"""

分页器

"""

from django.utils.safestring import mark_safe

from django.http import QueryDict

class Pagination:

    # request 为request请求， all_count为所有数据的个数， query_params为查询的时候将查询结果与页数进行拼接， per_num为一页展示多少数据， max_show分多少页

    def __init__(self, request, all_count, query_params=QueryDict(), per_num=10, max_show=11):

        # 基本的URL

        self.base_url = request.path_info

        # 查询条件

        self.query_params = query_params

        self.query_params._mutable = True

        # 当前页码

        try:

            self.current_page = int(request.GET.get('page', 1))

            if self.current_page <= 0:

                self.current_page = 1

        except Exception as e:

            self.current_page = 1

            print(e)

        # 最多显示的页码数

        self.max_show = max_show

        half_show = max_show // 2

        # 每页显示的数据条数

        self.per_num = per_num

        # 总数据量

        self.all_count = all_count

        # 总页码数

        self.total_num, more = divmod(all_count, per_num)

        if more:

            self.total_num += 1

        # 总页码数小于最大显示数：显示总页码数

        if self.total_num <= max_show:

            self.page_start = 1

            self.page_end = self.total_num

        else:

            # 总页码数大于最大显示数：最多显示11个

            if self.current_page <= half_show:

                self.page_start = 1

                self.page_end = max_show

            elif self.current_page + half_show >= self.total_num:

                self.page_end = self.total_num

                self.page_start = self.total_num - max_show + 1

            else:

                self.page_start = self.current_page - half_show

                self.page_end = self.current_page + half_show

    @property

    def start(self):

        return (self.current_page - 1) * self.per_num

    @property

    def end(self):

        return self.current_page * self.per_num

    @property

    def show_li(self):

        # 存放li标签的列表

        html_list = []

        self.query_params['page'] = 1

        # query=a&page=1

        first_li = '<li><a href="{}?{}">首页</a></li>'.format(self.base_url, self.query_params.urlencode())

        html_list.append(first_li)

        if self.current_page == 1:

            prev_li = '<li class="disabled"><a><<</a></li>'

        else:

            self.query_params['page'] = self.current_page - 1

            prev_li = '<li><a href="{0}?{1}"><<</a></li>'.format(self.base_url, self.query_params.urlencode())

        html_list.append(prev_li)

        for num in range(self.page_start, self.page_end + 1):

            self.query_params['page'] = num

            if self.current_page == num:

                li_html = '<li class="active"><a href="{0}?{1}">{2}</a></li>'.format(self.base_url,

                                                                                     self.query_params.urlencode(), num)

            else:

                li_html = '<li><a href="{0}?{1}">{2}</a></li>'.format(self.base_url,

                                                                       self.query_params.urlencode(), num)

            html_list.append(li_html)

        if self.current_page == self.total_num:

            next_li = '<li class="disabled"><a>>></a></li>'

        else:

            self.query_params['page'] = self.current_page + 1

            next_li = '<li><a href="{0}?{1}">>></a></li>'.format(self.base_url, self.query_params.urlencode())

        html_list.append(next_li)

        self.query_params['page'] = self.total_num

        last_li = '<li><a href="{}?{}">尾页</a></li>'.format(self.base_url, self.query_params.urlencode())

        html_list.append(last_li)

        return mark_safe(''.join(html_list))

# 解决搜索后的url翻页拼接问题

        print('query', request.GET)  # <QueryDict: {'query': [结果]}>

        # query=结果

        print(request.GET.urlencode())

        # _mutable=True  这样就可以修改了

        # query_params = copy.deepcopy(request.GET)

        query_params = request.GET.copy()  # 为了将查询结果与页数都放到url上

        # query_params._mutable = True

        page = pagination.Pagination(request, customer.count(), query_params, per_num=3)

        return render(request, 'crm/customer_list.html', {

            "customer": customer[page.start:page.end],

            'html_str': page.show_li,

        })