# Copyright 2019 AT&T Intellectual Property. All rights reserved.
#
# Licensed 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 jinja2 import Environment, FileSystemLoader
from robot import utils
from robot.api.deco import keyword
from string import Template


class TemplatingKeywords(object):
    """Templating is an ONAP resource for templating with strings in robot framework. Under the hood it uses the Jinja2
    templating engine
    """

    def __init__(self):
        self._cache = utils.ConnectionCache('No Jinja Environments created')

    @keyword
    def create_environment(self, alias, templates_folder):
        """create an environment under an alias for tempalte location"""
        jinja_env = Environment(
            loader=FileSystemLoader(templates_folder)
        )
        self._cache.register(jinja_env, alias=alias)

    @keyword
    def apply_template(self, alias, template_location, values):
        """returns a string that is the jinja template in template_location filled in via the dictionary in values """
        template = self._cache.switch(alias).get_template(template_location)
        return template.render(values)

    @keyword
    def template_string(self, template, values):
        """Template String takes in a string and its values and converts it using the string.Template class"""
        return Template(template).substitute(values)