# 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.
import json
import logging
from datetime import datetime
from io import BytesIO
from typing import Any, Dict, List, Optional
from zipfile import ZipFile

from flask import g, request, Response, send_file
from flask_appbuilder.api import expose, protect, rison, safe
from flask_appbuilder.models.sqla.interface import SQLAInterface
from marshmallow import ValidationError
from sqlalchemy.exc import NoSuchTableError, OperationalError, SQLAlchemyError

from superset import app, event_logger
from superset.commands.importers.exceptions import NoValidFilesFoundError
from superset.commands.importers.v1.utils import get_contents_from_bundle
from superset.constants import MODEL_API_RW_METHOD_PERMISSION_MAP, RouteMethod
from superset.databases.commands.create import CreateDatabaseCommand
from superset.databases.commands.delete import DeleteDatabaseCommand
from superset.databases.commands.exceptions import (
    DatabaseConnectionFailedError,
    DatabaseCreateFailedError,
    DatabaseDeleteDatasetsExistFailedError,
    DatabaseDeleteFailedError,
    DatabaseInvalidError,
    DatabaseNotFoundError,
    DatabaseUpdateFailedError,
    InvalidParametersError,
)
from superset.databases.commands.export import ExportDatabasesCommand
from superset.databases.commands.importers.dispatcher import ImportDatabasesCommand
from superset.databases.commands.test_connection import TestConnectionDatabaseCommand
from superset.databases.commands.update import UpdateDatabaseCommand
from superset.databases.commands.validate import ValidateDatabaseParametersCommand
from superset.databases.dao import DatabaseDAO
from superset.databases.decorators import check_datasource_access
from superset.databases.filters import DatabaseFilter
from superset.databases.schemas import (
    database_schemas_query_schema,
    DatabaseFunctionNamesResponse,
    DatabasePostSchema,
    DatabasePutSchema,
    DatabaseRelatedObjectsResponse,
    DatabaseTestConnectionSchema,
    DatabaseValidateParametersSchema,
    get_export_ids_schema,
    SchemasResponseSchema,
    SelectStarResponseSchema,
    TableMetadataResponseSchema,
)
from superset.databases.utils import get_table_metadata
from superset.db_engine_specs import get_available_engine_specs
from superset.errors import ErrorLevel, SupersetError, SupersetErrorType
from superset.exceptions import InvalidPayloadFormatError
from superset.extensions import security_manager
from superset.models.core import Database
from superset.typing import FlaskResponse
from superset.utils.core import error_msg_from_exception
from superset.views.base_api import BaseSupersetModelRestApi, statsd_metrics

logger = logging.getLogger(__name__)


class DatabaseRestApi(BaseSupersetModelRestApi):
    datamodel = SQLAInterface(Database)

    include_route_methods = RouteMethod.REST_MODEL_VIEW_CRUD_SET | {
        RouteMethod.EXPORT,
        RouteMethod.IMPORT,
        "table_metadata",
        "select_star",
        "schemas",
        "test_connection",
        "related_objects",
        "function_names",
        "available",
        "validate_parameters",
    }
    resource_name = "database"
    class_permission_name = "Database"
    method_permission_name = MODEL_API_RW_METHOD_PERMISSION_MAP
    allow_browser_login = True
    base_filters = [["id", DatabaseFilter, lambda: []]]
    show_columns = [
        "id",
        "database_name",
        "cache_timeout",
        "expose_in_sqllab",
        "allow_run_async",
        "allow_csv_upload",
        "configuration_method",
        "allow_ctas",
        "allow_cvas",
        "allow_dml",
        "backend",
        "force_ctas_schema",
        "allow_multi_schema_metadata_fetch",
        "impersonate_user",
        "encrypted_extra",
        "extra",
        "parameters",
        "server_cert",
        "sqlalchemy_uri",
    ]
    list_columns = [
        "allow_csv_upload",
        "allow_ctas",
        "allow_cvas",
        "allow_dml",
        "allow_multi_schema_metadata_fetch",
        "allow_run_async",
        "allows_cost_estimate",
        "allows_subquery",
        "allows_virtual_table_explore",
        "backend",
        "changed_on",
        "changed_on_delta_humanized",
        "created_by.first_name",
        "created_by.last_name",
        "database_name",
        "explore_database_id",
        "expose_in_sqllab",
        "force_ctas_schema",
        "id",
    ]
    add_columns = [
        "database_name",
        "sqlalchemy_uri",
        "cache_timeout",
        "expose_in_sqllab",
        "allow_run_async",
        "allow_csv_upload",
        "allow_ctas",
        "allow_cvas",
        "allow_dml",
        "configuration_method",
        "force_ctas_schema",
        "impersonate_user",
        "allow_multi_schema_metadata_fetch",
        "extra",
        "encrypted_extra",
        "server_cert",
    ]
    edit_columns = add_columns

    list_select_columns = list_columns + ["extra", "sqlalchemy_uri", "password"]
    order_columns = [
        "allow_csv_upload",
        "allow_dml",
        "allow_run_async",
        "changed_on",
        "changed_on_delta_humanized",
        "created_by.first_name",
        "database_name",
        "expose_in_sqllab",
    ]
    # Removes the local limit for the page size
    max_page_size = -1
    add_model_schema = DatabasePostSchema()
    edit_model_schema = DatabasePutSchema()

    apispec_parameter_schemas = {
        "database_schemas_query_schema": database_schemas_query_schema,
        "get_export_ids_schema": get_export_ids_schema,
    }
    openapi_spec_tag = "Database"
    openapi_spec_component_schemas = (
        DatabaseFunctionNamesResponse,
        DatabaseRelatedObjectsResponse,
        DatabaseTestConnectionSchema,
        DatabaseValidateParametersSchema,
        TableMetadataResponseSchema,
        SelectStarResponseSchema,
        SchemasResponseSchema,
    )

    @expose("/", methods=["POST"])
    @protect()
    @safe
    @statsd_metrics
    @event_logger.log_this_with_context(
        action=lambda self, *args, **kwargs: f"{self.__class__.__name__}.post",
        log_to_statsd=False,
    )
    def post(self) -> Response:
        """Creates a new Database
        ---
        post:
          description: >-
            Create a new Database.
          requestBody:
            description: Database schema
            required: true
            content:
              application/json:
                schema:
                  $ref: '#/components/schemas/{{self.__class__.__name__}}.post'
          responses:
            201:
              description: Database added
              content:
                application/json:
                  schema:
                    type: object
                    properties:
                      id:
                        type: number
                      result:
                        $ref: '#/components/schemas/{{self.__class__.__name__}}.post'
            302:
              description: Redirects to the current digest
            400:
              $ref: '#/components/responses/400'
            401:
              $ref: '#/components/responses/401'
            404:
              $ref: '#/components/responses/404'
            500:
              $ref: '#/components/responses/500'
        """

        if not request.is_json:
            return self.response_400(message="Request is not JSON")
        try:
            item = self.add_model_schema.load(request.json)
        # This validates custom Schema with custom validations
        except ValidationError as error:
            return self.response_400(message=error.messages)
        try:
            new_model = CreateDatabaseCommand(g.user, item).run()
            # Return censored version for sqlalchemy URI
            item["sqlalchemy_uri"] = new_model.sqlalchemy_uri
            return self.response(201, id=new_model.id, result=item)
        except DatabaseInvalidError as ex:
            return self.response_422(message=ex.normalized_messages())
        except DatabaseConnectionFailedError as ex:
            return self.response_422(message=str(ex))
        except DatabaseCreateFailedError as ex:
            logger.error(
                "Error creating model %s: %s",
                self.__class__.__name__,
                str(ex),
                exc_info=True,
            )
            return self.response_422(message=str(ex))

    @expose("/<int:pk>", methods=["PUT"])
    @protect()
    @safe
    @statsd_metrics
    @event_logger.log_this_with_context(
        action=lambda self, *args, **kwargs: f"{self.__class__.__name__}.put",
        log_to_statsd=False,
    )
    def put(  # pylint: disable=too-many-return-statements, arguments-differ
        self, pk: int
    ) -> Response:
        """Changes a Database
        ---
        put:
          description: >-
            Changes a Database.
          parameters:
          - in: path
            schema:
              type: integer
            name: pk
          requestBody:
            description: Database schema
            required: true
            content:
              application/json:
                schema:
                  $ref: '#/components/schemas/{{self.__class__.__name__}}.put'
          responses:
            200:
              description: Database changed
              content:
                application/json:
                  schema:
                    type: object
                    properties:
                      id:
                        type: number
                      result:
                        $ref: '#/components/schemas/{{self.__class__.__name__}}.put'
            400:
              $ref: '#/components/responses/400'
            401:
              $ref: '#/components/responses/401'
            403:
              $ref: '#/components/responses/403'
            404:
              $ref: '#/components/responses/404'
            422:
              $ref: '#/components/responses/422'
            500:
              $ref: '#/components/responses/500'
        """
        if not request.is_json:
            return self.response_400(message="Request is not JSON")
        try:
            item = self.edit_model_schema.load(request.json)
        # This validates custom Schema with custom validations
        except ValidationError as error:
            return self.response_400(message=error.messages)
        try:
            changed_model = UpdateDatabaseCommand(g.user, pk, item).run()
            # Return censored version for sqlalchemy URI
            item["sqlalchemy_uri"] = changed_model.sqlalchemy_uri
            return self.response(200, id=changed_model.id, result=item)
        except DatabaseNotFoundError:
            return self.response_404()
        except DatabaseInvalidError as ex:
            return self.response_422(message=ex.normalized_messages())
        except DatabaseConnectionFailedError as ex:
            return self.response_422(message=str(ex))
        except DatabaseUpdateFailedError as ex:
            logger.error(
                "Error updating model %s: %s",
                self.__class__.__name__,
                str(ex),
                exc_info=True,
            )
            return self.response_422(message=str(ex))

    @expose("/<int:pk>", methods=["DELETE"])
    @protect()
    @safe
    @statsd_metrics
    @event_logger.log_this_with_context(
        action=lambda self, *args, **kwargs: f"{self.__class__.__name__}" f".delete",
        log_to_statsd=False,
    )
    def delete(self, pk: int) -> Response:  # pylint: disable=arguments-differ
        """Deletes a Database
        ---
        delete:
          description: >-
            Deletes a Database.
          parameters:
          - in: path
            schema:
              type: integer
            name: pk
          responses:
            200:
              description: Database deleted
              content:
                application/json:
                  schema:
                    type: object
                    properties:
                      message:
                        type: string
            401:
              $ref: '#/components/responses/401'
            403:
              $ref: '#/components/responses/403'
            404:
              $ref: '#/components/responses/404'
            422:
              $ref: '#/components/responses/422'
            500:
              $ref: '#/components/responses/500'
        """
        try:
            DeleteDatabaseCommand(g.user, pk).run()
            return self.response(200, message="OK")
        except DatabaseNotFoundError:
            return self.response_404()
        except DatabaseDeleteDatasetsExistFailedError as ex:
            return self.response_422(message=str(ex))
        except DatabaseDeleteFailedError as ex:
            logger.error(
                "Error deleting model %s: %s",
                self.__class__.__name__,
                str(ex),
                exc_info=True,
            )
            return self.response_422(message=str(ex))

    @expose("/<int:pk>/schemas/")
    @protect()
    @safe
    @rison(database_schemas_query_schema)
    @statsd_metrics
    @event_logger.log_this_with_context(
        action=lambda self, *args, **kwargs: f"{self.__class__.__name__}" f".schemas",
        log_to_statsd=False,
    )
    def schemas(self, pk: int, **kwargs: Any) -> FlaskResponse:
        """Get all schemas from a database
        ---
        get:
          description: Get all schemas from a database
          parameters:
          - in: path
            schema:
              type: integer
            name: pk
            description: The database id
          - in: query
            name: q
            content:
              application/json:
                schema:
                  $ref: '#/components/schemas/database_schemas_query_schema'
          responses:
            200:
              description: A List of all schemas from the database
              content:
                application/json:
                  schema:
                    $ref: "#/components/schemas/SchemasResponseSchema"
            400:
              $ref: '#/components/responses/400'
            401:
              $ref: '#/components/responses/401'
            404:
              $ref: '#/components/responses/404'
            500:
              $ref: '#/components/responses/500'
        """
        database = self.datamodel.get(pk, self._base_filters)
        if not database:
            return self.response_404()
        try:
            schemas = database.get_all_schema_names(
                cache=database.schema_cache_enabled,
                cache_timeout=database.schema_cache_timeout,
                force=kwargs["rison"].get("force", False),
            )
            schemas = security_manager.get_schemas_accessible_by_user(database, schemas)
            return self.response(200, result=schemas)
        except OperationalError:
            return self.response(
                500, message="There was an error connecting to the database"
            )

    @expose("/<int:pk>/table/<table_name>/<schema_name>/", methods=["GET"])
    @protect()
    @check_datasource_access
    @safe
    @statsd_metrics
    @event_logger.log_this_with_context(
        action=lambda self, *args, **kwargs: f"{self.__class__.__name__}"
        f".table_metadata",
        log_to_statsd=False,
    )
    def table_metadata(
        self, database: Database, table_name: str, schema_name: str
    ) -> FlaskResponse:
        """Table schema info
        ---
        get:
          description: Get database table metadata
          parameters:
          - in: path
            schema:
              type: integer
            name: pk
            description: The database id
          - in: path
            schema:
              type: string
            name: table_name
            description: Table name
          - in: path
            schema:
              type: string
            name: schema_name
            description: Table schema
          responses:
            200:
              description: Table metadata information
              content:
                application/json:
                  schema:
                    $ref: "#/components/schemas/TableMetadataResponseSchema"
            400:
              $ref: '#/components/responses/400'
            401:
              $ref: '#/components/responses/401'
            404:
              $ref: '#/components/responses/404'
            422:
              $ref: '#/components/responses/422'
            500:
              $ref: '#/components/responses/500'
        """
        self.incr_stats("init", self.table_metadata.__name__)
        try:
            table_info = get_table_metadata(database, table_name, schema_name)
        except SQLAlchemyError as ex:
            self.incr_stats("error", self.table_metadata.__name__)
            return self.response_422(error_msg_from_exception(ex))
        self.incr_stats("success", self.table_metadata.__name__)
        return self.response(200, **table_info)

    @expose("/<int:pk>/select_star/<table_name>/", methods=["GET"])
    @expose("/<int:pk>/select_star/<table_name>/<schema_name>/", methods=["GET"])
    @protect()
    @check_datasource_access
    @safe
    @statsd_metrics
    @event_logger.log_this_with_context(
        action=lambda self, *args, **kwargs: f"{self.__class__.__name__}.select_star",
        log_to_statsd=False,
    )
    def select_star(
        self, database: Database, table_name: str, schema_name: Optional[str] = None
    ) -> FlaskResponse:
        """Table schema info
        ---
        get:
          description: Get database select star for table
          parameters:
          - in: path
            schema:
              type: integer
            name: pk
            description: The database id
          - in: path
            schema:
              type: string
            name: table_name
            description: Table name
          - in: path
            schema:
              type: string
            name: schema_name
            description: Table schema
          responses:
            200:
              description: SQL statement for a select star for table
              content:
                application/json:
                  schema:
                    $ref: "#/components/schemas/SelectStarResponseSchema"
            400:
              $ref: '#/components/responses/400'
            401:
              $ref: '#/components/responses/401'
            404:
              $ref: '#/components/responses/404'
            422:
              $ref: '#/components/responses/422'
            500:
              $ref: '#/components/responses/500'
        """
        self.incr_stats("init", self.select_star.__name__)
        try:
            result = database.select_star(
                table_name, schema_name, latest_partition=True, show_cols=True
            )
        except NoSuchTableError:
            self.incr_stats("error", self.select_star.__name__)
            return self.response(404, message="Table not found on the database")
        self.incr_stats("success", self.select_star.__name__)
        return self.response(200, result=result)

    @expose("/test_connection", methods=["POST"])
    @protect()
    @statsd_metrics
    @event_logger.log_this_with_context(
        action=lambda self, *args, **kwargs: f"{self.__class__.__name__}"
        f".test_connection",
        log_to_statsd=False,
    )
    def test_connection(  # pylint: disable=too-many-return-statements
        self,
    ) -> FlaskResponse:
        """Tests a database connection
        ---
        post:
          description: >-
            Tests a database connection
          requestBody:
            description: Database schema
            required: true
            content:
              application/json:
                schema:
                  $ref: "#/components/schemas/DatabaseTestConnectionSchema"
          responses:
            200:
              description: Database Test Connection
              content:
                application/json:
                  schema:
                    type: object
                    properties:
                      message:
                        type: string
            400:
              $ref: '#/components/responses/400'
            422:
              $ref: '#/components/responses/422'
            500:
              $ref: '#/components/responses/500'
        """
        if not request.is_json:
            return self.response_400(message="Request is not JSON")
        try:
            item = DatabaseTestConnectionSchema().load(request.json)
        # This validates custom Schema with custom validations
        except ValidationError as error:
            return self.response_400(message=error.messages)
        TestConnectionDatabaseCommand(g.user, item).run()
        return self.response(200, message="OK")

    @expose("/<int:pk>/related_objects/", methods=["GET"])
    @protect()
    @safe
    @statsd_metrics
    @event_logger.log_this_with_context(
        action=lambda self, *args, **kwargs: f"{self.__class__.__name__}"
        f".related_objects",
        log_to_statsd=False,
    )
    def related_objects(self, pk: int) -> Response:
        """Get charts and dashboards count associated to a database
        ---
        get:
          description:
            Get charts and dashboards count associated to a database
          parameters:
          - in: path
            name: pk
            schema:
              type: integer
          responses:
            200:
            200:
              description: Query result
              content:
                application/json:
                  schema:
                    $ref: "#/components/schemas/DatabaseRelatedObjectsResponse"
            401:
              $ref: '#/components/responses/401'
            404:
              $ref: '#/components/responses/404'
            500:
              $ref: '#/components/responses/500'
        """
        database = DatabaseDAO.find_by_id(pk)
        if not database:
            return self.response_404()
        data = DatabaseDAO.get_related_objects(pk)
        charts = [
            {
                "id": chart.id,
                "slice_name": chart.slice_name,
                "viz_type": chart.viz_type,
            }
            for chart in data["charts"]
        ]
        dashboards = [
            {
                "id": dashboard.id,
                "json_metadata": dashboard.json_metadata,
                "slug": dashboard.slug,
                "title": dashboard.dashboard_title,
            }
            for dashboard in data["dashboards"]
        ]
        return self.response(
            200,
            charts={"count": len(charts), "result": charts},
            dashboards={"count": len(dashboards), "result": dashboards},
        )

    @expose("/export/", methods=["GET"])
    @protect()
    @safe
    @statsd_metrics
    @rison(get_export_ids_schema)
    @event_logger.log_this_with_context(
        action=lambda self, *args, **kwargs: f"{self.__class__.__name__}.export",
        log_to_statsd=False,
    )
    def export(self, **kwargs: Any) -> Response:
        """Export database(s) with associated datasets
        ---
        get:
          description: Download database(s) and associated dataset(s) as a zip file
          parameters:
          - in: query
            name: q
            content:
              application/json:
                schema:
                  $ref: '#/components/schemas/get_export_ids_schema'
          responses:
            200:
              description: A zip file with database(s) and dataset(s) as YAML
              content:
                application/zip:
                  schema:
                    type: string
                    format: binary
            401:
              $ref: '#/components/responses/401'
            404:
              $ref: '#/components/responses/404'
            500:
              $ref: '#/components/responses/500'
        """
        token = request.args.get("token")
        requested_ids = kwargs["rison"]
        timestamp = datetime.now().strftime("%Y%m%dT%H%M%S")
        root = f"database_export_{timestamp}"
        filename = f"{root}.zip"

        buf = BytesIO()
        with ZipFile(buf, "w") as bundle:
            try:
                for file_name, file_content in ExportDatabasesCommand(
                    requested_ids
                ).run():
                    with bundle.open(f"{root}/{file_name}", "w") as fp:
                        fp.write(file_content.encode())
            except DatabaseNotFoundError:
                return self.response_404()
        buf.seek(0)

        response = send_file(
            buf,
            mimetype="application/zip",
            as_attachment=True,
            attachment_filename=filename,
        )
        if token:
            response.set_cookie(token, "done", max_age=600)
        return response

    @expose("/import/", methods=["POST"])
    @protect()
    @statsd_metrics
    @event_logger.log_this_with_context(
        action=lambda self, *args, **kwargs: f"{self.__class__.__name__}.import_",
        log_to_statsd=False,
    )
    def import_(self) -> Response:
        """Import database(s) with associated datasets
        ---
        post:
          requestBody:
            required: true
            content:
              multipart/form-data:
                schema:
                  type: object
                  properties:
                    formData:
                      description: upload file (ZIP)
                      type: string
                      format: binary
                    passwords:
                      description: JSON map of passwords for each file
                      type: string
                    overwrite:
                      description: overwrite existing databases?
                      type: boolean
          responses:
            200:
              description: Database import result
              content:
                application/json:
                  schema:
                    type: object
                    properties:
                      message:
                        type: string
            400:
              $ref: '#/components/responses/400'
            401:
              $ref: '#/components/responses/401'
            422:
              $ref: '#/components/responses/422'
            500:
              $ref: '#/components/responses/500'
        """
        upload = request.files.get("formData")
        if not upload:
            return self.response_400()
        with ZipFile(upload) as bundle:
            contents = get_contents_from_bundle(bundle)

        if not contents:
            raise NoValidFilesFoundError()

        passwords = (
            json.loads(request.form["passwords"])
            if "passwords" in request.form
            else None
        )
        overwrite = request.form.get("overwrite") == "true"

        command = ImportDatabasesCommand(
            contents, passwords=passwords, overwrite=overwrite
        )
        command.run()
        return self.response(200, message="OK")

    @expose("/<int:pk>/function_names/", methods=["GET"])
    @protect()
    @safe
    @statsd_metrics
    @event_logger.log_this_with_context(
        action=lambda self, *args, **kwargs: f"{self.__class__.__name__}"
        f".function_names",
        log_to_statsd=False,
    )
    def function_names(self, pk: int) -> Response:
        """Get function names supported by a database
        ---
        get:
          description:
            Get function names supported by a database
          parameters:
          - in: path
            name: pk
            schema:
              type: integer
          responses:
            200:
              description: Query result
              content:
                application/json:
                  schema:
                    $ref: "#/components/schemas/DatabaseFunctionNamesResponse"
            401:
              $ref: '#/components/responses/401'
            404:
              $ref: '#/components/responses/404'
            500:
              $ref: '#/components/responses/500'
        """
        database = DatabaseDAO.find_by_id(pk)
        if not database:
            return self.response_404()
        return self.response(200, function_names=database.function_names,)

    @expose("/available/", methods=["GET"])
    @protect()
    @statsd_metrics
    @event_logger.log_this_with_context(
        action=lambda self, *args, **kwargs: f"{self.__class__.__name__}" f".available",
        log_to_statsd=False,
    )
    def available(self) -> Response:
        """Return names of databases currently available
        ---
        get:
          description:
            Get names of databases currently available
          responses:
            200:
              description: Database names
              content:
                application/json:
                  schema:
                    type: array
                    items:
                      type: object
                      properties:
                        name:
                          description: Name of the database
                          type: string
                        engine:
                          description: Name of the SQLAlchemy engine
                          type: string
                        available_drivers:
                          description: Installed drivers for the engine
                          type: array
                          items:
                            type: string
                        default_driver:
                          description: Default driver for the engine
                          type: string
                        preferred:
                          description: Is the database preferred?
                          type: boolean
                        sqlalchemy_uri_placeholder:
                          description: Example placeholder for the SQLAlchemy URI
                          type: string
                        parameters:
                          description: JSON schema defining the needed parameters
                          type: object
            400:
              $ref: '#/components/responses/400'
            500:
              $ref: '#/components/responses/500'
        """
        preferred_databases: List[str] = app.config.get("PREFERRED_DATABASES", [])
        available_databases = []
        for engine_spec, drivers in get_available_engine_specs().items():
            payload: Dict[str, Any] = {
                "name": engine_spec.engine_name,
                "engine": engine_spec.engine,
                "available_drivers": sorted(drivers),
                "preferred": engine_spec.engine_name in preferred_databases,
            }

            if hasattr(engine_spec, "default_driver"):
                payload["default_driver"] = engine_spec.default_driver  # type: ignore

            # show configuration parameters for DBs that support it
            if (
                hasattr(engine_spec, "parameters_json_schema")
                and hasattr(engine_spec, "sqlalchemy_uri_placeholder")
                and getattr(engine_spec, "default_driver") in drivers
            ):
                payload[
                    "parameters"
                ] = engine_spec.parameters_json_schema()  # type: ignore
                payload[
                    "sqlalchemy_uri_placeholder"
                ] = engine_spec.sqlalchemy_uri_placeholder  # type: ignore

            available_databases.append(payload)

        # sort preferred first
        response = sorted(
            (payload for payload in available_databases if payload["preferred"]),
            key=lambda payload: preferred_databases.index(payload["name"]),
        )

        # add others
        response.extend(
            sorted(
                (
                    payload
                    for payload in available_databases
                    if not payload["preferred"]
                ),
                key=lambda payload: payload["name"],
            )
        )

        return self.response(200, databases=response)

    @expose("/validate_parameters", methods=["POST"])
    @protect()
    @statsd_metrics
    @event_logger.log_this_with_context(
        action=lambda self, *args, **kwargs: f"{self.__class__.__name__}"
        f".validate_parameters",
        log_to_statsd=False,
    )
    def validate_parameters(  # pylint: disable=too-many-return-statements
        self,
    ) -> FlaskResponse:
        """validates database connection parameters
        ---
        post:
          description: >-
            Validates parameters used to connect to a database
          requestBody:
            description: DB-specific parameters
            required: true
            content:
              application/json:
                schema:
                  $ref: "#/components/schemas/DatabaseValidateParametersSchema"
          responses:
            200:
              description: Database Test Connection
              content:
                application/json:
                  schema:
                    type: object
                    properties:
                      message:
                        type: string
            400:
              $ref: '#/components/responses/400'
            422:
              $ref: '#/components/responses/422'
            500:
              $ref: '#/components/responses/500'
        """
        if not request.is_json:
            raise InvalidPayloadFormatError("Request is not JSON")

        try:
            payload = DatabaseValidateParametersSchema().load(request.json)
        except ValidationError as error:
            errors = [
                SupersetError(
                    message="\n".join(messages),
                    error_type=SupersetErrorType.INVALID_PAYLOAD_SCHEMA_ERROR,
                    level=ErrorLevel.ERROR,
                    extra={"invalid": [attribute]},
                )
                for attribute, messages in error.messages.items()
            ]
            raise InvalidParametersError(errors)

        command = ValidateDatabaseParametersCommand(g.user, payload)
        command.run()
        return self.response(200, message="OK")