from django import forms
from django.contrib import admin
from django.utils.html import format_html
from import_export.admin import ImportExportModelAdmin

from article.models import NoticeReceipt, Notice, Article, Carousel, ArticleAttachment
from base.models import MainMenu
from users.models import User


# —————— 板块 ——————
# @admin.register(ArticleSection)
# class SectionAdmin(admin.ModelAdmin):
#     list_display = ('display_name', 'code', 'parent', 'is_enabled', 'order')
#     list_filter = ('parent', 'enabled')
#     search_fields = ('name', 'code')
#     ordering = ('order', 'name')
#     list_editable = ('order',)
#     fieldsets = (
#         ('基本信息', {
#             'fields': ('name', 'code', 'parent', 'enabled', 'order')
#         }),
#     )
#
#     def display_name(self, obj):
#         """在列表中显示层级缩进"""
#         if obj.is_sub:
#             return f"  └─ {obj.name}"  # 使用全角空格+符号模拟缩进
#         return obj.name
#
#     display_name.short_description = '板块名称'
#     display_name.admin_order_field = 'name'
#
#     def is_enabled(self, obj):
#         return obj.enabled
#
#     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"] = ArticleSection.objects.filter(parent__isnull=True)
#         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')
#

# —————— 轮播图 ——————
@admin.register(Carousel)
class CarouselAdmin(ImportExportModelAdmin):
    list_display = ('title', 'image_thumb', 'link_url', 'order', 'active')
    list_editable = ('order', 'active')
    ordering = ('order',)

    def image_thumb(self, obj):
        if obj.image:
            return format_html('<image src="{}" width="60" height="auto" />', obj.image.url)
        return "无图"

    image_thumb.short_description = "预览"


# --- 附件内联配置 ---
class ArticleAttachmentInline(admin.TabularInline):
    model = ArticleAttachment
    extra = 1  # 默认显示 1 个空白的附件上传框
    verbose_name = "附件"
    verbose_name_plural = "附件列表"
    # 如果附件较多，可以限制每页显示数量
    # max_num = 5


# 1. 定义自定义表单
class ArticleForm(forms.ModelForm):
    class Meta:
        model = Article
        fields = '__all__'

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        # 核心代码：过滤 section 字段，只保留有父级的分类（即二级分类）
        # 这里的 queryset 会直接作用于 Admin 的下拉选择框
        self.fields['section'].queryset = MainMenu.objects.filter(parent__isnull=False, visible=True)

        # 可选：优化显示格式，让用户知道是哪个主板块下的子板块
        # 例如显示："[新闻中心] 国内新闻"
        self.fields['section'].label_from_instance = lambda obj: f"[{obj.parent.title}] {obj.title}"


# —————— 文章 ——————
@admin.register(Article)
class ArticleAdmin(ImportExportModelAdmin):
    form = ArticleForm  # <--- 关联自定义表单
    list_display = ('title', 'section', 'author', 'is_published', 'created_at', 'attachment_count')
    list_filter = ('section', 'is_published', 'created_at')
    search_fields = ('title', 'content')
    date_hierarchy = 'created_at'
    autocomplete_fields = ('author',)  # 需要 UserAdmin 支持搜索

    # 核心配置：将附件内联注册到文章管理中
    inlines = [ArticleAttachmentInline]
    fieldsets = (
        ('基本信息', {'fields': ('title', 'section', 'cover')}),
        ('内容', {'fields': ('content',)}),
        ('发布设置', {'fields': ('is_published',)}),
    )

    # 2. 定义显示附件数量的方法
    def attachment_count(self, obj):
        # 使用 count() 方法统计数量
        count = obj.attachments.count()
        if count == 0:
            return "-"  # 没有附件显示横杠
        return f"📎 {count}"  # 有附件显示图标和数量

    # 3. 设置该列在后台的标题
    attachment_count.short_description = "附件"


# —————— 通知（带签收） ——————
@admin.register(Notice)
class NoticeAdmin(ImportExportModelAdmin):
    list_display = (
        'title',
        'publisher',
        'require_sign',
        'is_published',
        'signed_count',
        'total_target_users',
        'created_at'
    )
    list_filter = ('require_sign', 'is_published', 'created_at', 'target_departments')
    search_fields = ('title', 'content')
    filter_horizontal = ('target_departments',)
    readonly_fields = ('created_at', 'updated_at', 'publisher')
    date_hierarchy = 'created_at'

    fieldsets = (
        ('基本信息', {
            'fields': ('title', 'content', 'is_published')
        }),
        ('签收设置', {
            'fields': ('require_sign', 'target_departments'),
            'description': '勾选“是否需要签收”后，可指定接收部门。未指定则默认全员可见但不可签收。'
        }),
        ('时间信息', {
            'fields': ('created_at', 'updated_at'),
            'classes': ('collapse',)
        }),
    )

    def save_model(self, request, obj, form, change):
        if not change:
            obj.publisher = request.user
        super().save_model(request, obj, form, change)

    def signed_count(self, obj):
        return obj.receipts.count()

    signed_count.short_description = "已签收人数"

    def total_target_users(self, obj):
        if obj.target_departments.exists():
            count = User.objects.filter(
                dept__in=obj.target_departments.all(),
                is_active=True
            ).count()
        else:
            count = User.objects.filter(is_active=True).count()
        return count

    total_target_users.short_description = "应签收人数"


# —————— 签收记录 ——————
@admin.register(NoticeReceipt)
class NoticeReceiptAdmin(ImportExportModelAdmin):
    list_display = ('notice', 'user', 'signed_at')
    list_filter = ('signed_at', 'notice__title')
    search_fields = ('user__cname', 'user__username', 'notice__title')
    readonly_fields = ('notice', 'user', 'signed_at')

    def has_add_permission(self, request):
        return False  # 禁止手动添加