import os.path
import urllib.request
import urllib.error
import json

def get_jsonp_file(url, temp_fname, use_old, allow_old=True):
    try:
        return get_file(url, temp_fname, use_old, jsonp_load, allow_old)
    except json.decoder.JSONDecodeError as e:
        print("Failed to parse JSON from {}".format(temp_fname))
        raise

def get_json_file(url, temp_fname, use_old, allow_old=True):
    try:
        return get_file(url, temp_fname, use_old, json.load, allow_old)
    except json.decoder.JSONDecodeError as e:
        print("Failed to parse JSON from {}".format(temp_fname))
        raise

def jsonp_load(fp):
    return json.loads(fp.read()[1:-2])

def read_all(fp):
    return fp.read()

def get_file(url, temp_fname, use_old, consumer=read_all, allow_old=True):
    if not use_old or not os.path.isfile(temp_fname):
        try:
            urllib.request.urlretrieve(url, temp_fname)
        except urllib.error.HTTPError as e:
            print("Failed to download {url}".format(url=url))
            # Juvenes may fail with error code 500 if food is not available
            if not allow_old:
                return None
    try:
        with open(temp_fname, "r", encoding="utf-8") as fin:
            return consumer(fin)
    except OSError as e:
        pass