"""Admin building blocks. A service still registers its own models."""

from __future__ import annotations

from django.contrib import admin, messages
from django.utils.translation import gettext_lazy as _


class SourceAdminMixin:
    """The columns, filters and the run-now action every source list needs.

    ``run_task`` is the service's Celery task. It is queued rather than run
    inline so a slow upstream cannot hold the admin request open.
    """

    run_task = None

    list_filter = ("kind", "is_enabled", "is_public", "last_status")
    search_fields = ("name", "slug", "description")
    prepopulated_fields = {"slug": ("name",)}
    filter_horizontal = ("tracked_satellites",)
    readonly_fields = (
        "last_run_at", "last_status", "last_error",
        "success_count", "failure_count", "created_at", "updated_at",
    )

    @admin.action(description=_("Run selected sources now"))
    def run_now(self, request, queryset):
        if self.run_task is None:  # pragma: no cover - configuration error
            raise NotImplementedError("set run_task on the ModelAdmin")
        queued = 0
        for src in queryset:
            self.run_task.delay(src.pk)
            queued += 1
        messages.success(request, _("Queued %(n)d source(s) for fetch.") % {"n": queued})

    actions = ["run_now"]


class SourceRunAdminMixin:
    """Run history is a log: readable, filterable, never editable."""

    list_display = (
        "source", "started_at", "finished_at", "status", "fetched_count", "new_count",
    )
    list_filter = ("status", "source")
    search_fields = ("source__name", "source__slug")
    readonly_fields = (
        "source", "started_at", "finished_at",
        "status", "fetched_count", "new_count", "error",
    )
    date_hierarchy = "started_at"

    def has_add_permission(self, request):
        return False

    def has_change_permission(self, request, obj=None):
        return False