import random
from cfractions import Fraction


def create_number(i):
    get_number = random.randint(0, int(i))
    # print(get_number)
    return get_number


def create_sign():
    sign = ['+', '-', '*', '÷']
    get_sign = random.choice(sign)
    # print(get_sign)
    return get_sign


def create_formula(flag_num):
    total = [3, 5, 7]
    flag = random.choice(total)
    # 生成算式  result数组
    result = []
    for i in range(flag):
        # print(i)
        if i % 2 == 0:
            number = create_number(flag_num)
            result.append(number)
        else:
            sign = create_sign()
            if (i+1) != flag:
                result.append(sign)
    # print(result)
    # print("加入括号")
    length = len(result)
    brackets = [0, 1]
    bracket = random.choice(brackets)
    if length > 3:
        # 随机加入括号
        if bracket == 1:
            for i in range(length):
                if result[i] == '+' or result[i] == '-':
                    result.insert(i-1, '(')
                    result.insert(i+3, ')')
                    break

    # print(result)
    formula = str(str(result).replace("'", "").replace(
        ',', '')).replace('[', '').replace(']', '')
    # 计算
    while len(result) != 1:
        if '(' in result:
            number_sign = result.index('(')+2
            if result[number_sign] == '+':
                number_num = result[number_sign - 1] + result[number_sign + 1]
                result[number_sign - 2] = number_num
                result.remove(result[number_sign - 1])
                result.remove(result[number_sign - 1])
                result.remove(result[number_sign - 1])
                result.remove(result[number_sign - 1])

            elif result[number_sign] == '-':
                number_num = result[number_sign - 1] - result[number_sign + 1]
                result[number_sign - 2] = number_num
                result.remove(result[number_sign - 1])
                result.remove(result[number_sign - 1])
                result.remove(result[number_sign - 1])
                result.remove(result[number_sign - 1])

        else:
            if '*' in result:
                number_sign = result.index('*')
                # print(result)
                number_num = int(
                    float(result[number_sign - 1]) * float(result[number_sign + 1]))
                result[number_sign] = number_num
                result.remove(result[number_sign - 1])
                result.remove(result[number_sign])
                # print('*'+str(result))
            elif '÷' in result:
                number_sign = result.index('÷')
                if result[number_sign + 1] == 0 or result[number_sign + 1] == '0':
                    create_formula(flag_num)
                else:
                    # print(result[number_sign - 1],result[number_sign + 1])
                    number_num = Fraction(
                        int(result[number_sign - 1]), int(result[number_sign + 1]))
                    # print(number_num)
                    result[number_sign] = number_num
                    result.remove(result[number_sign - 1])
                    result.remove(result[number_sign])
                # print('÷'+str(result))
            elif '+' in result:
                number_sign = result.index('+')
                number_num = int(
                    float(result[number_sign - 1]) + float(result[number_sign + 1]))
                result[number_sign - 1] = number_num
                result.remove(result[number_sign])
                result.remove(result[number_sign])
                # print('+'+str(result))
            elif '-' in result:
                number_sign = result.index('-')
                number_num = int(
                    float(result[number_sign - 1]) - float(result[number_sign + 1]))
                result[number_sign - 1] = number_num
                result.remove(result[number_sign])
                result.remove(result[number_sign])
                # print('-'+str(result))

    result = str(result).replace('[', '').replace(']', '')
    # print('------------')
    # print(result)
    # print('+++++++++++++')
    if 'Fraction' in result:
        start = result.index('(')
        center = result.index(',')
        end = result.index(')')
        if result[start + 1] == 0 or result[start + 1] == '0':
            result = 0
        else:
            result = str(result)[start+1:center] + \
                '/' + str(result)[center+1:end]
        # print(result)
        # print(start,center,end)
    # print(formula)
    return result, formula