# Copyright 2022-2023 ETSI TeraFlowSDN - TFS OSG (https://tfs.etsi.org/)
#
# 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 flask import current_app, render_template, Blueprint, flash, session, redirect, url_for
from common.proto.context_pb2 import Empty, Link, LinkId, LinkList
from common.tools.context_queries.EndPoint import get_endpoint_names
from common.tools.context_queries.Link import get_link
from common.tools.context_queries.Topology import get_topology
from context.client.ContextClient import ContextClient


link = Blueprint('link', __name__, url_prefix='/link')
context_client = ContextClient()

@link.get('/')
def home():
    if 'context_uuid' not in session or 'topology_uuid' not in session:
        flash("Please select a context!", "warning")
        return redirect(url_for("main.home"))

    context_uuid = session['context_uuid']
    topology_uuid = session['topology_uuid']

    links, endpoint_ids = list(), list()
    device_names, endpoints_data = dict(), dict()

    context_client.connect()
    grpc_topology = get_topology(context_client, topology_uuid, context_uuid=context_uuid, rw_copy=False)
    if grpc_topology is None:
        flash('Context({:s})/Topology({:s}) not found'.format(str(context_uuid), str(topology_uuid)), 'danger')
    else:
        topo_link_uuids = {link_id.link_uuid.uuid for link_id in grpc_topology.link_ids}
        grpc_links: LinkList = context_client.ListLinks(Empty())
        for link_ in grpc_links.links:
            if link_.link_id.link_uuid.uuid not in topo_link_uuids: continue
            links.append(link_)
            endpoint_ids.extend(link_.link_endpoint_ids)
        device_names, endpoints_data = get_endpoint_names(context_client, endpoint_ids)
    context_client.close()

    return render_template('link/home.html', links=links, device_names=device_names, endpoints_data=endpoints_data)


@link.route('detail/<path:link_uuid>', methods=('GET', 'POST'))
def detail(link_uuid: str):
    context_client.connect()
    link_obj = get_link(context_client, link_uuid, rw_copy=False)
    if link_obj is None:
        flash('Link({:s}) not found'.format(str(link_uuid)), 'danger')
        link_obj = Link()
        device_names, endpoints_data = dict(), dict()
    else:
        device_names, endpoints_data = get_endpoint_names(context_client, link_obj.link_endpoint_ids)
    context_client.close()
    return render_template('link/detail.html',link=link_obj, device_names=device_names, endpoints_data=endpoints_data)

@link.get('<path:link_uuid>/delete')
def delete(link_uuid):
    try:

        # first, check if link exists!
        # request: LinkId = LinkId()
        # request.link_uuid.uuid = link_uuid
        # response: Link = client.GetLink(request)
        # TODO: finalize implementation

        request = LinkId()
        request.link_uuid.uuid = link_uuid # pylint: disable=no-member
        context_client.connect()
        context_client.RemoveLink(request)
        context_client.close()

        flash(f'Link "{link_uuid}" deleted successfully!', 'success')
    except Exception as e: # pylint: disable=broad-except
        flash(f'Problem deleting link "{link_uuid}": {e.details()}', 'danger')
        current_app.logger.exception(e)
    return redirect(url_for('link.home'))
