'''
Created on Dec 19, 2016

@author: klaehn
'''
import time
import mqtt
import gate_guard.data_buffer
import gate_guard.light_sensor
import gate_guard.engine
import gate_guard.power_sensor
import scipy
import scipy.stats
import logging

STATE_INIT = "init"
STATE_OPENED = "open"
STATE_CLOSED = "close"
STATE_OPENING = "opening"
STATE_CLOSING = "closing"
STATE_ERROR = "error"

LIGHT_READ_DELAY_S = 30
LIGHT_CONSECUTIVE_READS = 10
LIGHT_LX_THRESHOLD = {"open":10, "close":5}

MQTT_HOST = "proxy"
MQTT_TOPIC = "outdoor/chickenhouse/gate"

LIGHT_SENSOR_I2C_BUS = 1
LIGHT_SENSOR_I2C_ADDRESS = 0x23

POWER_SENSOR_I2C_BUS = 1
POWER_SENSOR_I2C_ADDRESS = 0x40

SLOPE_COUNT = 10
SLOPE_CNT_MIN = 2

MAX_GATE_RUNTIME = {"open":70, "close":60}
MAX_POWER_SLOPE = {"up":40, "down":15}

class Gate(object):
    def __init__(self):
        self.__state_handler = {STATE_INIT:self.__init_handler, \
                                STATE_OPENED:self.__opened_handler, \
                                STATE_CLOSED:self.__closed_handler, \
                                STATE_OPENING:self.__opening_handler, \
                                STATE_CLOSING:self.__closing_handler, \
                                STATE_ERROR:self.__error_handler}
        self.__next_state = STATE_INIT
        self.__last_state = STATE_ERROR

        self.__light_sensor = gate_guard.light_sensor.LightSensor(
            LIGHT_SENSOR_I2C_BUS, LIGHT_SENSOR_I2C_ADDRESS)
        self.__light_data = gate_guard.data_buffer.DataBuffer(
            LIGHT_CONSECUTIVE_READS)
        self.__comserver = mqtt.Mqtt(MQTT_HOST)
        self.__engine = gate_guard.engine.Engine(gpio_1=13, gpio_2=19)
        self.__power_sensor = gate_guard.power_sensor.PowerSensor(
            POWER_SENSOR_I2C_BUS, POWER_SENSOR_I2C_ADDRESS)
        self.__gate_move_timeout = 0
        self.__light_read_timeout = 0
        self.__error_count = 0

        self.slope_power = gate_guard.data_buffer.DataBuffer(SLOPE_COUNT)
        self.slope_time = gate_guard.data_buffer.DataBuffer(SLOPE_COUNT)

    def poll(self):
        current_time = time.time()
        if current_time >= self.__light_read_timeout:
            self.__light_read_timeout = current_time + LIGHT_READ_DELAY_S
            self.__light_data.push(self.__light_sensor.read())
        self.__state_handler[self.__next_state](self.__light_data.average())

    def __update_state(self, new_state):
        self.__last_state = self.__next_state
        self.__next_state = new_state


    def __is_transition(self):
        if self.__last_state != self.__next_state:
            logging.info('STATE: ' + self.__last_state + ' -> ' + \
                         self.__next_state)
            return True
        return False


    def __init_handler(self, light_avg):
        '''
        In init we don't know anything neither about gate state nor about
        light. So first we try to reach STATE_OPENED.
        '''
        #pylint: disable=unused-argument
        self.__comserver.connect()
        self.__comserver.transmit(MQTT_TOPIC, str(time.time()) + \
                                  " gate gard initiated")
        self.__comserver.disconnect()
        self.__update_state(STATE_OPENING)


    def __opened_handler(self, light_avg):
        next_state = self.__next_state
        if self.__is_transition():
            self.__engine.down()
            time.sleep(0.5)
            self.__engine.stop()
            slope, _, _, _, _ = scipy.stats.linregress(self.slope_time.get(),
                                                       self.slope_power.get())
            self.__comserver.transmit(MQTT_TOPIC, str(time.time()) + \
                                      " Opened " + \
                                      str(slope))
            self.slope_power.clear()
            self.slope_time.clear()

        if (light_avg != None) and (light_avg <= LIGHT_LX_THRESHOLD["close"]):
            next_state = STATE_CLOSING

        self.__update_state(next_state)


    def __closed_handler(self, light_avg):
        next_state = self.__next_state
        if self.__is_transition():
            self.__engine.up()
            time.sleep(0.5)
            self.__engine.stop()
            slope, _, _, _, _ = scipy.stats.linregress(self.slope_time.get(),
                                                       self.slope_power.get())
            self.__comserver.transmit(MQTT_TOPIC, str(time.time()) + \
                                      " Closed " + \
                                      str(slope))
            self.slope_power.clear()
            self.slope_time.clear()

        if (light_avg != None) and (light_avg > LIGHT_LX_THRESHOLD["open"]):
            next_state = STATE_OPENING

        self.__update_state(next_state)


    def __opening_handler(self, light_avg):
        next_state = self.__next_state
        if self.__is_transition():
            self.__engine.up()
            self.__gate_move_timeout = time.time() + MAX_GATE_RUNTIME["open"]
            self.__comserver.transmit(MQTT_TOPIC, str(time.time()) + \
                                      " Opening " + str(light_avg) + " lx")
        tm = time.time()
        if tm > self.__gate_move_timeout:
            next_state = STATE_ERROR
        else:
            pwr = self.__power_sensor.power_mw()
            self.slope_power.push(pwr)
            self.slope_time.push(tm)
            slope = 0
            if self.slope_power.length() >= SLOPE_CNT_MIN:
                slope, _, _, _, _ = scipy.stats.linregress(
                    self.slope_time.get(), self.slope_power.get())
            logging.debug('up: ' + str(tm) + ' ' + str(pwr) + ' ' + str(slope))
            if slope > MAX_POWER_SLOPE["up"]:
                next_state = STATE_OPENED
        self.__update_state(next_state)

    def __closing_handler(self, light_avg):
        next_state = self.__next_state
        if self.__is_transition():
            self.__engine.down()
            self.__gate_move_timeout = time.time() + MAX_GATE_RUNTIME["close"]
            self.__comserver.transmit(MQTT_TOPIC, str(time.time()) + \
                                      " Closing " + str(light_avg) + " lx")

        tm = time.time()
        if tm > self.__gate_move_timeout:
            next_state = STATE_ERROR
        else:
            pwr = self.__power_sensor.power_mw()
            self.slope_power.push(pwr)
            self.slope_time.push(tm)
            slope = 0
            if self.slope_power.length() >= SLOPE_CNT_MIN:
                slope, _, _, _, _ = scipy.stats.linregress(
                    self.slope_time.get(), self.slope_power.get())
            logging.debug('dw: ' + str(tm) + ' ' + str(pwr) + ' ' + str(slope))
            if slope > MAX_POWER_SLOPE["down"]:
                next_state = STATE_CLOSED
        self.__update_state(next_state)


    def __error_handler(self, light_avg):
        #pylint: disable=unused-argument
        if self.__is_transition():
            self.__engine.stop()
            self.__comserver.transmit(MQTT_TOPIC, str(time.time()) + \
                                      " Error handler!!!")
            self.__update_state(STATE_INIT)