekeys: Store new keys in the wallet (default:
            ``True``)
        :raises AccountExistsException: if the account already exists on
            the blockchain
        """
        if not registrar and self.config["default_account"]:
            registrar = self.config["default_account"]
        if not registrar:
            raise ValueError(
                "Not registrar account given. Define it with "
                + "registrar=x, or set the default_account using uptick"
            )
        if password and (owner_key or active_key or memo_key):
            raise ValueError("You cannot use 'password' AND provide keys!")

        if additional_owner_keys is None:
            additional_owner_keys = []
        if additional_active_keys is None:
            additional_active_keys = []
        if additional_owner_accounts is None:
            additional_owner_accounts = []
        if additional_active_accounts is None:
            additional_active_accounts = []

        try:
            Account(account_name, blockchain_instance=self)
            raise AccountExistsException
        except Exception:
            pass

        referrer = Account(referrer, blockchain_instance=self)
        registrar = Account(registrar, blockchain_instance=self)

        " Generate new keys from password"
        from bitsharesbase.account import PasswordKey, PublicKey

        owner_key_authority = []
        active_key_authority = []
        owner_accounts_authority = []
        active_accounts_authority = []

        if password:
            active_key = PasswordKey(account_name, password, role="active")
            owner_key = PasswordKey(account_name, password, role="owner")
            memo_key = PasswordKey(account_name, password, role="memo")
            active_pubkey = active_key.get_public_key()
            owner_pubkey = owner_key.get_public_key()
            memo_pubkey = memo_key.get_public_key()
            active_privkey = active_key.get_private_key()
            # owner_privkey   = owner_key.get_private_key()
            memo_privkey = memo_key.get_private_key()
            # store private keys
            if storekeys:
                self._store_keys(active_privkey, memo_privkey)
            owner_key_authority = [[format(owner_pubkey, self.prefix), 1]]
            active_key_authority = [[format(active_pubkey, self.prefix), 1]]
            memo = format(memo_pubkey, self.prefix)
        elif owner_key and active_key and memo_key:
            active_pubkey = PublicKey(active_key, prefix=self.prefix)
            owner_pubkey = PublicKey(owner_key, prefix=self.prefix)
            memo_pubkey = PublicKey(memo_key, prefix=self.prefix)
            owner_key_authority = [[format(owner_pubkey, self.prefix), 1]]
            active_key_authority = [[format(active_pubkey, self.prefix), 1]]
            memo = format(memo_pubkey, self.prefix)
        elif owner_account and active_account and memo_key:
            memo_pubkey = PublicKey(memo_key, prefix=self.prefix)
            memo = format(memo_pubkey, self.prefix)
            owner_account = Account(owner_account, blockchain_instance=self)
            active_account = Account(active_account, blockchain_instance=self)
            owner_accounts_authority = [[owner_account["id"], 1]]
            active_accounts_authority = [[active_account["id"], 1]]
        else:
            raise ValueError(
                "Call incomplete! Provide either a password, owner/active public keys "
                "or owner/active accounts + memo key!"
            )

        # additional authorities
        for k in additional_owner_keys:
            PublicKey(k, prefix=self.prefix)
            owner_key_authority.append([k, 1])
        for k in additional_active_keys:
            PublicKey(k, prefix=self.prefix)
            active_key_authority.append([k, 1])
        for k in additional_owner_accounts:
            addaccount = Account(k, blockchain_instance=self)
            owner_accounts_authority.append([addaccount["id"], 1])
        for k in additional_active_accounts:
            addaccount = Account(k, blockchain_instance=self)
            active_accounts_authority.append([addaccount["id"], 1])

        # voting account
        voting_account = Account(
            proxy_account or "proxy-to-self", blockchain_instance=self
        )

        op = {
            "fee": {"amount": 0, "asset_id": "1.3.0"},
            "registrar": registrar["id"],
            "referrer": referrer["id"],
            "referrer_percent": int(referrer_percent * 100),
            "name": account_name,
            "owner": {
                "account_auths": owner_accounts_authority,
                "key_auths": owner_key_authority,
                "address_auths": [],
                "weight_threshold": 1,
            },
            "active": {
                "account_auths": active_accounts_authority,
                "key_auths": active_key_authority,
                "address_auths": [],
                "weight_threshold": 1,
            },
            "options": {
                "memo_key": memo,
                "voting_account": voting_account["id"],
                "num_witness": 0,
                "num_committee": 0,
                "votes": [],
                "extensions": [],
            },
            "extensions": {},
            "prefix": self.prefix,
        }
        op = operations.Account_create(**op)
        return self.finalizeOp(op, registrar, "active", **kwargs)

    def upgrade_account(self, account=None, **kwargs):
        """
        Upgrade an account to Lifetime membership.

        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)
        op = operations.Account_upgrade(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account_to_upgrade": account["id"],
                "upgrade_to_lifetime_member": True,
                "prefix": self.prefix,
            }
        )
        return self.finalizeOp(op, account["name"], "active", **kwargs)

    def _test_weights_treshold(self, authority):
        """
        This method raises an error if the threshold of an authority cannot be reached
        by the weights.

        :param dict authority: An authority of an account
        :raises ValueError: if the threshold is set too high
        """
        weights = 0
        for a in authority["account_auths"]:
            weights += int(a[1])
        for a in authority["key_auths"]:
            weights += int(a[1])
        if authority["weight_threshold"] > weights:
            raise ValueError("Threshold too restrictive!")
        if authority["weight_threshold"] == 0:
            raise ValueError("Cannot have threshold of 0")

    def allow(
        self,
        foreign,
        weight=None,
        permission="active",
        account=None,
        threshold=None,
        **kwargs
    ):
        """
        Give additional access to an account by some other public key or account.

        :param str foreign: The foreign account that will obtain access
        :param int weight: (optional) The weight to use. If not
            define, the threshold will be used. If the weight is
            smaller than the threshold, additional signatures will
            be required. (defaults to threshold)
        :param str permission: (optional) The actual permission to
            modify (defaults to ``active``)
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        :param int threshold: The threshold that needs to be reached
            by signatures to be able to interact
        """
        from copy import deepcopy

        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")

        if permission not in ["owner", "active"]:
            raise ValueError("Permission needs to be either 'owner', or 'active")
        account = Account(account, blockchain_instance=self)

        if not weight:
            weight = account[permission]["weight_threshold"]

        authority = deepcopy(account[permission])
        try:
            pubkey = PublicKey(foreign, prefix=self.prefix)
            authority["key_auths"].append([str(pubkey), weight])
        except Exception:
            try:
                foreign_account = Account(foreign, blockchain_instance=self)
                authority["account_auths"].append([foreign_account["id"], weight])
            except Exception:
                raise ValueError("Unknown foreign account or invalid public key")
        if threshold:
            authority["weight_threshold"] = threshold
            self._test_weights_treshold(authority)

        op = operations.Account_update(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                permission: authority,
                "extensions": {},
                "prefix": self.prefix,
            }
        )
        if permission == "owner":
            return self.finalizeOp(op, account["name"], "owner", **kwargs)
        else:
            return self.finalizeOp(op, account["name"], "active", **kwargs)

    def disallow(
        self, foreign, permission="active", account=None, threshold=None, **kwargs
    ):
        """
        Remove additional access to an account by some other public key or account.

        :param str foreign: The foreign account that will obtain access
        :param str permission: (optional) The actual permission to
            modify (defaults to ``active``)
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        :param int threshold: The threshold that needs to be reached
            by signatures to be able to interact
        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")

        if permission not in ["owner", "active"]:
            raise ValueError("Permission needs to be either 'owner', or 'active")
        account = Account(account, blockchain_instance=self)
        authority = account[permission]

        try:
            pubkey = PublicKey(foreign, prefix=self.prefix)
            affected_items = list(
                filter(lambda x: x[0] == str(pubkey), authority["key_auths"])
            )
            authority["key_auths"] = list(
                filter(lambda x: x[0] != str(pubkey), authority["key_auths"])
            )
        except Exception:
            try:
                foreign_account = Account(foreign, blockchain_instance=self)
                affected_items = list(
                    filter(
                        lambda x: x[0] == foreign_account["id"],
                        authority["account_auths"],
                    )
                )
                authority["account_auths"] = list(
                    filter(
                        lambda x: x[0] != foreign_account["id"],
                        authority["account_auths"],
                    )
                )
            except Exception:
                raise ValueError("Unknown foreign account or unvalid public key")

        if not affected_items:
            raise ValueError("Changes nothing!")
        removed_weight = affected_items[0][1]

        # Define threshold
        if threshold:
            authority["weight_threshold"] = threshold

        # Correct threshold (at most by the amount removed from the
        # authority)
        try:
            self._test_weights_treshold(authority)
        except Exception:
            log.critical(
                "The account's threshold will be reduced by %d" % (removed_weight)
            )
            authority["weight_threshold"] -= removed_weight
            self._test_weights_treshold(authority)

        op = operations.Account_update(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                permission: authority,
                "extensions": {},
            }
        )
        if permission == "owner":
            return self.finalizeOp(op, account["name"], "owner", **kwargs)
        else:
            return self.finalizeOp(op, account["name"], "active", **kwargs)

    def update_memo_key(self, key, account=None, **kwargs):
        """
        Update an account's memo public key.

        This method does **not** add any private keys to your
        wallet but merely changes the memo public key.

        :param str key: New memo public key
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")

        PublicKey(key, prefix=self.prefix)

        account = Account(account, blockchain_instance=self)
        account["options"]["memo_key"] = key
        op = operations.Account_update(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                "new_options": account["options"],
                "extensions": {},
                "prefix": self.prefix,
            }
        )
        return self.finalizeOp(op, account["name"], "active", **kwargs)

    # -------------------------------------------------------------------------
    #  Approval and Disapproval of witnesses, workers, committee, and proposals
    # -------------------------------------------------------------------------
    def approvewitness(self, witnesses, account=None, **kwargs):
        """
        Approve a witness.

        :param list witnesses: list of Witness name or id
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)
        options = account["options"]

        if not isinstance(witnesses, (list, set, tuple)):
            witnesses = {witnesses}

        for witness in witnesses:
            witness = Witness(witness, blockchain_instance=self)
            options["votes"].append(witness["vote_id"])

        options["votes"] = list(set(options["votes"]))
        options["num_witness"] = len(
            list(filter(lambda x: float(x.split(":")[0]) == 1, options["votes"]))
        )
        options["voting_account"] = "1.2.5"  # Account("proxy-to-self")["id"]

        op = operations.Account_update(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                "new_options": options,
                "extensions": {},
                "prefix": self.prefix,
            }
        )
        return self.finalizeOp(op, account["name"], "active", **kwargs)

    def disapprovewitness(self, witnesses, account=None, **kwargs):
        """
        Disapprove a witness.

        :param list witnesses: list of Witness name or id
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)
        options = account["options"]

        if not isinstance(witnesses, (list, set, tuple)):
            witnesses = {witnesses}

        for witness in witnesses:
            witness = Witness(witness, blockchain_instance=self)
            if witness["vote_id"] in options["votes"]:
                options["votes"].remove(witness["vote_id"])

        options["votes"] = list(set(options["votes"]))
        options["num_witness"] = len(
            list(filter(lambda x: float(x.split(":")[0]) == 1, options["votes"]))
        )
        options["voting_account"] = "1.2.5"  # Account("proxy-to-self")["id"]

        op = operations.Account_update(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                "new_options": options,
                "extensions": {},
                "prefix": self.prefix,
            }
        )
        return self.finalizeOp(op, account["name"], "active", **kwargs)

    def approvecommittee(self, committees, account=None, **kwargs):
        """
        Approve a committee.

        :param list committees: list of committee member name or id
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)
        options = account["options"]

        if not isinstance(committees, (list, set, tuple)):
            committees = {committees}

        for committee in committees:
            committee = Committee(committee, blockchain_instance=self)
            options["votes"].append(committee["vote_id"])

        options["votes"] = list(set(options["votes"]))
        options["num_committee"] = len(
            list(filter(lambda x: float(x.split(":")[0]) == 0, options["votes"]))
        )
        options["voting_account"] = "1.2.5"  # Account("proxy-to-self")["id"]

        op = operations.Account_update(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                "new_options": options,
                "extensions": {},
                "prefix": self.prefix,
            }
        )
        return self.finalizeOp(op, account["name"], "active", **kwargs)

    def disapprovecommittee(self, committees, account=None, **kwargs):
        """
        Disapprove a committee.

        :param list committees: list of committee name or id
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)
        options = account["options"]

        if not isinstance(committees, (list, set, tuple)):
            committees = {committees}

        for committee in committees:
            committee = Committee(committee, blockchain_instance=self)
            if committee["vote_id"] in options["votes"]:
                options["votes"].remove(committee["vote_id"])

        options["votes"] = list(set(options["votes"]))
        options["num_committee"] = len(
            list(filter(lambda x: float(x.split(":")[0]) == 0, options["votes"]))
        )
        options["voting_account"] = "1.2.5"  # Account("proxy-to-self")["id"]

        op = operations.Account_update(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                "new_options": options,
                "extensions": {},
                "prefix": self.prefix,
            }
        )
        return self.finalizeOp(op, account["name"], "active", **kwargs)

    def approveproposal(self, proposal_ids, account=None, approver=None, **kwargs):
        """
        Approve Proposal.

        :param list proposal_id: Ids of the proposals
        :param str appprover: The account or key to use for approval
            (defaults to ``account``)
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        from .proposal import Proposal

        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)
        is_key = approver and approver[:3] == self.prefix
        if not approver and not is_key:
            approver = account
        elif approver and not is_key:
            approver = Account(approver, blockchain_instance=self)
        else:
            approver = PublicKey(approver)

        if not isinstance(proposal_ids, (list, set, tuple)):
            proposal_ids = {proposal_ids}

        op = []
        for proposal_id in proposal_ids:
            proposal = Proposal(proposal_id, blockchain_instance=self)
            update_dict = {
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "fee_paying_account": account["id"],
                "proposal": proposal["id"],
                "prefix": self.prefix,
            }
            if is_key:
                update_dict.update({"key_approvals_to_add": [str(approver)]})
            else:
                update_dict.update({"active_approvals_to_add": [approver["id"]]})
            op.append(operations.Proposal_update(**update_dict))
        if is_key:
            self.txbuffer.appendSigner(approver, "active")
            return self.finalizeOp(op, account["name"], "active", **kwargs)
        return self.finalizeOp(op, approver, "active", **kwargs)

    def disapproveproposal(self, proposal_ids, account=None, approver=None, **kwargs):
        """
        Disapprove Proposal.

        :param list proposal_ids: Ids of the proposals
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        from .proposal import Proposal

        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)
        if not approver:
            approver = account
        else:
            approver = Account(approver, blockchain_instance=self)

        if not isinstance(proposal_ids, (list, set, tuple)):
            proposal_ids = {proposal_ids}

        op = []
        for proposal_id in proposal_ids:
            proposal = Proposal(proposal_id, blockchain_instance=self)
            op.append(
                operations.Proposal_update(
                    **{
                        "fee": {"amount": 0, "asset_id": "1.3.0"},
                        "fee_paying_account": account["id"],
                        "proposal": proposal["id"],
                        "active_approvals_to_remove": [approver["id"]],
                        "prefix": self.prefix,
                    }
                )
            )
        return self.finalizeOp(op, account["name"], "active", **kwargs)

    def approveworker(self, workers, account=None, **kwargs):
        """
        Approve a worker.

        :param list workers: list of worker member name or id
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)
        options = account["options"]

        if not isinstance(workers, (list, set, tuple)):
            workers = {workers}

        for worker in workers:
            worker = Worker(worker, blockchain_instance=self)
            options["votes"].append(worker["vote_for"])
        options["votes"] = list(set(options["votes"]))
        options["voting_account"] = "1.2.5"  # Account("proxy-to-self")["id"]

        op = operations.Account_update(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                "new_options": options,
                "extensions": {},
                "prefix": self.prefix,
            }
        )
        return self.finalizeOp(op, account["name"], "active", **kwargs)

    def disapproveworker(self, workers, account=None, **kwargs):
        """
        Disapprove a worker.

        :param list workers: list of worker name or id
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)
        options = account["options"]

        if not isinstance(workers, (list, set, tuple)):
            workers = {workers}

        for worker in workers:
            worker = Worker(worker, blockchain_instance=self)
            if worker["vote_for"] in options["votes"]:
                options["votes"].remove(worker["vote_for"])
        options["votes"] = list(set(options["votes"]))
        options["voting_account"] = "1.2.5"  # Account("proxy-to-self")["id"]

        op = operations.Account_update(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                "new_options": options,
                "extensions": {},
                "prefix": self.prefix,
            }
        )
        return self.finalizeOp(op, account["name"], "active", **kwargs)

    def unset_proxy(self, account=None, **kwargs):
        """Unset the proxy account to start voting yourself."""
        return self.set_proxy("proxy-to-self", account=account, **kwargs)

    def set_proxy(self, proxy_account, account=None, **kwargs):
        """
        Set a specific proxy for account.

        :param bitshares.account.Account proxy_account: Account to be
                proxied
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)
        proxy = Account(proxy_account, blockchain_instance=self)
        options = account["options"]
        options["voting_account"] = proxy["id"]

        op = operations.Account_update(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                "new_options": options,
                "extensions": {},
                "prefix": self.prefix,
            }
        )
        return self.finalizeOp(op, account["name"], "active", **kwargs)

    def cancel(self, orderNumbers, account=None, **kwargs):
        """
        Cancels an order you have placed in a given market. Requires only the
        "orderNumbers". An order number takes the form ``1.7.xxx``.

        :param str orderNumbers: The Order Object ide of the form
            ``1.7.xxxx``
        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, full=False, blockchain_instance=self)

        if not isinstance(orderNumbers, (list, set, tuple)):
            orderNumbers = {orderNumbers}

        op = []
        for order in orderNumbers:
            op.append(
                operations.Limit_order_cancel(
                    **{
                        "fee": {"amount": 0, "asset_id": "1.3.0"},
                        "fee_paying_account": account["id"],
                        "order": order,
                        "extensions": [],
                        "prefix": self.prefix,
                    }
                )
            )
        return self.finalizeOp(op, account["name"], "active", **kwargs)

    def vesting_balance_withdraw(self, vesting_id, amount=None, account=None, **kwargs):
        """
        Withdraw vesting balance.

        :param str vesting_id: Id of the vesting object
        :param bitshares.amount.Amount Amount: to withdraw ("all" if not
            provided")
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)

        if not amount:
            obj = Vesting(vesting_id, blockchain_instance=self)
            amount = obj.claimable

        op = operations.Vesting_balance_withdraw(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "vesting_balance": vesting_id,
                "owner": account["id"],
                "amount": {"amount": int(amount), "asset_id": amount["asset"]["id"]},
                "prefix": self.prefix,
            }
        )
        return self.finalizeOp(op, account["name"], "active")

    def publish_price_feed(
        self, symbol, settlement_price, cer=None, mssr=110, mcr=200, account=None
    ):
        """
        Publish a price feed for a market-pegged asset.

        :param str symbol: Symbol of the asset to publish feed for
        :param bitshares.price.Price settlement_price: Price for settlement
        :param bitshares.price.Price cer: Core exchange Rate (default
            ``settlement_price + 5%``)
        :param float mssr: Percentage for max short squeeze ratio (default:
            110%)
        :param float mcr: Percentage for maintenance collateral ratio
            (default: 200%)
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)

        .. note:: The ``account`` needs to be allowed to produce a
                  price feed for ``symbol``. For witness produced
                  feeds this means ``account`` is a witness account!
        """
        assert mcr > 100
        assert mssr > 100
        assert isinstance(
            settlement_price, Price
        ), "settlement_price needs to be instance of `bitshares.price.Price`!"
        assert cer is None or isinstance(
            cer, Price
        ), "cer needs to be instance of `bitshares.price.Price`!"
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)
        asset = Asset(symbol, blockchain_instance=self, full=True)
        backing_asset = asset["bitasset_data"]["options"]["short_backing_asset"]
        assert (
            asset["id"] == settlement_price["base"]["asset"]["id"]
            or asset["id"] == settlement_price["quote"]["asset"]["id"]
        ), "Price needs to contain the asset of the symbol you'd like to produce a feed for!"
        assert asset.is_bitasset, "Symbol needs to be a bitasset!"
        assert (
            settlement_price["base"]["asset"]["id"] == backing_asset
            or settlement_price["quote"]["asset"]["id"] == backing_asset
        ), "The Price needs to be relative to the backing collateral!"

        settlement_price = settlement_price.as_base(symbol)

        if cer:
            cer = cer.as_base(symbol)
            if cer["quote"]["asset"]["id"] != "1.3.0":
                raise ValueError("CER must be defined against core asset '1.3.0'")
        else:
            if settlement_price["quote"]["asset"]["id"] != "1.3.0":
                raise ValueError(
                    "CER must be manually provided because it relates to core asset '1.3.0'"
                )
            cer = settlement_price.as_quote(symbol) * 0.95

        op = operations.Asset_publish_feed(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "publisher": account["id"],
                "asset_id": asset["id"],
                "feed": {
                    "settlement_price": settlement_price.as_base(symbol).json(),
                    "core_exchange_rate": cer.as_base(symbol).json(),
                    "maximum_short_squeeze_ratio": int(mssr * 10),
                    "maintenance_collateral_ratio": int(mcr * 10),
                },
                "prefix": self.prefix,
            }
        )
        return self.finalizeOp(op, account["name"], "active")

    def update_cer(self, symbol, cer, account=None):
        """
        Update the Core Exchange Rate (CER) of an asset.

        :param str symbol: Symbol of the asset to publish feed for
        :param bitshares.price.Price cer: Core exchange Rate
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        assert isinstance(
            cer, Price
        ), "cer needs to be instance of `bitshares.price.Price`!"
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)
        asset = Asset(symbol, blockchain_instance=self, full=True)
        assert (
            asset["id"] == cer["base"]["asset"]["id"]
            or asset["id"] == cer["quote"]["asset"]["id"]
        ), "Price needs to contain the asset of the symbol you'd like to produce a feed for!"

        cer = cer.as_base(symbol)
        if cer["quote"]["asset"]["id"] != "1.3.0":
            raise ValueError("CER must be defined against core asset '1.3.0'")

        options = asset["options"]
        options.update({"core_exchange_rate": cer.as_base(symbol).json()})
        op = operations.Asset_update(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "issuer": account["id"],
                "asset_to_update": asset["id"],
                "new_options": options,
                "extensions": [],
                "prefix": self.prefix,
            }
        )
        return self.finalizeOp(op, account["name"], "active")

    def update_witness(self, witness_identifier, url=None, key=None, **kwargs):
        """
        Upgrade a witness account.

        :param str witness_identifier: Identifier for the witness
        :param str url: New URL for the witness
        :param str key: Public Key for the signing
        """
        witness = Witness(witness_identifier)
        account = witness.account
        op = operations.Witness_update(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "prefix": self.prefix,
                "witness": witness["id"],
                "witness_account": account["id"],
                "new_url": url,
                "new_signing_key": key,
            }
        )
        return self.finalizeOp(op, account["name"], "active", **kwargs)

    def reserve(self, amount, account=None, **kwargs):
        """
        Reserve/Burn an amount of this shares.

        This removes the shares from the supply

        :param bitshares.amount.Amount amount: The amount to be burned.
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        assert isinstance(amount, Amount)
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)
        op = operations.Asset_reserve(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "payer": account["id"],
                "amount_to_reserve": {
                    "amount": int(amount),
                    "asset_id": amount["asset"]["id"],
                },
                "extensions": [],
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)

    def create_asset(
        self,
        symbol,
        precision,
        max_supply,
        description="",
        is_bitasset=False,
        is_prediction_market=False,
        market_fee_percent=0,
        max_market_fee=None,
        permissions=None,
        flags=None,
        whitelist_authorities=None,
        blacklist_authorities=None,
        whitelist_markets=None,
        blacklist_markets=None,
        bitasset_options=None,
        account=None,
        **kwargs
    ):
        """
        Create a new asset.

        :param str symbol: Asset symbol
        :param int precision: Asset precision
        :param int max_supply: Asset max supply
        :param str description: (optional) Asset description
        :param bool is_bitasset: (optional) True = bitasset, False = UIA (default:
            False)
        :param bool is_prediction_market: (optional) True: PD, False = plain
            smartcoin (default: False)
        :param float market_fee_percent: (optional) Charge market fee (0-100)
            (default: 0)
        :param float max_market_fee: (optional) Absolute amount of max
            market fee, value of this option should be a whole number (default:
            same as max_supply)
        :param dict permissions: (optional) Asset permissions
        :param dict flags: (optional) Enabled asset flags
        :param list whitelist_authorities: (optional) List of accounts that
            serve as whitelist authorities
        :param list blacklist_authorities: (optional) List of accounts that
            serve as blacklist authorities
        :param list whitelist_markets: (optional) List of assets to allow
            trading with
        :param list blacklist_markets: (optional) List of assets to prevent
            trading with
        :param dict bitasset_options: (optional) Bitasset settings
        :param str account: (optional) the issuer account
            to (defaults to ``default_account``)
        """

        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)

        if permissions is None:
            permissions = {
                "charge_market_fee": True,
                "white_list": True,
                "override_authority": True,
                "transfer_restricted": True,
                "disable_force_settle": True,
                "global_settle": True,
                "disable_confidential": True,
                "witness_fed_asset": True,
                "committee_fed_asset": True,
            }
        if flags is None:
            flags = {
                "charge_market_fee": False,
                "white_list": False,
                "override_authority": False,
                "transfer_restricted": False,
                "disable_force_settle": False,
                "global_settle": False,
                "disable_confidential": False,
                "witness_fed_asset": False,
                "committee_fed_asset": False,
            }
        if whitelist_authorities is None:
            whitelist_authorities = []
        if blacklist_authorities is None:
            blacklist_authorities = []
        if whitelist_markets is None:
            whitelist_markets = []
        if blacklist_markets is None:
            blacklist_markets = []
        if bitasset_options is None:
            bitasset_options = {
                "feed_lifetime_sec": 86400,
                "minimum_feeds": 7,
                "force_settlement_delay_sec": 86400,
                "force_settlement_offset_percent": 100,
                "maximum_force_settlement_volume": 50,
                "short_backing_asset": "1.3.0",
                "extensions": [],
            }

        if not is_bitasset:
            # Turn off bitasset-specific options
            permissions["disable_force_settle"] = False
            permissions["global_settle"] = False
            permissions["witness_fed_asset"] = False
            permissions["committee_fed_asset"] = False
            bitasset_options = None

        assert set(permissions.keys()).issubset(
            asset_permissions.keys()
        ), "unknown permission"
        assert set(flags.keys()).issubset(asset_permissions.keys()), "unknown flag"
        # Transform permissions and flags into bitmask
        permissions_int = toint(permissions)
        flags_int = toint(flags)

        if not max_market_fee:
            max_market_fee = max_supply

        op = operations.Asset_create(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "issuer": account["id"],
                "symbol": symbol,
                "precision": precision,
                "common_options": {
                    "max_supply": int(max_supply * 10 ** precision),
                    "market_fee_percent": int(market_fee_percent * 100),
                    "max_market_fee": int(max_market_fee * 10 ** precision),
                    "issuer_permissions": permissions_int,
                    "flags": flags_int,
                    "core_exchange_rate": {
                        "base": {"amount": 1, "asset_id": "1.3.0"},
                        "quote": {"amount": 1, "asset_id": "1.3.1"},
                    },
                    "whitelist_authorities": [
                        Account(a, blockchain_instance=self)["id"]
                        for a in whitelist_authorities
                    ],
                    "blacklist_authorities": [
                        Account(a, blockchain_instance=self)["id"]
                        for a in blacklist_authorities
                    ],
                    "whitelist_markets": [
                        Asset(a, blockchain_instance=self)["id"]
                        for a in whitelist_markets
                    ],
                    "blacklist_markets": [
                        Asset(a, blockchain_instance=self)["id"]
                        for a in blacklist_markets
                    ],
                    "description": description,
                    "extensions": [],
                },
                "bitasset_opts": bitasset_options,
                "is_prediction_market": is_prediction_market,
                "extensions": [],
            }
        )

        return self.finalizeOp(op, account, "active", **kwargs)

    def create_worker(
        self,
        name,
        daily_pay,
        end,
        url="",
        begin=None,
        payment_type="vesting",
        pay_vesting_period_days=0,
        account=None,
        **kwargs
    ):
        """
        Create a worker.

        This removes the shares from the supply

        **Required**

        :param str name: Name of the worke
        :param bitshares.amount.Amount daily_pay: The amount to be paid
            daily
        :param datetime end: Date/time of end of the worker

        **Optional**

        :param str url: URL to read more about the worker
        :param datetime begin: Date/time of begin of the worker
        :param string payment_type: ["burn", "refund", "vesting"] (default:
            "vesting")
        :param int pay_vesting_period_days: Days of vesting (default: 0)
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        from bitsharesbase.transactions import timeformat

        assert isinstance(daily_pay, Amount)
        assert daily_pay["asset"]["id"] == "1.3.0"
        if not begin:
            begin = datetime.utcnow() + timedelta(seconds=30)
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)

        if payment_type == "refund":
            initializer = [0, {}]
        elif payment_type == "vesting":
            initializer = [1, {"pay_vesting_period_days": pay_vesting_period_days}]
        elif payment_type == "burn":
            initializer = [2, {}]
        else:
            raise ValueError('payment_type not in ["burn", "refund", "vesting"]')

        op = operations.Worker_create(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "owner": account["id"],
                "work_begin_date": begin.strftime(timeformat),
                "work_end_date": end.strftime(timeformat),
                "daily_pay": int(daily_pay),
                "name": name,
                "url": url,
                "initializer": initializer,
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)

    def fund_fee_pool(self, symbol, amount, account=None, **kwargs):
        """
        Fund the fee pool of an asset.

        :param str symbol: The symbol to fund the fee pool of
        :param float amount: The amount to be burned.
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        assert isinstance(amount, float)
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        amount = Amount(amount, "1.3.0", blockchain_instance=self)
        account = Account(account, blockchain_instance=self)
        asset = Asset(symbol, blockchain_instance=self)
        op = operations.Asset_fund_fee_pool(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "from_account": account["id"],
                "asset_id": asset["id"],
                "amount": int(amount),
                "extensions": [],
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)

    def create_committee_member(self, url="", account=None, **kwargs):
        """
        Create a committee member.

        :param str url: URL to read more about the worker
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)

        op = operations.Committee_member_create(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "committee_member_account": account["id"],
                "url": url,
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)

    def account_whitelist(
        self,
        account_to_whitelist,
        lists=None,  # set of ['white'] and/or ['black']
        account=None,
        **kwargs
    ):
        """
        Account whitelisting.

        :param str account_to_whitelist: The account we want to add
            to either the white- or the blacklist
        :param set lists: (defaults to ``('white')``). Lists the
            user should be added to. Either empty set, 'black',
            'white' or both.
        :param str account: (optional) the account to allow access
            to (defaults to ``default_account``)
        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)
        account_to_list = Account(account_to_whitelist, blockchain_instance=self)

        if lists is None:
            lists = ["white"]

        if not isinstance(lists, (set, list)):
            raise ValueError('"lists" must be of instance list()')

        new_listing = operations.Account_whitelist.no_listing
        if "white" in lists:
            new_listing += operations.Account_whitelist.white_listed
        if "black" in lists:
            new_listing += operations.Account_whitelist.black_listed

        op = operations.Account_whitelist(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "authorizing_account": account["id"],
                "account_to_list": account_to_list["id"],
                "new_listing": new_listing,
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)

    def bid_collateral(
        self, additional_collateral, debt_covered, account=None, **kwargs
    ):
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)

        if not isinstance(additional_collateral, (Amount)):
            raise ValueError("additional_collateral must be of type Amount")

        if not isinstance(debt_covered, (Amount)):
            raise ValueError("debt_covered must be of type Amount")

        op = operations.Bid_collateral(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "bidder": account["id"],
                "additional_collateral": additional_collateral.json(),
                "debt_covered": debt_covered.json(),
                "extensions": [],
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)

    def asset_settle(self, amount, account=None, **kwargs):
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)

        if not isinstance(amount, (Amount)):
            raise ValueError("'amount' must be of type Amount")

        op = operations.Asset_settle(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                "amount": amount.json(),
                "extensions": [],
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)

    def htlc_create(
        self,
        amount,
        to,
        *args, # force remaining args to be named not positional
        hash_type=None,
        hash_hex=None,
        expiration=60 * 60,
        preimage=None,
        preimage_length=0,
        account=None,
        **kwargs
    ):
        """Create an HTLC contract.

        :param Amount amount: Amount to lock
        :param str to: Recipient
        :param int expiration: Contract duration in seconds
        :param str hash_hex: Hash as string of hex digits
        :param str preimage: Preimage as ascii string. Note hex digits would be
            interpretted as ascii text, not as bytes. Not generally recommended
            to use this option. Options hash_hex and preimage are mutually
            exclusive.
        :param int preimage_length: If non-zero, htlc contract will require
            preimage of exact length. Generally OK to leave this as zero. Note
            if preimage param is provided, this value SHOULD be either zero or
            match exactly the length of the preimage, else an irredeemable htlc
            will be created. Optionally, a sentinal value of -1 can be used to
            compute length automatically from the preimage param.
        """
        import hashlib
        from binascii import hexlify
        from graphenebase.base58 import ripemd160

        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)
        to = Account(to, blockchain_instance=self)

        if not isinstance(amount, (Amount)):
            raise ValueError("'amount' must be of type Amount")

        if preimage is not None and hash_hex is not None:
            raise ValueError("Must provide either a hash or a preimage, but not both")

        if hash_type == "ripemd160":
            preimage_type = 0
        elif hash_type == "sha1":
            preimage_type = 1
        elif hash_type == "sha256":
            preimage_type = 2
        elif hash_type == "hash160":
            preimage_type = 3
        else:
            raise ValueError(
                "Unknown 'hash_type'. Must be 'sha1', 'sha256', 'ripemd160', 'hash160'"
            )

        if preimage is not None:
            preimage_size = len(preimage) if preimage_length == -1 else preimage_length
            if hash_type == "ripemd160":
                preimage_hash = hexlify(
                    ripemd160(hexlify(bytes(preimage, "utf-8")))
                ).decode("ascii")
            elif hash_type == "sha1":
                preimage_hash = hashlib.sha1(bytes(preimage, "utf-8")).hexdigest()
            elif hash_type == "sha256":
                preimage_hash = hashlib.sha256(bytes(preimage, "utf-8")).hexdigest()
            elif hash_type == "hash160":
                preimage_hash = hexlify(ripemd160(
                        hashlib.sha256(bytes(preimage, "utf-8")).hexdigest()
                )).decode("ascii")
        elif hash_hex is not None:
            preimage_hash = hexlify(bytes.fromhex(hash_hex)).decode("ascii")
            preimage_size = preimage_length
        else:
            raise ValueError("Must provide either a hash or a preimage")

        op = operations.Htlc_create(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "from": account["id"],
                "to": to["id"],
                "amount": amount.json(),
                "preimage_hash": [preimage_type, preimage_hash],
                "preimage_size": preimage_size,
                "claim_period_seconds": expiration,
                "extensions": [],
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)


    def htlc_redeem(self, htlc_id, preimage, encoding="utf-8", account=None, **kwargs):
        """Redeem an htlc contract

        :param str preimage: The preimage that unlocks the htlc
        :param str encoding: "utf-8", ..., or "hex"
        """
        from binascii import hexlify

        htlc = Htlc(htlc_id, blockchain_instance=self)
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            account = htlc["to"]
        account = Account(account, blockchain_instance=self)

        if encoding=="hex":
            preimage_hex = hexlify(bytes.fromhex(preimage)).decode("ascii")
        else:
            preimage_hex = hexlify(bytes(preimage, encoding)).decode("ascii")

        op = operations.Htlc_redeem(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "redeemer": account["id"],
                "preimage": preimage_hex,
                "htlc_id": htlc["id"],
                "extensions": [],
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)


    def create_voting_ticket(self, target_type, amount_to_lock, account=None, **kwargs):
        """ Create a voting ticket

        :param int,str target_type: Lock period target. Should be a string from
                    operations.ticket_type_strings or the index of the intended
                    string.

        :param Amount amount_to_lock: Amount to lock up for the duration
                    selected in target_type.
        """

        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)

        if not isinstance(amount_to_lock, (Amount)):
            raise ValueError("'amount_to_lock' must be of type Amount")

        op = operations.Ticket_create_operation(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                "target_type": target_type,
                "amount": amount_to_lock.json(),
                "extensions": [],
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)


    def update_voting_ticket(self, ticket_id, new_target_type, amount_to_update,
                             account=None, **kwargs):
        """Update a voting ticket

        :param str ticket_id: Id (e.g. "1.18.xxx") of the ticket to update.

        :param int,str target_type: New lock period target. Should be a string
                    from operations.ticket_type_strings or the index of the
                    intended string.

        :param Amount,None amount_to_update: Amount to move over to the new
                    lock-up target. (Optional - absence implies update whole
                    amount.)
        """

        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)

        if isinstance(amount_to_update, (Amount)):
            amount_to_update = amount_to_update.json()
        elif amount_to_update is not None:
            raise ValueError("'amount_to_update' must be of type Amount or None")
        else:
            pass # None is a valid value for optional field

        op = operations.Ticket_update_operation(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "ticket": ticket_id,
                "account": account["id"],
                "target_type": new_target_type,
                "amount_for_new_target": amount_to_update,
                "extensions": [],
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)


    def create_liquidity_pool(self, asset_a, asset_b, share_asset,
                              taker_fee_percent, withdrawal_fee_percent,
                              account=None, **kwargs):
        """Create a liquidity pool

        :param str asset_a:  First asset in the pool pair.
        :param str asset_b:  Second asset in the pool pair.
        :param str share_asset:  The asset which represents shares in the pool.

        For asset parameters, these can be either symbols or asset_id
        strings. Note that network expects asset_a to have a lower-numbered
        asset_id than asset_b.

        :param float taker_fee_percent: The pool's taker fee percentage.
        :param float withdrawal_fee_percent: The pool's withdrawal fee percent.

        For percentages, meaningful range is [0.00, 100.00], where 1% is
        represented as 1.0.  Smallest non-zero value recognized by BitShares
        chain is 0.01 for 0.01%.

        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)

        asset_a = Asset(asset_a)["id"]
        asset_b = Asset(asset_b)["id"]
        share_asset = Asset(share_asset)["id"]

        if not (taker_fee_percent >=0 and taker_fee_percent <= 100):
            raise ValueError("Percentages must be in range [0.00, 100.00].")
        if not (withdrawal_fee_percent >=0 and withdrawal_fee_percent <= 100):
            raise ValueError("Percentages must be in range [0.00, 100.00].")
        graphene_1_percent = 100
        taker_fee_percent = int(taker_fee_percent * graphene_1_percent)
        withdrawal_fee_percent = int(withdrawal_fee_percent * graphene_1_percent)

        op = operations.Liquidity_pool_create(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                "asset_a": asset_a,
                "asset_b": asset_b,
                "share_asset": share_asset,
                "taker_fee_percent": taker_fee_percent,
                "withdrawal_fee_percent": withdrawal_fee_percent,
                "extensions": [],
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)


    def _find_liquidity_pool(self, pool):
        # Ad-hoc helper for the liquidity pool verbs. It locates a pool id
        # irrespective of whether 'pool' is already a pool id, or perhaps an
        # asset or asset_id of a share asset for a pool.  The approach is
        # ad-hoc.  Would be better if there was a Pool class to represent pool
        # objects like there is an Asset class to represent asset objects.
        # Then locating a pool could happen in the initialization of the Pool
        # object given either an id or asset/symbol. TBD someday.
        if isinstance(pool, str) and pool.startswith("1.19."):
            pool_id = pool
        else:
            try:
                pool_asset = Asset(pool, blockchain_instance=self)
            except:
                raise ValueError("'pool' is neither a pool id nor share asset.")
            if "for_liquidity_pool" in pool_asset:
                pool_id = pool_asset["for_liquidity_pool"]
            else:
                raise ValueError("Asset is not a share asset for a pool.")
        return pool_id


    def delete_liquidity_pool(self, pool, account=None, **kwargs):
        """Delete a liquidity pool

        :param str,Asset pool: The liquidity pool to delete. Can be the pool id
                as a string, or can be an Asset, asset_id, or symbol of the
                share asset for the pool.

        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)

        pool_id = self._find_liquidity_pool(pool)

        op = operations.Liquidity_pool_delete(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                "pool": pool_id,
                "extensions": [],
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)


    def deposit_into_liquidity_pool(self, pool, amount_a, amount_b, account=None, **kwargs):
        """Deposit assets into a liquidity pool

        :param str,Asset pool: The liquidity pool to use. Can be the pool id
                as a string, or can be an Asset, asset_id, or symbol of the
                share asset for the pool.

        :param Amount amount_a:
        :param Amount amount_b:

        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)

        pool_id = self._find_liquidity_pool(pool)

        num_id_a = int(amount_a.asset["id"].split(".")[-1])
        num_id_b = int(amount_b.asset["id"].split(".")[-1])
        if(num_id_b < num_id_a):
            amount_a, amount_b = amount_b, amount_a

        op = operations.Liquidity_pool_deposit(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                "pool": pool_id,
                "amount_a": amount_a.json(),
                "amount_b": amount_b.json(),
                "extensions": [],
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)


    def withdraw_from_liquidity_pool(self, pool, share_amount, account=None, **kwargs):
        """Withdraw stake from a liquidity pool

        :param str,Asset pool: The liquidity pool to use. Can be the pool id
                as a string, or can be an Asset, asset_id, or symbol of the
                share asset for the pool.

        :param Amount share_amount: Amount of share asset to redeem. Must be a
                quantity of the pool's share_asset.

        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)

        pool_id = self._find_liquidity_pool(pool)

        op = operations.Liquidity_pool_withdraw(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                "pool": pool_id,
                "share_amount": share_amount.json(),
                "extensions": [],
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)


    def exchange_with_liquidity_pool(self, pool, amount_to_sell, min_to_receive, account=None, **kwargs):
        """Exchange assets against a liquidity pool

        :param str,Asset pool: The liquidity pool to use. Can be the pool id
                as a string, or can be an Asset, asset_id, or symbol of the
                share asset for the pool.

        :param Amount amount_to_sell:
        :param Amount min_to_receive:

        """
        if not account:
            if "default_account" in self.config:
                account = self.config["default_account"]
        if not account:
            raise ValueError("You need to provide an account")
        account = Account(account, blockchain_instance=self)

        pool_id = self._find_liquidity_pool(pool)

        op = operations.Liquidity_pool_exchange(
            **{
                "fee": {"amount": 0, "asset_id": "1.3.0"},
                "account": account["id"],
                "pool": pool_id,
                "amount_to_sell": amount_to_sell.json(),
                "min_to_receive": min_to_receive.json(),
                "extensions": [],
            }
        )
        return self.finalizeOp(op, account, "active", **kwargs)