# server.py
#
# This source file is part of the FoundationDB open source project
#
# Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
#
# 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 Flask
import fdb

app = Flask(__name__)

fdb.api_version(510)
db=fdb.open()

COUNTER_KEY=fdb.tuple.pack(('counter',))
def _increment_counter(tr):
    counter_value = tr[COUNTER_KEY]
    if counter_value == None:
        counter = 1
    else:
        counter = fdb.tuple.unpack(counter_value)[0] + 1
    tr[COUNTER_KEY] = fdb.tuple.pack((counter,))
    return counter

@app.route("/counter", methods=['GET'])
def get_counter():
    counter_value = db[COUNTER_KEY]
    if counter_value == None:
        return '0'
    else:
        return str(fdb.tuple.unpack(counter_value)[0])

@app.route("/counter/increment", methods=['POST'])
def increment_counter():
    return str(_increment_counter(db))