#!/usr/bin/env python3
"""
Reminds of things.
"""
import os
import re
from datetime import datetime, timedelta
from collections import defaultdict

import tools
import config
import module

def setup(bot):
	bot.memory['lazy_remind'] = defaultdict(list)

regex = (
	"(?=\d+[ywdhms])"
	"(\d+y)?"
	"(\d+w)?"
	"(\d+d)?"
	"(\d+h)?"
	"(\d+m)?"
	"(\d+s)?"
)
shorthand = {
	'y': 'years',
	'w': 'weeks',
	'd': 'days',
	'h': 'hours',
	'm': 'minutes',
	's': 'seconds',
}

@module.commands('remind')
@module.example('.remind 3h45m Go to class')
def remind_recur(bot, trigger):
	"""
	Sets a recurring reminder.

	-s, --start  -  Starts the cycle at the given point in time instead of now.
	-l, --lazy  -  Only activates the reminder when you speak.
	-r, --recur  -  Repeats the reminder every given period.
	"""
	if len(trigger.args) < 2:
		return bot.msg("Missing arguments.")

	parser = tools.FulviaArgparse()
	parser.add_argument('period')
	parser.add_argument('reminder', nargs='*')
	parser.add_argument('-s', '--start', nargs=2)
	parser.add_argument('-l', '--lazy', action='store_true')
	parser.add_argument('-r', '--recur', action='store_true')
	try:
		args = parser.parse_args(trigger.args[1:])
	except Exception as e:
		return bot.reply(type(e).__name__ + ": " + str(e))

	if args.start:
		s = ' '.join(args.start)
		try:
			start = datetime.strptime(s,'%Y-%m-%d %H:%M:%S')
		except ValueError:
			return bot.msg("Datetime improperly formatted.")
	else:
		start = datetime.now()

	reg = re.search(regex, args.period)
	if not reg:
		return bot.reply("I didn't understand that time period.")
	parts = {shorthand[g[-1]]: int(g[:-1]) for g in reg.groups() if g}
	if parts.get('years'):
		parts['days'] = parts['years']*365 + parts.get('days', 0) # screw leap years
		del parts['years']
	delta = timedelta(**parts)
	sched_time = start + delta

	reminder = ' '.join(args.reminder)
	if reminder:
		reminder = trigger.nick + ': ' + reminder
	else:
		reminder = trigger.nick + '!'

	if args.recur:
		recur = delta
	else:
		recur = None

	if args.lazy:
		sched_args = (trigger.nick, reminder, recur)
		bot.scheduler.add_task(announce_lazy_reminder, sched_time, sched_args)
	else:
		sched_args = (trigger.channel, trigger.nick, reminder, recur)
		bot.scheduler.add_task(announce_reminder, sched_time, sched_args)

	msg = "Okay, will "
	msg += "\x0310lazy\x03 " if args.lazy else ""
	msg += "remind at "
	msg+= sched_time.strftime('[%Y-%m-%d %H:%M:%S]')
	bot.reply(msg)


@module.require_admin
@module.commands('clear_dup_reminders')
def remind_recur(bot, trigger):
	"""
	Clear out duplicate reminders from Fulvia's memory.
	This is only a temporary fix to the memory issue.
	"""
	bot.scheduler.tasks = list(dict.fromkeys(bot.scheduler.tasks))
	bot.scheduler.dump_database()


def announce_reminder(bot, sched_time, channel, remindee, reminder, delta=None):
	"""Announce the reminder."""
	bot.msg(channel, reminder)
	if delta:
		sched_time = sched_time + delta
		args = (channel, remindee, reminder, delta)
		bot.scheduler.add_task(announce_reminder, sched_time, args)


def announce_lazy_reminder(bot, sched_time, remindee, reminder, delta=None):
	"""Announce the reminder."""
	bot.memory['lazy_remind'][remindee].append(reminder)
	if delta:
		sched_time = sched_time + delta
		args = (remindee, reminder, delta)
		bot.scheduler.add_task(announce_lazy_reminder, sched_time, args)


@module.hook(True)
def lazy_remind(bot, trigger):
	"""Lazy reminds only activate when the person speaks."""
	for remind in list(bot.memory['lazy_remind'].get(trigger.nick, [])):
		bot.msg(remind)
		bot.memory['lazy_remind'][trigger.nick].remove(remind)