utils.py

# coding=utf-8
from __future__ import absolute_import, division, print_function, \
    unicode_literals

from typing import Generator, Iterable, List, Optional, Tuple

from iota import Address
from iota.adapter import BaseAdapter
from iota.commands.core.find_transactions import FindTransactionsCommand
from iota.commands.core.get_trytes import GetTrytesCommand
from iota.commands.extended.get_bundles import GetBundlesCommand
from iota.commands.extended.get_latest_inclusion import \
    GetLatestInclusionCommand
from iota.crypto.addresses import AddressGenerator
from iota.crypto.types import Seed
from iota.transaction.base import Bundle, Transaction
from iota.transaction.types import TransactionHash


def find_transaction_objects(adapter, **kwargs):
    # type: (BaseAdapter, **Iterable) -> List[Transaction]
    """
    Finds transactions matching the specified criteria, fetches the
    corresponding trytes and converts them into Transaction objects.
    """
    ft_response = FindTransactionsCommand(adapter)(**kwargs)

    hashes = ft_response['hashes']

    if hashes:
        gt_response = GetTrytesCommand(adapter)(hashes=hashes)

        return list(map(
            Transaction.from_tryte_string,
            gt_response.get('trytes') or [],
        ))  # type: List[Transaction]

    return []


def iter_used_addresses(
        adapter,  # type: BaseAdapter
        seed,  # type: Seed
        start,  # type: int
        security_level=None,  # type: Optional[int]
):
    # type: (...) -> Generator[Tuple[Address, List[TransactionHash]], None, None]
    """
    Scans the Tangle for used addresses.

    This is basically the opposite of invoking ``getNewAddresses`` with
    ``stop=None``.
    """
    if security_level is None:
        security_level = AddressGenerator.DEFAULT_SECURITY_LEVEL

    ft_command = FindTransactionsCommand(adapter)

    for addy in AddressGenerator(seed, security_level).create_iterator(start):
        ft_response = ft_command(addresses=[addy])

        if ft_response['hashes']:
            yield addy, ft_response['hashes']
        else:
            break

        # Reset the command so that we can call it again.
        ft_command.reset()


def get_bundles_from_transaction_hashes(
        adapter,
        transaction_hashes,
        inclusion_states,
):
    # type: (BaseAdapter, Iterable[TransactionHash], bool) -> List[Bundle]
    """
    Given a set of transaction hashes, returns the corresponding bundles,
    sorted by tail transaction timestamp.
    """
    transaction_hashes = list(transaction_hashes)
    if not transaction_hashes:
        return []

    my_bundles = []  # type: List[Bundle]

    # Sort transactions into tail and non-tail.
    tail_transaction_hashes = set()
    non_tail_bundle_hashes = set()

    gt_response = GetTrytesCommand(adapter)(hashes=transaction_hashes)
    all_transactions = list(map(
        Transaction.from_tryte_string,
        gt_response['trytes'],
    ))  # type: List[Transaction]

    for txn in all_transactions:
        if txn.is_tail:
            tail_transaction_hashes.add(txn.hash)
        else:
            # Capture the bundle ID instead of the transaction hash so
            # that we can query the node to find the tail transaction
            # for that bundle.
            non_tail_bundle_hashes.add(txn.bundle_hash)

    if non_tail_bundle_hashes:
        for txn in find_transaction_objects(
                adapter=adapter,
                bundles=list(non_tail_bundle_hashes),
        ):
            if txn.is_tail:
                if txn.hash not in tail_transaction_hashes:
                    all_transactions.append(txn)
                    tail_transaction_hashes.add(txn.hash)

    # Filter out all non-tail transactions.
    tail_transactions = [
        txn
        for txn in all_transactions
        if txn.hash in tail_transaction_hashes
    ]

    # Attach inclusion states, if requested.
    if inclusion_states:
        gli_response = GetLatestInclusionCommand(adapter)(
            hashes=list(tail_transaction_hashes),
        )

        for txn in tail_transactions:
            txn.is_confirmed = gli_response['states'].get(txn.hash)

    # Find the bundles for each transaction.
    for txn in tail_transactions:
        gb_response = GetBundlesCommand(adapter)(transaction=txn.hash)
        txn_bundles = gb_response['bundles']  # type: List[Bundle]

        if inclusion_states:
            for bundle in txn_bundles:
                bundle.is_confirmed = txn.is_confirmed

        my_bundles.extend(txn_bundles)

    return list(sorted(
        my_bundles,
        key=lambda bundle_: bundle_.tail_transaction.timestamp,
    ))