import tkinter as tk
from tkinter import messagebox
import re
#import math
from math import *

# 创建主窗口
window = tk.Tk()
# 设置窗口大小和位置
window.geometry('340x240+600+300')
# 不允许改变窗口大小
window.resizable(False, False)
# 设置窗口标题
window.title('计算器')
# 背景颜色
window.config(background="blue")
# 自动刷新字符串变量，可用 set 和 get 方法进行传值和取值
content_var = tk.StringVar(window, '')
# 创建单行文本框
content_entry = tk.Entry(window, textvariable=content_var)
# 设置文本框为只读
content_entry['state'] = 'readonly'
# 设置文本框坐标及宽高
content_entry.place(x=20, y=10, width=300, height=30)
# 按钮显示内容
value = ['e^x','√', 'π', '%', '//',
         '**','⌫', '(', ')', '/',
         'x!','7', '8', '9', '*',
         'x³','4', '5', '6', '-',
         'x²','1', '2', '3', '+',
         'C','+/-', '0', '.', '=']
index = 0
# 将按钮进行 6x5 放置
for row in range(6):
    for col in range(5):
        d = value[index]
        index += 1
        if (row==1 and (col==1 or col==2 or col==3)):
            btn_digit = tk.Button(window, text=d, command=lambda x=d: onclick(x), bg="gray", fg="black")
            btn_digit.place(x=20 + col * 62, y=50 + row * 30, width=50, height=20)
        elif (row==2 and (col==1 or col==2 or col==3)):
            btn_digit = tk.Button(window, text=d, command=lambda x=d: onclick(x), bg="LightPink", fg="red")
            btn_digit.place(x=20 + col * 62, y=50 + row * 30, width=50, height=20)
        elif (row==3 and (col==1 or col==2 or col==3)):
            btn_digit = tk.Button(window, text=d, command=lambda x=d: onclick(x), bg="LightPink", fg="red")
            btn_digit.place(x=20 + col * 62, y=50 + row * 30, width=50, height=20)
        elif (row==4 and (col==1 or col==2 or col==3)):
            btn_digit = tk.Button(window, text=d, command=lambda x=d: onclick(x), bg="LightPink", fg="red")
            btn_digit.place(x=20 + col * 62, y=50 + row * 30, width=50, height=20)
        elif (row==5 and col==2):
            btn_digit = tk.Button(window, text=d, command=lambda x=d: onclick(x), bg="LightPink", fg="red")
            btn_digit.place(x=20 + col * 62, y=50 + row * 30, width=50, height=20)
        elif (row==5 and col!=2):
            btn_digit = tk.Button(window, text=d, command=lambda x=d: onclick(x), bg="SpringGreen", fg="red")
            btn_digit.place(x=20 + col * 62, y=50 + row * 30, width=50, height=20)
        else:
            btn_digit = tk.Button(window, text=d, command=lambda x=d: onclick(x), bg="DeepSkyBlue", fg="purple")
            btn_digit.place(x=20 + col * 62, y=50 + row * 30, width=50, height=20)

# 点击事件
def onclick(key):
    # 运算符
    operation = ('+', '-', '*', '/', '**', '//', '%')
    # 获取文本框中的内容
    content = content_var.get()
    # 如果已有内容是以小数点开头的，在前面加 0
    if content.startswith('.'):
        content = '0' + content  # 字符串可以直接用+来增加字符
    # 根据不同的按钮作出不同的反应
    if key in '0123456789':
        # 按下 0-9 在 content 中追加
        content += key
    elif key == '.':
        # 将 content 从 +-*/ 这些字符的地方分割开来
        last_part = re.split(r'[+\-*/]', content)[-1]
        if '.' in last_part:
            # 信息提示对话框
            tk.messagebox.showerror('Error', 'Repeated decimal point')
            return
        else:
            content += key
    elif key == 'C':
        # 清除文本框
        content = ''
    elif key == '=':
        try:
            # 对输入的表达式求值
            content = str(eval(content.replace("π", str(pi))))
            content = str(eval(content))
        except ZeroDivisionError:
            tk.messagebox.showerror('Error', 'Division by zero is not allowed')
            return
        except Exception as e:
            tk.messagebox.showerror('Error', f'Invalid expression: {e}')
            return
    elif key in operation:
        if content.endswith(operation):
            tk.messagebox.showerror('Error', 'Consecutive operators not allowed')
            return
        content += key

    elif key == '+/-':
        # 将正负号切换
        if content.startswith('-'):
            content = content[1:]
        else:
            content = '-' + content
    elif key in '()':
        # 直接在内容后面追加括号
        content += key
    elif key == '√':
        # 从 . 处分割存入 n，n 是一个列表
        n = content.split('.')
        # 如果列表中所有的都是数字，就是为了检查表达式是不是正确的
        if all(map(lambda x: x.isdigit(), n)):
            content = sqrt(eval(content))
        else:
            tk.messagebox.showerror('Error', 'Invalid expression')
            return
    elif key == 'e^x':
        # 添加常数e的x次方
        content = exp(eval(content))
    elif key == '⌫':
        # 删除最后一个字符
        content = content[:-1]
    elif key == 'x²':
        # 计算平方
        try:
            content = str(float(content) ** 2)
        except Exception as e:
            tk.messagebox.showerror('Error', f'Invalid expression: {e}')
            return
    elif key == 'x³':
        # 计算立方
        try:
            content = str(float(content) ** 3)
        except Exception as e:
            tk.messagebox.showerror('Error', f'Invalid expression: {e}')
            return
    elif key == 'x!':
        # 计算阶乘
        try:
            num = int(content)
            if num < 0:
                tk.messagebox.showerror('Error', 'Please enter a non-negative integer')
                return
            content = str(factorial(num))
        except ValueError:
            tk.messagebox.showerror('Error', 'Please enter a non-negative integer')
            return
        except Exception as e:
            tk.messagebox.showerror('Error', f'Invalid expression: {e}')
            return
    elif key == 'π':
        # 添加常数π
        content += 'π'

    # 将结果显示到文本框中
    content_var.set(content)

# 运行主循环
window.mainloop()

#x = 2 + 9 * ((3*12) - 8) // 10
#print(x)