#!/usr/bin/env python3
# -*- coding:utf-8 -*-
# Author: kerlomz <kerlomz@gmail.com>
import io
import re
import os
import cv2
import time
import base64
import functools
import binascii
import datetime
import hashlib
import numpy as np
import tensorflow as tf
from PIL import Image as PIL_Image
from constants import Response, SystemConfig
from pretreatment import preprocessing, preprocessing_by_func
from config import ModelConfig, Config
from middleware.impl.gif_frames import concat_frames, blend_frame
from middleware.impl.rgb_filter import rgb_filter


class Arithmetic(object):

    def calc(self, formula):
        formula = re.sub(' ', '', formula)
        formula_ret = 0
        match_brackets = re.search(r'\([^()]+\)', formula)
        if match_brackets:
            calc_result = self.calc(match_brackets.group().strip("(,)"))
            formula = formula.replace(match_brackets.group(), str(calc_result))
            return self.calc(formula)
        else:
            formula = formula.replace('--', '+').replace('++', '+').replace('-+', '-').replace('+-', '-')
            while re.findall(r"[*/]", formula):
                get_formula = re.search(r"[.\d]+[*/]+[-]?[.\d]+", formula)
                if get_formula:
                    get_formula_str = get_formula.group()
                    if get_formula_str.count("*"):
                        formula_list = get_formula_str.split("*")
                        ret = float(formula_list[0]) * float(formula_list[1])
                    else:
                        formula_list = get_formula_str.split("/")
                        ret = float(formula_list[0]) / float(formula_list[1])
                    formula = formula.replace(get_formula_str, str(ret)).replace('--', '+').replace('++', '+')
            formula = re.findall(r'[-]?[.\d]+', formula)
            for num in formula:
                formula_ret += float(num)
        return formula_ret


class ParamUtils(object):

    @staticmethod
    def filter(param):
        if isinstance(param, list) and len(param) > 0 and isinstance(param[0], bytes):
            return param[0].decode()
        return param


class SignUtils(object):

    @staticmethod
    def md5(text):
        return hashlib.md5(text.encode('utf-8')).hexdigest()

    @staticmethod
    def timestamp():
        return int(time.mktime(datetime.datetime.now().timetuple()))


class PathUtils(object):

    @staticmethod
    def get_file_name(path: str):
        if '/' in path:
            return path.split('/')[-1]
        elif '\\' in path:
            return path.split('\\')[-1]
        else:
            return path


class ImageUtils(object):

    def __init__(self, conf: Config):
        self.conf = conf

    def get_bytes_batch(self, base64_or_bytes):
        response = Response(self.conf.response_def_map)
        b64_filter_s = lambda s: re.sub("data:image/.+?base64,", "", s, 1) if ',' in s else s
        b64_filter_b = lambda s: re.sub(b"data:image/.+?base64,", b"", s, 1) if b',' in s else s
        try:
            if isinstance(base64_or_bytes, bytes):
                if self.conf.split_flag in base64_or_bytes:
                    bytes_batch = base64_or_bytes.split(self.conf.split_flag)
                else:
                    bytes_batch = [base64_or_bytes]
            elif isinstance(base64_or_bytes, list):
                bytes_batch = [base64.b64decode(b64_filter_s(i).encode('utf-8')) for i in base64_or_bytes if
                               isinstance(i, str)]
                if not bytes_batch:
                    bytes_batch = [base64.b64decode(b64_filter_b(i)) for i in base64_or_bytes if isinstance(i, bytes)]
            else:
                base64_or_bytes = b64_filter_s(base64_or_bytes)
                bytes_batch = base64.b64decode(base64_or_bytes.encode('utf-8')).split(self.conf.split_flag)

        except binascii.Error:
            return None, response.INVALID_BASE64_STRING
        what_img = [ImageUtils.test_image(i) for i in bytes_batch]

        if None in what_img:
            return None, response.INVALID_IMAGE_FORMAT
        return bytes_batch, response.SUCCESS

    @staticmethod
    def get_image_batch(model: ModelConfig, bytes_batch, param_key=None, extract_rgb: list = None):
        # Note that there are two return objects here.
        # 1.image_batch, 2.response

        response = Response(model.conf.response_def_map)

        def load_image(image_bytes: bytes):
            data_stream = io.BytesIO(image_bytes)
            pil_image = PIL_Image.open(data_stream)

            gif_handle = model.pre_concat_frames != -1 or model.pre_blend_frames != -1

            if pil_image.mode == 'P' and not gif_handle:
                pil_image = pil_image.convert('RGB')

            rgb = pil_image.split()
            size = pil_image.size

            if (len(rgb) > 3 and model.pre_replace_transparent) and not gif_handle:
                background = PIL_Image.new('RGB', pil_image.size, (255, 255, 255))
                try:
                    background.paste(pil_image, (0, 0, size[0], size[1]), pil_image)
                    pil_image = background
                except:
                    pil_image = pil_image.convert('RGB')

            if len(pil_image.split()) > 3 and model.image_channel == 3:
                pil_image = pil_image.convert('RGB')

            if model.pre_concat_frames != -1:
                im = concat_frames(pil_image, model.pre_concat_frames)
            elif model.pre_blend_frames != -1:
                im = blend_frame(pil_image, model.pre_blend_frames)
            else:
                im = np.asarray(pil_image)

            if extract_rgb:
                im = rgb_filter(im, extract_rgb)

            im = preprocessing_by_func(
                exec_map=model.exec_map,
                key=param_key,
                src_arr=im
            )

            if model.image_channel == 1 and len(im.shape) == 3:
                im = cv2.cvtColor(im, cv2.COLOR_RGB2GRAY)

            im = preprocessing(
                image=im,
                binaryzation=model.pre_binaryzation,
            )

            if model.pre_horizontal_stitching:
                up_slice = im[0: int(size[1] / 2), 0: size[0]]
                down_slice = im[int(size[1] / 2): size[1], 0: size[0]]
                im = np.concatenate((up_slice, down_slice), axis=1)

            image = im.astype(np.float32)
            if model.resize[0] == -1:
                ratio = model.resize[1] / size[1]
                resize_width = int(ratio * size[0])
                image = cv2.resize(image, (resize_width, model.resize[1]))
            else:
                image = cv2.resize(image, (model.resize[0], model.resize[1]))
            image = image.swapaxes(0, 1)
            return (image[:, :, np.newaxis] if model.image_channel == 1 else image[:, :]) / 255.

        try:
            image_batch = [load_image(i) for i in bytes_batch]
            return image_batch, response.SUCCESS
        except OSError:
            return None, response.IMAGE_DAMAGE
        except ValueError as _e:
            print(_e)
            return None, response.IMAGE_SIZE_NOT_MATCH_GRAPH

    @staticmethod
    def size_of_image(image_bytes: bytes):
        _null_size = tuple((-1, -1))
        try:
            data_stream = io.BytesIO(image_bytes)
            size = PIL_Image.open(data_stream).size
            return size
        except OSError:
            return _null_size
        except ValueError:
            return _null_size

    @staticmethod
    def test_image(h):
        """JPEG"""
        if h[:3] == b"\xff\xd8\xff":
            return 'jpeg'
        """PNG"""
        if h[:8] == b"\211PNG\r\n\032\n":
            return 'png'
        """GIF ('87 and '89 variants)"""
        if h[:6] in (b'GIF87a', b'GIF89a'):
            return 'gif'
        """TIFF (can be in Motorola or Intel byte order)"""
        if h[:2] in (b'MM', b'II'):
            return 'tiff'
        if h[:2] == b'BM':
            return 'bmp'
        """SGI image library"""
        if h[:2] == b'\001\332':
            return 'rgb'
        """PBM (portable bitmap)"""
        if len(h) >= 3 and \
                h[0] == b'P' and h[1] in b'14' and h[2] in b' \t\n\r':
            return 'pbm'
        """PGM (portable graymap)"""
        if len(h) >= 3 and \
                h[0] == b'P' and h[1] in b'25' and h[2] in b' \t\n\r':
            return 'pgm'
        """PPM (portable pixmap)"""
        if len(h) >= 3 and h[0] == b'P' and h[1] in b'36' and h[2] in b' \t\n\r':
            return 'ppm'
        """Sun raster file"""
        if h[:4] == b'\x59\xA6\x6A\x95':
            return 'rast'
        """X bitmap (X10 or X11)"""
        s = b'#define '
        if h[:len(s)] == s:
            return 'xbm'
        return None


class SystemUtils(object):

    @staticmethod
    def datetime(origin=None, microseconds=None):
        now = origin if origin else time.time()
        if microseconds:
            return (
                    datetime.datetime.fromtimestamp(now) + datetime.timedelta(microseconds=microseconds)
            ).strftime('%Y-%m-%d %H:%M:%S.%f')
        return datetime.datetime.fromtimestamp(now).strftime('%Y-%m-%d %H:%M:%S.%f')

    @staticmethod
    def isdir(sftp, path):
        from stat import S_ISDIR
        try:
            return S_ISDIR(sftp.stat(path).st_mode)
        except IOError:
            return False

    @staticmethod
    def empty(sftp, path):
        from paramiko import SFTPClient
        if not SystemUtils.isdir(sftp, path):
            sftp.mkdir(path)

        files = sftp.listdir(path=path)

        for f in files:
            file_path = os.path.join(path, f)
            if SystemUtils.isdir(sftp, file_path):
                SystemUtils.empty(sftp, file_path)
            else:
                sftp.remove(file_path)