import re

import pytesseract
from PIL import Image

from correct import correct_sent

chinese_pat = re.compile(r"[\u4e00-\u9fa5]+")
english_pat = re.compile(r"[a-zA-Z]+")


def is_chinese(s):
    return chinese_pat.match(s) != None


def is_english(s):
    return english_pat.match(s) != None


def is_chinese_line(line, cc_ce_difference=5):
    '''return 1 if it is chinese line
    -1 if it is english line
    0 if not sure'''

    cc = 0
    ce = 0
    for c in line:
        if is_chinese(c):
            cc += 1
        elif is_english(c):
            ce += 1

        if abs(cc - ce) >= cc_ce_difference:
            return 1 if cc > ce else -1

    if cc == 0 and ce == 0:
        return 0
    else:
        return 1 if cc > ce else -1


space_pat = re.compile("\s+")


def remove_space(s):
    return space_pat.sub("", s)


def process_orc_text(text):
    lines = []
    for line in text.split("\n"):
        # 过滤掉空白行
        line = line.strip()
        if not line:
            continue

        chi = is_chinese_line(line)
        if chi == 1:
            # 中文行去掉空格
            line = remove_space(line)
        elif chi == -1:
            # 英文行进行错误修改
            line = correct_sent(line)
        else:
            pass
        lines.append(line)
    text = "\n".join(lines)
    return text


def img2text(imgpath, lang='chi_sim'):
    im = Image.open(imgpath)
    text = pytesseract.image_to_string(im,
                                       # lang='eng',
                                       # lang='chi_sim',
                                       lang=lang,
                                       )
    return process_orc_text(text)