wttr.in/lib/parse_query.py

import re
import json
import zlib
import base64


def serialize(parsed_query):
    return base64.b64encode(
        zlib.compress(json.dumps(parsed_query).encode("utf-8")), altchars=b"-_"
    ).decode("utf-8")


def deserialize(url):

    string = url[2:]

    extension = None
    if "." in string:
        string, extension = string.split(".", 1)

    try:
        result = json.loads(
            zlib.decompress(base64.b64decode(string, altchars=b"-_")).decode("utf-8")
        )
    except zlib.error:
        return None

    if extension == "png":
        result["png_filename"] = url
        result["html_output"] = False

    return result


def metric_or_imperial(query, lang, us_ip=False):
    """ """

    # what units should be used
    # metric or imperial
    # based on query and location source (imperial for US by default)
    if query.get("use_metric", False) and not query.get("use_imperial", False):
        query["use_imperial"] = False
        query["use_metric"] = True
    elif query.get("use_imperial", False) and not query.get("use_metric", False):
        query["use_imperial"] = True
        query["use_metric"] = False
    elif lang == "us":
        # slack uses m by default, to override it speciy us.wttr.in
        query["use_imperial"] = True
        query["use_metric"] = False
    else:
        if us_ip:
            query["use_imperial"] = True
            query["use_metric"] = False
        else:
            query["use_imperial"] = False
            query["use_metric"] = True

    return query


def parse_query(args):
    result = {}

    reserved_args = ["lang"]

    q = ""

    for key, val in args.items():
        if len(val) == 0:
            q += key
            continue
        if val == "True":
            val = True
        if val == "False":
            val = False
        result[key] = val

    if q is None:
        return result
    if "A" in q:
        result["force-ansi"] = True
    if "d" in q:
        result["dumb"] = True
    if "n" in q:
        result["narrow"] = True
    if "m" in q:
        result["use_metric"] = True
    if "M" in q:
        result["use_metric"] = True
        result["use_ms_for_wind"] = True
    if "u" in q:
        result["use_imperial"] = True
    if "I" in q:
        result["inverted_colors"] = True
    if "t" in q:
        result["transparency"] = "150"
    if "T" in q:
        result["no-terminal"] = True
    if "p" in q:
        result["padding"] = True

    for days in "0123":
        if days in q:
            result["days"] = days

    if "q" in q:
        result["no-caption"] = True
    if "Q" in q:
        result["no-city"] = True
    if "F" in q:
        result["no-follow-line"] = True

    for key, val in args.items():
        if val == "True":
            val = True
        if val == "False":
            val = False
        if val:
            result[key] = val

    # currently `view` is alias for `format`
    if "format" in result and not result.get("view"):
        result["view"] = result["format"]
        del result["format"]

    return result


def parse_wttrin_png_name(name):
    """
    Parse the PNG filename and return the result as a dictionary.
    For example:
        input = City_200x_lang=ru.png
        output = {
            "lang": "ru",
            "width": "200",
            "filetype": "png",
            "location": "City"
        }
    """

    parsed = {}
    to_be_parsed = {}

    if name.lower()[-4:] == ".png":
        parsed["filetype"] = "png"
        name = name[:-4]

    parts = name.split("_")
    parsed["location"] = parts[0]

    one_letter_options = ""
    for part in parts[1:]:
        if re.match("(?:[0-9]+)x", part):
            parsed["width"] = part[:-1]
        elif re.match("x(?:[0-9]+)", part):
            parsed["height"] = part[1:]
        elif re.match(part, "(?:[0-9]+)x(?:[0-9]+)"):
            parsed["width"], parsed["height"] = part.split("x", 1)
        elif "=" in part:
            arg, val = part.split("=", 1)
            to_be_parsed[arg] = val
        else:
            one_letter_options += part

    for letter in one_letter_options:
        to_be_parsed[letter] = ""

    parsed.update(parse_query(to_be_parsed))

    # currently `view` is alias for `format`
    if "format" in parsed and not parsed.get("view"):
        parsed["view"] = parsed["format"]
        del parsed["format"]

    return parsed