#gui lib
from tkinter import *
from  tkinter  import ttk
from tkinter.filedialog import askopenfilename
from tkinter import scrolledtext
# Import libraries
from PIL import Image
import pytesseract
import sys
from pdf2image import convert_from_path
import os
import shutil
import threading



def start_convert_file(file,page_start=1,page_end=None,language='kor'):
    my_print("*********  convert start ! *********")
    images_path = os.getcwd() + "\\images"
    output_path = os.path.dirname(file) + "\\output"
    if os.path.exists(images_path):
        shutil.rmtree(images_path)
    os.makedirs(images_path)

    if os.path.exists(output_path):
        shutil.rmtree(output_path)
    os.makedirs(output_path)
    if file.endswith(".pdf"):
        pages = convert_from_path(file,output_folder=images_path,thread_count=8,first_page=page_start,last_page=page_end)
        pages_num = len(pages)
        if page_end is None:
            page_end = page_start + pages_num - 1
            page_stop.set(page_end)
        my_print("all %d pages, from %d to %d" % (pages_num,page_start,page_end))
        pb["maximum"] = pages_num
        pb["value"] = 0
        
        page_num = page_start
        i = 0
        for page in pages:
            if page_num not in range(page_start,page_end+1):
                page_num = page_num + 1
                continue
            my_print("convert page %d..." % page_num)
            txt_filename = output_path + "\\page_"+str(page_num)+".txt"
            jpg_filename = output_path + "\\page_"+str(page_num)+".jpg"
            page.save(jpg_filename, 'JPEG')
            try:
                text = str(((pytesseract.image_to_string(page,lang=language))))
            except:
                my_print("[error] convert page %d failed!" % page_num)
            else:
                f = open(txt_filename, "a",encoding='utf-8')
                f.write(text)
                f.close()
                my_print("convert page %d success!" % page_num)
            page_num = page_num + 1
            i = i + 1
            pb["value"] = i
        my_print("output files in %s"%output_path)
    else:
        image_file = Image.open(file)
        my_print("convert jpg file %s..." % file)
        try:
            text = str(((pytesseract.image_to_string(image_file,lang=language))))
        except:
            my_print("[error] convert jpg file %s failed !" % file)
        else:
            f = open(os.path.splitext(file)[0] + ".txt", "a",encoding='utf-8')
            f.write(text)
            f.close()
            my_print("convert jpg file %s success !" % file)

    bt['state'] = NORMAL
    shutil.rmtree(images_path)
    my_print("**************** convert done ! ****************")
    my_print("************* thanks for using ^_^ *************\n")

root = Tk()
cb = ttk.Combobox(root)
pb = ttk.Progressbar(root,length=400)
t = scrolledtext.ScrolledText(root)


file_name = StringVar()
page_start = IntVar()
page_stop = IntVar()
language = ["kor","eng","chi_sim"]

def open_file():
    _file_name = askopenfilename(filetypes = (("PDF Files","*.pdf"),("JPG Files","*.jpg")))
    file_name.set(_file_name)


def start_click():
    bt['state'] = DISABLED
    __file = file_name.get()
    if __file == "":
        my_print("[error] please selece a pdf file!!!!!")
        return
    __page_start = page_start.get()
    if __page_start == 0:
        __page_start = 1
        page_start.set(__page_start)
    __page_stop = page_stop.get()
    if __page_stop == 0:
        __page_stop = None
    elif __page_stop < __page_start:
        __page_stop = __page_start
        page_stop.set(__page_stop)
    __language = language[cb.current()%3]
    th=threading.Thread(target=start_convert_file,args=(__file,__page_start,__page_stop,__language),daemon=True)
    th.start()

bt = Button(root,text="start",width=10,command =start_click)

def my_print(str):
    t.insert(END,str + "\n")
    t.see(END)

def start_gui():
    root.title("PDF OCR")
    Label(root,text="pdf file:").grid(row=1,sticky=W)
    Entry(root,textvariable = file_name,width=55).grid(row=1,column=1,columnspan=3,sticky=W)

    Button(root,text="open",width=10,command = open_file).grid(row=1,column=4)
    Label(root,text="language:").grid(row=2,sticky=W)
    
    cb.grid(row=2,column=1,sticky=W)
    cb["values"] = ("Korean", "English", "Chinese")
    cb.current(0)

    Label(root,text="page range:").grid(row=3,sticky=W)
    
    Entry(root,textvariable = page_start).grid(row=3,column=1,sticky=W)
    Label(root,text="~").grid(row=3,column=2)
    
    Entry(root,textvariable = page_stop).grid(row=3,column=3,sticky=W)

    Label(root,text="").grid(row=4)
    bt.grid(row=5,column=2)

    Label(root,text="").grid(row=6)
    
    pb.grid(row=7,columnspan=5)
    pb["maximum"] = 100
    pb["value"] = 0
    Label(root,text="").grid(row=8)
    
    t.grid(row=9,column=0,columnspan=5)

    root.mainloop()



class myStdout():
    def __init__(self):
        self.stdoutbak = sys.stdout		
        self.stderrbak = sys.stderr
        sys.stdout = self
        sys.stderr = self

    def write(self, info):
        t.insert('end', info)
        t.update()
        t.see(END)

    def restoreStd(self):
        sys.stdout = self.stdoutbak
        sys.stderr = self.stderrbak


if __name__=="__main__":
    mystd = myStdout()
    start_gui()