means = [0, 0, 0]  

loan = 0

rate = 0

pay = 0

investment = 0

annual_rate = 0





# 计算定投预期收益

# 定投收益的计算公式为：M=a(1+x)[-1+(1+x)^n]/x;

# 其中M代表预期收益，a代表每期定投金额，x代表收益率，而n代表定投期数。

# 假设用户每月定投金额为300元，一年也就是3600元，年收益率为15%，

# 定投期限为35年，则可以计算出收益为3600(1+15%)[-1+(1+15%)^35]/15%=3648044元。

def fixed_investment(inv, a_rate, y):

    global means

    inv = 12 * inv

    a_rate = a_rate / 100

    if a_rate == 0:

        expected = 0

    else:

        expected = inv * (1 + a_rate) * (pow((1 + a_rate), y) - 1) / a_rate

    print("定投的预期收入为: %.2f" % expected)

    means[1] = expected

    return expected





def balance():

    total = 0

    for i in means:

        total += i

    print("你的资产总额为：%.2f" % total)

    print("你的资产明细为：\n")

    print("存款：%.2f" % means[0])

    print("理财：%.2f" % means[1])

    print("负债：%.2f" % means[2])





def saving(amount):

    global means

    if amount < 0:

        print("存款金额不可小于 0！")

    else:

        means[0] += amount

        print("已存款：%.2f 元" % amount)

        print("当前余额：%.2f 元" % means[0])





def draw_money(drawing):

    global means

    if drawing < 0:

        print("取款金额不可小于 0！")

    elif drawing > means[0]:

        print("取款金额不可超过余额！")

    else:

        means[0] -= drawing

        print("已取款： %.2f 元" % drawing)

        print("当前余额： %.2f 元" % means[0])





def loans(loan, rate, pay, years):

    global means

    if pay < (loan - pay) * rate:

        print("你是还不完的！！！")

    else:

        if years == 0:

            count = 0

            while loan > 0:

                loan -= pay

                loan *= (1 + rate)

                count += 1

            print("将在 %d 年后还完贷款。" % count)

        else:

            for _ in range(years):

                loan -= pay

                if loan == 0:

                    break

                else:

                    loan *= (1 + rate)

                    print("你现在的负债是: %.2f" % loan)

            # means[2] = loan

            return loan





# 未来财务状况

def future(years):

    income = fixed_investment(investment, annual_rate, years)

    debt = loans(loan, rate, pay, years)

    captial = means[0] + income - debt

    print("你第%i年的总资产有: %.3f" % (years, captial))





def init():

    print()

    print('''以下为可办理的业务：

        1. 查询资产

        2. 存款

        3. 取款

        4. 计算复利

        5. 计算贷款

        6. 计算未来资产

        q. 退出''')





def main():

    init()

    while True:

        choice = input("请输入您要办理的业务代码: ")

        #  查询余额

        if choice == "1":

            balance()

        # 存款

        elif choice == "2":

            inc = float(input("请输入存款金额: "))

            saving(inc)

        # 取款

        elif choice == "3":

            dec = float(input("请输入取款金额: "))

            draw_money(dec)

        # 计算定投

        elif choice == "4":

            investment = float(input("请输入每月定投金额: "))

            annual_rate = float(input("请输入年收益率: "))

            years = int(input("请输入定投期限(年): "))

            if investment <= 0 or annual_rate <= 0 or years <= 0:

                print("输入的数据有误")

            else:

                money = fixed_investment(investment, annual_rate, years)

            print("最终收获: %.2f 元" % money)

        # 计算贷款

        elif choice == "5":

            loan = float(input("请输入当前贷款: "))

            rate = float(input("请输入年利率: "))

            pay = float(input("请输入每年还款: "))

            if loan <= 0 or rate <= 0 or pay <= 0:

                print("输入的数据有误")

            else:

                loans(loan, rate, pay, 0)

        elif choice == "6":

            years = int(input("希望查询多少年后的财务状况? "))

            future(years)

        # 退出

        elif choice == "q":

            print("欢迎下次光临！再见！")

            break

        else:

            print("你输入的指令有误，请重新输入\n")





if __name__ == '__main__':

    main()