import re
import chardet
from datetime import timedelta
import datetime


# 匹配正则表达式
matchs = {
  1:(r'\d{4}%s\d{1,2}%s\d{1,2}%s \d{1,2}%s\d{1,2}%s\d{1,2}%s','%%Y%s%%m%s%%d%s %%H%s%%M%s%%S%s'),
  2:(r'\d{4}%s\d{1,2}%s\d{1,2}%s \d{1,2}%s\d{1,2}%s','%%Y%s%%m%s%%d%s %%H%s%%M%s'),
  3:(r'\d{4}%s\d{1,2}%s\d{1,2}%s','%%Y%s%%m%s%%d%s'),
  4:(r'\d{2}%s\d{1,2}%s\d{1,2}%s','%%y%s%%m%s%%d%s'),
  
  # 没有年份
  5:(r'\d{1,2}%s\d{1,2}%s \d{1,2}%s\d{1,2}%s\d{1,2}%s','%%m%s%%d%s %%H%s%%M%s%%S%s'),
  6:(r'\d{1,2}%s\d{1,2}%s \d{1,2}%s\d{1,2}%s','%%m%s%%d%s %%H%s%%M%s'),
  7:(r'\d{1,2}%s\d{1,2}%s','%%m%s%%d%s'),
  

  # 没有年月日
  8:(r'\d{1,2}%s\d{1,2}%s\d{1,2}%s','%%H%s%%M%s%%S%s'),
  9:(r'\d{1,2}%s\d{1,2}%s','%%H%s%%M%s'),
}

# 正则中的%s分割
splits = [
  {1:[('年','月','日','点','分','秒'),('-','-','',':',':',''),('\/','\/','',':',':',''),('\.','\.','',':',':','')]},
  {2:[('年','月','日','点','分'),('-','-','',':',''),('\/','\/','',':',''),('\.','\.','',':','')]},
  {3:[('年','月','日'),('-','-',''),('\/','\/',''),('\.','\.','')]},
  {4:[('年','月','日'),('-','-',''),('\/','\/',''),('\.','\.','')]},

  {5:[('月','日','点','分','秒'),('-','',':',':',''),('\/','',':',':',''),('\.','',':',':','')]},
  {6:[('月','日','点','分'),('-','',':',''),('\/','',':',''),('\.','',':','')]},
  {7:[('月','日'),('-',''),('\/',''),('\.','')]},

  {8:[('点','分','秒'),(':',':','')]},
  {9:[('点','分'),(':','')]},
]

def func(parten,tp):
  re.search(parten,parten)
  

parten_other = '\d+天前|\d+分钟前|\d+小时前|\d+秒前'

class TimeFinder(object):

  def __init__(self,base_date=None):
    self.base_date = base_date
    self.match_item = []
    
    self.init_args()
    self.init_match_item()

  def init_args(self):
    # 格式化基础时间
    if not self.base_date:
      self.base_date = datetime.datetime.now()
      print(type(self.base_date))
    if self.base_date and not isinstance(self.base_date,datetime.datetime):
      try:
        self.base_date = datetime.datetime.strptime(self.base_date,'%Y-%m-%d %H:%M:%S')
      except Exception as e:
        raise 'type of base_date must be str of%Y-%m-%d %H:%M:%S or datetime'

  def init_match_item(self):
    # 构建穷举正则匹配公式 及提取的字符串转datetime格式映射
    for item in splits:
      for num,value in item.items():
        match = matchs[num]
        for sp in value:
          tmp = []
          for m in match:
            tmp.append(m%sp)
          self.match_item.append(tuple(tmp))

  def get_time_other(self,text):
    m = re.search('\d+',text)
    if not m:
      return None
    num = int(m.group())
    if '天' in text:
      return self.base_date - timedelta(days=num)
    elif '小时' in text:
      return self.base_date - timedelta(hours=num)
    elif '分钟' in text:
      return self.base_date - timedelta(minutes=num)
    elif '秒' in text:
      return self.base_date - timedelta(seconds=num)

    return None

  def find_time(self,text):
     # 格式化text为str类型
    if isinstance(text,bytes):
      encoding =chardet.detect(text)['encoding']
      text = text.decode(encoding)

    res = []
    parten = '|'.join([x[0] for x in self.match_item])

    parten = parten+ '|' +parten_other
    match_list = re.findall(parten,text)
    if not match_list:
      return None
    for match in match_list:
      for item in self.match_item:
        try:
          date = datetime.datetime.strptime(match,item[1].replace('\\',''))
          if date.year==1900:
            date = date.replace(year=self.base_date.year)
            if date.month==1:
              date = date.replace(month=self.base_date.month)
              if date.day==1:
                date = date.replace(day=self.base_date.day)
          res.append(datetime.datetime.strftime(date,'%Y-%m-%d %H:%M:%S'))
          break
        except Exception as e:
          date = self.get_time_other(match)
          if date:
            res.append(datetime.datetime.strftime(date,'%Y-%m-%d %H:%M:%S'))
            break
    if not res:
      return None
    return res

def test():
  timefinder =TimeFinder(base_date='2020-04-23 00:00:00')
  for text in ['2012年12月12日','3小时前','在2012/12/13哈哈','时间2012-12-11 12:22:30','日期2012-13-11','测试2013.12.24','今天12:13']:
    res = timefinder.find_time(text)
    print('text----',text)
    print('res---',res)

if __name__ == '__main__':
  test()