import sys

import re

import io

from itertools import groupby

from datetime import datetime

import shutil

import argparse

from zipfile import ZipFile

import urllib.request

from urllib.error import URLError

class Record:

	def __init__(self, tokens, source):

		self.source = source

		self.pin = int(tokens[0])

		self.country_code = tokens[2]

		self.rating_before = int(tokens[8])

		self.rating_after = int(tokens[9])

		tournament_code = tokens[5]

		self.date = datetime.strptime(tournament_code[1:7], "%y%m%d")

		self.rank_change = ("", "")

	@classmethod

	def parse(cls, line):

		tokens = re.split(r" {2,}", line.strip())

		if len(tokens) != 10:

			return None

		return cls(tokens, line)

	def __str__(self):

		s = self.source + "  {} -> {}".format(*self.rank_change)

		return s

class RankTracker:

	def __init__(self, rating):

		assert rating >= -900

		self._rounded_rating = round_rating(rating)

		self._best = self._rounded_rating

	@property

	def rank(self):

		return rating_to_rank(self._rounded_rating)

	@property

	def rounded_rating(self):

		return self._rounded_rating

	def update(self, rating):

		assert rating >= -900

		rounded_rating = round_rating(rating)

		old_rank = self.rank

		if rounded_rating == self._rounded_rating:

			pass

		elif rounded_rating > self._rounded_rating:  # promotion

			# when pushing the best by 2 and more ranks you have to cross the hundred, not just the fifty

			if rounded_rating >= self._best+200 and rating < rounded_rating:

				self._rounded_rating = rounded_rating-100

			else:

				self._rounded_rating = rounded_rating

		else:  # demotion

			# 100 points for 5k and better

			if self._rounded_rating >= 1600 and self._rounded_rating - rating > 100:

				self._rounded_rating = rounded_rating

			# 150 points for the others

			elif self._rounded_rating - rating > 150:

				self._rounded_rating = rounded_rating+100

			else:

				pass

		self._best = max(self._best, self._rounded_rating)

		new_rank = self.rank

		return new_rank if new_rank != old_rank else False

def parse_record(record):

	types = [int, str, str, str, str, str, int, int, int, int]

	columns = [f(token) for (f, token) in zip(types, record)] + [datetime.strptime(record[5][1:7], "%y%m%d")]

	return tuple(columns)

def round_rating(r):

	return (r+50)//100*100

def rating_to_rank(rating):

	rank_list = [str(i)+"k" for i in range(30, 0, -1)] + [str(i)+"d" for i in range(1, 8)]

	key = round_rating(rating)//100

	return rank_list[min(key+9, 36)]

def main(s, since, to, args):

	records = [Record.parse(line) for line in s.splitlines()]

	records = filter(lambda rec: rec is not None, records)

	national_records = filter(lambda rec: rec.country_code == args.country_code, records)

	player_records = groupby(national_records, lambda rec: rec.pin)

	print("Detecting rank changes...")

	hr = "=" * shutil.get_terminal_size().columns

	found_anything = False

	print(hr)

	for (pin, recs) in player_records:

		tourneys = list(recs)

		tracker = RankTracker(tourneys[0].rating_before)

		steps = []

		for r in tourneys:

			# omit reset ratings

			if tracker.rounded_rating != round_rating(r.rating_before):

				tracker = RankTracker(r.rating_before)

			old_rank = tracker.rank

			new_rank = tracker.update(r.rating_after)

			if new_rank is not False:

				r.rank_change = (old_rank, new_rank)

				steps.append(r)

		steps = [r for r in steps if since <= r.date <= to]

		if steps:

			print("\n".join(map(str, steps)))

			found_anything = True

	if not found_anything:

		print("Nothing found.")

	print(hr)

if __name__ == "__main__":

	parser.add_argument("since", help="a date in YYYYMMDD format")

	parser.add_argument("to", nargs="?", help="a date in YYYYMMDD format")

	parser.add_argument("-c", "--country-code", default="CZ", help="a two letter country code, default=CZ")

	parser.add_argument("-f", "--file", help="a path to the rating history file")

	args = parser.parse_args()

	since = datetime.strptime(args.since, "%Y%m%d")

	to = datetime.strptime(args.to, "%Y%m%d") if args.to else datetime.now()

	if args.file:

		print("Reading {} ...".format(args.file))

		with ZipFile(args.file) as f:

			s = f.read("all.hst").decode("utf-8")

	else:

		url = "https://europeangodatabase.eu/EGD/EGD_2_0/downloads/hisgor.zip"

		print("Downloading data from {} ...".format(url))

		try:

			with urllib.request.urlopen(url) as f:

				compressed_data = f.read()

				with ZipFile(io.BytesIO(compressed_data)) as g:

					s = g.read("all.hst").decode("utf-8")

		except URLError as e:

			print(

				"* Failed to connect to the server. "

				"You can try again later or download {} and run the program with the -f parameter.\n"

				"The error message:\n{}".format(url, e)

			)

			sys.exit(1)

	print("Processing...")

	main(s, since, to, args)

	print("Done.")