# 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 contextlib
import json
import logging
import re
from re import Pattern
from typing import Any, TYPE_CHECKING, TypedDict

import pandas as pd
from apispec import APISpec
from apispec.ext.marshmallow import MarshmallowPlugin
from flask import g
from flask_babel import gettext as __
from marshmallow import fields, Schema
from marshmallow.exceptions import ValidationError
from requests import Session
from sqlalchemy.engine import create_engine
from sqlalchemy.engine.url import URL

from superset import db, security_manager
from superset.constants import PASSWORD_MASK
from superset.databases.schemas import encrypted_field_properties, EncryptedString
from superset.db_engine_specs.shillelagh import ShillelaghEngineSpec
from superset.errors import ErrorLevel, SupersetError, SupersetErrorType
from superset.exceptions import SupersetException

if TYPE_CHECKING:
    from superset.models.core import Database
    from superset.sql_parse import Table

_logger = logging.getLogger()

EXAMPLE_GSHEETS_URL = (
    "https://docs.google.com/spreadsheets/d/"
    "1LcWZMsdCl92g7nA-D6qGRqg1T5TiHyuKJUY1u9XAnsk/edit#gid=0"
)

SYNTAX_ERROR_REGEX = re.compile('SQLError: near "(?P<server_error>.*?)": syntax error')

ma_plugin = MarshmallowPlugin()


class GSheetsParametersSchema(Schema):
    catalog = fields.Dict()
    service_account_info = EncryptedString(
        required=False,
        metadata={
            "description": "Contents of GSheets JSON credentials.",
            "field_name": "service_account_info",
        },
    )


class GSheetsParametersType(TypedDict):
    service_account_info: str
    catalog: dict[str, str] | None


class GSheetsPropertiesType(TypedDict):
    parameters: GSheetsParametersType
    catalog: dict[str, str]


class GSheetsEngineSpec(ShillelaghEngineSpec):
    """Engine for Google spreadsheets"""

    engine_name = "Google Sheets"
    engine = "gsheets"
    allows_joins = True
    allows_subqueries = True

    parameters_schema = GSheetsParametersSchema()
    default_driver = "apsw"
    sqlalchemy_uri_placeholder = "gsheets://"

    custom_errors: dict[Pattern[str], tuple[str, SupersetErrorType, dict[str, Any]]] = {
        SYNTAX_ERROR_REGEX: (
            __(
                'Please check your query for syntax errors near "%(server_error)s". '
                "Then, try running your query again.",
            ),
            SupersetErrorType.SYNTAX_ERROR,
            {},
        ),
    }

    supports_file_upload = True

    @classmethod
    def get_url_for_impersonation(
        cls,
        url: URL,
        impersonate_user: bool,
        username: str | None,
    ) -> URL:
        if impersonate_user and username is not None:
            user = security_manager.find_user(username=username)
            if user and user.email:
                url = url.update_query_dict({"subject": user.email})

        return url

    @classmethod
    def extra_table_metadata(
        cls,
        database: Database,
        table_name: str,
        schema_name: str | None,
    ) -> dict[str, Any]:
        with database.get_raw_connection(schema=schema_name) as conn:
            cursor = conn.cursor()
            cursor.execute(f'SELECT GET_METADATA("{table_name}")')
            results = cursor.fetchone()[0]
        try:
            metadata = json.loads(results)
        except Exception:  # pylint: disable=broad-except
            metadata = {}

        return {"metadata": metadata["extra"]}

    @classmethod
    def build_sqlalchemy_uri(
        cls,
        _: GSheetsParametersType,
        encrypted_extra: None  # pylint: disable=unused-argument
        | (dict[str, Any]) = None,
    ) -> str:
        return "gsheets://"

    @classmethod
    def get_parameters_from_uri(
        cls,
        uri: str,  # pylint: disable=unused-argument
        encrypted_extra: dict[str, Any] | None = None,
    ) -> Any:
        # Building parameters from encrypted_extra and uri
        if encrypted_extra:
            return {**encrypted_extra}

        raise ValidationError("Invalid service credentials")

    @classmethod
    def mask_encrypted_extra(cls, encrypted_extra: str | None) -> str | None:
        if encrypted_extra is None:
            return encrypted_extra

        try:
            config = json.loads(encrypted_extra)
        except (TypeError, json.JSONDecodeError):
            return encrypted_extra

        with contextlib.suppress(KeyError):
            config["service_account_info"]["private_key"] = PASSWORD_MASK
        return json.dumps(config)

    @classmethod
    def unmask_encrypted_extra(cls, old: str | None, new: str | None) -> str | None:
        """
        Reuse ``private_key`` if available and unchanged.
        """
        if old is None or new is None:
            return new

        try:
            old_config = json.loads(old)
            new_config = json.loads(new)
        except (TypeError, json.JSONDecodeError):
            return new

        if "service_account_info" not in new_config:
            return new

        if "private_key" not in new_config["service_account_info"]:
            return new

        if new_config["service_account_info"]["private_key"] == PASSWORD_MASK:
            new_config["service_account_info"]["private_key"] = old_config[
                "service_account_info"
            ]["private_key"]

        return json.dumps(new_config)

    @classmethod
    def parameters_json_schema(cls) -> Any:
        """
        Return configuration parameters as OpenAPI.
        """
        if not cls.parameters_schema:
            return None

        spec = APISpec(
            title="Database Parameters",
            version="1.0.0",
            openapi_version="3.0.0",
            plugins=[ma_plugin],
        )

        ma_plugin.init_spec(spec)
        ma_plugin.converter.add_attribute_function(encrypted_field_properties)
        spec.components.schema(cls.__name__, schema=cls.parameters_schema)
        return spec.to_dict()["components"]["schemas"][cls.__name__]

    @classmethod
    def validate_parameters(
        cls,
        properties: GSheetsPropertiesType,
    ) -> list[SupersetError]:
        errors: list[SupersetError] = []

        # backwards compatible just incase people are send data
        # via parameters for validation
        parameters = properties.get("parameters", {})
        if parameters and parameters.get("catalog"):
            table_catalog = parameters.get("catalog", {})
        else:
            table_catalog = properties.get("catalog", {})

        encrypted_credentials = parameters.get("service_account_info") or "{}"

        # On create the encrypted credentials are a string,
        # at all other times they are a dict
        if isinstance(encrypted_credentials, str):
            encrypted_credentials = json.loads(encrypted_credentials)

        if not table_catalog:
            # Allowing users to submit empty catalogs
            errors.append(
                SupersetError(
                    message="Sheet name is required",
                    error_type=SupersetErrorType.CONNECTION_MISSING_PARAMETERS_ERROR,
                    level=ErrorLevel.WARNING,
                    extra={"catalog": {"idx": 0, "name": True}},
                ),
            )
            return errors

        # We need a subject in case domain wide delegation is set, otherwise the
        # check will fail. This means that the admin will be able to add sheets
        # that only they have access, even if later users are not able to access
        # them.
        subject = g.user.email if g.user else None

        engine = create_engine(
            "gsheets://",
            service_account_info=encrypted_credentials,
            subject=subject,
        )
        conn = engine.connect()
        idx = 0

        for name, url in table_catalog.items():
            if not name:
                errors.append(
                    SupersetError(
                        message="Sheet name is required",
                        error_type=SupersetErrorType.CONNECTION_MISSING_PARAMETERS_ERROR,
                        level=ErrorLevel.WARNING,
                        extra={"catalog": {"idx": idx, "name": True}},
                    ),
                )
                return errors

            if not url:
                errors.append(
                    SupersetError(
                        message="URL is required",
                        error_type=SupersetErrorType.CONNECTION_MISSING_PARAMETERS_ERROR,
                        level=ErrorLevel.WARNING,
                        extra={"catalog": {"idx": idx, "url": True}},
                    ),
                )
                return errors

            try:
                results = conn.execute(f'SELECT * FROM "{url}" LIMIT 1')
                results.fetchall()
            except Exception:  # pylint: disable=broad-except
                errors.append(
                    SupersetError(
                        message=(
                            "The URL could not be identified. Please check for typos "
                            "and make sure that ‘Type of Google Sheets allowed’ "
                            "selection matches the input."
                        ),
                        error_type=SupersetErrorType.TABLE_DOES_NOT_EXIST_ERROR,
                        level=ErrorLevel.WARNING,
                        extra={"catalog": {"idx": idx, "url": True}},
                    ),
                )
            idx += 1
        return errors

    @staticmethod
    def _do_post(
        session: Session,
        url: str,
        body: dict[str, Any],
        **kwargs: Any,
    ) -> dict[str, Any]:
        """
        POST to the Google API.

        Helper function that handles logging and error handling.
        """
        _logger.info("POST %s", url)
        _logger.debug(body)
        response = session.post(
            url,
            json=body,
            **kwargs,
        )

        payload = response.json()
        _logger.debug(payload)

        if "error" in payload:
            raise SupersetException(payload["error"]["message"])

        return payload

    @classmethod
    def df_to_sql(  # pylint: disable=too-many-locals
        cls,
        database: Database,
        table: Table,
        df: pd.DataFrame,
        to_sql_kwargs: dict[str, Any],
    ) -> None:
        """
        Create a new sheet and update the DB catalog.

        Since Google Sheets is not a database, uploading a file is slightly different
        from other traditional databases. To create a table with a given name we first
        create a spreadsheet with the contents of the dataframe, and we later update the
        database catalog to add a mapping between the desired table name and the URL of
        the new sheet.

        If the table already exists and the user wants it replaced we clear all the
        cells in the existing sheet before uploading the new data. Appending to an
        existing table is not supported because we can't ensure that the schemas match.
        """
        # pylint: disable=import-outside-toplevel
        from shillelagh.backends.apsw.dialects.base import get_adapter_for_table_name

        # grab the existing catalog, if any
        extra = database.get_extra()
        engine_params = extra.setdefault("engine_params", {})
        catalog = engine_params.setdefault("catalog", {})

        # sanity checks
        spreadsheet_url = catalog.get(table.table)
        if spreadsheet_url and "if_exists" in to_sql_kwargs:
            if to_sql_kwargs["if_exists"] == "append":
                # no way we're going to append a dataframe to a spreadsheet, that's
                # never going to work
                raise SupersetException("Append operation not currently supported")
            if to_sql_kwargs["if_exists"] == "fail":
                raise SupersetException("Table already exists")
            if to_sql_kwargs["if_exists"] == "replace":
                pass

        # get the Google session from the Shillelagh adapter
        with cls.get_engine(database) as engine:
            with engine.connect() as conn:
                # any GSheets URL will work to get a working session
                adapter = get_adapter_for_table_name(
                    conn,
                    spreadsheet_url or EXAMPLE_GSHEETS_URL,
                )
                session = adapter._get_session()  # pylint: disable=protected-access

        # clear existing sheet, or create a new one
        if spreadsheet_url:
            spreadsheet_id = adapter._spreadsheet_id  # pylint: disable=protected-access
            range_ = adapter._sheet_name  # pylint: disable=protected-access
            url = (
                "https://sheets.googleapis.com/v4/spreadsheets/"
                f"{spreadsheet_id}/values/{range_}:clear"
            )
            cls._do_post(session, url, {})
        else:
            payload = cls._do_post(
                session,
                "https://sheets.googleapis.com/v4/spreadsheets",
                {"properties": {"title": table.table}},
            )
            spreadsheet_id = payload["spreadsheetId"]
            range_ = payload["sheets"][0]["properties"]["title"]
            spreadsheet_url = payload["spreadsheetUrl"]

        # insert data
        data = df.fillna("").values.tolist()
        data.insert(0, df.columns.values.tolist())
        body = {
            "range": range_,
            "majorDimension": "ROWS",
            "values": data,
        }
        url = (
            "https://sheets.googleapis.com/v4/spreadsheets/"
            f"{spreadsheet_id}/values/{range_}:append"
        )
        cls._do_post(
            session,
            url,
            body,
            params={"valueInputOption": "USER_ENTERED"},
        )

        # update catalog
        catalog[table.table] = spreadsheet_url
        database.extra = json.dumps(extra)
        db.session.add(database)
        db.session.commit()