#!/usr/bin/env python3
"""
Reminds of things.
"""
import os
import re
import time
import threading
import collections
import codecs

import pytz

from datetime import datetime
from module import commands, example, NOLIMIT
import tools
from tools.time import get_timezone, format_time

def filename(self):
	name = self.nick + '-' + self.config.core.host + '.reminders.db'
	return os.path.join(self.config.core.homedir, name)


def load_database(name):
	data = {}
	if os.path.isfile(name):
		f = codecs.open(name, 'r', encoding='utf-8')
		for line in f:
			unixtime, channel, nick, message = line.split('\t')
			message = message.rstrip('\n')
			t = int(float(unixtime))  # WTFs going on here?
			reminder = (channel, nick, message)
			try:
				data[t].append(reminder)
			except KeyError:
				data[t] = [reminder]
		f.close()
	return data


def dump_database(name, data):
	f = codecs.open(name, 'w', encoding='utf-8')
	for unixtime, reminders in tools.iteritems(data):
		for channel, nick, message in reminders:
			f.write('%s\t%s\t%s\t%s\n' % (unixtime, channel, nick, message))
	f.close()


def setup(bot):
	bot.rfn = filename(bot)
	bot.rdb = load_database(bot.rfn)

	def monitor(bot):
		time.sleep(5)
		while True:
			now = int(time.time())
			unixtimes = [int(key) for key in bot.rdb]
			oldtimes = [t for t in unixtimes if t <= now]
			if oldtimes:
				for oldtime in oldtimes:
					for (channel, nick, message) in bot.rdb[oldtime]:
						if message:
							bot.say(nick + ': ' + message, channel)
						else:
							bot.say(nick + '!', channel)
					del bot.rdb[oldtime]
				dump_database(bot.rfn, bot.rdb)
			time.sleep(2.5)

	targs = (bot,)
	t = threading.Thread(target=monitor, args=targs)
	t.start()

scaling = collections.OrderedDict([
	('years', 365.25 * 24 * 3600),
	('year', 365.25 * 24 * 3600),
	('yrs', 365.25 * 24 * 3600),
	('y', 365.25 * 24 * 3600),

	('months', 29.53059 * 24 * 3600),
	('month', 29.53059 * 24 * 3600),
	('mo', 29.53059 * 24 * 3600),

	('weeks', 7 * 24 * 3600),
	('week', 7 * 24 * 3600),
	('wks', 7 * 24 * 3600),
	('wk', 7 * 24 * 3600),
	('w', 7 * 24 * 3600),

	('days', 24 * 3600),
	('day', 24 * 3600),
	('d', 24 * 3600),

	('hours', 3600),
	('hour', 3600),
	('hrs', 3600),
	('hr', 3600),
	('h', 3600),

	('minutes', 60),
	('minute', 60),
	('mins', 60),
	('min', 60),
	('m', 60),

	('seconds', 1),
	('second', 1),
	('secs', 1),
	('sec', 1),
	('s', 1),
])

periods = '|'.join(scaling.keys())


@commands('remind')
@example('.remind 3h45m Go to class')
def remind(bot, trigger):
	"""Gives you a reminder in the given amount of time."""
	if not trigger.group(2):
		bot.say("Missing arguments for reminder command.")
		return NOLIMIT
	if trigger.group(3) and not trigger.group(4):
		bot.say("No message given for reminder.")
		return NOLIMIT
	duration = 0
	message = filter(None, re.split('(\d+(?:\.\d+)? ?(?:(?i)' + periods + ')) ?',
									trigger.group(2))[1:])
	reminder = ''
	stop = False
	for piece in message:
		grp = re.match('(\d+(?:\.\d+)?) ?(.*) ?', piece)
		if grp and not stop:
			length = float(grp.group(1))
			factor = scaling.get(grp.group(2).lower(), 60)
			duration += length * factor
		else:
			reminder = reminder + piece
			stop = True
	if duration == 0:
		return bot.reply("Sorry, didn't understand the input.")

	if duration % 1:
		duration = int(duration) + 1
	else:
		duration = int(duration)
	timezone = get_timezone(
		bot.db, bot.config, None, trigger.nick, trigger.sender)
	create_reminder(bot, trigger, duration, reminder, timezone)


@commands('at')
@example('.at 13:47 Do your homework!')
def at(bot, trigger):
	"""
	Gives you a reminder at the given time. Takes hh:mm:ssTimezone
	message. Timezone is any timezone Sopel takes elsewhere; the best choices
	are those from the tzdb; a list of valid options is available at
	http://sopel.chat/tz . The seconds and timezone are optional.
	"""
	if not trigger.group(2):
		bot.say("No arguments given for reminder command.")
		return NOLIMIT
	if trigger.group(3) and not trigger.group(4):
		bot.say("No message given for reminder.")
		return NOLIMIT
	regex = re.compile(r'(\d+):(\d+)(?::(\d+))?([^\s\d]+)? (.*)')
	match = regex.match(trigger.group(2))
	if not match:
		bot.reply("Sorry, but I didn't understand your input.")
		return NOLIMIT
	hour, minute, second, tz, message = match.groups()
	if not second:
		second = '0'

	if pytz:
		timezone = get_timezone(bot.db, bot.config, tz,
								trigger.nick, trigger.sender)
		if not timezone:
			timezone = 'UTC'
		now = datetime.now(pytz.timezone(timezone))
		at_time = datetime(now.year, now.month, now.day,
						   int(hour), int(minute), int(second),
						   tzinfo=now.tzinfo)
		timediff = at_time - now
	else:
		if tz and tz.upper() != 'UTC':
			bot.reply("I don't have timzeone support installed.")
			return NOLIMIT
		now = datetime.now()
		at_time = datetime(now.year, now.month, now.day,
						   int(hour), int(minute), int(second))
		timediff = at_time - now

	duration = timediff.seconds

	if duration < 0:
		duration += 86400
	create_reminder(bot, trigger, duration, message, 'UTC')


def create_reminder(bot, trigger, duration, message, tz):
	t = int(time.time()) + duration
	reminder = (trigger.sender, trigger.nick, message)
	try:
		bot.rdb[t].append(reminder)
	except KeyError:
		bot.rdb[t] = [reminder]

	dump_database(bot.rfn, bot.rdb)

	if duration >= 60:
		remind_at = datetime.utcfromtimestamp(t)
		timef = format_time(bot.db, bot.config, tz, trigger.nick,
							trigger.sender, remind_at)

		bot.reply('Okay, will remind at %s' % timef)
	else:
		bot.reply('Okay, will remind in %s secs' % duration)