/**
 * RegionBackfillCard — admin-only: backfill missing `city`/`country` tags on the
 * logged-in user's own legacy spots & shops.
 *
 * Why: spots created before reverse geocoding existed have coordinates (so they
 * appear on the map) but no region tags (so `/stats` can only call them
 * "Uncategorised", under-counting the country vs the map). This re-derives the
 * tags from each pin and republishes the addressable event.
 *
 * Renders nothing for non-admins, so it can sit in Settings → Advanced beside the
 * other owner cards.
 */

import { useState } from 'react';
import { MapPin, Loader2 } from 'lucide-react';

import { Card, CardContent } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { useCurrentUser } from '@/hooks/useCurrentUser';
import { useRegionBackfill, type BackfillResult } from '@/hooks/useRegionBackfill';
import { isAdminPubkey } from '@/lib/admins';
import { toast } from '@/hooks/useToast';
import { useTranslation } from '@/contexts/language';

export function RegionBackfillCard() {
  const { user } = useCurrentUser();
  const isAdmin = isAdminPubkey(user?.pubkey);
  const { candidates, isLoading, backfill, progress, isRunning } = useRegionBackfill(isAdmin);
  const [summary, setSummary] = useState<BackfillResult | null>(null);
  const { t } = useTranslation();

  if (!isAdmin) return null;

  const count = candidates.length;

  const run = async () => {
    setSummary(null);
    try {
      const result = await backfill();
      setSummary(result);
      if (result.updated > 0) {
        toast({
          title: t('settingsUi.regionBackfill.taggedTitle', { count: result.updated, s: result.updated === 1 ? '' : 's' }),
          description:
            result.skipped > 0
              ? t('settingsUi.regionBackfill.taggedSkipped', { count: result.skipped })
              : t('settingsUi.regionBackfill.taggedOk'),
        });
      } else {
        toast({
          title: t('settingsUi.regionBackfill.nothingTitle'),
          description: t('settingsUi.regionBackfill.nothingDesc'),
          variant: 'destructive',
        });
      }
    } catch (err) {
      toast({
        title: t('settingsUi.regionBackfill.failedTitle'),
        description: err instanceof Error ? err.message : t('common.tryAgain'),
        variant: 'destructive',
      });
    }
  };

  return (
    <Card className="border-white/10 bg-white/2">
      <CardContent className="py-3.5 space-y-2.5">
        <p className="flex items-center gap-2 text-sm font-bold text-white">
          <MapPin className="h-4 w-4 text-[#ccff00]" />
          {t('settingsUi.regionBackfill.title')}
          <span className="rounded bg-[#ccff00]/10 px-1.5 py-0.5 text-[9px] font-black uppercase tracking-widest text-[#ccff00]/70">
            {t('settingsUi.regionBackfill.admin')}
          </span>
        </p>
        <p className="text-xs text-muted-foreground">
          {t('settingsUi.regionBackfill.descBefore')}{' '}
          <strong>{t('settingsUi.regionBackfill.descStrong')}</strong>{' '}
          {t('settingsUi.regionBackfill.descAfter')}
        </p>

        {isLoading ? (
          <p className="text-xs text-muted-foreground">{t('settingsUi.regionBackfill.scanning')}</p>
        ) : count === 0 ? (
          <p className="text-xs text-[#ccff00]">
            {t('settingsUi.regionBackfill.allTagged')}
          </p>
        ) : (
          <>
            <p className="text-xs text-muted-foreground">
              {t('settingsUi.regionBackfill.countLine', { count, s: count === 1 ? '' : 's' })}
            </p>
            <div className="flex flex-wrap items-center gap-2">
              <Button
                onClick={run}
                disabled={isRunning}
                className="h-9 gap-1.5 bg-[#ccff00] font-bold text-black hover:bg-[#ccff00]/90"
              >
                {isRunning ? (
                  <Loader2 className="h-4 w-4 animate-spin" />
                ) : (
                  <MapPin className="h-4 w-4" />
                )}
                {isRunning && progress
                  ? t('settingsUi.regionBackfill.tagging', { done: progress.done, total: progress.total })
                  : t('settingsUi.regionBackfill.run')}
              </Button>
              {summary && (
                <span className="text-xs text-muted-foreground">
                  {t('settingsUi.regionBackfill.summary', { updated: summary.updated, skipped: summary.skipped, failed: summary.failed })}
                </span>
              )}
            </div>
          </>
        )}
      </CardContent>
    </Card>
  );
}