import { useQuery } from '@tanstack/react-query';
import { getLatestReflectionForTask } from '../../api';

interface ReflectionBadgeProps {
  taskId: number;
}

/**
 * Shows a "🧠 Learned N things [+ piece edit]" pill when the most recent
 * reflection for this task applied changes. Hidden when:
 *  - no reflection exists yet
 *  - outcome is 'abstained' or 'failed'
 *  - no memory changes AND no piece edit
 *
 * Clicking navigates to Settings > Memory & Learning (?page=settings&section=memory-learning)
 * anchored at the snapshot via a hash fragment.
 */
export function ReflectionBadge({ taskId }: ReflectionBadgeProps) {
  const { data } = useQuery({
    queryKey: ['reflection-for-task', taskId],
    queryFn: () => getLatestReflectionForTask(taskId),
    staleTime: 30_000,
  });

  if (!data) return null;
  if (data.outcome === 'abstained' || data.outcome === 'failed') return null;

  const n = data.memoryChanges ?? 0;
  if (n === 0 && !data.pieceEdited) return null;

  const label = data.pieceEdited
    ? `Learned ${n} ${n === 1 ? 'thing' : 'things'} + piece edit`
    : `Learned ${n} ${n === 1 ? 'thing' : 'things'}`;

  // Navigate to Settings > Memory & Learning, anchored at the snapshot.
  // The app uses query-string-based URL state (no react-router), so we build
  // the URL directly. The hash lets MemoryLearningForm scroll to the snapshot
  // when the section loads.
  const href = `?page=settings&section=memory-learning#snapshot-${data.snapshotId}`;

  return (
    <a
      href={href}
      className="inline-flex items-center gap-1 rounded-full bg-amber-50 px-2 py-0.5 text-xs text-amber-700 hover:bg-amber-100"
    >
      🧠 {label}
    </a>
  );
}
