# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
from __future__ import annotations

import logging
import uuid
from datetime import datetime, timedelta, timezone
from typing import Any, Literal, Optional

import jwt
from flask import Flask, Request, request, Response, session
from flask_caching.backends.base import BaseCache

from superset.async_events.cache_backend import (
    RedisCacheBackend,
    RedisSentinelCacheBackend,
)
from superset.utils import json
from superset.utils.core import get_user_id

logger = logging.getLogger(__name__)


class CacheBackendNotInitialized(Exception):  # noqa: N818
    pass


class AsyncQueryTokenException(Exception):  # noqa: N818
    pass


class UnsupportedCacheBackendError(Exception):  # noqa: N818
    pass


class AsyncQueryJobException(Exception):  # noqa: N818
    pass


def build_job_metadata(
    channel_id: str, job_id: str, user_id: Optional[int], **kwargs: Any
) -> dict[str, Any]:
    return {
        "channel_id": channel_id,
        "job_id": job_id,
        "user_id": user_id,
        "status": kwargs.get("status"),
        "errors": kwargs.get("errors", []),
        "result_url": kwargs.get("result_url"),
    }


def parse_event(event_data: tuple[str, dict[str, Any]]) -> dict[str, Any]:
    event_id = event_data[0]
    event_payload = event_data[1]["data"]
    return {"id": event_id, **json.loads(event_payload)}


def increment_id(entry_id: str) -> str:
    # redis stream IDs are in this format: '1607477697866-0'
    try:
        prefix, last = entry_id[:-1], int(entry_id[-1])
        return prefix + str(last + 1)
    except Exception:  # pylint: disable=broad-except
        return entry_id


def get_cache_backend(
    config: dict[str, Any],
) -> RedisCacheBackend | RedisSentinelCacheBackend:
    cache_config = config.get("GLOBAL_ASYNC_QUERIES_CACHE_BACKEND", {})
    cache_type = cache_config.get("CACHE_TYPE")

    if cache_type == "RedisCache":
        return RedisCacheBackend.from_config(cache_config)

    if cache_type == "RedisSentinelCache":
        return RedisSentinelCacheBackend.from_config(cache_config)

    # TODO: Expand cache backend options.
    raise UnsupportedCacheBackendError("Unsupported cache backend configuration")


class AsyncQueryManager:
    MAX_EVENT_COUNT = 100
    STATUS_PENDING = "pending"
    STATUS_RUNNING = "running"
    STATUS_ERROR = "error"
    STATUS_DONE = "done"

    def __init__(self) -> None:
        super().__init__()
        self._cache: Optional[BaseCache] = None
        self._stream_prefix: str = ""
        self._stream_limit: Optional[int]
        self._stream_limit_firehose: Optional[int]
        self._jwt_cookie_name: str = ""
        self._jwt_cookie_secure: bool = False
        self._jwt_cookie_domain: Optional[str]
        self._jwt_cookie_samesite: Optional[Literal["None", "Lax", "Strict"]] = None
        self._jwt_secret: str
        self._jwt_expiration_seconds: int = 0
        self._load_chart_data_into_cache_job: Any = None
        # pylint: disable=invalid-name
        self._load_explore_json_into_cache_job: Any = None

    def init_app(self, app: Flask) -> None:
        cache_type = app.config.get("CACHE_CONFIG", {}).get("CACHE_TYPE")
        data_cache_type = app.config.get("DATA_CACHE_CONFIG", {}).get("CACHE_TYPE")
        if cache_type in [None, "null"] or data_cache_type in [None, "null"]:
            raise Exception(  # pylint: disable=broad-exception-raised
                """
                Cache backends (CACHE_CONFIG, DATA_CACHE_CONFIG) must be configured
                and non-null in order to enable async queries
                """
            )

        self._cache = get_cache_backend(app.config)
        logger.debug("Using GAQ Cache backend as %s", type(self._cache).__name__)

        if len(app.config["GLOBAL_ASYNC_QUERIES_JWT_SECRET"]) < 32:
            raise AsyncQueryTokenException(
                "Please provide a JWT secret at least 32 bytes long"
            )

        self._stream_prefix = app.config["GLOBAL_ASYNC_QUERIES_REDIS_STREAM_PREFIX"]
        self._stream_limit = app.config["GLOBAL_ASYNC_QUERIES_REDIS_STREAM_LIMIT"]
        self._stream_limit_firehose = app.config[
            "GLOBAL_ASYNC_QUERIES_REDIS_STREAM_LIMIT_FIREHOSE"
        ]
        self._jwt_cookie_name = app.config["GLOBAL_ASYNC_QUERIES_JWT_COOKIE_NAME"]
        self._jwt_cookie_secure = app.config["GLOBAL_ASYNC_QUERIES_JWT_COOKIE_SECURE"]
        self._jwt_cookie_samesite = app.config[
            "GLOBAL_ASYNC_QUERIES_JWT_COOKIE_SAMESITE"
        ]
        self._jwt_cookie_domain = app.config["GLOBAL_ASYNC_QUERIES_JWT_COOKIE_DOMAIN"]
        self._jwt_secret = app.config["GLOBAL_ASYNC_QUERIES_JWT_SECRET"]
        self._jwt_expiration_seconds = app.config[
            "GLOBAL_ASYNC_QUERIES_JWT_EXPIRATION_SECONDS"
        ]

        if app.config["GLOBAL_ASYNC_QUERIES_REGISTER_REQUEST_HANDLERS"]:
            self.register_request_handlers(app)

        # pylint: disable=import-outside-toplevel
        from superset.tasks.async_queries import (
            load_chart_data_into_cache,
            load_explore_json_into_cache,
        )

        self._load_chart_data_into_cache_job = load_chart_data_into_cache
        self._load_explore_json_into_cache_job = load_explore_json_into_cache

    def register_request_handlers(self, app: Flask) -> None:
        @app.after_request
        def validate_session(response: Response) -> Response:
            user_id = get_user_id()

            reset_token = (
                not request.cookies.get(self._jwt_cookie_name)
                or "async_channel_id" not in session
                or "async_user_id" not in session
                or user_id != session["async_user_id"]
            )

            if reset_token:
                async_channel_id = str(uuid.uuid4())
                session["async_channel_id"] = async_channel_id
                session["async_user_id"] = user_id

                sub = str(user_id) if user_id else None
                now = datetime.now(tz=timezone.utc)
                token = jwt.encode(
                    {
                        "channel": async_channel_id,
                        "sub": sub,
                        "exp": now + timedelta(seconds=self._jwt_expiration_seconds),
                    },
                    self._jwt_secret,
                    algorithm="HS256",
                )

                response.set_cookie(
                    self._jwt_cookie_name,
                    value=token,
                    httponly=True,
                    secure=self._jwt_cookie_secure,
                    domain=self._jwt_cookie_domain,
                    samesite=self._jwt_cookie_samesite,
                    max_age=self._jwt_expiration_seconds,
                )

            return response

    def parse_channel_id_from_request(self, req: Request) -> str:
        token = req.cookies.get(self._jwt_cookie_name)
        if not token:
            raise AsyncQueryTokenException("Token not preset")

        try:
            return jwt.decode(token, self._jwt_secret, algorithms=["HS256"])["channel"]
        except Exception as ex:
            logger.warning("Parse jwt failed", exc_info=True)
            raise AsyncQueryTokenException("Failed to parse token") from ex

    def init_job(self, channel_id: str, user_id: Optional[int]) -> dict[str, Any]:
        job_id = str(uuid.uuid4())
        return build_job_metadata(
            channel_id, job_id, user_id, status=self.STATUS_PENDING
        )

    # pylint: disable=too-many-arguments
    def submit_explore_json_job(
        self,
        channel_id: str,
        form_data: dict[str, Any],
        response_type: str,
        force: Optional[bool] = False,
        user_id: Optional[int] = None,
    ) -> dict[str, Any]:
        # pylint: disable=import-outside-toplevel
        from superset import security_manager

        job_metadata = self.init_job(channel_id, user_id)
        self._load_explore_json_into_cache_job.delay(
            {**job_metadata, "guest_token": guest_user.guest_token}
            if (guest_user := security_manager.get_current_guest_user_if_guest())
            else job_metadata,
            form_data,
            response_type,
            force,
        )
        return job_metadata

    def submit_chart_data_job(
        self,
        channel_id: str,
        form_data: dict[str, Any],
        user_id: Optional[int] = None,
    ) -> dict[str, Any]:
        # pylint: disable=import-outside-toplevel
        from superset import security_manager

        # if it's guest user, we want to pass the guest token to the celery task
        # chart data cache key is calculated based on the current user
        # this way we can keep the cache key consistent between sync and async command
        # so that it can be looked up consistently
        job_metadata = self.init_job(channel_id, user_id)
        self._load_chart_data_into_cache_job.delay(
            {**job_metadata, "guest_token": guest_user.guest_token}
            if (guest_user := security_manager.get_current_guest_user_if_guest())
            else job_metadata,
            form_data,
        )
        return job_metadata

    def read_events(
        self, channel: str, last_id: Optional[str]
    ) -> list[Optional[dict[str, Any]]]:
        if not self._cache:
            raise CacheBackendNotInitialized("Cache backend not initialized")

        stream_name = f"{self._stream_prefix}{channel}"
        start_id = increment_id(last_id) if last_id else "-"
        results = self._cache.xrange(stream_name, start_id, "+", self.MAX_EVENT_COUNT)
        # Decode bytes to strings, decode_responses is not supported at RedisCache and RedisSentinelCache  # noqa: E501
        if isinstance(self._cache, (RedisSentinelCacheBackend, RedisCacheBackend)):
            decoded_results = [
                (
                    event_id.decode("utf-8"),
                    {
                        key.decode("utf-8"): value.decode("utf-8")
                        for key, value in event_data.items()
                    },
                )
                for event_id, event_data in results
            ]
            return (
                [] if not decoded_results else list(map(parse_event, decoded_results))
            )
        return [] if not results else list(map(parse_event, results))

    def update_job(
        self, job_metadata: dict[str, Any], status: str, **kwargs: Any
    ) -> None:
        if not self._cache:
            raise CacheBackendNotInitialized("Cache backend not initialized")

        if "channel_id" not in job_metadata:
            raise AsyncQueryJobException("No channel ID specified")

        if "job_id" not in job_metadata:
            raise AsyncQueryJobException("No job ID specified")

        updates = {"status": status, **kwargs}
        event_data = {"data": json.dumps({**job_metadata, **updates})}

        full_stream_name = f"{self._stream_prefix}full"
        scoped_stream_name = f"{self._stream_prefix}{job_metadata['channel_id']}"

        logger.debug("********** logging event data to stream %s", scoped_stream_name)
        logger.debug(event_data)

        self._cache.xadd(scoped_stream_name, event_data, "*", self._stream_limit)
        self._cache.xadd(full_stream_name, event_data, "*", self._stream_limit_firehose)