import gzip
from datetime import datetime
import os
import lxml.etree as etree
# import glob
import tempfile
import filecmp
# import re
import errno
import json
# import shotiser
import sys

from shutil import copyfile


# re_changed = re.compile('It\\s+was\\s+last\\s+changed' +
#                         '\\s+on\\s+\\d{4}.\\d{2}.\\d{2}\\.\\s*')
# re_whitespace = re.compile('\\s+')
#
#
# # # a helper for the download
# def temp_warc_path():
#     pid = os.getpid()
#     tist = datetime.now().strftime('%s')
#     warc_path = '/tmp/' + str(pid) + '_' + tist
#     return warc_path
#
#
def prepare(filename):
     if not os.path.exists(os.path.dirname(filename)):
         try:
             os.makedirs(os.path.dirname(filename))
         except OSError as exc: # Guard against race condition
             if exc.errno != errno.EEXIST:
                raise


def install_xml(ele, fufi):
    temp_file_name = tempfile.NamedTemporaryFile(delete=False).name
    et = etree.ElementTree(ele)
    et.write(temp_file_name, pretty_print=True)
    prepare(fufi)
    if(os.path.exists(fufi)):
        if(filecmp.cmp(temp_file_name, fufi, shallow=True)):
            os.remove(temp_file_name)
            return
    copyfile(temp_file_name, fufi)
    os.remove(temp_file_name)


def load(fufi):
    if(fufi[-3:] != '.gz'):
        with open(fufi) as the_file:
            data = json.load(the_file)
        return data
    with gzip.GzipFile(fufi, 'r') as json_file:
        json_bytes = json_file.read()
        json_string = json_bytes.decode('utf-8')
        data = json.loads(json_string)
    return data


def dump(a1 , a2):
    if(isinstance(a1, str)):
        fufi = a1
        data = a2
    else:
        fufi = a2
        data = a1
    if(fufi[-3:] != '.gz'):
        with open(fufi, 'w') as the_file:
            json.dump(data, the_file, indent=1)
        return fufi
    dump_string = json.dumps(data, ensure_ascii=False, indent=1).encode('utf-8')
    with gzip.GzipFile(fufi, 'w') as the_file:
        the_file.write(dump_string)
        del dump_string
    return fufi


#def mtime(fufi):
#    mtime = os.path.getmtime(fufi)
#    mtime = int(mtime)
#    return mtime
#
#
# def shoti(fufi):
#     mtime = os.path.getmtime(fufi)
#     mtime = int(mtime)
#     mshoti = shotiser.make(mtime)
#     return mshoti
#
#
#def age(fufi):
#    mtime = os.path.getmtime(fufi)
#    now = datetime.now().strftime('%s')
#    age = int(now) - mtime
#    return age
#
#
#def concat(canonic_fufi, supplem_fufi, do_verbose=False):
#    if(do_verbose):
#        print("I append " + supplem_fufi + ' to ' + canonic_fufi)
#    with open(canonic_fufi, 'ab') as canonic_file:
#        with open(supplem_fufi, 'rb') as supplem_file:
#            canonic_file.write(supplem_file.read())
#
#
#def bread(fufi):
#    if(not os.path.isfile(fufi)):
#        raise Exception(fufi + ' is not there.')
#    the_file = open(fufi, 'br')
#    string = the_file.read()
#    the_file.close()
#    return string
#
#

def sread(fufi):
    if(not os.path.isfile(fufi)):
        raise Exception(fufi + ' is not there.')
    if(fufi[-3:] != '.gz'):
        with open(fufi, "r") as the_file:
            string = the_file.read()
    else:
        with gzip.GzipFile(fufi, 'r') as the_file:
            string = the_file.read()
            string = string.decode()
        the_file.close()
    return string


#def brite(fufi, string, with_backup=False, do_verbose=False):
#    # # if exists, check for changes before writing
#    if(os.path.isfile(fufi)):
#        old_string = bread(fufi)
#        if(old_string == string):
#            if(do_verbose):
#                print("No change in " + fufi)
#            return False
#    the_file = open(fufi, 'bw')
#    the_file.write(string)
#    the_file.close()
#    if(do_verbose):
#        print("I write " + fufi)
#    return True


def srite(fufi, string, do_backup=False, do_verbose=False,
          do_change_check=True, do_preserve_time=None):
    if (do_preserve_time is True):
        time = os.path.getmtime(fufi)
    elif isinstance(do_preserve_time, float):
        time = do_preserve_time
    elif isinstance(do_preserve_time, int):
        time = do_preserve_time
    # # if exists, check for changes before writing
    if do_change_check and os.path.isfile(fufi):
        old_string = sread(fufi)
        if(old_string == string):
            if(do_verbose):
                print("filer: I keep " + fufi)
            return False
    the_file = open(fufi, 'w')
    if(fufi[-3:] != '.gz'):
        with open(fufi, 'w') as the_file:
            the_file.write(string)
    else:
        with gzip.open(fufi, 'wb') as the_file:
            the_file.write(string.encode())
    the_file.close()
    if do_verbose:
        print("filer: I wrote " + fufi)
    if not os.path.isfile(fufi):
        raise Exception(f"{fufi} should have been written.")
    if do_preserve_time is not None:
        os.utime(fufi, (time, time))
    return True

def donere(out_fufi, in_fufis, do_verbose=False, do_allow_empty=False):
    """does need renewal"""
    if not os.path.isfile(out_fufi):
        if do_verbose:
            print("filer.donore does not see " + out_fufi)
        return True
    out_info = os.stat(out_fufi)
    out_size = out_info.st_size
    if out_size == 0 and not do_allow_empty:
        if do_verbose:
            print(f'{out_fufi} is empty')
        return True
    out_mtime = out_info.st_mtime
    if not isinstance(in_fufis, list):
        raise Exception('filer.donere needs a list of in_fufis')
    for in_fufi in in_fufis:
        if not os.path.isfile(in_fufi):
            print("donere does not see the in_fufi " + in_fufi,
                  file=sys.stderr)
            continue
        in_info = os.stat(in_fufi)
        in_mtime = in_info.st_mtime
        if in_mtime > out_mtime:
            if do_verbose:
                print(f'{out_fufi} older than {in_fufi}')
            return True
    if do_verbose:
        print("filer.donere skips " + out_fufi)
    return False