"""GAMEBEAST JSON signing. Kept independent for the downloadable Python example."""
import hashlib
import json
import math


def number_string(value):
    # JSON numbers are IEEE-754 Numbers in the existing JavaScript caller.
    n=float(value)
    if math.isnan(n):return 'NaN'
    if math.isinf(n):return 'Infinity' if n>0 else '-Infinity'
    if not n:return '0'
    sign='-' if n<0 else '';n=abs(n)
    s=repr(n).lower()
    mantissa,_,exponent=s.partition('e')
    whole,_,fraction=mantissa.partition('.')
    digits=(whole+fraction).rstrip('0')
    point=len(whole)+int(exponent or 0)
    if 1e-6<=n<1e21:
        if point<=0:return sign+'0.'+'0'*(-point)+digits
        if point>=len(digits):return sign+digits+'0'*(point-len(digits))
        return sign+digits[:point]+'.'+digits[point:]
    power=point-1
    return sign+digits[0]+('.'+digits[1:] if len(digits)>1 else '')+'e'+('+' if power>=0 else '-')+str(abs(power))


def quote(value):
    # Well-formed JSON.stringify escapes lone surrogates, but keeps non-ASCII.
    raw=json.dumps(value,ensure_ascii=False,separators=(',',':'))
    return ''.join('\\u%04x'%ord(ch) if 0xd800<=ord(ch)<=0xdfff else ch for ch in raw)


def json_stringify(value):
    if value is None:return 'null'
    if value is True:return 'true'
    if value is False:return 'false'
    if isinstance(value,str):return quote(value)
    if isinstance(value,(int,float)):
        return number_string(value) if math.isfinite(float(value)) else 'null'
    if isinstance(value,list):return '['+','.join(json_stringify(x) for x in value)+']'
    if isinstance(value,dict):
        # JS enumeration puts array-index keys first, then insertion-order keys.
        indices=sorted((k for k in value if k.isascii() and k.isdigit() and str(int(k))==k and int(k)<4294967295),key=int)
        keys=indices+[k for k in value if k not in indices]
        return '{'+','.join(quote(k)+':'+json_stringify(value[k]) for k in keys)+'}'
    raise TypeError('JSON value required')


def scalar(value):
    if isinstance(value,(dict,list)):return json_stringify(value)
    if isinstance(value,str):return value
    return json_stringify(value) if not isinstance(value,(int,float)) or isinstance(value,bool) else number_string(value)


def create_sign(secret,params):
    keys=sorted(params,key=lambda k:k.encode('utf-16-be','surrogatepass'))
    body='&'.join(k+'='+scalar(params[k]) for k in keys if k not in ('sign','cards') and params[k] is not None and params[k]!='')
    text=(secret+body+secret).lower()
    # Buffer.from(text, 'utf8') replaces unpaired UTF-16 code units with U+FFFD.
    text=text.encode('utf-16-le','surrogatepass').decode('utf-16-le','replace')
    return hashlib.md5(text.encode('utf-8')).hexdigest()