import json
import random
import urllib.request

default_base_url = 'https://api.cardcastgame.com/v1/decks/'
default_timeout = 10

class CodeValidationError(Exception): pass

def check_code(code):
	if not all(i.isalnum() or i == '-' for i in code):
		raise CodeValidationError('Code %s contains disallowed characters (0-9 A-Z a-z - are allowed)' % code)

def request(base_url, additional, timeout):
	if base_url is None:
		base_url = default_base_url
	if timeout is None:
		timeout = default_timeout

	url = base_url + additional
	with urllib.request.urlopen(url, timeout = timeout) as r:
		return json.loads(r.read())

def info(code, *, base_url = None, timeout = None):
	check_code(code)
	return request(base_url, code, timeout)

def cards(code, *, base_url = None, timeout = None):
	check_code(code)

	data = request(base_url, code + '/cards', timeout)

	calls = [i['text'] for i in data['calls']]
	responses = [i['text'] for i in data['responses']]

	# Both calls and responses are stored as a list of parts
	# For calls, the blanks go between the parts so that ['foo', 'bar'] is
	# "foo _ bar", but for resposes there is never more than one part
	# Therefore, remove the additional layer of list
	responses = [i for (i,) in responses]

	return (calls, responses)

def random_code(*, base_url = None, timeout = None, count = None):

	if count is None:
		# Get number of cards
		results = request(base_url, '?category=&direction=desc&limit=1&sort=rating&offset=0', timeout)
		count = results['results']['count']

	# Generate a random number [0, count[
	offset = random.randint(0, count - 1)

	# Get the data on the selected deck
	results = request(base_url, '?category=&direction=desc&limit=1&sort=rating&offset=%i' % offset, timeout)

	return (results['results']['data'][0]['code'], count)