#!/usr/bin/env python3
import logging
import re
import datetime
import json

from typing import Optional, Tuple
from argparse import ArgumentParser
from html import escape
from inverter_wrapper import wrapper_instance as inverter
from monitor import InverterMonitor, ChargingEvent, BatteryState
from inverterd import Format, InverterError
from telegram import (
    Update,
    ParseMode,
    InlineKeyboardButton,
    InlineKeyboardMarkup,
    ReplyKeyboardMarkup
)
from telegram.ext import (
    Updater,
    Filters,
    CommandHandler,
    MessageHandler,
    CallbackContext,
    CallbackQueryHandler
)
from telegram.error import TimedOut

monitor: Optional[InverterMonitor] = None
updater: Optional[Updater] = None
notify_to: list[int] = []
LT = escape('<=')
flags_map = {
    'buzzer': 'BUZZ',
    'overload_bypass': 'OLBP',
    'escape_to_default_screen_after_1min_timeout': 'LCDE',
    'overload_restart': 'OLRS',
    'over_temp_restart': 'OTRS',
    'backlight_on': 'BLON',
    'alarm_on_on_primary_source_interrupt': 'ALRM',
    'fault_code_record': 'FTCR',
}
_strings = {
    'status': 'Status',
    'generation': 'Generation',

    # flags
    'flag_buzzer': 'Buzzer',
    'flag_overload_bypass': 'Overload bypass',
    'flag_escape_to_default_screen_after_1min_timeout': 'Reset to default LCD page after 1min timeout',
    'flag_overload_restart': 'Restart on overload',
    'flag_over_temp_restart': 'Restart on overtemp',
    'flag_backlight_on': 'LCD backlight',
    'flag_alarm_on_on_primary_source_interrupt': 'Beep on primary source interruption',
    'flag_fault_code_record': 'Fault code recording',

    # monitor
    'chrg_evt_started': 'Started charging from AC.',
    'chrg_evt_finished': 'Finished charging from AC.',
    'chrg_evt_disconnected': 'AC disconnected.',
    'chrg_evt_current_changed': 'AC charging current set to <b>%dA</b>.',
    'chrg_evt_not_charging': 'AC connected but not charging.',
    'chrg_evt_na_solar': 'AC connected, but battery won\'t be charged due to active solar power line.',
    'battery_level_changed': 'Battery level: <b>%s</b> (<b>%0.1f V</b> under <b>%d W</b> load)',
    'error_message': '<b>Error:</b> %s.'
}
logger = logging.getLogger(__name__)


#
# helpers
#

def _(key, *args):
    global _strings
    return (_strings[key] if key in _strings else f'{{{key}}}') % args


def get_usage(command: str, arguments: dict) -> str:
    blocks = []
    argument_names = []
    argument_lines = []
    for k, v in arguments.items():
        argument_names.append(k)
        argument_lines.append(
            f'<code>{k}</code>: {v}'
        )

    command = f'/{command}'
    if argument_names:
        command += ' ' + ' '.join(argument_names)

    blocks.append(
        '<b>Usage</b>\n'
        f'<code>{command}</code>'
    )

    if argument_lines:
        blocks.append(
            '<b>Arguments</b>\n' + '\n'.join(argument_lines)
        )

    return '\n\n'.join(blocks)


def get_markup() -> ReplyKeyboardMarkup:
    button = [
        [
            _('status'),
            _('generation')
        ],
    ]
    return ReplyKeyboardMarkup(button, one_time_keyboard=False)


def reply(update: Update, text: str, reply_markup=None) -> None:
    if reply_markup is None:
        reply_markup = get_markup()

    update.message.reply_text(text,
                              reply_markup=reply_markup,
                              parse_mode=ParseMode.HTML)


def notify_all(text: str) -> None:
    for chat_id in notify_to:
        updater.bot.send_message(chat_id=chat_id,
                                 text=text,
                                 parse_mode='HTML',
                                 reply_markup=get_markup())


def handle_exc(update: Update, e) -> None:
    logging.exception(str(e))

    if isinstance(e, InverterError):
        try:
            err = json.loads(str(e))['message']
        except json.decoder.JSONDecodeError:
            err = str(e)
        err = re.sub(r'((?:.*)?error:) (.*)', r'<b>\1</b> \2', err)
        reply(update, err)

    elif not isinstance(e, TimedOut):
        reply(update, 'exception: ' + str(e))


def beautify_table(s):
    lines = s.split('\n')
    lines = list(map(lambda line: re.sub(r'\s+', ' ', line), lines))
    lines = list(map(lambda line: re.sub(r'(.*?): (.*)', r'<b>\1:</b> \2', line), lines))
    return '\n'.join(lines)


#
# command/message handlers
#


def start(update: Update, context: CallbackContext) -> None:
    reply(update, 'Select a command on the keyboard.')


def msg_status(update: Update, context: CallbackContext) -> None:
    try:
        gs = inverter.exec('get-status')['data']

        # render response
        power_direction = gs['battery_power_direction'].lower()
        power_direction = re.sub(r'ge$', 'ging', power_direction)

        charging_rate = ''
        if power_direction == 'charging':
            charging_rate = ' @ %s %s' % (
            gs['battery_charging_current']['value'], gs['battery_charging_current']['unit'])
        elif power_direction == 'discharging':
            charging_rate = ' @ %s %s' % (
            gs['battery_discharging_current']['value'], gs['battery_discharging_current']['unit'])

        html = '<b>Battery:</b> %s %s' % (gs['battery_voltage']['value'], gs['battery_voltage']['unit'])
        html += ' (%s%s)' % (power_direction, charging_rate)

        html += '\n<b>Load:</b> %s %s' % (gs['ac_output_active_power']['value'], gs['ac_output_active_power']['unit'])
        html += ' (%s%%)' % (gs['output_load_percent']['value'])

        if gs['pv1_input_power']['value'] > 0:
            html += '\n<b>Input power:</b> %s %s' % (gs['pv1_input_power']['value'], gs['pv1_input_power']['unit'])

        if gs['grid_voltage']['value'] > 0 or gs['grid_freq']['value'] > 0:
            html += '\n<b>Generator:</b> %s %s' % (gs['grid_voltage']['unit'], gs['grid_voltage']['value'])
            html += ', %s %s' % (gs['grid_freq']['value'], gs['grid_freq']['unit'])

        # send response
        reply(update, html)
    except Exception as e:
        handle_exc(update, e)


def msg_generation(update: Update, context: CallbackContext) -> None:
    try:
        today = datetime.date.today()
        yday = today - datetime.timedelta(days=1)
        yday2 = today - datetime.timedelta(days=2)

        gs = inverter.exec('get-status')['data']
        # sleep(0.1)

        gen_today = inverter.exec('get-day-generated', (today.year, today.month, today.day))['data']
        gen_yday = None
        gen_yday2 = None

        if yday.month == today.month:
            # sleep(0.1)
            gen_yday = inverter.exec('get-day-generated', (yday.year, yday.month, yday.day))['data']

        if yday2.month == today.month:
            # sleep(0.1)
            gen_yday2 = inverter.exec('get-day-generated', (yday2.year, yday2.month, yday2.day))['data']

        # render response
        html = '<b>Input power:</b> %s %s' % (gs['pv1_input_power']['value'], gs['pv1_input_power']['unit'])
        html += ' (%s %s)' % (gs['pv1_input_voltage']['value'], gs['pv1_input_voltage']['unit'])

        html += '\n<b>Today:</b> %s Wh' % (gen_today['wh'])

        if gen_yday is not None:
            html += '\n<b>Yesterday:</b> %s Wh' % (gen_yday['wh'])

        if gen_yday2 is not None:
            html += '\n<b>The day before yesterday:</b> %s Wh' % (gen_yday2['wh'])

        # send response
        reply(update, html)
    except Exception as e:
        handle_exc(update, e)


def msg_all(update: Update, context: CallbackContext) -> None:
    reply(update, "Command not recognized. Please try again.")


def on_set_ac_charging_current(update: Update, context: CallbackContext) -> None:
    allowed_values = inverter.exec('get-allowed-ac-charging-currents')['data']

    try:
        current = int(context.args[0])
        if current not in allowed_values:
            raise ValueError(f'invalid value {current}')

        response = inverter.exec('set-max-ac-charging-current', (0, current))
        reply(update, 'OK' if response['result'] == 'ok' else 'ERROR')

    except (IndexError, ValueError):
        usage = get_usage('setgencc', {
            'A': 'max charging current, allowed values: ' + ', '.join(map(lambda x: str(x), allowed_values))
        })
        reply(update, usage)


def on_set_ac_charging_thresholds(update: Update, context: CallbackContext) -> None:
    try:
        cv = float(context.args[0])
        dv = float(context.args[1])

        if 44 <= cv <= 51 and 48 <= dv <= 58:
            response = inverter.exec('set-charging-thresholds', (cv, dv))
            reply(update, 'OK' if response['result'] == 'ok' else 'ERROR')
            monitor.set_battery_ac_charging_thresholds(cv, dv)
        else:
            raise ValueError('invalid values')

    except (IndexError, ValueError):
        usage = get_usage('setgenct', {
            'CV': f'charging voltage, 44 {LT} CV {LT} 51',
            'DV': f'discharging voltage, 48 {LT} DV {LT} 58'
        })
        reply(update, usage)


def on_set_battery_under_voltage(update: Update, context: CallbackContext) -> None:
    try:
        v = float(context.args[0])

        if 40.0 <= v <= 48.0:
            response = inverter.exec('set-battery-cut-off-voltage', (v,))
            reply(update, 'OK' if response['result'] == 'ok' else 'ERROR')
            monitor.set_battery_under_voltage(v)
        else:
            raise ValueError('invalid voltage')

    except (IndexError, ValueError):
        usage = get_usage('setbatuv', {
            'V': f'floating point number, 40.0 {LT} V {LT} 48.0'
        })
        reply(update, usage)


def build_flags_keyboard(flags: dict) -> Tuple[str, InlineKeyboardMarkup]:
    keyboard = []
    for k, v in flags.items():
        label = ('✅' if v else '❌') + ' ' + _(f'flag_{k}')
        proto_flag = flags_map[k]
        keyboard.append([InlineKeyboardButton(label, callback_data=f'flag_{proto_flag}')])

    text = 'Press a button to toggle a flag.'

    return text, InlineKeyboardMarkup(keyboard)


def on_flags(update: Update, context: CallbackContext) -> None:
    flags = inverter.exec('get-flags')['data']
    text, markup = build_flags_keyboard(flags)
    reply(update, text, reply_markup=markup)


def on_status(update: Update, context: CallbackContext) -> None:
    try:
        status = inverter.exec('get-status', format=Format.TABLE)
        reply(update, beautify_table(status))
    except Exception as e:
        handle_exc(update, e)


def on_config(update: Update, context: CallbackContext) -> None:
    try:
        rated = inverter.exec('get-rated', format=Format.TABLE)
        reply(update, beautify_table(rated))
    except Exception as e:
        handle_exc(update, e)


def on_errors(update: Update, context: CallbackContext) -> None:
    try:
        errors = inverter.exec('get-errors', format=Format.TABLE)
        reply(update, beautify_table(errors))
    except Exception as e:
        handle_exc(update, e)


def on_button(update: Update, context: CallbackContext) -> None:
    query = update.callback_query

    if query.data.startswith('flag_'):
        flag = query.data[5:]
        found = False
        json_key = None
        for k, v in flags_map.items():
            if v == flag:
                found = True
                json_key = k
                break
        if not found:
            query.answer('unknown flag')
            return

        flags = inverter.exec('get-flags')['data']
        cur_flag_value = flags[json_key]
        target_flag_value = '0' if cur_flag_value else '1'

        # set flag
        response = inverter.exec('set-flag', (flag, target_flag_value))

        # notify user
        query.answer('Done' if response['result'] == 'ok' else 'failed to toggle flag')

        # edit message
        flags[json_key] = not cur_flag_value
        text, markup = build_flags_keyboard(flags)
        query.edit_message_text(text, reply_markup=markup)

    else:
        query.answer('unexpected callback data')


#
# InverterMonitor event handlers
#

def monitor_charging_event_handler(event: ChargingEvent, **kwargs) -> None:
    args = []
    if event == ChargingEvent.AC_CHARGING_STARTED:
        key = 'started'
    elif event == ChargingEvent.AC_CHARGING_FINISHED:
        key = 'finished'
    elif event == ChargingEvent.AC_DISCONNECTED:
        key = 'disconnected'
    elif event == ChargingEvent.AC_NOT_CHARGING:
        key = 'not_charging'
    elif event == ChargingEvent.AC_CURRENT_CHANGED:
        key = 'current_changed'
        args.append(kwargs['current'])
    elif event == ChargingEvent.AC_CHARGING_UNAVAILABLE_BECAUSE_SOLAR:
        key = 'na_solar'
    else:
        logger.error('unknown charging event:', event)
        return

    notify_all(_(f'chrg_evt_{key}', *args))


def monitor_battery_event_handler(state: BatteryState, v: float, load_watts: int) -> None:
    if state == BatteryState.NORMAL:
        label = '✅ Normal'
    elif state == BatteryState.LOW:
        label = '⚠️ Low'
    elif state == BatteryState.CRITICAL:
        label = '‼️ Critical'
    else:
        logger.error('unknown battery state:', state)
        return

    notify_all(_('battery_level_changed', label, v, load_watts))


def monitor_error_handler(error: str) -> None:
    notify_all(_('error_message', error))


if __name__ == '__main__':
    # command-line arguments
    parser = ArgumentParser()
    parser.add_argument('--token', required=True, type=str,
                        help='Telegram bot token')
    parser.add_argument('--users-whitelist', nargs='+',
                        help='ID of users allowed to use the bot')
    parser.add_argument('--notify-to', nargs='+')
    parser.add_argument('--ac-current-range', nargs='+', default=(10, 30))
    parser.add_argument('--inverterd-host', default='127.0.0.1', type=str)
    parser.add_argument('--inverterd-port', default=8305, type=int)
    parser.add_argument('--verbose', action='store_true')
    args = parser.parse_args()

    whitelist = list(map(lambda x: int(x), args.users_whitelist))
    notify_to = list(map(lambda x: int(x), args.notify_to)) if args.notify_to is not None else []

    # connect to inverterd
    inverter.init(host=args.inverterd_host, port=args.inverterd_port)

    # start monitoring
    monitor = InverterMonitor(args.ac_current_range)
    monitor.set_charging_event_handler(monitor_charging_event_handler)
    monitor.set_battery_event_handler(monitor_battery_event_handler)
    monitor.set_error_handler(monitor_error_handler)
    monitor.start()

    # configure logging
    logging_level = logging.DEBUG if args.verbose else logging.INFO
    logging.basicConfig(format='%(asctime)s - %(name)s - %(levelname)s - %(message)s',
                        level=logging_level)

    # configure bot
    updater = Updater(args.token, request_kwargs={'read_timeout': 6, 'connect_timeout': 7})
    dispatcher = updater.dispatcher

    user_filter = Filters.user(whitelist)

    dispatcher.add_handler(CommandHandler('start', start))
    dispatcher.add_handler(MessageHandler(Filters.text(_('status')) & user_filter, msg_status))
    dispatcher.add_handler(MessageHandler(Filters.text(_('generation')) & user_filter, msg_generation))

    dispatcher.add_handler(CommandHandler('setgencc', on_set_ac_charging_current))
    dispatcher.add_handler(CommandHandler('setgenct', on_set_ac_charging_thresholds))
    dispatcher.add_handler(CommandHandler('setbatuv', on_set_battery_under_voltage))

    dispatcher.add_handler(CallbackQueryHandler(on_button))
    dispatcher.add_handler(CommandHandler('flags', on_flags))
    dispatcher.add_handler(CommandHandler('status', on_status))
    dispatcher.add_handler(CommandHandler('config', on_config))
    dispatcher.add_handler(CommandHandler('errors', on_errors))

    dispatcher.add_handler(MessageHandler(Filters.all & user_filter, msg_all))

    # start the bot
    updater.start_polling()

    # run the bot until the user presses Ctrl-C or the process receives SIGINT, SIGTERM or SIGABRT
    updater.idle()

    monitor.stop()