#!/usr/bin/env python3
"""
Search for and pull information about XKCD comics.
"""
import random

import requests

from module import commands, url_callback


def get_info(number=None):
	if number:
		url = f"https://xkcd.com/{number}/info.0.json"
	else:
		url = "https://xkcd.com/info.0.json"
	res = requests.get(url, verify=True)
	res.raise_for_status()
	data = res.json()
	data['url'] = f"https://xkcd.com/{data['num']}"
	return data


def validate_num(num, max_int):
	"""Ensures that the given number is a valid comic id."""
	if num < 0:  # nth latest
		num += max_int
		if num < 0:
			num = 1

	elif num == 0:
		num = 1

	elif num > max_int:
		num = max_int
	return num


def parse_data(data):
	"""Parses the retrieved data into a proper message for the bot."""
	msg = f"[\x0304XKCD\x03] \x0307{data['url']}\x03 | " \
		+ f"\x0310{data['safe_title']}\x03 | " \
		+ f"\x0310Alt-text: \x0312{data['alt']}"
	return msg


@commands('xkcd')
def xkcd(bot, trigger):
	"""
	.xkcd - Finds an xkcd comic strip.
	If no input is provided it will return a random comic
	If numeric input is provided it will return that comic, or the nth-latest
	comic if the number is non-positive
	"""
	latest = get_info()
	max_int = latest['num']
	if trigger.group(2):
		try:
			num = int(trigger.group(2))
		except ValueError:
			return bot.reply("Invalid input.")
		num = validate_num(num, max_int)
		data = get_info(num)
	else:
		num = random.randint(1, max_int)
		data = get_info(num)

	msg = parse_data(data)
	bot.msg(msg)


@url_callback('xkcd.com/')
def get_url(bot, url):
	"""Callback for the URL module."""
	_, _, num = url.partition("xkcd.com/")
	try:
		num = int(num)
	except ValueError:
		return
	latest = get_info()
	max_int = latest['num']
	num = validate_num(num, max_int)
	data = get_info(num)
	msg = parse_data(data)
	bot.msg(msg)