# -*- coding: utf-8 -*-
#!/usr/bin/env python
import os

from typing import List
from functools import partial

from dotenv import load_dotenv
from passlib.context import CryptContext


load_dotenv('.env.simulator')

class CMD(object):

    HAND_SHAKE = 200
    GET_INFO = 201
    CONFIG_DEVICE = 202

    #: init mobile payment, publish by app
    MOBILE_PAY_INIT = 203
    #: finish mobile payment, publish by the device smartbox
    MOBILE_PAY_FIN = 204

    PUT_COIN = 205
    HEARTBEAT = 207
    OFFLINE = 208

DEVICE_TOPIC_PREFIX = 'smart_box'
SERVER_TOPIC_PREFIX = 'server'
MQTT_QOS = 0
MQTT_QOS1 = 1

MQTT_HOSTNAME = os.environ.get('MQTT_HOSTNAME', '127.0.0.1')
MQTT_PORT = int(os.environ.get('MQTT_PORT', 1999))
MQTT_BROKER_URL = os.environ.get('MQTT_BROKER_URL', 'localhost')
MQTT_BROKER_SCHEME = os.environ.get('MQTT_BROKER_SCHEME', 'tcp')

DEFAULT_DEVICE_IMEI = os.environ.get('DEFAULT_DEVICE_IMEI')

# constants

SINGLE_LEVEL_ALL = '+'
MULTI_LEVEL_ALL = '#'

def get_topic(prefix, imei, cmd):
    # type: (str, str, int)->str
    return '{prefix}/{imei}/{cmd}'.format(prefix=prefix, imei=imei, cmd=cmd)

def get_device_topic(imei, cmd):
    # type: (str, int)->str

    return get_topic(prefix=DEVICE_TOPIC_PREFIX, imei=imei, cmd=cmd)

def get_server_topic(imei, cmd):
    # type: (str, int)->str

    return get_topic(prefix=SERVER_TOPIC_PREFIX, imei=imei, cmd=cmd)

#: topics

handshake_topic = partial(get_server_topic, cmd=CMD.HAND_SHAKE)
get_info_topic = partial(get_server_topic, cmd=CMD.GET_INFO)
config_device_topic = partial(get_server_topic, cmd=CMD.CONFIG_DEVICE)
mobile_pay_init_topic = partial(get_server_topic, cmd=CMD.MOBILE_PAY_INIT)
mobile_pay_finish_topic = partial(get_server_topic, cmd=CMD.MOBILE_PAY_FIN)
put_coin_topic = partial(get_server_topic, cmd=CMD.PUT_COIN)
heartbeat_topic = partial(get_server_topic, cmd=CMD.HEARTBEAT)
offline_topic = partial(get_server_topic, cmd=CMD.OFFLINE)

SERVER_TOPICS = [
    get_server_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.HAND_SHAKE),
    get_server_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.GET_INFO),
    get_server_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.CONFIG_DEVICE),
    get_server_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.MOBILE_PAY_INIT),
    get_server_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.MOBILE_PAY_FIN),
    get_server_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.PUT_COIN),
    get_server_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.HEARTBEAT),
    get_server_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.OFFLINE),
] # type: List[str]

DEVICE_TOPICS = [
    get_device_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.HAND_SHAKE),
    get_device_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.GET_INFO),
    get_device_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.CONFIG_DEVICE),
    get_device_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.MOBILE_PAY_INIT),
    get_device_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.MOBILE_PAY_FIN),
    get_device_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.PUT_COIN),
    get_device_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.HEARTBEAT),
    get_device_topic(imei=SINGLE_LEVEL_ALL, cmd=CMD.OFFLINE),
]

DEV_STATUS_IDLE = 0
DEV_STATUS_BUSY = 1

DEV_OFFLINE = 0
DEV_ONLINE = 1


class BaseProtocolHandler(object):

    def handle(self, payload):

        methname = 'handle_{cmd}'.format(cmd=payload['cmd'])

        method = getattr(self, methname)

        if not method:
            raise RuntimeError('no command {} handler found!')
        else:
            method(payload)


#: encryption

pwd_context = CryptContext(
        schemes=["pbkdf2_sha256"],
        default="pbkdf2_sha256",
        pbkdf2_sha256__default_rounds=30000
)


def encrypt_password(password):
    return pwd_context.hash(password)


def check_encrypted_password(password, hashed):
    return pwd_context.verify(password, hashed)