from django.contrib import admin
from django.contrib.auth import get_user_model
from django.contrib.auth.admin import UserAdmin
from django.db.models import Q

from apps.core.admin_video import video_admin_preview
from apps.core.video import VIDEO_ADMIN_FIELDSET
from .access import accessible_projects, can_access_project, can_create_project, project_for_related

from .models import (
    Article, ArticleCitation, ArticlePerson, ArticleSection, MainProduct,
    MainProductPerson, ProductVideo, ProjectAccess, ProjectAccessPolicy,
    SubProduct, SubProductPerson,
)


class ProjectAccessPolicyInline(admin.StackedInline):
    model = ProjectAccessPolicy
    extra = 1
    max_num = 1
    fields = ("mode",)


class ProjectAccessInline(admin.TabularInline):
    model = ProjectAccess
    extra = 1
    fields = ("main_product", "sub_product", "level")
    verbose_name = "Project access override"
    verbose_name_plural = "Project access overrides (choose one project per row)"


User = get_user_model()
admin.site.unregister(User)


@admin.register(User)
class ProjectUserAdmin(UserAdmin):
    inlines = (ProjectAccessPolicyInline, ProjectAccessInline)

    def get_inlines(self, request, obj=None):
        return self.inlines if request.user.is_superuser else ()


class ProjectInlineAccessMixin:
    def has_view_permission(self, request, obj=None):
        return request.user.is_staff and (obj is None or can_access_project(request.user, project_for_related(obj)))

    def has_change_permission(self, request, obj=None):
        return request.user.is_staff and (obj is None or can_access_project(request.user, project_for_related(obj), edit=True))

    def has_add_permission(self, request, obj=None):
        return request.user.is_staff and (obj is None or can_access_project(request.user, project_for_related(obj), edit=True))

    def has_delete_permission(self, request, obj=None):
        return request.user.is_superuser


class ProjectAdminAccessMixin:
    def has_module_permission(self, request):
        return request.user.is_staff

    def get_queryset(self, request):
        queryset = super().get_queryset(request)
        main = accessible_projects(request.user, MainProduct)
        sub = accessible_projects(request.user, SubProduct)
        if self.model is MainProduct:
            return queryset.filter(pk__in=main)
        if self.model is SubProduct:
            return queryset.filter(pk__in=sub)
        if self.model in (Article, ProductVideo):
            return queryset.filter(Q(main_product__in=main) | Q(sub_product__in=sub))
        if self.model is ArticleSection:
            return queryset.filter(Q(article__main_product__in=main) | Q(article__sub_product__in=sub))
        return queryset.none()

    def has_view_permission(self, request, obj=None):
        return request.user.is_staff and (obj is None or can_access_project(request.user, project_for_related(obj)))

    def has_change_permission(self, request, obj=None):
        return request.user.is_staff and (obj is None or can_access_project(request.user, project_for_related(obj), edit=True))

    def has_add_permission(self, request):
        return request.user.is_staff and can_create_project(request.user)

    def has_delete_permission(self, request, obj=None):
        return request.user.is_superuser

    def formfield_for_foreignkey(self, db_field, request, **kwargs):
        if db_field.name == "main_product":
            kwargs["queryset"] = accessible_projects(request.user, MainProduct, edit=True)
        elif db_field.name == "sub_product":
            kwargs["queryset"] = accessible_projects(request.user, SubProduct, edit=True)
        elif db_field.name == "article":
            main = accessible_projects(request.user, MainProduct, edit=True)
            sub = accessible_projects(request.user, SubProduct, edit=True)
            kwargs["queryset"] = Article.objects.filter(Q(main_product__in=main) | Q(sub_product__in=sub))
        return super().formfield_for_foreignkey(db_field, request, **kwargs)


class PersonInline(ProjectInlineAccessMixin, admin.StackedInline):
    extra = 0
    fields = ("role", "name", "description", "read_more_description", "image", "image_alt", "url", "order")
    ordering = ("order",)


class MainProductPersonInline(PersonInline):
    model = MainProductPerson


class SubProductPersonInline(PersonInline):
    model = SubProductPerson


class ArticlePersonInline(PersonInline):
    model = ArticlePerson


class ArticleCitationInline(ProjectInlineAccessMixin, admin.TabularInline):
    model = ArticleCitation
    extra = 1
    fields = ("text", "read_more_text", "url", "order")
    ordering = ("order",)


class ArticleSectionInline(ProjectInlineAccessMixin, admin.TabularInline):
    model = ArticleSection
    extra = 1
    fields = ("title", "value_format", "value", "read_more_value", "order")
    ordering = ("order",)


class SubProductArticleInline(ProjectInlineAccessMixin, admin.StackedInline):
    model = Article
    fk_name = "sub_product"
    extra = 0
    fields = ("badge", "title", "description", "read_more_description", "order")
    ordering = ("order",)
    show_change_link = True


class MainProductArticleInline(ProjectInlineAccessMixin, admin.StackedInline):
    model = Article
    fk_name = "main_product"
    extra = 0
    fields = ("badge", "title", "description", "read_more_description", "order")
    ordering = ("order",)
    show_change_link = True


class ProductVideoInline(ProjectInlineAccessMixin, admin.StackedInline):
    model = ProductVideo
    fk_name = "main_product"
    extra = 0
    fields = (
        "badge",
        "title",
        "description_format",
        "description",
        "read_more_description",
        "video_source",
        "video_url",
        "video_file",
        "video_poster",
        "video_size",
        "video_aspect_ratio",
        "video_styled_background",
        "order",
        "is_active",
    )
    ordering = ("order",)


class SubProductInline(ProjectInlineAccessMixin, admin.StackedInline):
    model = SubProduct
    extra = 0
    fields = ("name", "slug", "short_description", "read_more_short_description", "image", "logo", "show_on_homepage", "homepage_order", "order", "is_active")
    ordering = ("order",)
    show_change_link = True
    prepopulated_fields = {"slug": ("name",)}

    def get_queryset(self, request):
        return super().get_queryset(request).filter(pk__in=accessible_projects(request.user, SubProduct, edit=True))


@admin.register(MainProduct)
class MainProductAdmin(ProjectAdminAccessMixin, admin.ModelAdmin):
    list_display = ("name", "created_by", "show_on_homepage", "homepage_order", "order", "is_active", "created_at")
    list_filter = ("is_active", "show_on_homepage")
    search_fields = ("name", "description")
    prepopulated_fields = {"slug": ("name",)}
    inlines = [MainProductPersonInline, MainProductArticleInline, ProductVideoInline, SubProductInline]
    fieldsets = (
        (
            None,
            {
                "fields": (
                    "name",
                    "slug",
                    "short_description",
                    "read_more_short_description",
                )
            },
        ),
        ("Description", {"fields": ("description_format", "description", "read_more_description")}),
        ("Media", {"fields": ("image",)}),
        ("Homepage", {"fields": ("show_on_homepage", "homepage_order")}),
        ("Settings", {"fields": ("order", "is_active")}),
    )

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

    def save_formset(self, request, form, formset, change):
        instances = formset.save(commit=False)
        for deleted in formset.deleted_objects:
            deleted.delete()
        for instance in instances:
            if isinstance(instance, SubProduct) and not instance.created_by_id:
                instance.created_by = request.user
            instance.save()
        formset.save_m2m()


class SubProductVideoInline(ProjectInlineAccessMixin, admin.StackedInline):
    model = ProductVideo
    fk_name = "sub_product"
    extra = 0
    fields = (
        "badge",
        "title",
        "description_format",
        "description",
        "read_more_description",
        "video_source",
        "video_url",
        "video_file",
        "video_poster",
        "video_size",
        "video_aspect_ratio",
        "video_styled_background",
        "order",
        "is_active",
    )
    ordering = ("order",)


@admin.register(SubProduct)
class SubProductAdmin(ProjectAdminAccessMixin, admin.ModelAdmin):
    list_display = (
        "name",
        "main_product",
        "created_by",
        "show_on_homepage",
        "homepage_order",
        "order",
        "is_active",
        "created_at",
    )
    list_filter = ("is_active", "main_product", "show_on_homepage")
    search_fields = ("name", "description", "main_product__name")
    prepopulated_fields = {"slug": ("name",)}
    raw_id_fields = ("main_product",)
    inlines = [SubProductPersonInline, SubProductArticleInline, SubProductVideoInline]
    fieldsets = (
        (
            None,
            {
                "fields": (
                    "main_product",
                    "name",
                    "slug",
                    "short_description",
                    "read_more_short_description",
                )
            },
        ),
        ("Description", {"fields": ("description_format", "description", "read_more_description")}),
        ("Media", {"fields": ("image", "logo")}),
        ("Homepage", {"fields": ("show_on_homepage", "homepage_order")}),
        ("Settings", {"fields": ("order", "is_active")}),
    )

    def get_readonly_fields(self, request, obj=None):
        fields = super().get_readonly_fields(request, obj)
        return (*fields, "main_product") if obj and not request.user.is_superuser else fields

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


@admin.register(Article)
class ArticleAdmin(ProjectAdminAccessMixin, admin.ModelAdmin):
    list_display = ("title", "parent", "order", "created_at")
    list_filter = ("main_product", "sub_product__main_product")
    search_fields = ("title", "description", "main_product__name", "sub_product__name")
    raw_id_fields = ("main_product", "sub_product")
    inlines = [ArticlePersonInline, ArticleSectionInline, ArticleCitationInline]
    fieldsets = (
        (None, {"fields": ("main_product", "sub_product", "badge", "title")}),
        ("Description", {"fields": ("description_format", "description", "read_more_description")}),
        ("Citation Badge", {"fields": ("citation_count_display", "citation_count_label"), "description": "Number and optional label for the dashed citation circle badge. Both are optional — a label without a number shows an empty circle with the label; neither hides the badge entirely."}),
        ("Settings", {"fields": ("order",)}),
    )

    def get_readonly_fields(self, request, obj=None):
        fields = super().get_readonly_fields(request, obj)
        return (*fields, "main_product", "sub_product") if obj and not request.user.is_superuser else fields

    @admin.display(description="Parent")
    def parent(self, obj):
        if obj.main_product_id:
            return obj.main_product
        if obj.sub_product_id:
            return obj.sub_product
        return "—"


@admin.register(ProductVideo)
class ProductVideoAdmin(ProjectAdminAccessMixin, admin.ModelAdmin):
    list_display = ("title", "parent", "video_source", "video_size", "order", "is_active")
    list_filter = ("video_source", "is_active", "main_product", "sub_product__main_product")
    search_fields = ("title", "description", "video_url", "main_product__name", "sub_product__name")
    raw_id_fields = ("main_product", "sub_product")
    readonly_fields = ("video_preview",)
    fieldsets = (
        (None, {"fields": ("main_product", "sub_product", "badge", "title", "description_format", "description", "read_more_description")}),
        VIDEO_ADMIN_FIELDSET,
        ("Settings", {"fields": ("order", "is_active")}),
    )

    def get_readonly_fields(self, request, obj=None):
        fields = super().get_readonly_fields(request, obj)
        return (*fields, "main_product", "sub_product") if obj and not request.user.is_superuser else fields

    @admin.display(description="Parent")
    def parent(self, obj):
        if obj.main_product_id:
            return obj.main_product
        if obj.sub_product_id:
            return obj.sub_product
        return "—"

    @admin.display(description="Preview")
    def video_preview(self, obj):
        return video_admin_preview(obj)


@admin.register(ArticleSection)
class ArticleSectionAdmin(ProjectAdminAccessMixin, admin.ModelAdmin):
    list_display = ("title", "article", "value_format", "order")
    search_fields = ("title", "value", "article__title")
    raw_id_fields = ("article",)
    fieldsets = (
        (None, {"fields": ("article", "title")}),
        ("Content", {"fields": ("value_format", "value", "read_more_value")}),
        ("Settings", {"fields": ("order",)}),
    )

    def get_readonly_fields(self, request, obj=None):
        fields = super().get_readonly_fields(request, obj)
        return (*fields, "article") if obj and not request.user.is_superuser else fields