import os
import tkinter as tk
import tkinter.messagebox
import tkinter.font as tf

zhuizhong = ""
wenfa = {"非左遞歸文法"}
xi_ = ""
huo = ""

window = tk.Tk()
window.title('消除左遞歸')
window.minsize(500,500)
#轉換坐標顯示形式為元組
def getIndex(text, pos):
  return tuple(map(int, str.split(text.index(pos), ".")))

def zhijie(x,y):
  if not len(y):
    pass
  else:
    if x == y[0]:
      wenfa.discard("非左遞歸文法")
      #處理直接左遞歸
      zuobian = y.split('|')
      feizhongjie = []
      zhongjie = []
      for item in zuobian:
        if x in item:
          item = item[1:]
          textt = str(item) + str(x) + "'"
          feizhongjie.append(textt)
        else:
          text = str(item) + str(x) + "'"
          zhongjie.append(text)
      if not zhongjie:#處理A -> Ax的情況
        zhongjie.append(str(x + "'"))
      cheng = str(x) + " -> " + "|".join(zhongjie)
      zi = str(x) + "'" + " -> " + "|".join(feizhongjie) + "|є"
      text_output.insert('insert','直接左遞歸文法','tag1')
      text_output.insert('insert','\n')
      text_output.insert('insert',cheng,'tag2')
      text_output.insert('insert','\n')
      text_output.insert('insert',zi,'tag2')
    '''
    加上會判斷輸出非遞歸產生式，但會導致間接左遞歸不能刪除多余產生式
    else:
      h ="不變： " + x + " -> " + y
      text_output.insert('insert','非左遞歸文法','tag1')
      text_output.insert('insert','\n')
      text_output.insert('insert',h,'tag2')
    '''
    text_output.insert('insert','\n')

def zhijie2(x,y):
  if not len(y):
    pass
  else:
    if x == y[0]:
      wenfa.discard("非左遞歸文法")
      #處理直接左遞歸
      zuobian = y.split('|')
      feizhongjie = []
      zhongjie = []
      for item in zuobian:
        if x in item:
          item = item[1:]
          textt = str(item) + str(x) + "'"
          feizhongjie.append(textt)
        else:
          text = str(item) + str(x) + "'" 
          zhongjie.append(text)
      cheng = str(x) + " -> " + "|".join(zhongjie)
      zi = str(x) + "'" + " -> " + "|".join(feizhongjie) + "|є"
      text_output.insert('insert',"間接左遞歸文法",'tag1')
      text_output.insert('insert','\n')
      text_output.insert('insert',cheng,'tag2')
      text_output.insert('insert','\n')
      text_output.insert('insert',zi,'tag2')

    text_output.insert('insert','\n')

def tihuan(xk,yi,yk):
  yi_you = []
  yi_wu =[]
  yi_he = ""
  yi_wuhe = ""
  yi_zhong = ""
  yi_feizhong = []
  if xk in yi:
    yk_replace = yk.split('|')
    yi_fenjie = yi.split('|')#將含非終結與不含分開
    for ba in yi_fenjie:
      if xk in ba:
        yi_you.append(ba)
      else:
        yi_wu.append(ba)

    yi_he = "|".join(yi_you)

    for item in yk_replace:
      yi_zhong = yi_he.replace(xk,item)#替換
      yi_feizhong.append(yi_zhong)
    yi_wuhe = "|".join(yi_wu)#再合并
    global zhuizhong
    zhuizhong = "|".join(yi_feizhong) + "|" + yi_wuhe

#點擊按鈕后執(zhí)行的函數
def changeString():
  text_output.delete('1.0','end')
  text = text_input.get('1.0','end')
  text_list = list(text.split('\n'))#一行一行的拿文法
  text_list.pop()
  if not text_list[0]:
    print(tkinter.messagebox.showerror(title = '出錯了！',message='輸入不能為空'))
  else:
    for cfg in text_list:
      
      x,y = cfg.split('->')#將文法左右分開
      x = ''.join(x.split())#消除空格
      y = ''.join(y.split())
      if not (len(x) == 1 and x >= 'A' and x <= 'Z'):
        pos = text_input.search(x, '1.0', stopindex="end")
        result = tkinter.messagebox.showerror(title = '出錯了！',
        message='非上下文無關文法!坐標%s'%(getIndex(text_input, pos),))
        # 返回值為：ok
        print(result)
        return 0
      else:
        zhijie(x,y)
      
    for i in range(len(text_list)):
      for k in range(i):
        xi,yi = text_list[i].split('->')
        xi = ''.join(xi.split())#消除空格
        yi = ''.join(yi.split())
        
        xk,yk = text_list[k].split('->')
        xk = ''.join(xk.split())#消除空格
        yk = ''.join(yk.split())

        tihuan(xk,yi,yk)
        tihuan(xk,zhuizhong,yk)
        global xi_
        xi_ = xi
    zhijie2(xi_,zhuizhong)

    for item in wenfa:
      text_output.insert('insert',item,'tag1')  

    
#創(chuàng)建文本輸入框和按鈕
text_input = tk.Text(window, width=80, height=16)
text_output = tk.Text(window, width=80, height=20)
#簡單樣式
ft = tf.Font(family='微軟雅黑',size=12)
text_output.tag_config("tag1",background="yellow",foreground="red",font=ft)
text_output.tag_config('tag2',font = ft)
#按鈕
button = tk.Button(window,text="消除左遞歸",command=changeString,padx=32,pady=4,bd=4)
 
text_input.pack()
text_output.pack()
button.pack()
window.mainloop()