#!/usr/bin/env python # vim: set encoding=utf-8 """ Main wttr.in rendering function implementation """ import logging import io import os import time from gevent.threadpool import ThreadPool from flask import render_template, send_file, make_response import fmt.png import parse_query from translations import get_message, FULL_TRANSLATION, PARTIAL_TRANSLATION, SUPPORTED_LANGS from buttons import add_buttons from globals import get_help_file, remove_ansi, \ BASH_FUNCTION_FILE, TRANSLATION_FILE, LOG_FILE, \ NOT_FOUND_LOCATION, \ MALFORMED_RESPONSE_HTML_PAGE, \ PLAIN_TEXT_AGENTS, PLAIN_TEXT_PAGES, \ MY_EXTERNAL_IP, QUERY_LIMITS from location import is_location_blocked, location_processing from limits import Limits from view.wttr import get_wetter from view.moon import get_moon from view.line import wttr_line import cache if not os.path.exists(os.path.dirname(LOG_FILE)): os.makedirs(os.path.dirname(LOG_FILE)) logging.basicConfig(filename=LOG_FILE, level=logging.INFO, format='%(asctime)s %(message)s') LIMITS = Limits(whitelist=[MY_EXTERNAL_IP], limits=QUERY_LIMITS) TASKS = ThreadPool(25) def show_text_file(name, lang): """ show static file `name` for `lang` """ text = "" if name == ":help": text = open(get_help_file(lang), 'r').read() text = text.replace('FULL_TRANSLATION', ' '.join(FULL_TRANSLATION)) text = text.replace('PARTIAL_TRANSLATION', ' '.join(PARTIAL_TRANSLATION)) elif name == ":bash.function": text = open(BASH_FUNCTION_FILE, 'r').read() elif name == ":iterm2": text = open("share/iterm2.txt", 'r').read() elif name == ":translation": text = open(TRANSLATION_FILE, 'r').read() text = text\ .replace('NUMBER_OF_LANGUAGES', str(len(SUPPORTED_LANGS)))\ .replace('SUPPORTED_LANGUAGES', ' '.join(SUPPORTED_LANGS)) return text def _client_ip_address(request): """Return client ip address for flask `request`. """ if request.headers.getlist("X-PNG-Query-For"): ip_addr = request.headers.getlist("X-PNG-Query-For")[0] if ip_addr.startswith('::ffff:'): ip_addr = ip_addr[7:] elif request.headers.getlist("X-Forwarded-For"): ip_addr = request.headers.getlist("X-Forwarded-For")[0] if ip_addr.startswith('::ffff:'): ip_addr = ip_addr[7:] else: ip_addr = request.remote_addr return ip_addr def _parse_language_header(header): """ >>> _parse_language_header("en-US,en;q=0.9") >>> _parse_language_header("en-US,en;q=0.9,zh-CN;q=0.8,zh;q=0.7") >>> _parse_language_header("xx, fr-CA;q=0.8, da-DK;q=0.9") 'da' """ def _parse_accept_language(accept_language): languages = accept_language.split(",") locale_q_pairs = [] for language in languages: try: if language.split(";")[0] == language: # no q => q = 1 locale_q_pairs.append((language.strip(), 1)) else: locale = language.split(";")[0].strip() weight = float(language.split(";")[1].split("=")[1]) locale_q_pairs.append((locale, weight)) except (IndexError, ValueError): pass return locale_q_pairs def _find_supported_language(accepted_languages): def supported_langs(): """Yields all pairs in the Accept-Language header supported in SUPPORTED_LANGS or None if 'en' is the preferred""" for lang_tuple in accepted_languages: lang = lang_tuple[0] if '-' in lang: lang = lang.split('-', 1)[0] if lang in SUPPORTED_LANGS: yield lang, lang_tuple[1] elif lang == 'en': yield None, lang_tuple[1] try: return max(supported_langs(), key=lambda lang_tuple: lang_tuple[1])[0] except ValueError: return None return _find_supported_language(_parse_accept_language(header)) def get_answer_language_and_view(request): """ Return preferred answer language based on domain name, query arguments and headers """ lang = None view_name = None hostname = request.headers['Host'] if hostname != 'wttr.in' and hostname.endswith('.wttr.in'): lang = hostname[:-8] if lang.startswith("v2") or lang.startswith("v3"): view_name = lang lang = None if 'lang' in request.args: lang = request.args.get('lang') if lang.lower() == 'none': lang = None header_accept_language = request.headers.get('Accept-Language', '') if lang is None and header_accept_language: lang = _parse_language_header(header_accept_language) return lang, view_name def get_output_format(query, parsed_query): """ Return preferred output format: ansi, text, html or png based on arguments and headers in `request`. Return new location (can be rewritten) """ if ('view' in query and not query["view"].startswith("v2") and not query["view"].startswith("v3")) \ or parsed_query.get("png_filename") \ or query.get('force-ansi'): return False user_agent = parsed_query.get("user_agent", "").lower() html_output = not any(agent in user_agent for agent in PLAIN_TEXT_AGENTS) return html_output def _cyclic_location_selection(locations, period): """Return one of `locations` (: separated list) basing on the current time and query interval `period` """ locations = locations.split(':') max_len = max(len(x) for x in locations) locations = [x.rjust(max_len) for x in locations] try: period = int(period) except ValueError: period = 1 index = int(time.time()/period) % len(locations) return locations[index] def _response(parsed_query, query, fast_mode=False): """Create response text based on `parsed_query` and `query` data. If `fast_mode` is True, process only requests that can be handled very fast (cached and static files). """ answer = None cache_signature = cache.get_signature( parsed_query["user_agent"], parsed_query["request_url"], parsed_query["ip_addr"], parsed_query["lang"]) answer = cache.get(cache_signature) if parsed_query['orig_location'] in PLAIN_TEXT_PAGES: answer = show_text_file(parsed_query['orig_location'], parsed_query['lang']) if parsed_query['html_output']: answer = render_template('index.html', body=answer) if answer or fast_mode: return answer # at this point, we could not handle the query fast, # so we handle it with all available logic loc = (parsed_query['orig_location'] or "").lower() if parsed_query.get("view"): if not parsed_query.get("location"): parsed_query["location"] = loc output = wttr_line(query, parsed_query) elif loc == 'moon' or loc.startswith('moon@'): output = get_moon(parsed_query) else: output = get_wetter(parsed_query) if parsed_query.get('png_filename'): if parsed_query.get("view") != "v3": # originally it was just a usual function call, # but it was a blocking call, so it was moved # to separate threads: # # output = fmt.png.render_ansi( # output, options=parsed_query) result = TASKS.spawn(fmt.png.render_ansi, cache._update_answer(output), options=parsed_query) output = result.get() else: if query.get('days', '3') != '0' \ and not query.get('no-follow-line') \ and ((parsed_query.get("view") or "v2")[:2] in ["v2", "v3"]): if parsed_query['html_output']: output = add_buttons(output) else: message = get_message('FOLLOW_ME', parsed_query['lang']) if parsed_query.get('no-terminal', False): message = remove_ansi(message) output += '\n' + message + '\n' return cache.store(cache_signature, output) def parse_request(location, request, query, fast_mode=False): """Parse request and provided extended information for the query, including location data, language, output format, view, etc. Incoming data: `location` location name extracted from the query url `request.args` `request.headers` `request.remote_addr` `request.referrer` `request.query_string` `query` parsed command line arguments Parameters priorities (from low to high): * HTTP-header * Domain name * URL * Filename Return: dictionary with parsed parameters """ if location and location.startswith("b_"): result = parse_query.deserialize(location) result["request_url"] = request.url if result: return result png_filename = None if location is not None and location.lower().endswith(".png"): png_filename = location location = location[:-4] if location and ':' in location and location[0] != ":": location = _cyclic_location_selection(location, query.get('period', 1)) parsed_query = { 'ip_addr': _client_ip_address(request), 'user_agent': request.headers.get('User-Agent', '').lower(), 'request_url': request.url, } if png_filename: parsed_query["png_filename"] = png_filename parsed_query.update(parse_query.parse_wttrin_png_name(png_filename)) lang, _view = get_answer_language_and_view(request) parsed_query["view"] = parsed_query.get("view", query.get("view", _view)) parsed_query["location"] = parsed_query.get("location", location) parsed_query["orig_location"] = parsed_query["location"] parsed_query["lang"] = parsed_query.get("lang", lang) parsed_query["html_output"] = get_output_format(query, parsed_query) parsed_query["json_output"] = (parsed_query.get("view", "") or "").startswith("j") if not fast_mode: # not png_filename and not fast_mode: location, override_location_name, full_address, country, query_source_location, hemisphere = \ location_processing(parsed_query["location"], parsed_query["ip_addr"]) us_ip = query_source_location[2] in ["United States", "United States of America"] \ and 'slack' not in parsed_query['user_agent'] query = parse_query.metric_or_imperial(query, lang, us_ip=us_ip) if country and location != NOT_FOUND_LOCATION: location = "%s,%s" % (location, country) parsed_query.update({ 'location': location, 'override_location_name': override_location_name, 'full_address': full_address, 'country': country, 'query_source_location': query_source_location, 'hemisphere': hemisphere}) parsed_query.update(query) return parsed_query def wttr(location, request): """Main rendering function, it processes incoming weather queries, and depending on the User-Agent string and other paramters of the query it returns output in HTML, ANSI or other format. """ def _wrap_response(response_text, html_output, json_output, png_filename=None): if not isinstance(response_text, str) and \ not isinstance(response_text, bytes): return response_text if png_filename: response = make_response(send_file( io.BytesIO(response_text), attachment_filename=png_filename, mimetype='image/png')) for key, value in { 'Cache-Control': 'no-cache, no-store, must-revalidate', 'Pragma': 'no-cache', 'Expires': '0', }.items(): response.headers[key] = value else: response = make_response(response_text) if html_output: response.mimetype = "text/html" elif json_output: response.mimetype = "application/json" else: response.mimetype = "text/plain" return response if is_location_blocked(location): return ("", 403) # Forbidden try: LIMITS.check_ip(_client_ip_address(request)) except RuntimeError as exception: return (str(exception), 429) # Too many requests query = parse_query.parse_query(request.args) # first, we try to process the query as fast as possible # (using the cache and static files), # and only if "fast_mode" was unsuccessful, # use the full track parsed_query = parse_request(location, request, query, fast_mode=True) response = _response(parsed_query, query, fast_mode=True) http_code = 200 try: if not response: parsed_query = parse_request(location, request, query) response = _response(parsed_query, query) #if not response or (isinstance(response, str) and not response.strip()): # return RuntimeError("Empty answer") if parsed_query["location"] == NOT_FOUND_LOCATION: http_code = 404 # pylint: disable=broad-except except Exception as exception: logging.error("Exception has occured", exc_info=1) if parsed_query['html_output']: response = MALFORMED_RESPONSE_HTML_PAGE http_code = 500 # Internal Server Error else: response = get_message('CAPACITY_LIMIT_REACHED', parsed_query['lang']) http_code = 503 # Service Unavailable # if exception is occured, we return not a png file but text if "png_filename" in parsed_query: del parsed_query["png_filename"] return (_wrap_response( response, parsed_query['html_output'], parsed_query['json_output'], png_filename=parsed_query.get('png_filename')), http_code) if __name__ == "__main__": import doctest doctest.testmod()