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

import bottle
import typing as t
from dataclasses import dataclass, asdict
from mypy_boto3_dynamodb.service_resource import Table

from hmalib import metrics
from hmalib.aws_secrets import AWSSecrets
from hmalib.common.config import HMAConfig
from hmalib.common import config as hmaconfig
from hmalib.common.s3_adapters import ThreatExchangeS3PDQAdapter, S3ThreatDataConfig
from hmalib.common.configs.fetcher import (
    ThreatExchangeConfig,
    AdditionalMatchSettingsConfig,
)
from hmalib.common.threatexchange_config import (
    create_privacy_group_if_not_exists,
    sync_privacy_groups,
    try_api_token,
)

from hmalib.lambdas.api.middleware import (
    jsoninator,
    JSONifiable,
    DictParseable,
    SubApp,
)


@dataclass
class Dataset(JSONifiable):
    privacy_group_id: t.Union[int, str]
    privacy_group_name: str
    description: str
    fetcher_active: bool
    matcher_active: bool
    write_back: bool
    in_use: bool

    def to_json(self) -> t.Dict:
        return asdict(self)

    @classmethod
    def from_dict(cls, d: dict) -> "Dataset":
        return cls(
            d["privacy_group_id"],
            d["privacy_group_name"],
            d["description"],
            d["fetcher_active"],
            d["matcher_active"],
            d["write_back"],
            d["in_use"],
        )

    @classmethod
    def from_collab(cls, collab: ThreatExchangeConfig) -> "Dataset":
        return cls(
            collab.privacy_group_id,
            collab.privacy_group_name,
            collab.description,
            collab.fetcher_active,
            collab.matcher_active,
            collab.write_back,
            collab.in_use,
        )


@dataclass
class SyncDatasetResponse(JSONifiable):
    response: str

    def to_json(self) -> t.Dict:
        return asdict(self)


@dataclass
class DeleteDatasetResponse(JSONifiable):
    response: str

    def to_json(self) -> t.Dict:
        return asdict(self)


@dataclass
class UpdateDatasetRequest(DictParseable):
    privacy_group_id: t.Union[int, str]
    fetcher_active: bool
    matcher_active: bool
    write_back: bool
    pdq_match_threshold: str

    @classmethod
    def from_dict(cls, d: dict) -> "UpdateDatasetRequest":
        return cls(
            d["privacy_group_id"],
            d["fetcher_active"],
            d["matcher_active"],
            d["write_back"],
            d.get("pdq_match_threshold", ""),
        )


@dataclass
class CreateDatasetRequest(DictParseable):
    privacy_group_id: t.Union[int, str]
    privacy_group_name: str
    description: str
    fetcher_active: bool
    matcher_active: bool
    write_back: bool

    @classmethod
    def from_dict(cls, d: dict) -> "CreateDatasetRequest":
        return cls(
            d["privacy_group_id"],
            d["privacy_group_name"],
            d["description"],
            d["fetcher_active"],
            d["matcher_active"],
            d["write_back"],
        )


@dataclass
class CreateDatasetResponse(JSONifiable):
    response: str

    def to_json(self) -> t.Dict:
        return asdict(self)


@dataclass
class ThreatExchangeDatasetSummary(Dataset):
    """
    Factual information about a ThreatExchange dataset. This could be
    information like the name of the privacy group, the type of content it
    covers, the number of hashes it has etc.

    At the same time, it is not meant to replace the Dataset type. It will *not*
    contain configs that the user can edit. Eg. writeback_active,
    fetcher_active. Those continue to stay in the Dataset super class.
    """

    hash_count: int
    match_count: int
    pdq_match_threshold: t.Optional[str]

    def to_json(self) -> t.Dict:
        dataset_json = super().to_json()
        dataset_json.update(
            hash_count=self.hash_count,
            match_count=self.match_count,
            pdq_match_threshold=self.pdq_match_threshold,
        )

        return dataset_json


@dataclass
class DatasetSummariesResponse(JSONifiable):
    threat_exchange_datasets: t.List[ThreatExchangeDatasetSummary]

    def to_json(self) -> t.Dict:
        return {
            "threat_exchange_datasets": [
                dataset.to_json() for dataset in self.threat_exchange_datasets
            ]
        }


@dataclass
class MatchSettingsResponseBody(JSONifiable):
    config: AdditionalMatchSettingsConfig

    def to_json(self) -> t.Dict:
        return {
            "privacy_group_id": self.config.name,
            "pdq_match_threshold": self.config.pdq_match_threshold,
        }


@dataclass
class MatchSettingsResponse(JSONifiable):
    match_settings: t.List[MatchSettingsResponseBody]

    def to_json(self) -> t.Dict:
        return {
            "match_settings": [settings.to_json() for settings in self.match_settings]
        }


@dataclass
class MatchSettingsUpdateRequest(DictParseable):
    privacy_group_id: str
    pdq_match_threshold: int

    @classmethod
    def from_dict(cls, d: dict) -> "MatchSettingsUpdateRequest":
        return cls(
            d["privacy_group_id"],
            d["pdq_match_threshold"],
        )


@dataclass
class MatchSettingsUpdateResponse(JSONifiable):
    response: str

    def to_json(self) -> t.Dict:
        return asdict(self)


def _get_signal_hash_count_and_last_modified(
    threat_exchange_data_bucket_name: str,
    threat_exchange_data_folder: str,
) -> t.Dict[str, t.Tuple[int, str]]:
    # TODO this method is expensive some cache or memoization method might be a good idea.

    s3_config = S3ThreatDataConfig(
        threat_exchange_data_bucket_name=threat_exchange_data_bucket_name,
        threat_exchange_data_folder=threat_exchange_data_folder,
    )
    pdq_storage = ThreatExchangeS3PDQAdapter(
        config=s3_config, metrics_logger=metrics.names.api_hash_count()
    )
    pdq_data_files = pdq_storage.load_data()
    return {
        file_name.split("/")[-1].split(".")[0]: (
            len(rows),
            pdq_storage.last_modified[file_name],
        )
        for file_name, rows in pdq_data_files.items()
    }


def _get_threat_exchange_datasets(
    table: Table,
    threat_exchange_data_bucket_name: str,
    threat_exchange_data_folder: str,
) -> t.List[ThreatExchangeDatasetSummary]:
    collaborations = ThreatExchangeConfig.get_all()
    hash_counts: t.Dict[
        str, t.Tuple[int, str]
    ] = _get_signal_hash_count_and_last_modified(
        threat_exchange_data_bucket_name,
        threat_exchange_data_folder,
    )

    summaries = []
    for collab in collaborations:
        if additional_config := AdditionalMatchSettingsConfig.get(
            str(collab.privacy_group_id)
        ):
            pdq_match_threshold = str(additional_config.pdq_match_threshold)
        else:
            pdq_match_threshold = ""
        summaries.append(
            ThreatExchangeDatasetSummary(
                collab.privacy_group_id,
                collab.privacy_group_name,
                collab.description,
                collab.fetcher_active,
                collab.matcher_active,
                collab.write_back,
                collab.in_use,
                hash_count=t.cast(
                    int,
                    hash_counts.get(
                        collab.privacy_group_id,
                        [-1, ""],
                    )[0],
                ),
                match_count=-1,  # fix will be based on new count system
                pdq_match_threshold=pdq_match_threshold,
            )
        )

    return summaries


def get_datasets_api(
    hma_config_table: str,
    datastore_table: Table,
    threat_exchange_data_bucket_name: str,
    threat_exchange_data_folder: str,
) -> bottle.Bottle:
    """
    ToDo / FixMe: this file is probably more about privacy groups than datasets...
    """
    # The documentation below expects prefix to be '/datasets/'
    datasets_api = SubApp()
    HMAConfig.initialize(hma_config_table)

    @datasets_api.get("/", apply=[jsoninator])
    def get_all_dataset_summaries() -> DatasetSummariesResponse:
        """
        Returns summaries for all datasets. Summary includes all facts that are
        not configurable. Eg. its name, the number of hashes it has, the
        number of matches it has caused, etc.
        """
        return DatasetSummariesResponse(
            threat_exchange_datasets=_get_threat_exchange_datasets(
                datastore_table,
                threat_exchange_data_bucket_name,
                threat_exchange_data_folder,
            )
        )

    @datasets_api.post("/update", apply=[jsoninator(UpdateDatasetRequest)])
    def update_dataset(request: UpdateDatasetRequest) -> Dataset:
        """
        Update dataset values: fetcher_active, write_back, and matcher_active.
        """
        config = ThreatExchangeConfig.getx(str(request.privacy_group_id))
        config.fetcher_active = request.fetcher_active
        config.write_back = request.write_back
        config.matcher_active = request.matcher_active
        updated_config = hmaconfig.update_config(config).__dict__
        updated_config["privacy_group_id"] = updated_config["name"]

        additional_config = AdditionalMatchSettingsConfig.get(
            str(request.privacy_group_id)
        )
        if request.pdq_match_threshold:
            if additional_config:
                additional_config.pdq_match_threshold = int(request.pdq_match_threshold)
                hmaconfig.update_config(additional_config)
            else:
                additional_config = AdditionalMatchSettingsConfig(
                    str(request.privacy_group_id), int(request.pdq_match_threshold)
                )
                hmaconfig.create_config(additional_config)
        elif additional_config:  # pdq_match_threshold was set and now should be removed
            hmaconfig.delete_config(additional_config)

        return Dataset.from_dict(updated_config)

    @datasets_api.post("/create", apply=[jsoninator(CreateDatasetRequest)])
    def create_dataset(request: CreateDatasetRequest) -> CreateDatasetResponse:
        """
        Create a local dataset (defaults defined in CreateDatasetRequest)
        """
        assert isinstance(request, CreateDatasetRequest)

        create_privacy_group_if_not_exists(
            privacy_group_id=str(request.privacy_group_id),
            privacy_group_name=request.privacy_group_name,
            description=request.description,
            in_use=True,
            fetcher_active=request.fetcher_active,
            matcher_active=request.matcher_active,
            write_back=request.write_back,
        )

        return CreateDatasetResponse(
            response=f"Created dataset {request.privacy_group_id}"
        )

    @datasets_api.post("/sync", apply=[jsoninator])
    def sync_datasets() -> SyncDatasetResponse:
        """
        Fetch new collaborations from ThreatExchange and sync with the configs stored in DynamoDB.
        """
        sync_privacy_groups()
        return SyncDatasetResponse(response="Privacy groups are up to date")

    @datasets_api.post("/delete/<key>", apply=[jsoninator])
    def delete_dataset(key=None) -> DeleteDatasetResponse:
        """
        Delete the dataset with key=<key>
        """
        config = ThreatExchangeConfig.getx(str(key))
        hmaconfig.delete_config(config)
        return DeleteDatasetResponse(response="The privacy group is deleted")

    @datasets_api.get("/match-settings", apply=[jsoninator])
    def get_all_match_settings() -> MatchSettingsResponse:
        """
        Return all match settings configs
        """
        return MatchSettingsResponse(
            match_settings=[
                MatchSettingsResponseBody(c)
                for c in AdditionalMatchSettingsConfig.get_all()
            ]
        )

    @datasets_api.get("/match-settings/<key>", apply=[jsoninator])
    def get_match_settings(
        key=None,
    ) -> MatchSettingsResponseBody:
        """
        Return a match settings config for a given privacy_group_id
        """
        if config := AdditionalMatchSettingsConfig.get(str(key)):
            return MatchSettingsResponseBody(config)
        return bottle.abort(400, f"No match_settings for pg_id {key} found")

    @datasets_api.post(
        "/match-settings", apply=[jsoninator(MatchSettingsUpdateRequest)]
    )
    def create_or_update_match_settings(
        request: MatchSettingsUpdateRequest,
    ) -> MatchSettingsUpdateResponse:
        """
        Create or update a match settings config for a given privacy_group_id
        """
        if config := AdditionalMatchSettingsConfig.get(request.privacy_group_id):
            config.pdq_match_threshold = request.pdq_match_threshold
            hmaconfig.update_config(config)

            return MatchSettingsUpdateResponse(
                f"match_settings updated for pg_id {request.privacy_group_id} with pdq_match_threshold={request.pdq_match_threshold}"
            )

        config = AdditionalMatchSettingsConfig(
            request.privacy_group_id, request.pdq_match_threshold
        )
        hmaconfig.create_config(config)
        return MatchSettingsUpdateResponse(
            f"match_settings created for pg_id {request.privacy_group_id} with pdq_match_threshold={request.pdq_match_threshold}"
        )

    @datasets_api.delete("/match-settings/<key>", apply=[jsoninator])
    def delete_match_settings(
        key=None,
    ) -> MatchSettingsUpdateResponse:
        """
        Delete a match settings config for a given privacy_group_id
        """
        if config := AdditionalMatchSettingsConfig.get(str(key)):
            hmaconfig.delete_config(config)
            return MatchSettingsUpdateResponse(
                f"match_settings deleted for pg_id {key}"
            )
        return bottle.abort(400, f"No match_settings for pg_id {key} found")

    @datasets_api.post("/update-threatexchange-token")
    def update_threatexchange_token() -> t.Dict:
        """
        Given a new threatexchange token as part of the request, makes dummy
        call to threatexchange to see if it is a valid token. If found valid,
        updates the secret.

        Returns 200 if successful, 400 if the token is invalid. Response body is
        always and empty JSON object.

        Expected JSON Keys:
        * `token`: the threatexchange token
        """
        token = bottle.request.json["token"]
        is_valid_token = try_api_token(token)
        if is_valid_token:
            AWSSecrets().update_te_api_token(token)
            return {}

        bottle.response.status_code = 400
        return {}

    return datasets_api