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# 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 os

from flask import flash, g, redirect
from flask_appbuilder import SimpleFormView
from flask_appbuilder.models.sqla.interface import SQLAInterface
from flask_babel import lazy_gettext as _
from werkzeug.utils import secure_filename
from wtforms.fields import StringField
from wtforms.validators import ValidationError

import superset.models.core as models
from superset import app, db
from superset.connectors.sqla.models import SqlaTable
from superset.utils import core as utils
from superset.views.base import DeleteMixin, SupersetModelView, YamlExportMixin

from .forms import CsvToDatabaseForm
from .mixins import DatabaseMixin
from .validators import schema_allows_csv_upload, sqlalchemy_uri_validator

config = app.config
stats_logger = config["STATS_LOGGER"]


def sqlalchemy_uri_form_validator(_, field: StringField) -> None:
    """
        Check if user has submitted a valid SQLAlchemy URI
    """
    sqlalchemy_uri_validator(field.data, exception=ValidationError)


class DatabaseView(
    DatabaseMixin, SupersetModelView, DeleteMixin, YamlExportMixin
):  # pylint: disable=too-many-ancestors
    datamodel = SQLAInterface(models.Database)

    add_template = "superset/models/database/add.html"
    edit_template = "superset/models/database/edit.html"
    validators_columns = {"sqlalchemy_uri": [sqlalchemy_uri_form_validator]}

    yaml_dict_key = "databases"

    def _delete(self, pk):
        DeleteMixin._delete(self, pk)


class CsvToDatabaseView(SimpleFormView):
    form = CsvToDatabaseForm
    form_template = "superset/form_view/csv_to_database_view/edit.html"
    form_title = _("CSV to Database configuration")
    add_columns = ["database", "schema", "table_name"]

    def form_get(self, form):
        form.sep.data = ","
        form.header.data = 0
        form.mangle_dupe_cols.data = True
        form.skipinitialspace.data = False
        form.skip_blank_lines.data = True
        form.infer_datetime_format.data = True
        form.decimal.data = "."
        form.if_exists.data = "fail"

    def form_post(self, form):
        database = form.con.data
        schema_name = form.schema.data or ""

        if not schema_allows_csv_upload(database, schema_name):
            message = _(
                'Database "%(database_name)s" schema "%(schema_name)s" '
                "is not allowed for csv uploads. Please contact your Superset Admin.",
                database_name=database.database_name,
                schema_name=schema_name,
            )
            flash(message, "danger")
            return redirect("/csvtodatabaseview/form")

        csv_file = form.csv_file.data
        form.csv_file.data.filename = secure_filename(form.csv_file.data.filename)
        csv_filename = form.csv_file.data.filename
        path = os.path.join(config["UPLOAD_FOLDER"], csv_filename)
        try:
            utils.ensure_path_exists(config["UPLOAD_FOLDER"])
            csv_file.save(path)
            table_name = form.name.data

            con = form.data.get("con")
            database = (
                db.session.query(models.Database).filter_by(id=con.data.get("id")).one()
            )
            database.db_engine_spec.create_table_from_csv(form, database)

            table = (
                db.session.query(SqlaTable)
                .filter_by(
                    table_name=table_name,
                    schema=form.schema.data,
                    database_id=database.id,
                )
                .one_or_none()
            )
            if table:
                table.fetch_metadata()
            if not table:
                table = SqlaTable(table_name=table_name)
                table.database = database
                table.database_id = database.id
                table.user_id = g.user.id
                table.schema = form.schema.data
                table.fetch_metadata()
                db.session.add(table)
            db.session.commit()
        except Exception as e:  # pylint: disable=broad-except
            db.session.rollback()
            try:
                os.remove(path)
            except OSError:
                pass
            message = _(
                'Unable to upload CSV file "%(filename)s" to table '
                '"%(table_name)s" in database "%(db_name)s". '
                "Error message: %(error_msg)s",
                filename=csv_filename,
                table_name=form.name.data,
                db_name=database.database_name,
                error_msg=str(e),
            )

            flash(message, "danger")
            stats_logger.incr("failed_csv_upload")
            return redirect("/csvtodatabaseview/form")

        os.remove(path)
        # Go back to welcome page / splash screen
        message = _(
            'CSV file "%(csv_filename)s" uploaded to table "%(table_name)s" in '
            'database "%(db_name)s"',
            csv_filename=csv_filename,
            table_name=form.name.data,
            db_name=table.database.database_name,
        )
        flash(message, "info")
        stats_logger.incr("successful_csv_upload")
        return redirect("/tablemodelview/list/")


class DatabaseTablesAsync(DatabaseView):  # pylint: disable=too-many-ancestors
    list_columns = ["id", "all_table_names_in_database", "all_schema_names"]


class DatabaseAsync(DatabaseView):  # pylint: disable=too-many-ancestors
    list_columns = [
        "id",
        "database_name",
        "expose_in_sqllab",
        "allow_ctas",
        "force_ctas_schema",
        "allow_run_async",
        "allow_dml",
        "allow_multi_schema_metadata_fetch",
        "allow_csv_upload",
        "allows_subquery",
        "backend",
    ]
