import itertools
import json
import re
from typing import List


def group(_input):
    d = list(itertools.chain(*list(map(lambda x: list(x.items()), _input))))
    _s = [[a, [c for _, c in b]] for a, b in itertools.groupby(sorted(d, key=lambda x: x[0]), key=lambda x: x[0])]
    return {a: group(b) if all(isinstance(i, dict) for i in b) else list(itertools.chain(*b)) for a, b in _s}


def fix_values(dic):
    for k, v in dic.items():
        if isinstance(v, list):
            dic[k] = ''.join(v)
        else:
            fix_values(v)
    return dic


def trim(s):
    """clear all white characters"""
    return re.sub(r'\s', '', s)


def build_query(items, indent=2):
    """
    transform a tree into grqphql query string
    """
    dic = build_dict(items)
    return re.sub(r'["\s]', '', json.dumps(dic, indent=indent))[1:-1]


def build_dict(items):
    """
    transform a list of conditions into dictionary
    """
    dicts = []
    for item in items:
        json_str = '{' + re.sub(r'([$\w]+)', r'"\1"', item) + '}'
        dic = json.loads(json_str)
        dicts.append(dic)
    dic = group(dicts)
    return fix_values(dic)