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

import config
import module

def setup(bot):
	bot.db.execute("CREATE TABLE IF NOT EXISTS lazy_remind ("
		"nick TEXT,"
		"datetime TIMESTAMP,"
		"reminder TEXT)")
	lazy_reminds = bot.db.execute("SELECT * FROM lazy_remind").fetchall()
	bot.memory['lazy_remind'] = defaultdict(list)
	for remind in lazy_reminds:
		bot.memory['lazy_remind'][remind[0]].append(remind[1:3])

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(bot, trigger):
	"""
	Gives you a reminder in the given amount of time.

	-l, --lazy  -  Only activates the reminder when you speak.
	"""
	if len(trigger.args) == 1:
		return bot.msg("Missing arguments for reminder command.")
	if trigger.args[1] in ['-l', '--lazy']:
		if len(trigger.args) == 2:
			return bot.msg("Missing arguments for reminder command.")
		lazy = True
		trigger.args.pop(1)
	else:
		lazy = False

	reg = re.search(regex, trigger.args[1])
	if not reg:
		return bot.reply("I didn't understand that.")
	args = {shorthand[g[-1]]: int(g[:-1]) for g in reg.groups() if g}
	if args.get('years'):
		args['days'] = args['years']*365 + args.get('days', 0) # screw leap years
		del args['years']
	delta = timedelta(**args)
	dt = datetime.now() + delta
	reminder = ' '.join(trigger.args[2:])
	if lazy:
		bot.memory['lazy_remind'][trigger.nick].append((dt, reminder))
		bot.db.execute("INSERT INTO lazy_remind VALUES(?,?,?)",
			(trigger.nick, dt, reminder))
	else:
		args = (trigger.channel, trigger.nick, reminder)
		bot.scheduler.add_task(announce_reminder, dt, args)
	msg = "Okay, will "
	msg += "\x0310lazy\x03 " if lazy else ""
	msg += "remind at "
	msg+= dt.strftime('[%Y-%m-%d %H:%M:%S]')
	bot.reply(msg)


@module.commands('at')
@module.example('.at 2012-12-21 18:00:00 End the world.')
def at(bot, trigger):
	"""
	Gives you a reminder at the given time and date. Datetime must be in
	YYYY-MM-DD HH:MM:SS format. Only the bot's timezone is used. If
	YYYY-MM-DD is excluded, it is assumed to be today's date.

	-l, --lazy  -  Only activates the reminder when you speak.
	"""
	if len(trigger.args) < 2:
		return bot.msg("Missing arguments for reminder command.")
	if trigger.args[1] in ['-l', '--lazy']:
		if len(trigger.args) < 3:
			return bot.msg("Missing arguments for reminder command.")
		lazy = True
		trigger.args.pop(1)
	else:
		lazy = False
	if ':' in trigger.args[1]:
		at_time = datetime.now().strftime('%Y-%m-%d') + ' ' + trigger.args[1]
		reminder = ' '.join(trigger.args[2:])
	else:
		at_time = ' '.join(trigger.args[1:3])
		reminder = ' '.join(trigger.args[3:])

	try:
		dt = datetime.strptime(at_time, '%Y-%m-%d %H:%M:%S')
	except ValueError:
		return bot.msg("Datetime improperly formatted.")

	if lazy:
		bot.memory['lazy_remind'][trigger.nick].append((dt, reminder))
		bot.db.execute("INSERT INTO lazy_remind VALUES(?,?,?)",
			(trigger.nick, dt, reminder))
	else:
		args = (trigger.channel, trigger.nick, reminder)
		bot.scheduler.add_task(announce_reminder, dt, args)
	msg = "Okay, will "
	msg += "\x0310lazy\x03 " if lazy else ""
	msg += "remind at "
	msg+= dt.strftime('[%Y-%m-%d %H:%M:%S]')
	bot.reply(msg)


def announce_reminder(bot, channel, remindee, reminder):
	"""Announce the reminder."""
	if reminder:
		msg = f"{remindee}: {reminder}"
	else:
		msg = f"{remindee}!"
	bot.msg(channel, msg)


@module.hook(True)
def lazy_remind(bot, trigger):
	"""Lazy reminds only activate when the person speaks."""
	if trigger.nick not in bot.memory['lazy_remind']:
		return
	due = [r for r in bot.memory['lazy_remind'][trigger.nick] if r[0] <= datetime.now()]
	if not due:
		return
	for remind in due:
		if remind[1]:
			bot.reply(remind[1])
		else:
			bot.msg(trigger.nick + '!')
		bot.memory['lazy_remind'][trigger.nick].remove(remind)
		bot.db.execute("DELETE FROM lazy_remind "
			"WHERE nick = ? AND datetime = ? AND reminder = ?",
			(trigger.nick,) + tuple(remind))