from __future__ import unicode_literals
import logging
import serial
import re
import threading
import time

# from pypca.exceptions import PCAException
import pypca.constants as CONST

_LOGGER = logging.getLogger(__name__)


# get ready-> get last line not second or something, or flush output after ready
class PCA:

    _serial = None
    _stopevent = None
    _thread = None
    _re_reading = re.compile(
        r"OK 24 (\d+) 4 (\d+) (\d+) (\d+) (\d+) (\d+) (\d+) (\d+) (\d+)"
    )
    _re_devices = re.compile(
        r"L 24 (\d+) (\d+) : (\d+) 4 (\d+) (\d+) (\d+) (\d+) (\d+) (\d+) (\d+) (\d+)"
    )

    def __init__(self, port, timeout=2):
        """Initialize the pca device."""
        self._devices = {}
        self._port = port
        self._baud = 57600
        self._timeout = timeout
        self._serial = serial.Serial(timeout=timeout)

    def open(self):
        """Open the device."""
        self._serial.port = self._port
        self._serial.baudrate = self._baud
        self._serial.timeout = self._timeout
        self._serial.open()
        self._serial.flushInput()
        self._serial.flushOutput()
        self.get_ready()

    def close(self):
        """Close the device."""
        self._stop_worker()
        self._serial.close()

    def get_ready(self):
        """Wait til the device is ready"""
        line = self._serial.readline().decode("utf-8")
        start = time.time()
        timeout = 5
        while self._re_reading.match(line) is None and time.time() - start < timeout:
            line = self._serial.readline().decode("utf-8")
        return True

    def get_devices(self):
        """Get all the devices with the help of the l switch"""
        self._write_cmd("l")
        line = self._serial.readline().decode("utf-8")
        while self._re_devices.match(line) is not None:
            # add the line to devices dict
            line = line.split(" ")
            deviceId = (
                str(line[7]).zfill(3) + str(line[8]).zfill(3) + str(line[9]).zfill(3)
            )
            self._devices[deviceId] = {}
            self._devices[deviceId]["state"] = line[10]
            self._devices[deviceId]["power"] = (
                int(line[11]) * 256 + int(line[12])
            ) / 10.0
            self._devices[deviceId]["consumption"] = (
                int(line[13]) * 256 + int(line[14])
            ) / 100.0
            line = self._serial.readline().decode("utf-8")
            time.sleep(
                0.05
            )  # sleep here, otherwise the loop will lock the serial interface
        return self._devices

    def get_current_power(self, deviceId):
        """Get current power usage of given DeviceID."""
        return self._devices[deviceId]["power"]

    def get_total_consumption(self, deviceId):
        """Get total power consumption of given DeviceID in KWh."""
        return self._devices[deviceId]["consumption"]

    def get_state(self, deviceId):
        """Get state of given DeviceID."""
        return self._devices[deviceId]["state"]

    def _stop_worker(self):
        if self._stopevent is not None:
            self._stopevent.set()
        if self._thread is not None:
            self._thread.join()

    def start_scan(self):
        """Start scan task in background."""
        self.get_devices()
        self._start_worker()

    def _write_cmd(self, cmd):
        """Write a cmd."""
        self._serial.write(cmd.encode())

    def _start_worker(self):
        """Start the scan worker."""
        if self._thread is not None:
            return
        self._stopevent = threading.Event()
        self._thread = threading.Thread(target=self._refresh, args=())
        self._thread.daemon = True
        self._thread.start()

    def turn_off(self, deviceId):
        """Turn off given DeviceID."""
        address = re.findall("...", deviceId)
        offCommand = "1,5,{},{},{},{},255,255,255,255{}".format(
            address[0].lstrip("0"),
            address[1].lstrip("0"),
            address[2].lstrip("0"),
            "0",
            CONST.SEND_SUFFIX,
        )
        self._write_cmd(offCommand)
        self._devices[deviceId]["state"] = 0
        return True

    def turn_on(self, deviceId):
        """Turn on given DeviceID."""
        address = re.findall("...", deviceId)
        onCommand = "1,5,{},{},{},{},255,255,255,255{}".format(
            address[0].lstrip("0"),
            address[1].lstrip("0"),
            address[2].lstrip("0"),
            "1",
            CONST.SEND_SUFFIX,
        )
        self._write_cmd(onCommand)
        self._devices[deviceId]["state"] = 1
        return True

    def _refresh(self):
        """Background refreshing thread."""

        while not self._stopevent.isSet():
            line = self._serial.readline()
            # this is for python2/python3 compatibility. Is there a better way?
            try:
                line = line.encode().decode("utf-8")
            except AttributeError:
                line = line.decode("utf-8")

            if self._re_reading.match(line):
                line = line.split(" ")
                deviceId = (
                    str(line[4]).zfill(3)
                    + str(line[5]).zfill(3)
                    + str(line[6]).zfill(3)
                )
                self._devices[deviceId]["power"] = (
                    int(line[8]) * 256 + int(line[9])
                ) / 10.0
                self._devices[deviceId]["state"] = int(line[7])
                self._devices[deviceId]["consumption"] = (
                    int(line[10]) * 256 + int(line[11])
                ) / 100.0