from django.contrib import admin, messages
from django.core.cache import cache
from import_export.admin import ImportExportModelAdmin

from base.models import MainMenu, BaseInfo, LinkCategory, FriendLink, PictureLink


# —————— 主菜单 ——————
@admin.register(MainMenu)
class MainMenuAdmin(ImportExportModelAdmin):
    list_display = ('display_name', 'code', 'url', 'parent', 'order', 'visible')
    list_editable = ('order', 'visible')
    list_filter = ('parent', 'visible')
    search_fields = ('title', 'url')
    ordering = ('id',)

    def display_name(self, obj):
        """在列表中显示层级缩进"""
        if obj.is_sub:
            return f"  └─ {obj.title}"  # 使用全角空格+符号模拟缩进
        return obj.title

    display_name.short_description = '板块名称'
    display_name.admin_order_field = 'name'

    def is_enabled(self, obj):
        return obj.visible

    is_enabled.boolean = True
    is_enabled.short_description = '启用'

    def formfield_for_foreignkey(self, db_field, request, **kwargs):
        """限制 parent 只能选择主板块（无父级的板块）"""
        if db_field.name == "parent":
            kwargs["queryset"] = MainMenu.objects.filter(parent__isnull=True, is_external=False)
        return super().formfield_for_foreignkey(db_field, request, **kwargs)

    def get_queryset(self, request):
        """优化查询，避免 N+1"""
        return super().get_queryset(request).select_related('parent')


# 1. 注册分类管理
@admin.register(LinkCategory)
class LinkCategoryAdmin(ImportExportModelAdmin):
    list_display = ('name', 'code', 'order', 'is_active')
    list_editable = ('order', 'is_active')


# 2. 注册链接管理
@admin.register(FriendLink)
class FriendLinkAdmin(ImportExportModelAdmin):
    list_display = ('name', 'category', 'url', 'order', 'is_active')
    list_filter = ('category', 'is_active')  # 左侧过滤器，方便筛选
    search_fields = ('name', 'url')

    # 优化：在添加链接时，只显示启用的分类
    def formfield_for_foreignkey(self, db_field, request, **kwargs):
        if db_field.name == "category":
            kwargs["queryset"] = LinkCategory.objects.filter(is_active=True)
        return super().formfield_for_foreignkey(db_field, request, **kwargs)


@admin.register(PictureLink)
class PictureLinkAdmin(admin.ModelAdmin):
    list_display = ['name', 'order', 'is_active', 'created_at']

    def save_model(self, request, obj, form, change):
        # 1. 先执行 Model 的 save 方法（这里会触发逻辑判断和消息暂存）
        super().save_model(request, obj, form, change)

        # 2. 【关键】检查有没有暂存的消息
        # 获取 key（如果是新建对象，obj.pk 此时已经有了，如果是内存中的临时对象则用 id）
        msg_key = obj.pk if obj.pk else id(obj)
        key = f"picture_count_limit_{msg_key}"
        msg = cache.get(key)  # 缓存 30 秒
        if msg:
            # 取出消息并弹窗
            cache.delete(key)
            self.message_user(request, msg, level=messages.WARNING)


# —————— 页脚链接 ——————
@admin.register(BaseInfo)
class BaseInfoAdmin(ImportExportModelAdmin):
    list_display = ('title', 'address', 'unit', 'postal', 'telephone', 'fax', 'filing')
    list_editable = ('postal', 'telephone', 'fax', 'unit', 'filing',)