# Zxy导入Django的admin模块
from django.contrib import admin
# Zxy导入Django的LogEntry模型
from django.contrib.admin.models import DELETION
# Zxy导入Django的内容类型模型
from django.contrib.contenttypes.models import ContentType
# Zxy导入Django的URL工具
from django.urls import reverse, NoReverseMatch
# Zxy导入Django的编码工具
from django.utils.encoding import force_str
# Zxy导入Django的HTML工具
from django.utils.html import escape
# Zxy导入Django的安全字符串工具
from django.utils.safestring import mark_safe
# Zxy导入Django的翻译工具
from django.utils.translation import gettext_lazy as _

# Zxy定义LogEntryAdmin类
class LogEntryAdmin(admin.ModelAdmin):
    list_filter = ['content_type']  # Zxy按内容类型过滤
    search_fields = ['object_repr', 'change_message']  # Zxy搜索字段

    list_display_links = ['action_time', 'get_change_message']  # Zxy显示链接的字段
    list_display = ['action_time', 'user_link', 'content_type', 'object_link', 'get_change_message']  # Zxy显示字段

    # Zxy检查是否有添加权限
    def has_add_permission(self, request):
        return False

    # Zxy检查是否有修改权限
    def has_change_permission(self, request, obj=None):
        return (
                request.user.is_superuser or
                request.user.has_perm('admin.change_logentry')
        ) and request.method != 'POST'

    # Zxy检查是否有删除权限
    def has_delete_permission(self, request, obj=None):
        return False

    # Zxy获取对象链接
    def object_link(self, obj):
        object_link = escape(obj.object_repr)  # Zxy转义对象表示
        content_type = obj.content_type

        if obj.action_flag != DELETION and content_type is not None:  # Zxy检查是否为删除操作
            try:
                url = reverse(  # Zxy生成反向URL
                    'admin:{}_{}_change'.format(content_type.app_label, content_type.model),
                    args=[obj.object_id]
                )
                object_link = '<a href="{}">{}</a>'.format(url, object_link)  # Zxy生成链接
            except NoReverseMatch:
                pass
        return mark_safe(object_link)  # Zxy标记为安全字符串

    object_link.admin_order_field = 'object_repr'  # Zxy排序字段
    object_link.short_description = _('object')  # Zxy字段描述

    # Zxy获取用户链接
    def user_link(self, obj):
        content_type = ContentType.objects.get_for_model(type(obj.user))  # Zxy获取用户的内容类型
        user_link = escape(force_str(obj.user))  # Zxy转义用户表示

        try:
            url = reverse(  # Zxy生成反向URL
                'admin:{}_{}_change'.format(content_type.app_label, content_type.model),
                args=[obj.user.pk]
            )
            user_link = '<a href="{}">{}</a>'.format(url, user_link)  # Zxy生成链接
        except NoReverseMatch:
            pass
        return mark_safe(user_link)  # Zxy标记为安全字符串

    user_link.admin_order_field = 'user'  # Zxy排序字段
    user_link.short_description = _('user')  # Zxy字段描述

    # Zxy获取查询集
    def get_queryset(self, request):
        queryset = super(LogEntryAdmin, self).get_queryset(request)
        return queryset.prefetch_related('content_type')  # Zxy预加载内容类型

    # Zxy获取操作
    def get_actions(self, request):
        actions = super(LogEntryAdmin, self).get_actions(request)
        if 'delete_selected' in actions:  # Zxy移除删除操作
            del actions['delete_selected']
        return actions