wttr.in/lib/location.py

"""
All location related functions and converters.

The main entry point is `location_processing`
which gets `location` and `source_ip_address`
and basing on this information generates
precise location description.

"""
from __future__ import print_function

import sys
import os
import json
import socket
import requests
import geoip2.database

from globals import GEOLITE, GEOLOCATOR_SERVICE, IP2LCACHE, IP2LOCATION_KEY, NOT_FOUND_LOCATION, \
                    ALIASES, BLACKLIST, IATA_CODES_FILE, IPLOCATION_ORDER, IPINFO_TOKEN

GEOIP_READER = geoip2.database.Reader(GEOLITE)

def ascii_only(string):
    "Check if `string` contains only ASCII symbols"

    try:
        for _ in range(5):
            string = string.encode('utf-8')
        return True
    except UnicodeDecodeError:
        return False

def is_ip(ip_addr):
    """
    Check if `ip_addr` looks like an IP Address
    """

    if sys.version_info[0] < 3:
        ip_addr = ip_addr.encode("utf-8")

    try:
        socket.inet_pton(socket.AF_INET, ip_addr)
        return True
    except socket.error:
        try:
            socket.inet_pton(socket.AF_INET6, ip_addr)
            return True
        except socket.error:
            return False

def location_normalize(location):
    """
    Normalize location name `location`
    """
    #translation_table = dict.fromkeys(map(ord, '!@#$*;'), None)
    def _remove_chars(chars, string):
        return ''.join(x for x in string if x not in chars)

    location = location.lower().replace('_', ' ').replace('+', ' ').strip()
    if not location.startswith('moon@'):
        location = _remove_chars(r'!@#$*;:\\', location)
    return location



def geolocator(location):
    """
    Return a GPS pair for specified `location` or None
    if nothing can't be found
    """

    try:
        geo = requests.get('%s/%s' % (GEOLOCATOR_SERVICE, location)).text
    except requests.exceptions.ConnectionError as exception:
        print("ERROR: %s" % exception)
        return None

    if geo == "":
        return None

    try:
        answer = json.loads(geo.encode('utf-8'))
        return answer
    except ValueError as exception:
        print("ERROR: %s" % exception)
        return None

    return None


def ipcachewrite(ip_addr, location):
    cached = os.path.join(IP2LCACHE, ip_addr)
    if not os.path.exists(IP2LCACHE):
        os.makedirs(IP2LCACHE)
    with open(cached, 'w') as file:
        file.write(location[0] + ';' + location[1])

def ipcache(ip_addr):
    cached = os.path.join(IP2LCACHE, ip_addr)
    if not os.path.exists(IP2LCACHE):
        os.makedirs(IP2LCACHE)

    location = None

    if os.path.exists(cached):
        location = open(cached, 'r').read().split(';')
        if len(location) > 3:
            return location[3], location[1]
        elif len(location) > 1:
            return location[0], location[1]
        else:
            return location[0], None

    return None, None

def ip2location(ip_addr):
    "Convert IP address `ip_addr` to a location name"

    location = ipcache(ip_addr)
    if location:
        return location

    # if IP2LOCATION_KEY is not set, do not the query,
    # because the query wont be processed anyway
    if IP2LOCATION_KEY:
        try:
            location = requests\
                    .get('http://api.ip2location.com/?ip=%s&key=%s&package=WS3' \
                         % (ip_addr, IP2LOCATION_KEY)).text
        except requests.exceptions.ConnectionError:
            pass

    if location and ';' in location:
        ipcachewrite(ip_addr, location)
        _, country, region, city = location.split(';')
        location = city, region, country
    else:
        location = location, None, None

    return location


def ipinfo(ip_addr):
    location = ipcache(ip_addr)
    if location:
        return location
    if IPINFO_TOKEN:
        r = requests.get('https://ipinfo.io/%s/json?token=%s' %
                         (ip_addr, IPINFO_TOKEN))
        if r.status_code == 200:
            r_json = r.json()
            location = r_json["city"], r_json["region"], r_json["country"]
        else:
            location = None, None, None
    if location:
        ipcachewrite(ip_addr, location)
    return location


def geoip(ip_addr):
    location = ipcache(ip_addr)
    if location:
        return location

    try:
        response = GEOIP_READER.city(ip_addr)
        location = response.city.name, response.subdivisions.name, response.country.name
    except geoip2.errors.AddressNotFoundError:
        location = None, None, None
    if location:
        ipcachewrite(ip_addr, location)
    return location

def workaround(city, region, country):
    # workaround for the strange bug with the country name
    # maybe some other countries has this problem too
    #
    # Having these in a separate function will help if this gets to
    # be a problem
    if country == 'Russian Federation':
        country = 'Russia'
    return city, region, country

def get_location(ip_addr):
    """
    Return location pair (CITY, COUNTRY) for `ip_addr`
    """
    for method in IPLOCATION_ORDER:
        if method == 'geoip':
            city, country = geoip(ip_addr)
        elif method == 'ip2location':
            city, country = ip2location(ip_addr)
        elif method == 'ipinfo':
            city, country = ipinfo(ip_addr)
        else:
            print("ERROR: invalid iplocation method speficied: %s" % method)
        if city is not None:
            city, country = workaround(city, country)
            return city, country
    #
    # temporary disabled it because of geoip services capcacity
    #
    #if city is None and response.location:
    #    coord = "%s, %s" % (response.location.latitude, response.location.longitude)
    #    try:
    #        location = geolocator.reverse(coord, language='en')
    #        city = location.raw.get('address', {}).get('city')
    #    except:
    #        pass

    # No methods resulted in a location - return default
    return NOT_FOUND_LOCATION, None


def location_canonical_name(location):
    "Find canonical name for `location`"

    location = location_normalize(location)
    if location.lower() in LOCATION_ALIAS:
        return LOCATION_ALIAS[location.lower()]
    return location

def load_aliases(aliases_filename):
    """
    Load aliases from the aliases file
    """
    aliases_db = {}
    with open(aliases_filename, 'r') as f_aliases:
        for line in f_aliases.readlines():
            try:
                from_, to_ = line.decode('utf-8').split(':', 1)
            except AttributeError:
                from_, to_ = line.split(':', 1)

            aliases_db[location_normalize(from_)] = location_normalize(to_)
    return aliases_db

def load_iata_codes(iata_codes_filename):
    """
    Load IATA codes from the IATA codes file
    """
    with open(iata_codes_filename, 'r') as f_iata_codes:
        result = []
        for line in f_iata_codes.readlines():
            result.append(line.strip())
    return set(result)

LOCATION_ALIAS = load_aliases(ALIASES)
LOCATION_BLACK_LIST = [x.strip() for x in open(BLACKLIST, 'r').readlines()]
IATA_CODES = load_iata_codes(IATA_CODES_FILE)

def is_location_blocked(location):
    """
    Return True if this location is blocked
    or False if it is allowed
    """
    return location is not None and location.lower() in LOCATION_BLACK_LIST


def get_hemisphere(location):
    """
    Return hemisphere of the location (True = North, False = South).
    Assume North and return True if location can't be found.
    """
    location_string = location[0]
    if location[1] is not None:
        location_string += ",%s" % location[1]
    geolocation = geolocator(location_string)
    if geolocation is None:
        return True
    return geolocation["latitude"] > 0

def location_processing(location, ip_addr):
    """
    """

    # if location is starting with ~
    # or has non ascii symbols
    # it should be handled like a search term (for geolocator)
    override_location_name = None
    full_address = None
    hide_full_address = False
    force_show_full_address = location is not None and location.startswith('~')

    # location ~ means that it should be detected automatically,
    # and shown in the location line below the report
    if location == '~':
        location = None

    if location and location.lstrip('~ ').startswith('@'):
        try:
            location, country = get_location(
                socket.gethostbyname(
                    location.lstrip('~ ')[1:]))
            location = '~' + location
            if country:
                location += ", %s" % country
            hide_full_address = not force_show_full_address
        except:
            location, country = NOT_FOUND_LOCATION, None

    query_source_location = get_location(ip_addr)

    # For moon queries, hemisphere must be found
    # True for North, False for South
    hemisphere = False
    if location is not None and (location.lower()+"@").startswith("moon@"):
        hemisphere = get_hemisphere(query_source_location)

    country = None
    if not location or location == 'MyLocation':
        location = ip_addr

    if is_ip(location):
        location, country = get_location(location)

        # here too
        if location:
            location = '~' + location
            if country:
                location += ", %s" % country
            hide_full_address = not force_show_full_address

    if location and not location.startswith('~'):
        tmp_location = location_canonical_name(location)
        if tmp_location != location:
            override_location_name = location
            location = tmp_location

    # up to this point it is possible that the name
    # contains some unicode symbols
    # here we resolve them
    if location is not None: # and not ascii_only(location):
        location = "~" + location.lstrip('~ ')
        if not override_location_name:
            override_location_name = location.lstrip('~')

    # if location is not None and location.upper() in IATA_CODES:
    #     location = '~%s' % location

    if location is not None and not location.startswith("~-,") and location.startswith('~'):
        geolocation = geolocator(location_canonical_name(location[1:]))
        if geolocation is not None:
            if not override_location_name:
                override_location_name = location[1:].replace('+', ' ')
            location = "%s,%s" % (geolocation['latitude'], geolocation['longitude'])
            country = None
            if not hide_full_address:
                full_address = geolocation['address']
            else:
                full_address = None
        else:
            location = NOT_FOUND_LOCATION #location[1:]


    return location, \
            override_location_name, \
            full_address, \
            country, \
            query_source_location, \
            hemisphere