# Copyright 2018 Xiaomi, Inc.  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.

import json
import socket
import itertools
import sys

import six


class FalconCli(object):
    def __init__(self, addr, debug=True, buf_size=1000):
        self.socket_ = socket.create_connection(addr)
        self.stream = self.socket_.makefile()
        self.id_counter = itertools.count()
        self.debug = debug
        self.buf_size = buf_size

    def __del__(self):
        self.socket_.close()
        self.stream.close()

    @classmethod
    def connect(cls,
                server,
                port=8433,
                debug=True,
                buf_size=1000):
        try:
            return FalconCli((server, port), debug, buf_size)
        except socket.error as exc:
            six.print_("error: connect to %s:%s error: %s"
                       % (server, port, exc), file=sys.stderr)

    def call(self, name, *params):
        request = dict(
            id=next(self.id_counter), params=list(params), method=name)
        payload = json.dumps(request).encode()
        if self.debug:
            six.print_("--> req:", payload)
        self.socket_.sendall(payload)

        response = self.stream.readline()
        if not response:
            raise Exception('empty response')

        if self.debug:
            six.print_("<-- resp:", response)

        response = json.loads(response.decode("utf8"))
        if response.get('error') is not None:
            raise Exception(response.get('error'))

        return response.get('result')

    def update(self, lines):
        s = 0
        resp = []

        while True:
            buf = lines[s:s + self.buf_size]
            s = s + self.buf_size
            if len(buf) == 0:
                break
            r = self.call("Transfer.Update", buf)
            resp.append(r)

        return resp
