#!/usr/bin/env python3
from __future__ import annotations

import logging
import locale
import queue
import time
import threading
import paho.mqtt.client as mqtt

from home.bot import Wrapper, Context, text_filter, handlermethod
from home.api.types import BotType
from home.mqtt import MQTTBase
from home.config import config
from polaris import (
    Kettle,
    PowerType,
    DeviceListener,
    IncomingMessageListener,
    ConnectionStatusListener,
    ConnectionStatus
)
import polaris.protocol as kettle_proto
from typing import Optional, Tuple, List
from collections import namedtuple
from functools import partial
from datetime import datetime
from abc import abstractmethod
from telegram.error import TelegramError
from telegram import (
    ReplyKeyboardMarkup,
    InlineKeyboardMarkup,
    InlineKeyboardButton,
    Message
)
from telegram.ext import (
    CallbackQueryHandler,
    MessageHandler,
    CommandHandler
)

logger = logging.getLogger(__name__)
kc: Optional[KettleController] = None
bot: Optional[Wrapper] = None
RenderedContent = Tuple[str, Optional[InlineKeyboardMarkup]]
tasks_lock = threading.Lock()


class KettleInfoListener:
    @abstractmethod
    def info_updated(self, field: str):
        pass


# class that holds data coming from the kettle over mqtt
class KettleInfo:
    update_time: int
    _mode: Optional[PowerType]
    _temperature: Optional[int]
    _target_temperature: Optional[int]
    _update_listener: KettleInfoListener

    def __init__(self, update_listener: KettleInfoListener):
        self.update_time = 0
        self._mode = None
        self._temperature = None
        self._target_temperature = None
        self._update_listener = update_listener

    def _update(self, field: str):
        self.update_time = int(time.time())
        if self._update_listener:
            self._update_listener.info_updated(field)

    @property
    def temperature(self) -> int:
        return self._temperature

    @temperature.setter
    def temperature(self, value: int):
        self._temperature = value
        self._update('temperature')

    @property
    def mode(self) -> PowerType:
        return self._mode

    @mode.setter
    def mode(self, value: PowerType):
        self._mode = value
        self._update('mode')

    @property
    def target_temperature(self) -> int:
        return self._target_temperature

    @target_temperature.setter
    def target_temperature(self, value: int):
        self._target_temperature = value
        self._update('target_temperature')


class KettleController(threading.Thread,
                       MQTTBase,
                       DeviceListener,
                       IncomingMessageListener,
                       KettleInfoListener,
                       ConnectionStatusListener):
    kettle: Kettle
    info: KettleInfo

    _logger: logging.Logger
    _stopped: bool
    _restart_server_at: int
    _lock: threading.Lock
    _info_lock: threading.Lock
    _accumulated_updates: dict
    _info_flushed_time: float
    _mqtt_root_topic: str
    _muts: List[MessageUpdatingTarget]

    def __init__(self):
        # basic setup
        MQTTBase.__init__(self, clean_session=False)
        threading.Thread.__init__(self)

        self._logger = logging.getLogger(self.__class__.__name__)

        self.kettle = Kettle(mac=config['kettle']['mac'],
                             device_token=config['kettle']['token'])
        self.kettle_reconnect()

        # info
        self.info = KettleInfo(update_listener=self)
        self._accumulated_updates = {}
        self._info_flushed_time = 0

        # mqtt
        self._mqtt_root_topic = '/polaris/6/'+config['kettle']['token']+'/#'
        self.connect_and_loop(loop_forever=False)

        # thread loop related
        self._stopped = False
        # self._lock = threading.Lock()
        self._info_lock = threading.Lock()
        self._restart_server_at = 0

        # bot
        self._muts = []
        self._muts_lock = threading.Lock()

        self.start()

    def kettle_reconnect(self):
        self.kettle.discover(wait=False, listener=self)

    def stop_all(self):
        self.kettle.stop_all()
        self._stopped = True

    def add_updating_message(self, mut: MessageUpdatingTarget):
        with self._muts_lock:
            for m in self._muts:
                if m.user_id == m.user_id and m.user_did_turn_on() or m.user_did_turn_on() != mut.user_did_turn_on():
                    m.delete()
            self._muts.append(mut)

    # ---------------------
    # threading.Thread impl

    def run(self):
        while not self._stopped:
            # do_restart_srv = False
            #
            # with self._lock:
            #     if self._restart_server_at != 0 and time.time() - self._restart_server_at:
            #         self._restart_server_at = 0
            #         do_restart_srv = True
            #
            # if do_restart_srv:
            #     self.kettle_connect()

            updates = []
            deletions = []
            with self._muts_lock and self._info_lock:
                # self._logger.debug('muts size: '+str(len(self._muts)))
                if self._muts and self._accumulated_updates and (self._info_flushed_time == 0 or time.time() - self._info_flushed_time >= 1):
                    forget = []
                    deletions = []

                    for mut in self._muts:
                        upd = mut.update(
                            mode=self.info.mode,
                            current_temp=self.info.temperature,
                            target_temp=self.info.target_temperature)

                        if upd.finished or upd.delete:
                            forget.append(mut)

                        if upd.delete:
                            deletions.append(upd)
                        elif upd.changed:
                            updates.append(upd)

                    if forget:
                        for mut in forget:
                            self._logger.debug(f'loop: removing mut {mut}')
                            self._muts.remove(mut)

                    self._info_flushed_time = time.time()
                    self._accumulated_updates = {}

            for upd in updates:
                self._logger.debug(f'loop: got update: {upd}')
                try:
                    bot.edit_message_text(upd.user_id, upd.message_id,
                                          text=upd.html,
                                          reply_markup=upd.markup)
                except TelegramError as exc:
                    self._logger.error(f'loop: edit_message_text failed for update: {upd}')
                    self._logger.exception(exc)

            for upd in deletions:
                self._logger.debug(f'loop: got deletion: {upd}')
                try:
                    bot.delete_message(upd.user_id, upd.message_id)
                except TelegramError as exc:
                    self._logger.error(f'loop: delete_message failed for update: {upd}')
                    self._logger.exception(exc)

            time.sleep(0.5)

    # -------------------
    # DeviceListener impl

    def device_updated(self):
        self._logger.info(f'device updated: {self.kettle.device.si}')
        self.kettle.start_server_if_needed(incoming_message_listener=self,
                                           connection_status_listener=self)

    # -----------------------
    # KettleInfoListener impl

    def info_updated(self, field: str):
        with self._info_lock:
            newval = getattr(self.info, field)
            self._logger.debug(f'info_updated: updated {field}, new value is {newval}')
            self._accumulated_updates[field] = newval

    # ----------------------------
    # IncomingMessageListener impl

    def incoming_message(self, message: kettle_proto.Message) -> Optional[kettle_proto.Message]:
        self._logger.info(f'incoming message: {message}')

        if isinstance(message, kettle_proto.ModeMessage):
            self.info.mode = message.pt
        elif isinstance(message, kettle_proto.CurrentTemperatureMessage):
            self.info.temperature = message.current_temperature
        elif isinstance(message, kettle_proto.TargetTemperatureMessage):
            self.info.target_temperature = message.temperature

        return kettle_proto.AckMessage()

    # -----------------------------
    # ConnectionStatusListener impl

    def connection_status_updated(self, status: ConnectionStatus):
        self._logger.info(f'connection status updated: {status}')
        if status == ConnectionStatus.DISCONNECTED:
            self.kettle.stop_all()
            self.kettle_reconnect()

    # -------------
    # MQTTBase impl

    def on_connect(self, client: mqtt.Client, userdata, flags, rc):
        super().on_connect(client, userdata, flags, rc)
        client.subscribe(self._mqtt_root_topic, qos=1)
        self._logger.info(f'subscribed to {self._mqtt_root_topic}')

    def on_message(self, client: mqtt.Client, userdata, msg):
        try:
            topic = msg.topic[len(self._mqtt_root_topic)-2:]
            pld = msg.payload.decode()

            self._logger.debug(f'mqtt: on message: topic={topic} pld={pld}')

            if topic == 'state/sensor/temperature':
                self.info.temperature = int(float(pld))
            elif topic == 'state/mode':
                self.info.mode = PowerType(int(pld))
            elif topic == 'state/temperature':
                self.info.target_temperature = int(float(pld))

        except Exception as e:
            self._logger.exception(str(e))


class Renderer:
    @classmethod
    def index(cls, ctx: Context) -> RenderedContent:
        html = f'<b>{ctx.lang("settings")}</b>\n\n'
        html += ctx.lang('select_place')
        return html, None

    @classmethod
    def status(cls, ctx: Context,
               connected: bool,
               mode: PowerType,
               current_temp: int,
               target_temp: int,
               update_time: int) -> RenderedContent:
        if not connected:
            return cls.not_connected(ctx)
        else:
            # power status
            if mode != PowerType.OFF:
                html = ctx.lang('status_on', target_temp)
            else:
                html = ctx.lang('status_off')

            # current temperature
            html += '\n'
            html += ctx.lang('status_current_temp', current_temp)

            # updated on
            html += '\n'
            html += cls.updated(ctx, update_time)

        return html, None

    @classmethod
    def turned_on(cls, ctx: Context,
                  target_temp: int,
                  current_temp: int,
                  mode: PowerType,
                  update_time: Optional[int] = None,
                  reached=False,
                  no_keyboard=False) -> RenderedContent:
        if mode == PowerType.OFF and not reached:
            html = ctx.lang('enabling')
        else:
            if not reached:
                emoji = '♨️' if current_temp <= 90 else '🔥'
                html = ctx.lang('enabled', emoji, target_temp)

                # current temperature
                html += '\n'
                html += ctx.lang('status_current_temp', current_temp)
            else:
                html = ctx.lang('enabled_reached', current_temp)

            # updated on
            if not reached and update_time is not None:
                html += '\n'
                html += cls.updated(ctx, update_time)

        return html, None if no_keyboard else cls.wait_buttons(ctx)

    @classmethod
    def turned_off(cls, ctx: Context,
                   mode: PowerType,
                   update_time: Optional[int] = None,
                   reached=False,
                   no_keyboard=False) -> RenderedContent:
        if mode != PowerType.OFF:
            html = ctx.lang('disabling')
        else:
            html = ctx.lang('disabled')

            # updated on
            if not reached and update_time is not None:
                html += '\n'
                html += cls.updated(ctx, update_time)

        return html, None if no_keyboard else cls.wait_buttons(ctx)

    @classmethod
    def not_connected(cls, ctx: Context) -> RenderedContent:
        return ctx.lang('status_not_connected'), None

    @classmethod
    def smth_went_wrong(cls, ctx: Context) -> RenderedContent:
        html = ctx.lang('smth_went_wrong')
        return html, None

    @classmethod
    def updated(cls, ctx: Context, update_time: int):
        locale_bak = locale.getlocale(locale.LC_TIME)
        locale.setlocale(locale.LC_TIME, 'ru_RU.UTF-8' if ctx.user_lang == 'ru' else 'en_US.UTF-8')
        dt = datetime.fromtimestamp(update_time)
        html = ctx.lang('status_update_time', dt.strftime(ctx.lang('status_update_time_fmt')))
        locale.setlocale(locale.LC_TIME, locale_bak)
        return html

    @classmethod
    def wait_buttons(cls, ctx: Context):
        return InlineKeyboardMarkup([
            [
                InlineKeyboardButton(ctx.lang('please_wait'), callback_data='wait')
            ]
        ])


def run_tasks(tasks: queue.SimpleQueue, done: callable):
    def next_task(r: Optional[kettle_proto.MessageResponse]):
        if r is not None:
            try:
                assert r is not False, 'server error'
            except AssertionError as exc:
                logger.exception(exc)
                tasks_lock.release()
                return done(False)

        if not tasks.empty():
            task = tasks.get()
            args = task[1:]
            args.append(next_task)
            f = getattr(kc.kettle, task[0])
            f(*args)
        else:
            tasks_lock.release()
            return done(True)

    tasks_lock.acquire()
    next_task(None)


MUTUpdate = namedtuple('MUTUpdate', 'message_id, user_id, finished, changed, delete, html, markup')


class MessageUpdatingTarget:
    ctx: Context
    message: Message
    user_target_temp: Optional[int]
    user_enabled_power_mode: PowerType
    initial_power_mode: PowerType
    need_to_delete: bool
    rendered_content: Optional[RenderedContent]

    def __init__(self,
                 ctx: Context,
                 message: Message,
                 user_enabled_power_mode: PowerType,
                 initial_power_mode: PowerType,
                 user_target_temp: Optional[int] = None):
        self.ctx = ctx
        self.message = message
        self.initial_power_mode = initial_power_mode
        self.user_enabled_power_mode = user_enabled_power_mode
        self.ignore_pm = initial_power_mode is PowerType.OFF and self.user_did_turn_on()
        self.user_target_temp = user_target_temp
        self.need_to_delete = False
        self.rendered_content = None
        self.last_reported_temp = None

    def set_rendered_content(self, content: RenderedContent):
        self.rendered_content = content

    def rendered_content_changed(self, content: RenderedContent) -> bool:
        return content != self.rendered_content

    def update(self,
               mode: PowerType,
               current_temp: int,
               target_temp: int) -> MUTUpdate:

        # determine whether status updating is finished
        finished = False
        reached = False
        if self.ignore_pm:
            if mode != PowerType.OFF:
                self.ignore_pm = False
        elif mode == PowerType.OFF:
            reached = True
            if self.user_did_turn_on():
                # when target is 100 degrees, this kettle sometimes turns off at 91, sometimes at 95, sometimes at 98.
                # it's totally unpredictable, so in this case, we keep updating the message until it reaches at least 97
                # degrees, or if temperature started dropping.
                if self.user_target_temp < 100 \
                        or current_temp >= self.user_target_temp - 3 \
                        or current_temp < self.last_reported_temp:
                    finished = True
            else:
                finished = True

        self.last_reported_temp = current_temp

        # render message
        if self.user_did_turn_on():
            rc = Renderer.turned_on(self.ctx,
                                    target_temp=target_temp,
                                    current_temp=current_temp,
                                    mode=mode,
                                    reached=reached,
                                    no_keyboard=finished)
        else:
            rc = Renderer.turned_off(self.ctx,
                                     mode=mode,
                                     reached=reached,
                                     no_keyboard=finished)

        changed = self.rendered_content_changed(rc)
        update = MUTUpdate(message_id=self.message.message_id,
                           user_id=self.ctx.user_id,
                           finished=finished,
                           changed=changed,
                           delete=self.need_to_delete,
                           html=rc[0],
                           markup=rc[1])
        if changed:
            self.set_rendered_content(rc)
        return update

    def user_did_turn_on(self) -> bool:
        return self.user_enabled_power_mode in (PowerType.ON, PowerType.CUSTOM)

    def delete(self):
        self.need_to_delete = True

    @property
    def user_id(self) -> int:
        return self.ctx.user_id


class KettleBot(Wrapper):
    def __init__(self):
        super().__init__()

        self.lang.ru(
            start_message="Выберите команду на клавиатуре",
            unknown_command="Неизвестная команда",
            unexpected_callback_data="Ошибка: неверные данные",
            enable_70="♨️ 70 °C",
            enable_80="♨️ 80 °C",
            enable_90="♨️ 90 °C",
            enable_100="🔥 100 °C",
            disable="❌ Выключить",
            server_error="Ошибка сервера",

            # /status
            status_not_connected="😟 Связь с чайником не установлена",
            status_on="✅ Чайник <b>включён</b> (до <b>%d °C</b>)",
            status_off="❌ Чайник <b>выключен</b>",
            status_current_temp="Сейчас: <b>%d °C</b>",
            status_update_time="<i>Обновлено %s</i>",
            status_update_time_fmt="%d %b в %H:%M:%S",

            # enable
            enabling="💤 Чайник включается...",
            disabling="💤 Чайник выключается...",
            enabled="%s Чайник <b>включён</b>.\nЦель: <b>%d °C</b>",
            enabled_reached="✅ <b>Готово!</b> Чайник вскипел, температура <b>%d °C</b>.",
            disabled="✅ Чайник <b>выключен</b>.",
            please_wait="⏳ Ожидайте..."
        )

        self.lang.en(
            start_message="Select command on the keyboard",
            unknown_command="Unknown command",
            unexpected_callback_data="Unexpected callback data",
            enable_70="♨️ 70 °C",
            enable_80="♨️ 80 °C",
            enable_90="♨️ 90 °C",
            enable_100="🔥 100 °C",
            disable="❌ Turn OFF",
            server_error="Server error",

            # /status
            not_connected="😟 Connection has not been established",
            status_on="✅ Turned <b>ON</b>! Target: <b>%d °C</b>",
            status_off="❌ Turned <b>OFF</b>",
            status_current_temp="Now: <b>%d °C</b>",
            status_update_time="<i>Updated on %s</i>",
            status_update_time_fmt="%b %d, %Y at %H:%M:%S",

            # enable
            enabling="💤 Turning on...",
            disabling="💤 Turning off...",
            enabled="%s The kettle is <b>turned ON</b>.\nTarget: <b>%d °C</b>",
            enabled_reached="✅ It's <b>done</b>! The kettle has boiled, the temperature is <b>%d °C</b>.",
            disabled="✅ The kettle is <b>turned OFF</b>.",
            please_wait="⏳ Please wait..."
        )

        # commands
        self.add_handler(CommandHandler('status', self.status))

        # messages
        for temp in (70, 80, 90, 100):
            self.add_handler(MessageHandler(text_filter(self.lang.all(f'enable_{temp}')), self.wrap(partial(self.on, temp))))

        self.add_handler(MessageHandler(text_filter(self.lang.all('disable')), self.off))

    def markup(self, ctx: Optional[Context]) -> Optional[ReplyKeyboardMarkup]:
        buttons = [
            [ctx.lang(f'enable_{x}') for x in (70, 80, 90, 100)],
            [ctx.lang('disable')]
        ]
        return ReplyKeyboardMarkup(buttons, one_time_keyboard=False)

    def on(self, temp: int, ctx: Context) -> None:
        if not kc.kettle.is_connected():
            text, markup = Renderer.not_connected(ctx)
            ctx.reply(text, markup=markup)
            return

        tasks = queue.SimpleQueue()
        if temp == 100:
            power_mode = PowerType.ON
        else:
            power_mode = PowerType.CUSTOM
            tasks.put(['set_target_temperature', temp])
        tasks.put(['set_power', power_mode])

        def done(ok: bool):
            if not ok:
                html, markup = Renderer.smth_went_wrong(ctx)
            else:
                html, markup = Renderer.turned_on(ctx,
                                                  target_temp=temp,
                                                  current_temp=kc.info.temperature,
                                                  mode=kc.info.mode)
            message = ctx.reply(html, markup=markup)
            logger.info(f'ctx.reply returned message: {message}')

            mut = MessageUpdatingTarget(ctx, message,
                                        initial_power_mode=kc.info.mode,
                                        user_enabled_power_mode=power_mode,
                                        user_target_temp=temp)
            mut.set_rendered_content((html, markup))
            kc.add_updating_message(mut)

        run_tasks(tasks, done)

    @handlermethod
    def off(self, ctx: Context) -> None:
        if not kc.kettle.is_connected():
            text, markup = Renderer.not_connected(ctx)
            ctx.reply(text, markup=markup)
            return

        def done(ok: bool):
            if not ok:
                html, markup = Renderer.smth_went_wrong(ctx)
            else:
                html, markup = Renderer.turned_off(ctx, mode=kc.info.mode)
            message = ctx.reply(html, markup=markup)
            logger.info(f'ctx.reply returned message: {message}')

            mut = MessageUpdatingTarget(ctx, message,
                                        initial_power_mode=kc.info.mode,
                                        user_enabled_power_mode=PowerType.OFF)
            mut.set_rendered_content((html, markup))
            kc.add_updating_message(mut)

        tasks = queue.SimpleQueue()
        tasks.put(['set_power', PowerType.OFF])
        run_tasks(tasks, done)

    @handlermethod
    def status(self, ctx: Context):
        text, markup = Renderer.status(ctx,
                                       connected=kc.kettle.is_connected(),
                                       mode=kc.info.mode,
                                       current_temp=kc.info.temperature,
                                       target_temp=kc.info.target_temperature,
                                       update_time=kc.info.update_time)
        return ctx.reply(text, markup=markup)


if __name__ == '__main__':
    config.load('polaris_kettle_bot')

    kc = KettleController()

    bot = KettleBot()
    if 'api' in config:
        bot.enable_logging(BotType.POLARIS_KETTLE)
    bot.run()

    # bot library handles signals, so when sigterm or something like that happens, we should stop all other threads here
    kc.stop_all()