#!/usr/bin/env python3
"""
Reminds of things.
"""
import os
import re
import time
import sqlite3
import threading
import collections
from datetime import datetime

import pytz

from module import commands, example, NOLIMIT
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 init_database(bot):
	"""
	Initializes the 'remind' table in the bot's database. Does nothing if
	the table already exists.
	"""
	con = bot.db.connect()
	cur = con.cursor()
	try:
		cur.execute("SELECT * FROM remind").fetchone()
	except sqlite3.OperationalError:
		cur.execute("CREATE TABLE remind("
			"unixtime INT DEFAULT (STRFTIME('%s', 'now')),"
			"channel STRING,"
			"nick STRING,"
			"message STRING)")
		con.commit()
	con.close()


def load_database(bot):
	"""
	Loads all entries from the 'remind' table in the bot's database and
	stores them in memory
	"""
	data = {}
	con = bot.db.connect()
	cur = con.cursor()
	reminds = cur.execute("SELECT * FROM remind").fetchall()
	con.close()

	for remind in reminds:
		unixtime, channel, nick, message = remind
		reminder = (channel, nick, message)
		try:
			data[unixtime].append(reminder)
		except KeyError:
			data[unixtime] = [reminder]
	return data


def insert_reminder(bot, unixtime, reminder):
	"""
	Inserts a new reminder into the 'remind' table in the bot's database.
	reminder - a tuple containing (channel, nick, message)
	"""
	con = bot.db.connect()
	cur = con.cursor()
	cur.execute("INSERT INTO remind (unixtime, channel, nick, message) "
		"VALUES(?,?,?,?)", (unixtime,) + reminder)
	con.commit()
	con.close()


def delete_reminder(bot, unixtime):
	"""
	Deletes a reminder from the 'remind' table in the bot's database, using
	unixtime as the key.
	"""
	con = bot.db.connect()
	cur = con.cursor()
	cur.execute("DELETE FROM remind WHERE unixtime = ?", (unixtime,))
	con.commit()
	con.close()


def setup(bot):
	init_database(bot)
	bot.rdb = load_database(bot)

	def monitor(bot):
		time.sleep(10)
		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]
					delete_reminder(bot, oldtime)
			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]

	insert_reminder(bot, t, reminder)

	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)