#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Author: anchen
# @Date:   2017-07-07 15:42:44
# @Last Modified by:   anchen
# @Last Modified time: 2018-03-08 14:46:29


import random
from PIL import Image, ImageDraw, ImageFont, ImageFilter
from io import BytesIO
import requests
from . import pool
import redis


# 验证码
_letter_cases = "abcdefghjkmnpqrstuvwxy"  # 小写字母，去除可能干扰的i，l，o，z
_upper_cases = _letter_cases.upper()  # 大写字母
_numbers = ''.join(map(str, range(3, 10)))  # 数字
init_chars = ''.join((_letter_cases, _upper_cases, _numbers))
fontType = "Arial.ttf"


def create_validate_code(size=(120, 30),
                         chars=init_chars,
                         img_type="GIF",
                         mode="RGB",
                         bg_color=(255, 255, 255),
                         fg_color=(0, 0, 255),
                         font_size=18,
                         font_type=fontType,
                         length=4,
                         draw_lines=True,
                         n_line=(1, 2),
                         draw_points=True,
                         point_chance=2):
    '''
    @todo: 生成验证码图片
    @param size: 图片的大小，格式（宽，高），默认为(120, 30)
    @param chars: 允许的字符集合，格式字符串
    @param img_type: 图片保存的格式，默认为GIF，可选的为GIF，JPEG，TIFF，PNG
    @param mode: 图片模式，默认为RGB
    @param bg_color: 背景颜色，默认为白色
    @param fg_color: 前景色，验证码字符颜色，默认为蓝色#0000FF
    @param font_size: 验证码字体大小
    @param font_type: 验证码字体，默认为 Arial.ttf
    @param length: 验证码字符个数
    @param draw_lines: 是否划干扰线
    @param n_lines: 干扰线的条数范围，格式元组，默认为(1, 2)，只有draw_lines为True时有效
    @param draw_points: 是否画干扰点
    @param point_chance: 干扰点出现的概率，大小范围[0, 100]
    @return: [0]: PIL Image实例
    @return: [1]: 验证码图片中的字符串
    '''

    width, height = size  # 宽， 高
    img = Image.new(mode, size, bg_color)  # 创建图形
    draw = ImageDraw.Draw(img)  # 创建画笔
    if draw_lines:
        create_lines(draw, n_line, width, height)
    if draw_points:
        create_points(draw, point_chance, width, height)
    strs = create_strs(draw, chars, length, font_type,
                       font_size, width, height, fg_color)

    # 图形扭曲参数
    params = [1 - float(random.randint(1, 2)) / 100,
              0,
              0,
              0,
              1 - float(random.randint(1, 10)) / 100,
              float(random.randint(1, 2)) / 500,
              0.001,
              float(random.randint(1, 2)) / 500
              ]
    img = img.transform(size, Image.PERSPECTIVE, params)  # 创建扭曲

    img = img.filter(ImageFilter.EDGE_ENHANCE_MORE)  # 滤镜，边界加强（阈值更大）

    return img, strs


def create_lines(draw, n_line, width, height):
    '''绘制干扰线'''
    line_num = random.randint(n_line[0], n_line[1])  # 干扰线条数
    for i in range(line_num):
        # 起始点
        begin = (random.randint(0, width), random.randint(0, height))
        # 结束点
        end = (random.randint(0, width), random.randint(0, height))
        draw.line([begin, end], fill=(0, 0, 0))


def create_points(draw, point_chance, width, height):
    '''绘制干扰点'''
    chance = min(100, max(0, int(point_chance)))  # 大小限制在[0, 100]

    for w in range(width):
        for h in range(height):
            tmp = random.randint(0, 100)
            if tmp > 100 - chance:
                draw.point((w, h), fill=(0, 0, 0))


def create_strs(draw, chars, length, font_type, font_size, width, height, fg_color):
    '''绘制验证码字符'''
    '''生成给定长度的字符串，返回列表格式'''
    c_chars = random.sample(chars, length)
    # 每个字符前后以空格隔开
    strs = ' %s ' % ' '.join(c_chars)

    font = ImageFont.truetype(font_type, font_size)
    font_width, font_height = font.getsize(strs)

    draw.text(((width - font_width) / 3, (height - font_height) / 3),
              strs, font=font, fill=fg_color)

    return ''.join(c_chars)


# 返回验证码数据流和字符
def generate_verification_code():
    code_img, str_text = create_validate_code()
    buf = BytesIO()
    code_img.save(buf, 'JPEG', quality=70)
    buf_str = buf.getvalue()
    return buf_str, str_text


# 异地登录检测
def check_remote_login(last_ip, current_ip):
    # 'http://int.dpool.sina.com.cn/iplookup/iplookup.php?format=json&ip={}' 新浪的不可用了
    inquire_api = 'http://ip.taobao.com/service/getIpInfo.php?ip={}'

    if last_ip == current_ip:
        return None

    location = None
    try:
        data = requests.get(inquire_api.format(last_ip), timeout=1).json()
        if not isinstance(data, dict):
            location = u'异常登录提醒: 您上次登录ip为{ip} 地点无法确定'.format(ip=last_ip)
        else:
            data = data.get('data') or data
            country = data.get('country') if data.get('country') else ''
            province = data.get('province') or data.get('region') \
                if data.get('province') or data.get('region') else ''
            city = data.get('city') if data.get('city') else ''
            if country or province or city:
                location = u'异常登录提醒：你上次登录ip为{ip} 地点在 {country} {province} {city}'.format(
                    ip=last_ip, country=country, province=province, city=city)
            else:
                location = u'异常登录提醒: 您上次登录ip为{ip} 地点无法确定'.format(
                    ip=last_ip)
    except Exception as e:
        location = u'异常登录提醒: 您上次登录ip为{ip} 地点无法确定'.format(ip=last_ip)
    return location

# 检测ip or session是否被锁


def check_is_locked(ip, session):
    r = redis.Redis(connection_pool=pool)
    if r.get('USER-BLOCK-{ip}'.format(ip=ip)) or \
            r.get('USER-BLOCK-{session}'.format(session=session)):
        return True
    return False


# 解除ip or session封禁
def lift_ban(ip, session):
    r = redis.Redis(connection_pool=pool)
    r.delete('USER-BLOCK-{ip}'.format(ip=ip))
    r.delete('USER-BLOCK-{session}'.format(session=session))

# 分页
class Pagination(object):
    def __init__(self, page, per_page, count):
        self.page = page
        self.prev_num = page - 1
        self.next_num = page + 1
        self.per_page = per_page

        self.pages = int(count / self.per_page) + \
            1 if count % self.per_page else int(
                count / self.per_page)

    @property
    def has_prev(self):
        return self.page > 1

    @property
    def has_next(self):
        return self.page < self.pages

    def iter_pages(self):
        if self.page <= 5:
            for p in range(1, self.page + 1):
                yield p
        else:
            yield 1
            yield 2

        if self.page > 5:
            yield '...'
            yield self.page - 2
            yield self.page - 1
            yield self.page

        if self.pages - self.page > 4:
            yield self.page + 1
            yield self.page + 2
            yield '...'

        if self.pages - self.page <= 4:
            for p in range(self.page + 1, self.pages + 1):
                yield p
        else:
            yield self.pages - 1
            yield self.pages
