hasher-matcher-actioner/hmalib/banks/bank_operations.py

# Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved

"""
Defines the "Banks" API. What operations can be done on a bank?

Coordinates common operations. Conceptually midway between the API and the DB
Layer. 
"""
import typing as t
import json

from mypy_boto3_sqs.client import SQSClient

from threatexchange.content_type.content_base import ContentType
from threatexchange.signal_type.signal_base import SignalType

from hmalib.lambdas.api.submit import create_presigned_url
from hmalib.common.models import content
from hmalib.common.messages.bank import BankSubmissionMessage
from hmalib.common.models.bank import BankMember, BankMemberSignal, BanksTable


def add_bank_member(
    banks_table: BanksTable,
    sqs_client: SQSClient,
    submissions_queue_url: str,
    bank_id: str,
    content_type: t.Type[ContentType],
    storage_bucket: t.Optional[str],
    storage_key: t.Optional[str],
    raw_content: t.Optional[str],
    notes: str,
    bank_member_tags: t.Set[str],
) -> BankMember:
    """
    Write bank-member to database. Send a message to hashing lambda to extract signals.
    """
    member = banks_table.add_bank_member(
        bank_id=bank_id,
        content_type=content_type,
        storage_bucket=storage_bucket,
        storage_key=storage_key,
        raw_content=raw_content,
        notes=notes,
        bank_member_tags=bank_member_tags,
    )

    submission_message = BankSubmissionMessage(
        content_type=content_type,
        url=create_presigned_url(storage_bucket, storage_key, None, 3600, "get_object"),
        bank_id=bank_id,
        bank_member_id=member.bank_member_id,
    )
    sqs_client.send_message(
        QueueUrl=submissions_queue_url,
        MessageBody=json.dumps(submission_message.to_sqs_message()),
    )

    return member


def remove_bank_member(
    banks_table: BanksTable,
    bank_member_id: str,
):
    """
    Remove bank member. Marks the member as removed and all its signals are
    removed from the GSI used to build HMA indexes.

    NOTE: If we ever start incremental updates to HMA indexes, removing bank
    members will stop working.
    """
    banks_table.remove_bank_member_signals_to_process(bank_member_id=bank_member_id)
    banks_table.remove_bank_member(bank_member_id=bank_member_id)


def add_bank_member_signal(
    banks_table: BanksTable,
    bank_id: str,
    bank_member_id: str,
    signal_type: t.Type[SignalType],
    signal_value: str,
) -> BankMemberSignal:
    """
    Add a bank member signal. Will deduplicate a signal_value + signal_type
    tuple before writing to the database.

    Calling this API also makes the signal (new or existing) available to
    process into matching indices.
    """
    return banks_table.add_bank_member_signal(
        bank_id=bank_id,
        bank_member_id=bank_member_id,
        signal_type=signal_type,
        signal_value=signal_value,
    )


def add_detached_bank_member_signal(
    banks_table: BanksTable,
    bank_id: str,
    content_type: t.Type[ContentType],
    signal_type: t.Type[SignalType],
    signal_value: str,
) -> BankMemberSignal:
    """
    Add a bank member signal without a BankMember. Will deduplicate a
    signal_value + signal_type tuple before writing to the database.

    Will make signals available for processing into indices.
    """
    return banks_table.add_detached_bank_member_signal(
        bank_id=bank_id,
        content_type=content_type,
        signal_type=signal_type,
        signal_value=signal_value,
    )


"""
Represents a single detached signal being added to a bank. Container
ContentType, SignalType and the signal value.
"""


class Signal(t.NamedTuple):
    content_type: t.Type[ContentType]
    signal_type: t.Type[SignalType]
    signal_value: str


def add_detached_bank_member_signal_batch(
    banks_table: BanksTable,
    bank_id: str,
    signals: t.Iterable[Signal],
) -> t.Iterable[BankMemberSignal]:
    """
    Dump multiple detached signals into a bank. Check
    add_detached_bank_member_signal for more details.

    TODO: At this point, is dumb. Does not actually batch the requests, instead
    loops through signals and calls single APIs.
    """
    return list(
        map(
            lambda signal: banks_table.add_detached_bank_member_signal(
                bank_id=bank_id,
                content_type=signal.content_type,
                signal_type=signal.signal_type,
                signal_value=signal.signal_value,
            ),
            signals,
        )
    )