# 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.
"""Contains the logic to create cohesive forms on the explore view"""
from typing import List  # pylint: disable=unused-import

from flask_appbuilder.fieldwidgets import BS3TextFieldWidget
from wtforms import Field


class CommaSeparatedListField(Field):
    widget = BS3TextFieldWidget()
    data = []  # type: List[str]

    def _value(self):
        if self.data:
            return u", ".join(self.data)

        return u""

    def process_formdata(self, valuelist):
        if valuelist:
            self.data = [x.strip() for x in valuelist[0].split(",")]
        else:
            self.data = []


def filter_not_empty_values(value):
    """Returns a list of non empty values or None"""
    if not value:
        return None
    data = [x for x in value if x]
    if not data:
        return None
    return data